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Nitrogen footprints: Regional realities and options to reduce nitrogen loss to the environment
Abstract
Nitrogen (N) management presents a sustainability dilemma: N is strongly linked to energy and food production, but excess reactive N causes environmental pollution. The N footprint is an indicator that quantifies reactive N losses to the environment from consumption and production of food and the use of energy. The average per capita N footprint (calculated using the N-Calculator methodology) of ten countries varies from 15 to 47 kg N capita−1 year−1. The major cause of the difference is the protein consumption rates and food production N losses. The food sector dominates all countries’ N footprints. Global connections via trade significantly affect the N footprint in countries that rely on imported foods and feeds. The authors present N footprint reduction strategies (e.g., improve N use efficiency, increase N recycling, reduce food waste, shift dietary choices) and identify knowledge gaps (e.g., the N footprint from nonfood goods and soil N process).
... 10 For a given commodity in the food chain, NUE is defined as a ratio of N available for the consumption of that commodity (output N) to the N input to produce it (input N), and Nr loss is the difference between input N and output N. 10 To increase NUE and decrease Nr loss in the food chain, we first need to investigate how N inputs to the system flow through these processes. 6 Nitrogen loss generated during these processes and NUE in the system are controlled by several factors, including landscape characteristics, 11,12 production-based factors like land use, 8,13,14 and agricultural practices, 15 consumption-based factors like dietary choices, 15,16 and food trade patterns. 15−18 These factors also vary spatially and temporally. ...
... 10 For a given commodity in the food chain, NUE is defined as a ratio of N available for the consumption of that commodity (output N) to the N input to produce it (input N), and Nr loss is the difference between input N and output N. 10 To increase NUE and decrease Nr loss in the food chain, we first need to investigate how N inputs to the system flow through these processes. 6 Nitrogen loss generated during these processes and NUE in the system are controlled by several factors, including landscape characteristics, 11,12 production-based factors like land use, 8,13,14 and agricultural practices, 15 consumption-based factors like dietary choices, 15,16 and food trade patterns. 15−18 These factors also vary spatially and temporally. ...
... Also, they often do not provide detailed information on how commodity trade affects the Nr loss amount and spatial flow. Despite the further adjustments in NF models by incorporating food and feed trade 15 and a per-area basis estimation of Nr loss intensity, 1,22 they still estimate the total Nr loss from an entity's food consumption without determining where the loss is released. ...
In the Chesapeake Bay Watershed, excess nitrogen has contributed to poor water quality, leading to nitrogen mitigation efforts to restore and protect the watershed. The food production system is a top contributor to this nitrogen pollution. While the food trade plays a vital role in distancing the environmental impacts of nitrogen use from the consumer, previous work on nitrogen pollution and management in the Bay is yet to carefully consider the effect of embedded nitrogen found in products (nitrogen mass within the product) imported and exported throughout the Bay. Our work advances understanding across this area by creating a mass flow model of nitrogen embedded in the food production chain throughout the Chesapeake Bay Watershed that separates phases of the production and consumption processes for crops, live animals, and animal products and considers commodity trade at each phase by combining aspects of both nitrogen footprint and nitrogen budget models. Also, by tracking nitrogen embedded in products imported and exported in these processes, we distinguished between direct nitrogen pollution and nitrogen pollution externalities (displaced N pollution from other regions) from outside of the Bay. We developed the model for the watershed and all its counties for major agricultural commodities and food products for 4 years 2002, 2007, 2012, and 2017 with a specific focus on 2012. Using the developed model, we determined the spatiotemporal drivers of nitrogen loss to the environment from the food chain within the watershed. Recent literature leveraging mass balance approaches has suggested that previous long-term declines in nitrogen surplus and improvements in nutrient use efficiency have stagnated or begun to reverse. Our results suggest that within the Chesapeake Bay, increased corn and wheat acreage and steadily increasing livestock/poultry production may have led to the stagnation in decreasing N loss trends from agricultural production observed over the past two decades. We also show that at the watershed scale, trade has reduced the food chain nitrogen loss by about 40 million metric tons. This model has the potential to quantify the effect of various decision scenarios, including trade, dietary choices, production patterns, and agricultural practices, on the food production chain nitrogen loss at multiple scales. In addition, the model's ability to distinguish between nitrogen loss from local and nonlocal (due to trade) sources makes it a potential tool to optimize regional domestic production and trade to meet local watershed's needs while minimizing the resulting nitrogen loss.
... The VNF is the emission intensity for a food item, counting only the emissions occurring before consumption (Leach et al 2012). We used VNFs from a mix of European studies (Shibata et al 2017) and from a recent German study (Klement et al 2021) because most food imported to Sweden is produced in Europe . ...
... When replacing our estimates of VNFs (preconsumption emission factors) of imported food by VNFs from other European studies, the total N footprint of Swedish food consumption increased by 24% when using the Europe average from Shibata et al (2017) or 1% using the results from Germany of Klement et al (2021); see also figures SM9 and SM10. ...
... ). While our results here agree with previous studies (e.g.Leach et al 2012, Shibata et al 2017, Klement et al 2021 on the large differences between different food categories and thus give useful information about the mitigation potential of dietary change, there remains a need for research on (a) how N footprints correlate with more specific impact indicators, and (b) based on this, what role the N footprint can usefully play in guiding policy towards desirable outcomes. ...
Food systems are major drivers of environmental and health impacts. While the emissions and other pressures causing these impacts mainly occur in primary agricultural production, the deeper causes and much of the mitigation potential are distributed throughout food systems, including dietary choices and multiple inefficiencies in the whole chain from agricultural production to consumption and waste management. An environmental indicator based on this systems perspective is the nitrogen (N) footprint, defined as the emissions of reactive N due to the consumption of an individual or other entity. Here, we present a method to estimate the N footprint of Swedish food consumption, using a detailed inventory of agricultural production, food and feed processing, food waste, waste management, and wastewater treatment. Limitations of data sources and methods are discussed in detail. The estimated Swedish food N footprint is 12.1 kg N capita ⁻¹ year ⁻¹ , of which 42% is emitted in Swedish production, 38% in production abroad, 1% in consumer waste management, and 19% in wastewater treatment. Animal food products account for 81% of the food N footprint and 70% of the protein intake. Average protein intake exceeds nutritional requirements by about 60%, which suggests that at least 35% reduction of food-related reactive N emissions could be achieved through dietary change. Of the apparent food N consumption (6.9 kg N capita ⁻¹ year ⁻¹ ), about 22% is food waste N (1.5 kg N capita ⁻¹ year ⁻¹ ). We estimate that 76% of food waste N is unavoidable (bones and other parts not commonly eaten). Avoidable food waste is about 7% of the edible food supply, implying that a hypothetical complete elimination of food waste would reduce emissions by about 7%. In summary, we present a detailed method, discuss its limitations, and demonstrate possible uses of the N footprint as a complement to existing territorial and sectoral environmental indicators.
... The nitrogen footprint of a country has therefore emerged as the most useful tool to identify the reactive nitrogen emission during the production and handling of an entity, irrespective of its domestic and worldwide use [3,8,9]. Previously nitrogen footprint per capita were calculated for Germany [8,10], US [8], UK [11], Netherlands [8], Austria [12], Australia [13], Japan [14,15] and Tanzania [16]. ...
... Nearly 80% of the total nitrogen footprint was estimated as food nitrogen footprint. Consequently, 50% of the food nitrogen footprint was predicted as beef nitrogen footprint, followed by pork and poultry nitrogen footprint [13,15]. This accounted for a staggering one-third of total nitrogen emissions from the global economy [18] and was able to reduce 0.3-3% of global gross domestic product (GDP) [19]. ...
... Membrane filtration 10.0-30.0 Zero liquid discharge 58.6 [35] Although many studies have already predicted the amount of nitrogen waste due to beef, pork and poultry meat production [8,11,12,15], little research has been conducted so far on its direct correlation with manure generation and the corresponding nitrogen loss through it. Furthermore, it is the need of the hour to estimate the energy required to recover the potentially lost nitrogen through manure to have an outlook of the real price of meat. ...
Intensive livestock farming has negatively impacted the environment by contributing to the release of ammonia and nitrous oxide, groundwater nitrate pollution and eutrophication of rivers and estuaries. The nitrogen footprint calculator has predicted the large impact of meat production on global nitrogen loss, but it could not form the relationship between meat production and the corresponding manure generation. Here we report on the formation of direct relationships between beef, pork and poultry meat production and the corresponding amount of nitrogen loss through manure. Consequently, the energy demand for ammonium nitrogen recovery from manure is also reported. Nitrogen loss to the environment per unit of meat production was found directly proportional to the virtual nitrogen factors. The relationship between total nitrogen intake and the corresponding nitrogen loss per kg of meat production was also found linear. Average nitrogen loss due to manure application was calculated at 110 g kg−1 for poultry. The average nitrogen loss increased to 190 and 370 g-N kg−1 for pork and beef productions, respectively. Additionally, 147 kg ammonium nitrogen was calculated to be recovered from 123 m3 of manure. This corresponded to 1 Mg of beef production. The recovery of ammonium nitrogen was reduced to 126 and 52 kg from 45 and 13 m3 of pork and poultry manure, respectively. The ammonium nitrogen recovery values were calculated with respect to 1 Mg of both pork and poultry meat productions. Consequently, the specific energy demand of ammonium nitrogen recovery from beef manure was noticed at 49 kWh kg−1, which was significantly 57% and 69% higher than that of pork and poultry manure, respectively.
... Unlike the natural N cycle, this anthropogenically modified N cycle could cause Nr to become a major factor for the occurrences of multiple environmental pollution in sequence (e.g. smog, acid rain formation, water eutrophication, soil acidification and global warming), which have negative impacts on human health and the biosphere (Galloway et al 2003, Shibata et al 2017. This makes the accurate assessment of Nr emissions from human activities an urgent priority, especially if we wish to sustainably reduce Nr (Gu et al 2019) and keep countries and the world within 'planetary boundaries' , which are defined as the safe operating space for humanity based on the intrinsic biogeochemical processes supporting Earth's stability (Steffen et al 2015). ...
... The INI 2016 Conference addressed the need to raise conscious awareness of the nitrogen footprint (NF) (Gu et al 2019). The concept of NF was proposed at the INI 2010 conference, and was developed after the conceptualization of ecological, carbon, and water footprints, which have since been widely applied as effective indicators to guide reductions in negative human impacts on the environment (Leach et al 2012, Pierer et al 2014, Shibata et al 2017. The NF was defined as the total amount of Nr released into the environment as a result of individual or collective resource consumption, and expressed in total units of N atomic weight, which can be estimated through the online platform of the N-Calculator model (www.nprint.org) ...
... In general, the per-capita energy consumption in China was lower than in most of the developed countries mentioned above. However, from the perspective of regional NF production, urban agglomeration tended to produce high-proportioned ENF due to the limited control measures to reduce NO x emissions from fossil fuel combustion that mainly occurred in cities (Shibata et al 2017). In Australia, beef consumption and coal combustion for electricity are key drivers of higher national NF (Liang et al 2016). ...
Overgrowth of reactive nitrogen (Nr, all species of nitrogen except N2 gas) emissions is a major cause of environmental pollution especially in rapidly urbanizing regions. The Nitrogen Footprint (NF) indicator has been widely used to assess Nr losses occurring from consumption of food and energy. We undertake the first attempt to apply NF methods to explore the spatial-temporal NF characteristics of major urban agglomerations in China between 2000-2019, and find that the higher level of annual NF (average 3868 Gg N yr-1) was produced by the Yangtze River Delta urban agglomeration (YRDUA), followed by the Beijing-Tianjin-Hebei urban agglomeration (BTHUA) (average 2657 Gg N yr-1); their NF growth rates showed similar downward trends during the study period, while Pearl River Delta urban agglomeration (PRDUA) (average 1528 Gg N yr-1) retained a higher growth rate. The average proportions of food NF in BTHUA, YRDUA and PRDUA were 57.64%, 68.64% and 66.79%, respectively. Compared to the food NF, the energy NF gradually play a more important role in the China’s urban agglomerations compared to other countries. Analysis of underlying drivers showed that increasing urbanization rate boosted the NF of YRDUA, and rising GDP per capita significantly contributed to the NF growths of BTHUA and PRDUA. Through scenario analysis, we found that shifting to healthy dietary patterns and partial substitution of fossil fuels with clean energy, as well as improvements in rural wastewater treatment, contribute to NF reductions by 2030. The largest potential NF reduction is predicted in PRDUA (29% reduction), followed by YRDUA (23% reduction) and BTHUA (18% reduction). The energy reduction scenario is considered to be the most realistic in reducing the NF. We demonstrate the potential of NF as a tool for the assessment of sustainable development in urban agglomeration, which may prove instructive for broader research on sustainable Nr management.
... The sum of Nr emitted from various human activities is indicated by the nitrogen footprint (NFP), which allows us to understand how much Nr losses from daily activities impact the environment (8). The sources of NFP include diets, housing, transportation, and goods and services, with the largest contributor being food (9,10). The dietary NFP is calculated based on people's protein intake, considering the emitted Nr from all the processes of food production, such as fertilizer not incorporated into the plant, crop residues, feed not incorporated into the animal product, processing waste, and food waste from households. ...
... NFPi5NIi3(VNFi11) where the subscript i denotes the variable is for a food group i. VNF describe the total nitrogen lost to the environment during food production per unit nitrogen in the final food product consumed. This value is generally highest for beef, followed by that for other meats, fedfarmed seafood, vegetables, grains, pulses, and natural and non-fed-farmed seafood (9). VNFs were defined for each food group: cereals, potatoes, pulses, vegetables, fruits, seaweeds, fish and seafood, meat (beef, pork, chicken, and others), eggs, dairy products, miso, soy sauce, and other foods. ...
With the growing interest in healthy and sustainable diets, studying diets with high nutritional quality and low environmental impact is needed. We focused on the nitrogen footprint (NFP)-an indicator of reactive nitrogen loss that causes various environmental impacts-of Japanese diets using individual dietary records and identified the characteristics of lower NFP diets. This cross-sectional study was a secondary data analysis from the 2017 Saitama Prefecture Nutrition Survey. We analyzed the data obtained from a questionnaire and two-day dietary records of 479 men and women aged 30-65 y who had no misreported or missing data. The NFP was calculated using the virtual nitrogen factors of each food group reported in a previous study. After assessing NFP and its contributions, we conducted sub-group analysis for participants with appropriate weight status and adequate protein intake, classifying them into three groups according to tertiles of NFP to protein ratio. We compared NFP, its contributions, and nutrient intake between the groups. The total NFP (kg N/y) was 18.2±5.0 in men and 16.1±4.4 in women. In the sub-group analysis, total NFPs of the lower NFP group were 16.5±3.1 in men and 13.6±2.8 in women. Cereals, pulses, and fish and seafood contributed more significantly to the total NFP in the lower NFP group than in the higher NFP group. These results suggest that adequate protein intake from a variety of food sources is required to lower the environmental impact of adequate diets.
... In the last decades, the rate of fertilizer application has increased to such an extent that the nitrogen cycle of intensive agricultural areas has become disrupted (Biermann et al., 2016;Shibata et al., 2017;Galloway et al., 2017;Erisman, 2021). Leakage of bioavailable nitrogen to the air, surface waters and fragile ecosystems have led to increased attention to the nitrogen deposits. ...
... In effect, serial selection, or enrichment strategies have been successfully implemented in culture-dependent experiments to isolate root colonizing bacteria in combination with a trait-specific selection pressure, like the degradation of hydrocarbons in polluted soils (Kuiper et al., 2001) Wheat is a nitrogen demanding crop. However, in the last decades, the rate of fertilizer application has increased to such an extent that the nitrogen cycle of intensive agricultural areas has become disrupted (Biermann et al., 2016;Shibata et al., 2017;Galloway et al., 2017;Erisman, 2021). Leakage of nitrogen to the air, surface waters and fragile ecosystems and the heavy dependency on fossil fuels for the production of nitrogen fertilizers are among the major contributors to the climate crisis. ...
As pressure increases on agricultural practice to reduce its synthetic inputs there is a need for biological alternatives (agrobiologicals). At present a vast amount of beneficial organisms is described in literature, however only a fraction of those are available as commercial products. In collaboration with Aphea.Bio and Ghent University this thesis tries to tap into the potential of the plant associated microbiome to discover and validate efficient agrobiologicals. Triticum aestivum L., or bread wheat, is one of the world’s top 3 food crops. With an estimated gross production value of 188 billion USD per year, it contributes to 20% of the total dietary calories and proteins worldwide (FAO, 2002). For the production of wheat, a high amount of nitrogen fertilizer is needed. However, in the last decades, the rate of fertilizer application has increased to such an extent that the nitrogen cycle has become disrupted, with detrimental environmental consequences (Stutton et al., 2011). There is an urgency to reduce the nitrogen input in agroecosystems while also safeguarding food production. Fusarium head blight (FHB) is a is a devastating disease in wheat caused by a phytopathogenic fungus. In addition to causing significant yield loss, FHB produces mycotoxins in the infected grain, which are highly toxic when consumed by human and animal. One of the main species in the FHB disease complex is Fusarium graminearum. The overall aim of this thesis is to discover and validate bacterial strains that aid wheat in its nitrogen acquisition (biostimulant) and reduce the disease pressure of F. graminearum (biocontrol). We tried this by implementing an enrichment strategy, selecting for bacteria based on 3 specific traits: (i) association with wheat and improvement of the plant growth under (ii) biotic or (iii) abiotic stress. Enrichment strategies have been successfully implemented in culture-depended experiments to isolate root colonizing bacteria. These experiments include a trait-specific selection pressure, like the degradation of hydrocarbons in polluted soils (Kuiper et al., 2001) and selection for biocontrol against soil pathogens (Kamilova et al., 2005). Recent studies using a culture-independent strategy have revealed robust microbiome selection is possible via both habitat and host-dependant pressures (Morella et al., 2020). Other authors found that abiotic-dependant selection could increase the drought and salt tolerance in the wheat through changes in its rhizosphere microbiome (Mueller et al., 2019; Jochum et al., 2019). Additionally it was found that wheat can adapt to biotic stresses by changing the composition of its root exudates to select a health-promoting microbiome. This “cry-for-help” model allowed stressed plants to recruit beneficial bacteria from the environment (Gomez Exposito et al., 2017; Rolfe et al., 2019). Wheat plants in the field have also been found to attract beneficial microbes in their root zone depending on the nitrogen availability (Chen et al., 2019). Rather than creating synthetic consortia “bottom up”, Swenson et al. (2000) proposed that ecosystem selection could lead to beneficial microbiomes “top down”, by creating a large number of ecosystems and selecting those that best solve the problem to create the next generation of ecosystems. In this thesis nitrogen limitation was chosen as a relevant abiotic stress as a trait-specific selection pressure. To maximize ecological relevance we chose to implement a culture-independent approach. Eight different bulk soil samples were collected from agricultural and natural landscapes and used as ecosystems (bulk soil inoculum) to recruit beneficial microbiomes. These soils were used in a trapping experiment, whereafter 3 subsequent enrichment cycles were performed. Throughout the enrichment we observed significant increases in nitrogen concentration, for half of the enrichment lines, while the biomass remained constant. When analysing the microbiome composition during the enrichment, we found that the diversity of the bacterial community reduced throughout the cycles. Additionally, the different enrichment lines exposed to the same selection pressure became more similar over time. However the importance of the bulk soil inoculum explaining dissimilarity increased. Furthermore we observed that a small amount of persisting ASVs dominated the microbiome in later cycles of the enrichment. Interestingly, adding just 1% (w/w) of roots from the previous cycle was enough to significantly shape the rhizosphere microbiome of the next cycle, even after 4 weeks of growth. After the enrichment cycles bacteria were isolated from the best performing enrichment lines. Based on the combination of microbiome and phenotype data, predictions were made of isolate performance. Next, 30 isolates were selected with a positive correlation between its relative abundance and plant phenotype during the enrichment cycles. These isolates were tested as single strains for plant growth promotion in planta. Additionally 30 isolates with no correlation were tested, serving as a negative control. We found that the correlation analysis was not indicative of the isolates performance in planta. However, in total 20% of all tested isolates showed a positive effect on either dry weight, wet weight or tillering in greenhouse trials. In parallel to the enrichment for abiotic stress, a culture independent enrichment cycle under biotic stress was performed. F. graminearum infection was chosen as a relevant trait-specific selection pressure. Four ear microbiome extracts from old wheat varieties were used as ecosystems to recruit beneficial microbiomes. During 3 enrichment cycles, a small but significant reduction of disease severity was observed in one of the enrichment lines. Bacteria were isolated and screened in 3 rounds of assays with increasing ecological relevance: in vitro co-culturing, in planta detached leaf and in planta detached spike assay. In the final detached spike assay one isolate was able to significantly reduce the disease pressure of F. graminearum when applied one day before inoculation. In this thesis we showed that culture independent in planta enrichment with a trait specific selection pressure can result in the reduction of abiotic and biotic stresses. Microbiome analysis of the rhizosphere microbiome reviled the important dynamics occurring during enrichment. Finally, isolations from the enriched microbiomes provided bacterial strains that showed plant growth promoting effects and biocontrol activity when tested against their relative traits in planta.
... Reactive nitrogen (Nr), i.e., all forms of nitrogen (N) compounds except N 2 , is mainly lost to the atmosphere and freshwater from croplands through NH 3 volatilization, N 2 O and NO emissions, runoff, and leaching, which damages the natural environment and human health (Erisman, 2021;Gu et al., 2023). The high global input of synthetic N fertilizer (~120 Tg N yr − 1 ) contributed to 68-93% of anthropogenic Nr losses worldwide (Shibata et al., 2017;Galloway et al., 2003). China is the world's largest rice producer, contributing 28% of global production while consuming 25% of global N fertilizer use (Heffer et al., 2017). ...
Anthropogenic reactive nitrogen (Nr) loss has been a critical environmental issue. However, due to the limitations of data availability and appropriate methods, the estimation of Nr loss from rice paddies and associated spatial patterns at a fine scale remain unclear. Here, we estimated the background Nr loss (BNL, i.e., Nr loss from soils without fertilization) and the loss factors (the percentage of Nr loss from synthetic fertilizer, LFs) for five loss pathways in rice paddies and identified the national 1 × 1 km spatial variations using data-driven models combined with multi-source data. Based on established machine learning models, an average of 23.4% (15.3–34.6%, 95% confidence interval) of the synthetic N fertilizer was lost to the environment, in the forms of NH3 (17.4%, 10.9–26.7%), N2O (0.5%, 0.3–0.8%), NO (0.2%, 0.1–0.4%), N leaching (3.1%, 0.8–5.7%), and runoff (2.3%, 0.6–4.5%). The total Nr loss from Chinese rice paddies was estimated to be 1.92 ± 0.52 Tg N yr−1 in 2021, in which synthetic fertilizer-induced Nr loss accounted for 69% and BNL accounted for the other 31%. The hotspots of Nr loss were concentrated in the middle and lower regions of the Yangtze River, an area with extensive rice cultivation. This study improved the estimation accuracy of Nr losses and identified the hotspots, which could provide updated insights for policymakers to set the priorities and strategies for Nr loss mitigation.
... 15 N uptake% showed a negative linear correlation with N rate (Fig. 4c). The lower NUE is mainly due to the imbalance between the wheat uptake and the soil N supply (Jin et al., 2012;Meisinger et al., 2008;Zhu et al., 2016), coupled with the fact that the main source of wheat N uptake is soil N pool, soil residues of N fertilizer are less variable, which ultimately leads to considerable N loss (Shibata et al., 2017). The greater the N surplus was, the more the losses from different pathways increased with elevated 15 N loss% (Fig. 4e). ...
... It has been predicted that between 2030 and 2050 global food demand will increase 50% as a result of fast population growth, urbanization, and an enhanced quality of living. In most areas the demand for dairy goods is predicted to rise by up to 70% from current levels until the year 2050, while for meat products the demand is expected to rise by 40% and 69% between 2015 and 2050, respectively, in higher and lower-income nations (Sanaullah et al., 2020;Shibata et al., 2017, Kumar et al., 2022. ...
Environmental security is essential to ensuring food security for an ever-growing population. Agriculture is the significant contributor to greenhouse gas (GHGs) emissions due to the imbalance and excessive use of chemical compounds, energy, and high consumption of fossil-fuel. Ploughing, irrigation, and applying synthetic fertilisers or pesticides are only few examples of agricultural operations that contribute a large amount of GHGs emission. Food for a large share of the world׳s population is grown in the South Asian Indo-Gangetic Plains (IGPs). A larger crop yield is attributed to the harvesting of a greater number of diverse cropping systems/crops on the same land in the same year. There are about 26 million acres of rice-wheat cropping systems in the IGPs of South Africa, and these systems are the primary contributors to anthropogenic GHG emissions, including methane (CH4), nitrogen oxide (N2O), and ammonia volatilization (NH3). It is carbon (C) and nitrogen (N) footprints, which are critical to the direct and indirect balance of many components in nature, that are directly connected to increased GHG production. Consequently, C and N in a variety of forms govern a wide range of biochemical processes, including those in the soil and plants as well as in the atmosphere. Users of N-fertilizers, improved farm equipment efficiency, and changes in Rice Wheat Cropping System (RWCS) regional distribution are all need to minimize GHG emissions from agriculture. The current chapter focuses on the issue of carbon and nitrogen footprints in agricultural systems, which are connected to GHGs emission via pre-, on-, and post-farm activities. Several techniques to alleviating agricultural practises are also suggested as a road map for policymakers, land managers and researchers, and aid with the modeling of C and N footprints for environmental, food, nutritional and economic security in a changing climatic context.
... This evaluation can be done at various scales, ranging from individual to country levels, considering the subsequent effects on the environment and human health (Leach et al., 2012;Einarsson and Cederberg, 2019). The NF serves as an indicator of potential N losses/wastes throughout the entire productionconsumption chain of all products and services consumed or used by an individual over a certain period (Leach et al., 2012;Shibata et al., 2017). Although an individual may change what they consume or use, there are also aspects of the infrastructure and supply chain that are beyond the individual's control. ...
Unintended reactive nitrogen (N) losses from agriculture, energy and transportation pose significant environmental hazards, including eutrophication, acidification, water and air pollution, biodiversity loss, human health risks and climate change. The concept of a Nitrogen Footprint (NF) emerges as a pivotal metric, reflecting potential N losses in the entire production-consumption chain of goods and services used by an individual within a defined timeframe.
In a pioneering assessment of per capita NF in Ukraine, key factors, such as the food production chain, consumption patterns, wastewater treatment (WWT) facilities and connection to sewage system, were identified as critical components. Addressing specific challenges, such as data availability, soil N depletion and manure waste, was found to be particularly complex. The individual Ukraine NF (22.1 kg N cap-1 yr-1 as of 2017) was much lower than that of the US and Australia being comparable to Western European countries. Even so, significant opportunities for reduction remain through a wide range of options towards healthier and more sustainable dietary choices. Potential reductions, ranging from 22% to 69%, were shown for omnivore, reduced red meat, no red meat, half meat products, vegetarian and vegan diets.
The war's impact is assumed to result in a slight increase or no changes in individual food consumption NFs and an increase in food production NFs for local products, while reductions in individual transport and energy NFs were likely across Ukraine. Nonetheless, refugees massively displaced to less affected regions overload a largely outdated civilian infrastructure, leading to higher N losses.
Looking ahead, sustained support, capital investments, legislative enhancements and regulatory frameworks, especially upon post-war renovation of Ukraine, are imperative for reducing the individual NF. This involves enhancing nitrogen use efficiency in agriculture, establishing efficient manure management, upgrading WWT facilities, promoting renewable energy adoption, bolstering requisite infrastructure and raising public awareness on environmental sustainability.
... For example, while organic and regenerative agriculture have proven their positive impacts on soil quality, biodiversity, and farmers' livelihood, there are also potentially negative consequences on the land footprint and many other uncertainties that still need to be explored [72]. Considering the nitrogen crisis in the Netherlands, where food production (and mostly livestock) is responsible for 91% of the country's nitrogen emissions [73], transitioning toward low-impact agricultural practices is critical for a sustainable food transition. ...
The environmental gains of dietary change are often assessed in relation to average national diets, overlooking differences in individual consumption habits and preferences. As a result, we ignore the roles and impacts of different consumer groups in a sustainable dietary transition. This study combines micro data on food intake and consumer behaviour to elicit the likely environmental gains of dietary shifts. We focus on the Netherlands owing to the county’s ambition to halve its dietary footprint by 2050. Linking food recall survey data from a cross-section of the population (n=4,313), life cycle inventory analysis for 220 food products, and behavioural survey data (n=1,233), we estimate the dietary footprints of consumer groups across water, land, biodiversity and greenhouse gas footprints. We find that meat and dairy significantly contribute to the dietary greenhouse gas (GHG) footprint (59%), land footprint (55%), and biodiversity footprint (57%) of all consumer groups, and that male consumers impose a 30-32% greater burden than women across these impact areas. Our scenario analysis reveals that simply replacing cow milk with soy milk could reduce the GHG, land and biodiversity footprints of food consumption by ±8% if widely adopted by the Dutch adult population. These impacts could be further reduced by ±20% from a full adoption of a sustainable diet, as recommended by the EAT-Lancet Commission, but would significantly increase the blue water footprint of Dutch food consumption. While the EAT-Lancet recommended diet is preferred in terms of impacts and nutrition, it would necessitate a complete overhaul of individual dietary habits, whereas shifting to soy milk is a simple single product substitution and a more accessible choice for consumers. However, when incorporating gender- and age-specific willingness for meat and dairy consumption reduction, the environmental gains resulting from partial adoption of the EAT diet and No-Milk diet diminish to a mere ±4.5% and ±0.8%, respectively. Consequently, consumer motivation alone is insufficient to realise the significant environmental gains often promised by dietary change. Our findings highlight that specific and targeted policies are needed to overcome the barriers that consumers face to adopting a more sustainable diet.
... These results indicated that the system had the capacity to reduce N losses. According to Shibata et al., 26 the term nitrogen use efficiency (NUE) may be applied to agricultural practices, including the manner of fertilization. The system applied in this research may improve NUE focused on the reduction of nitrogen losses. ...
Urea is the nitrogen-containing fertilizer most used in agricultural fields; however, the nutrient given by the urea is lost into the environment. The aim of this research was to determine the effect of two soil textures by applying a prolonged-release system of urea (PRSU) on the N losses. This research shows an important decrease of the nitrate and ammonium losses from 24.91 to 87.94%. Also, the microbiological population increases after the application of the PRSU. It was concluded that both soil textures presented the same loss-reduction pattern, where the N from the nitrates and ammonium was reduced in the leachates, increasing the quality of the soil and the microbial population in both soil textures after the PRSU application.
... Nitrogen (N) is a fundamental component of proteins, nucleic acids, and other vital living substances [1,2]. However, the excessive use of chemical fertilizers and fossil fuels as well as high food consumption have resulted in the release of large amounts of reactive nitrogen (Nr: all species of nitrogen (N) except N 2 ) into the environment, which has led to environmental pollution such as water eutrophication, atmospheric pollution, and acid rain [3,4]. Research has suggested that 75% of Nr production on land arises from human activities [5]. ...
Reactive nitrogen (Nr) has been confirmed as an indispensable nutrient for the city ecosystem, but high-intensity human activities have led to nitrogen pollution in cities, especially in coastal cities, jeopardizing ecosystem services and human health. Despite this, the characteristics and influencing factors of Nr remain unclear in coastal cities, particularly in the context of rapid urbanization. This study used the material flow analysis method to estimate Nr emissions in Xiamen from 1995 to 2018 and evaluated the characteristics of excessive Nr emissions. The STIRPAT model was used to identify and explore factors contributing to observed Nr levels in coastal cities. As indicated by the results, (1) the quantity of Nr generated by human activities increased 3.5 times from 1995 to 2018. Specifically, the total Nr entering the water environment showed a general increase with fluctuations, exhibiting an average annual growth rate of 3.1%, increasing from 17.2 Gg to 35.1 Gg. (2) Nr loads in the nearby sea increased notably from 8.1 Gg in 1995 to 25.4 Gg in 2018, suggesting a threefold augmentation compared with surface waters and groundwater. (3) NOx was the gaseous Nr with the greatest effect on the atmosphere in Xiamen, which was primarily due to fossil fuel consumption. (4) Population and per capita GDP were major factors contributing to Nr load in the water environment, while Nr emission to the atmosphere was influenced by population and energy consumption. These findings provide valuable insights for tailored approaches to sustainable nitrogen management in coastal cities.
... Integrated considerable efforts in reducing food waste along food production and food consumption should mainly be contributed by retailers, food service providers and consumers (Zhang et al., 2018). It was well recorded that decreasing food waste where possible will lead to decreasing in the losses of nutrients like N and P to the environment (Shibata et al., 2017) thereby reducing greenhouse gases emissions, the cost spent for food for better economy and personal savings and finally safeguarding the environment. The promotion of most effective and efficient measures in motivating food waste reduction along the food chain should be enhanced in many ways (Goossens et al., 2019) e.g., by sometimes adjusting some wasteful cultural behaviors. ...
... The process called Haber-Bosch which a chemical nitrogen production permitted the huge production of fertilizers at large industrial-scale that supported global need, but simultaneously releases reactive nitrogen to environment. "However, the release of this reactive nitrogen in atmosphere, soil and water has been generated critical environmental issues recently" [5]. The anthropogenic source of emission of nitrous oxide (N 2 O) is increasing from agricultural lands. ...
Agriculture is one among the sources of greenhouse gas emission in the World. Agriculture, being a prominent source of economic sectors in developing countries its impact on environmental climate changes both directly and indirectly through emission of greenhouse gases. To achieve reduced GHGs emissions in agriculture sector, there is a need to adopt climate smart activities and improved food and nutritional security to ensure a climate-smart sustainable agriculture. This short Review Article Devi et al.; Int. 279 article explores the key ways to mitigate green house gases emissions in agriculture and critically highlights the potential for bacterial nitrogen fixation in soybean which is a recent approach. Symbiotic nitrogen fixation shows a great potential for GHGs mitigation while supporting the agriculture simultaneously. Other agronomic practices include tillage, residue management, rice field management, climate smart agriculture, organic farming and bio energy etc. This will help the farmers and other stakeholders to bring an environmentally friendly agriculture towards more ecological farming approach for future sustainability.
... Since the excessive use of N fertilizers negatively affects the functioning of ecosystems and increases the carbon footprint [34,35], from the point of view of food security and the principles of sustainable agriculture, the priority should be to increase the productivity of plants, including soybean, through the implementation of more efficient cultivation technologies, taking into account the need to minimize the negative effects of N fertilization on the natural environment. ...
Legumes’ nutrition relies on two sources of nitrogen (N): mineral N from soil, and biological N fixation (BNF). The aim of this study was to verify the effect of bacterial inoculation, as well as to compare it with the effect of different mineral N fertilization on the main nodulation characteristics, yield components and seed yield of two soybean (Glycine max (L.) Merr.) cultivars in the conditions of south-eastern Poland. A randomized block design was used with four replications and combining the application rates of mineral N (0, 30 and 60 kg·ha−1), and seed inoculation with Bradyrhizobium japonicum (HiStick® Soy and Nitragina) were applied for two soybean cultivars (Aldana, Annushka). It has been shown that inoculation of B. japonicum increases the nodulation on plant roots, yield components and seed yield, but no significant effect of the bacterial preparation used on the seed yield was observed. The application of 30 kg N·ha−1 did not result in a significant reduction in the number and weight of nodules, including on the main root and lateral roots, compared to seeds inoculated and not fertilized with N, as observed under a dose of 60 kg N·ha−1, but resulted in an increase in the number of pods and the number and weight of seeds per plant. For both soybean cultivars, the best combination was nitrogen fertilization at 30 kg N·ha−1 and seed inoculation with B. japonicum, regardless of the bacterial preparation used.
... Tese are technologies that focus to increase the availability of N, enhancing legume productivity, and production systems that improve economic and ecological environmental conservation [6,49,[67][68][69][70][71]. BNF is an alternative example that can supply N, reduce the high cost of N fertilizers, and subsequently limit the environmental footprint of N [72]. Oil seed legumes such as groundnut (Arachis hypogaea L.) and soybean are more efcient in fxing N, estimated globally at 6.3 times greater BNF when combined yearly (18.5 Tg·year −1 ) compared with food legumes like common beans (0.58 Tg), chickpea (Cicer arietinum L.) (0.60 Tg), pea (Pisum sativum L.) (0.57 Tg), and other pulses (0.47 Tg) [73]. ...
Soybean (Glycine max L. Merril) is among the key oil seed crops worldwide providing several benefits from human consumption to the enhancement of soil productivity. In Uganda, legumes are cultivated on roughly 1.5 million ha with soybean being produced on a lower production area of 150,000 ha compared to beans (925,000 ha) and groundnuts (253,000 ha). In terms of achievable yield, soybean emerges the highest at 1.2 t ha-1 as compared to beans (0.5 t ha-1) and groundnuts (0.7 t ha-1). Despite the smallest production coverage area, the crop’s feasible grain yield is projected at 4.6 t ha-1 under optimal environmental conditions. The major bottleneck to the crop’s production is the decreasing soil fertility, mainly caused by not only low nitrogen (N) but also phosphorus (P) levels in the soil. There is a high potential for supplying N from the atmosphere through biological N fixation (BNF), a natural process mediated by the symbiotic bacteria Bradyrhizobium japonicum, which requires optimum P levels for effective N fixation and increased yield. The current work reviews the present status of soybean production in Uganda highlighting its ecological requirements, importance, and constraints and proposes the use of inoculation and P application to boost its production.
... The diet of the rich consists of animal feed products, and the rich consumer needs relatively more resources to consume than resources required for the basic diet. Therefore, rich diets have a greater impact on the environment (Kastner et al., 2012;Hoekstra & Mekonnen, 2012;Leach et al., 2012;Ranganathan et al., 2016;Shibata et al., 2016). ...
Food is one of the basic necessities that play a major role in human life. Over the past two decades, food consumption patterns in many countries have changed rapidly. The concern of food security has emerged as a global food crisis in recent decades. These global changes probably affect Sri Lankan food consumption habits. Sustainability is an essential component and a precondition for long-term food security. Hence, this study used an in-depth non-systematic literature review on a global scale emphasizing the Sri Lankan context, to better understand the situation of changes in food consumption patterns using comprehensive household survey data in Sri Lanka. The study found out that income growth, urbanization, structural changes in the population on demographics, and several other socioeconomic changes significantly influenced transformations in global food consumption patterns. Other than these, many significant differences are evident in food consumption patterns especially geographically, in urban, rural, and estate sectors in Sri Lanka. The Sri Lankan diet shows a tendency to shift from traditional cereal consumption to meat, fish, dairy products, and fast foods and processed foods, posing a significant threat concerning the future food security and sustainability of Sri Lanka. Therefore, the study recommended a critical analysis of changes in food consumption patterns in Sri Lanka.
... The N management is critical for agricultural profitability and environmental sustainability. The excessive N fertilizer input means the possibility of an imbalance in the N balance of farmland, which may lead to the direct or indirect negative influence on human health and agricultural profitability (Shibata et al., 2017). As the N balance increased in the paddy field, the profitability increased gradually, up to a certain value, beyond which the profitability did not increase statistically significantly or even declined rapidly (Fig. 3). ...
... Over the past 40 years, agro-environmental research has focused on improving N cycling processes and strategies to reduce N losses to the environment. Some of the researches and mitigation strategies that can be used to reduce environmental N pollution (Stark and Richards, 2008;Shibata et al., 2017) have been discussed in this chapter. ...
... The N management is critical for agricultural profitability and environmental sustainability. The excessive N fertilizer input means the possibility of an imbalance in the N balance of farmland, which may lead to the direct or indirect negative influence on human health and agricultural profitability (Shibata et al., 2017). As the N balance increased in the paddy field, the profitability increased gradually, up to a certain value, beyond which the profitability did not increase statistically significantly or even declined rapidly (Fig. 3). ...
CONTEXT
To avoid excessive chemical-fertilizer application and improve agricultural productivity in rice, a fertilizer recommendation system called Nutrient Expert® (NE) was designed. However, the ability of NE to balance yield, profitability and environmental sustainability in rice production needs to be further evaluated, as it is still difficult for farmers to assess the proper nitrogen (N) application rate.
OBJECTIVE
The objective of this study was to demonstrate the advantages of the NE system in balancing yield, profitability and N loss in rice production, and recommend proper N application rates for different cropping seasons of rice.
METHODS
This study describes results from field experiments conducted in five main rice cropping provinces from 2017 to 2020 in China, to investigate any advantages of NE compared with local farmers' practice (FP), and to determine the proper N application rates for different cropping seasons of rice.
RESULTS AND CONCLUSIONS
Compared with FP, NE had 12.1% lower N-fertilizer application, but increased rice grain yield by 4.3% and net profit by 7.4%, and decreased yield-scaled N loss by 20.7%. We showed how yield, profitability and N loss were affected by N balance (i.e., N applied to the field minus N removed from the field by the harvested crop biomass), and quantified relationships between N balance and N application rate, and between N output and input. Based on relationships between N balance and N application rate, we recommend N application rates in a range from 122 to 214 kg ha⁻¹, depending on cropping seasons of rice. We demonstrated that NE can simultaneously improve yield, profitability and environmental sustainability.
SIGNIFICANCE
Our study provided quantitative support for NE-based recommendations on the N application rate for smallholders farming in different rice cropping systems, and these recommendations can serve as a reference for avoiding excessive N application rate in paddy fields in other regions with similar eco-environment.
... A national-scale analysis of the input and output of N (N budgets) provides the following advantages: an efficient instrument for visualizing the complex N flows and their potential impact, thus helping raise awareness; information for policymakers to identify intervention points and develop efficient emission reduction measures; a tool for monitoring the impact and environmental integrity of implemented policies; availability of comparisons across countries; and identification of knowledge gaps, thus contributing to improving the scientific understanding of N cycling (Leip et al. 2011). Moreover, processing the data of N budgets provides various indicators such as NUEs of human activity (economy-wide and each of crop, animal, fish, industrial, and energy production), N balance as surplus or deficit of a target subsystem typically cropland, critical loads to forest and water body (discussed below), and N footprint of food, goods, and energy consumption (Leach et al. 2012;Shibata et al. 2016). The total N input to Japanese soil from 2010 to 2015 was approximately 200 kg N ha -1 yr -1 for agricultural lands (cropland and grassland, except natural grassland) and ca. ...
Soil is a hotspot of the terrestrial nitrogen (N) cycling. Nitrogen is an indispensable component of fertilizers for producing crops in agricultural soils and is a macronutrient for natural soils driving the food chain, including microbial activities in terrestrial ecosystems. Humans acquired the technology of artificial N fixation during the early 20th century and used the fixed N for fertilizer and industrial materials. Artificial N fixations have amounted to ca. 150 Tg N yr–1 in recent years, surpassing terrestrial biological N fixation. Consequently, a large amount of reactive N (N compounds other than dinitrogen) is lost to the environment, inducing various forms of N pollution and threatening human and environmental health. This review aims to highlight future research on N cycling and management from the soil science perspective based on the author’s experience. The review covers the following themes: N processes to be elucidated preferentially in agricultural soils, interactions between soil and N cycling in the polar regions storing a large amount of organic matter and susceptible to climate change, and N management at national and international scales focusing on how soils are treated.
... The additional income appears to readily exceed the likely additional costs of adopting UDP, as long as labor was available at the time of application. Additionally, the small losses of N from UDP results in rice with a low environmental footprint (Galloway et al., 2014;Shibata et al., 2017), which could, with appropriate policy and N credits for farmers (Gu et al., 2021), have potential for a premium price in the market, attracting farmers to adopt the practice. The reduction in N losses from the crop-soil system means that it may be possible for rice paddy systems to come close to achieving N balance, and possibly even build fertility over time with the inclusion of additional practices such as crop residue retention. ...
Nitrogen (N) recoveries in rice paddies have barely exceeded 60%, despite the implementation of several management strategies, amounting to significant N being lost to the environment. We conducted field experiments for three consecutive rice growing seasons at two locations in Myanmar to investigate the performance of urea-briquette deep placement (UDP) against variable rates of surface broadcast urea for improving N recovery and yields in rice paddies. The experiment consisted of a control (N0), 77.6 kg N ha⁻¹ as UDP, and surface broadcast urea at 77.6 kg N ha⁻¹ (N78), 100 kg N ha⁻¹ (N100) and 160 kg N ha⁻¹ (N160). Surface broadcast urea was applied in two equal splits at 10 days after transplanting (10 DAT) and at panicle initiation (PI) stage. Urea briquettes (2.7 g) were deep placed (75 mm) in the middle of four rice hills between alternate rows as a single dose at 10 DAT. Microplots receiving ¹⁵N labeled urea were installed in each treatment plot (except N100) to trace the fate of the applied N. Nitrogen input almost always produced higher grain yields (p < 0.05) compared to the control. Rice grain yield in the UDP treatment was similar or higher than in the N78, N100 and N160 treatments. Crop dry biomass yield in the UDP treatment was mostly higher (p < 0.05) than in the N78 and always similar to the N160 treatment. Higher crop (47–61%) and soil (24–40%) recovery of ¹⁵N was observed in the UDP treatment than in the N78 and N160 treatments, leading to total recoveries of 77–95%. The N78 treatment had crop recoveries of 30–37% and total recoveries of 41–60% and the N160 treatment had crop recoveries of 29–39% and total recoveries of 40–54%. The rice plants in the UDP treatment relied less on native soil N, indicating that the UDP practice can minimize soil N depletion. Our results show that UDP has substantial advantages over surface broadcasting in terms of N fertilizer recovery and may provide environmental benefits.
... It focuses on the use of technologies that aim at increasing the availability of N and the productivity of legumes, emphasizing the economic and ecological aspects of production systems Raza et al. 2021;Paudyal and Gupta 2018;Soratto et al. 2022). An example of this is biological N fixation (BNF), which can be an alternative for the supply of N, reducing the use of N fertilizers and, consequently, minimizing the environmental impacts of N leaching in rivers and lakes ( Figure 1) (Shibata et al. 2017). ...
Common bean (Phaseolus vulgaris) is one of the most important legumes for human consumption. It is highly adaptable to different edaphoclimatic conditions, being an important crop in addressing global food security challenges. The common bean production segment has undergone an intense technological advance, with a focus on the use of technologies to increase the availability of nitrogen (N) and the crops’ seed yield, while enhancing economic and ecological sustainability. Based on this, the present meta-analysis aimed to evaluate the effects of Rhizobium inoculation (RI), in comparison with mineral-N fertilization (NF), on the main nodulation characteristics, yield components, and seed yield of common beans. This study represents the largest assessment yet on this topic. We used data from peer-reviewed publications and, after extensive bibliographic research, analyzed 68 studies from seven countries. We found that RI increased seed yield (32.96%) but not to the same extent as NF. The RI is on average 12.31% less efficient than NF; however, when we categorized the factors, such as the time of year when common beans were grown, the soil management system, and the soil physicochemical characteristics, the RI effects were more promising. Here we show for the first time that RI was more efficient than NF when common beans were cultivated in the dry season, under a no-tillage system, and in soils with high organic matter content, with a potentially positive impact on yields. In addition, the difference in the efficiencies of RI and NF was attenuated when common beans were grown in soils with a clay texture, eutrophic, with low to neutral acidity, and with an adequate phosphorus availability, and using at least 10 g of rhizobial inoculum per kg of seeds.
... However, relevant studies concerning the temporal and spatial characteristics of Nrelated environmental footprints in rural China remain lacking. One of the most important indicators reflecting the impact of human consumption on the environment (13), nitrogen footprint (NF) indicates the total amount of Nr losses to the environment from the consumption and associated production of food and energy by entities (14), and it has been widely applied to link consumers with their environmental impacts in recent case studies on different scales, namely countries (6,15), basins (16), cities (17,18), and institutions (19). Normally, personal N footprint can be calculated through the online platform of the N-Calculator model (www.n-print.org), in order to learn how changes in N-content resource consumption affect individual N footprints. ...
... For example, annual amounts of per capita FNFs in United States, Netherlands, and United Kingdom were 28.0, 20.24, and 23.0 kg, respectively [8]. Concurrently, nitrogen footprint of animal-sourced food was higher than that of other food [9][10]. Therefore, it is urgent to reduce FNF in the processes of food production and consumption [11]. ...
Global anthropogenic emissions of reactive nitrogen (Nr) from food production and consumption were regarded as main contributors to nitrogen - related pollution. Food nitrogen footprint analysis could help quantify the amount of Nr release to the environment during the processes of food production and consumption, which plays an important role in nitrogen emission management. In this study, the N - Calculator model was used to quantify the food nitrogen footprint in Guangdong province from 2013 to 2017. The results indicated that: nitrogen footprint of anaimal-sourced food was higher than that of others, and with the increase of animal-sourced food consumption in Guangdong province during the research period, the amount of per capita food nitrogen footprint increased from 19.22 to 21.33 kg N, nearly reaching to the amount of developed countries. Food nitrogen footprint of rural residents was larger than that of urban residents in Guangdong province. Exceeding the recommended amounts of animal - sourced food in the dietary guideline, recent dietary patterns in Guangdong province should be further optimized.
... An LCA-based method was used to calculate N footprint in the study, which was mainly based on empirical formulae and large-scale field surveys, that can relatively well reflect the environmental effects of N application in agricultural production across the NCP (Qin et al., 2011;Shibata et al., 2017). Empirical formulas based on experiments were used to estimate the amount of N volatilization (NH 3 ), nitrous oxide (N 2 O) and nitrate leaching (NO 3 -) in the study (Table S1), which performed well in calculating N footprint across the NCP (Bellarby et al., 2018). ...
Achieving a pathway for green development is a critically important challenge for agriculture in China and beyond. The current study evaluates the effects of a range of management interventions including planting, fertilizer nitrogen (N) rate optimization and increasing farm size to promote agricultural green development across the North China Plain (NCP) based on large-scale farm surveys. Our results showed that the mean annual N fertilizer rate for wheat-soybean rotation was much lower than that of wheat-maize and wheat-peanut. Interestingly, our study indicated strong pre-crop effects of summer soybean (Glycine max (Linn.) Merr.) on the following winter wheat (Triticum aestivum Linn.) in N saving compared to summer maize (Zea mays Linn.) and summer peanuts (Arachis hypogaea Linn.), the low N rate for summer soybean and its ‘legume’ carryover effects led to the low N rate, N surplus and N footprint, and high N use efficiency (NUE) in wheat-soybean. The survey results showed that the optimal N rates for achieving maximum yield of summer maize, summer peanuts and winter wheat were 229, 249 and 236–260 kg ha⁻¹ across the NCP, respectively. Moreover, better N management is beneficial for reducing the N surplus and leads to higher NUE and lower N footprint. Generally, large farms applied less N fertilizer than small farms, thus leading to a lower N surplus and higher N partial factor productivity with the same yield level. Here we show for the first time that the combinations of crop rotation design, optimizing N rate application and increasing farm size are very efficient in reducing N fertilizer applications and the N footprint with stable crop yields. N management should play a more important role in agricultural green development across the NCP and similar regions around the world.
... Adopted from Venterea et al. (2012). researches and mitigation strategies that can be used to reduce environmental N pollution (Stark and Richards, 2008;Shibata et al., 2017) have been discussed in this chapter. ...
Nitrogen Assessment: Pakistan as a Case-Study provides a detailed overview of issues and challenges related to nitrogen use and overuse, thus serving as a reference for researchers in Pakistan and providing important insights for other geographic regions. Excess and inefficient nitrogen use in crops and livestock sectors is polluting our rivers, seas, atmosphere, and ecosystems, contributing to climate change, hampering biodiversity, and contributing to stratospheric ozone depletion. This book covers the importance of nitrogen in relation to food security, human health, and economic stability in South Asia. It also discusses nitrogen status, sources, sinks, and drivers of nitrogen use in Pakistan, focusing on current nitrogen measures and policies.
Nitrogen pollution is one of the biggest challenges of 21st Century, and the international scientific community is beginning to recognize the significance of nitrogen pollution and to explore how to combat it. The editors’ institution, University of Agriculture, Faisalabad, partners with South Asia Nitrogen Hub, which includes about 30 organizations from South Asia and UK working on nitrogen assessment, budgeting, awareness, and policy guidance, as well as possible measures to reduce nitrogen pollution.
Nitrogen Assessment: Pakistan as a Case-Study provides an important guide to this work and is written in a way that is accessible to an audience with a wide range of experience from advanced students to seasoned researchers.
... This has sparked a prioritised list of options to improve current Western dietary patterns (Aiking and de Boer, 2020) with respect to both public health and sustainability. (Shibata et al., 2017). This is attributable to lower consumption levels and food production with much lower N inputs. ...
With climate change now firmly on the political agenda of many countries, the Netherlands is adding another issue to its agenda: the nitrogen crisis. While reactive nitrogen is naturally present at low levels and essential to life, human activities have caused a surplus in reactive Nitrogen, negatively impacting water quality, air quality, soil degradation, climate change, stratospheric ozone and causing significant loss of biodiversity.
The biggest contributor to this surplus in reactive Nitrogen is the agriculture needed to support our current dietary habits, which are highly focused on animal protein. Currently, more than 50% of the population is fed thanks to synthetic nitrogen fertilizers.
There are two ways we, as individuals, can positively impact (reduce) the reactive Nitrogen levels in our environment: (1) through our food choices (choosing plant protein over animal protein) and (2) through reducing food waste (both discarded food and overconsumption).
Such a transition would not only help reduce reactive Nitrogen levels, but would also benefit our health and reduce climate change and biodiversity loss.
Other solutions should be implemented mainly at the governmental level to support sustainable agriculture and food production (improve N use efficiency).
The nitrogen crisis is as important as the carbon crisis. Moreover, it embraces both climate change and biodiversity loss. Importantly, a dietary transition from animal to plant proteins will have a beneficial impact on both.
In addition, it will reduce the use of valuable resources, such as freshwater and land use and, last but not least, it will benefit human health! Together with the change in diet, we also need improved sustainable food production through agricultural and technological changes within the limits of the environment, and reduced food waste across the food chain from production to consumption. There is an urgent need to establish the required sense of urgency, especially among governments worldwide regarding the nitrogen crisis and prevention of environmental pollution and biodiversity loss.
... For the sake of brevity, we refer to Nr loss to the air and water as 'Nr emissions' in this article. Prior research on understanding the drivers of Nr emissions has focused on nitrogen footprint and related assessments (Leach et al 2012, Galloway et al 2014, Oita et al 2016, Shibata et al 2017, Hamilton et al 2018. 'Nitrogen footprint' is an indicator that captures Nr emissions from a life-cycle perspective for satisfying human consumption. ...
Nitrogen is crucial for sustaining life. However, excessive reactive nitrogen (Nr) in the form of ammonia, nitrates, nitrogen oxides or nitrous oxides affects the quality of water, air and soil, resulting in human health risks. This study aims to assess the drivers of Nr emissions by analysing six determinants: nitrogen efficiency (Nr emissions per unit of production), production recipe (inter-sectoral dependencies), final demand composition (consumption baskets of households), final demand destination (consumption vs. investment balance), affluence (final consumption per capita) and population. To this end, we construct a detailed multi-regional input-output database featuring data on international trade between 186 countries to undertake a global structural decomposition analysis of a change in global Nr emissions from 1997-2017. Our analysis shows that nitrogen efficiency has improved over the assessed time-period, however affluence, final demand destination and population growth have resulted in an overall increase in Nr emissions. We provide a global perspective of the drivers of nitrogen emissions at a detailed country level, and breakdown the change in emissions into contribution from domestic footprint and rest-of-world footprint. We highlight that food production coupled with growing international trade is increasing Nr emissions worldwide.
... Most of those food losses happen before reaching markets or consumers, particularly in rural areas, due to poor infrastructure and physical topography. Decreasing food wastage during FC is a feasible way to reduce environmental N losses (Shibata et al., 2017). To overcome such wastage, consumers, food-service providers, and retailers could be liable for underrating wastage of food by adopting new technologies capable of converting Nr to atmospheric N 2 (Zhang et al., 2018). ...
This study presents the first detailed estimate of Rwanda’s nitrogen (N) flows and N footprint for food (NFfood) from 1961 to 2018. Low N fertilizer inputs, substandard production techniques, and inefficient agricultural management practices are focal causes of low crop yields, environmental pollution, and food insecurity. We therefore assessed the N budget, N use efficiency (NUE), virtual N factors (VNFs), soil N mining factors (SNMFs), and N footprint for the agro-food systems of Rwanda with consideration of scenarios of fertilized and unfertilized farms. The total N input to croplands increased from 14.6 kg N ha⁻¹ yr⁻¹ (1960s) to 34.1 kg N ha⁻¹ yr⁻¹ (2010–2018), while the total crop N uptake increased from 18 kg N ha⁻¹yr⁻¹ (1960s) to 28.2 kg N ha⁻¹yr⁻¹ (2010–2018), reflecting a decline of NUE from 124% (1960s) to 85% (2010–2018). Gaseous N losses of NH3, N2O, and NO increased from 0.45 (NH3), 0.03 (N2O), and 0.00 (NO) Gg N yr⁻¹ (1960s) to 6.98 (NH3), 0.58 (N2O), and 0.10 (NO) Gg N yr⁻¹ (2010–2018). Due to the low N inputs, SNMFs were in the range of 0.00 and 2.99 and the rice production, cash-crop production, and livestock production systems have greater SNMFs in Rwanda. The weighted NFfood per capita that presents the actual situation of fertilized and unfertilized croplands increased from 4.0 kg N cap⁻¹ yr⁻¹ (1960s) to 6.3 kg N cap⁻¹ yr⁻¹ (2010–2018). The NFfood per capita would increase from 3.5 kg N cap⁻¹ yr⁻¹ to 4.8 kg N cap⁻¹ yr⁻¹ under a scenario of all croplands without N fertilizer application and increase from 6.0 to 8.7 kg N cap⁻¹ yr⁻¹ under the situation of all croplands receiving N fertilizer. The per capita agro-food production accounted for approximately 58% of the national NFfood. The present study indicates that Rwanda is currently suffering from low N inputs, high soil N depletion, food insecurity, and environmental N losses. Therefore, suggesting that the implementation of N management policies of increasing agricultural N inputs and rehabilitating the degraded soils with organic amendments of human and animal waste needs to be carefully considered in Rwanda.
... Adopted from Venterea et al. (2012). researches and mitigation strategies that can be used to reduce environmental N pollution (Stark and Richards, 2008;Shibata et al., 2017) have been discussed in this chapter. ...
The trends in human population growth suggest that population will be a primary driver to produce more with limiting resources. Here, we discuss the correlation between population growth and the projected changes in various sectors and the resultant increase in nitrogen (N) use in Pakistan. Main drivers for increasing N use are (i) population; (ii) food and feed production; (iii) livestock population; (iv) land use; (v) dietary patterns; (vi) power generation; (vii) industry; and (viii) transport. As N use increases, it adds into N emissions, impacts biodiversity, and increases air and water pollution and eutrophication, which raise concerns about human health and socioecological sustainability and abatement costs. Given the important role of N in economy, food security, human health, and environment, a detailed discussion on critical N drivers is essential to improve our understanding about N cycling/dynamics. In Pakistan, a steadily increasing N consumption calls for optimizing N demand and use. Development and enforcement of regulatory measures are needed to reduce N footprints both for the industrial and agriculture sector in Pakistan. Recognizing the cross-related sectors and interrelated drivers, a holistic approach is required to be adopted for regular assessment of N dynamics.
... Over the past 40 years, agro-environmental research has focused on improving N cycling processes and strategies to reduce N losses to the environment. Some of the researches and mitigation strategies that can be used to reduce environmental N pollution (Stark and Richards, 2008;Shibata et al., 2017) have been discussed in this chapter. ...
Nitrogenous fertilizers are fundamental to crop production, and the global consumption of these fertilizers is increasing to meet the demand of growing population at the cost of environmental footprints. Nitrogen use efficiency (NUE) of crops is low due to excessive use of nitrogen (N) in soil–plant system that results in greenhouse gases (GHGs) emissions and cause global warming. This chapter discusses possible reasons for GHGs emissions and its mitigation potential through soil, plant, and sensors-based approaches. Potential of split N application, different nitrification inhibitors, green manure crops, and biological nitrogen fixation including the use of legumes as cover crops have also been highlighted. Furthermore, the significance of promotion of innovative on-farm technologies has also been discussed. Integrated strategies including site-specific N management, crop residues management, higher plant densities, weed and pest control, and balanced fertilization with other nutrients can help reduce N losses. Food waste, manure, and sewage can be used to improve NUE for achieving UN Sustainable Development Goals.
... The diet of the rich consists of animal feed products, and the rich consumer needs relatively more resources to consume than resources required for the basic diet. Therefore, rich diets have a greater impact on the environment (Kastner et al., 2012;Hoekstra & Mekonnen, 2012;Leach et al., 2012;Ranganathan et al., 2016;Shibata et al., 2016). ...
Abstract
Food is one of the basic necessities that play a major role in human life. Over the past two decades, food consumption patterns in many countries have changed rapidly. The concern of food security has emerged as a global food crisis in recent decades. These global changes probably affect Sri Lankan food consumption habits. Sustainability is an essential component and a precondition for long-term food security. Hence, this study used an in-depth non-systematic literature review on a global scale emphasizing the Sri Lankan context, to better understand the situation of changes in food consumption patterns using comprehensive household survey data in Sri Lanka. The study found out that income growth, urbanization, structural changes in the population on demographics, and several other socio-economic changes significantly influenced transformations in global food consumption patterns. Other than these, many significant differences are evident in food consumption patterns especially geographically, in urban, rural, and estate sectors in Sri Lanka. The Sri Lankan diet shows a tendency to shift from traditional cereal consumption to meat, fish, dairy products, and fast foods and processed foods, posing a significant threat concerning the future food security and sustainability of Sri Lanka. Therefore, the study recommended a critical analysis of changes in food consumption patterns in Sri Lanka.
Keywords
Sri Lanka, Consumption Patterns, Food Security, Sustainability, Food Habits
Tea, an important cash crop of many developing countries, has considerable socio-economic importance for rural development and poverty alleviation. More than three billion people in 160 countries and regions drink tea. Major tea producing countries of the world are China, India, Kenya, and Sri Lanka and they cultivate tea under different geo-physical environments existing in their countries. Long-term intensive tea cultivation deteriorates soil quality status and degrade land sustainability. Prolonged exploitation of tea growing soils through perennial monoculturing often causes significant changes, with acidification being the most important problem. Since tea is cultivated exclusively for leaves as the economic part, it requires heavy fertilizer application, especially of N, which often leads to high acidification and other related problems. Therefore, development and application of management strategies that enable to overcome various problems is essential to reduce the risks and ensure sustainable development of tea.
This chapter provides an extensive overview on soil acidification, its causes, and amelioration methods; role of major, secondary and micronutrients in tea growth, yield and quality; fertilizer application; chances of heavy metal contamination in the soil and their effect on tea quality; agroecological and organic management of tea plantations; best agro-management practices for sustained soil health and tea production; role of microbes in soil fertility; impact of climate change and tea growth; and the way forward for efficient soil health management of tea plantations aimed at sustained production of quality produce.
To investigate the effect of nitrogen (N) application on the carbon metabolism and yield of flag leaves and grains of spring wheat under drip irrigation in Xinjiang, a split-zone design was adopted from 2020 to 2021, with strong-gluten wheat, Xinchun 37 (XC37), and medium-gluten wheat, Xinchun 6 (XC 6), as the main zones and different nitrogen application rates as the sub-zones. Four nitrogen application rates of 0, 210, 255, and 300 kg·ha−1 (CK2, B1, A1, and CK1, respectively) were set to analyze and compare the nitrogen response of key enzyme activity, soluble sugar, and sucrose and starch content in flag leaves and grains to control yield formation. The results showed that with the increase in nitrogen application, the activities of sucrose phosphate synthase (SPS) and sucrose synthase (SS) in flag leaves; the activities of SS, adenosine diphosphate glucose pyrophosphorylase (ADPG-PPase), soluble starch synthase (SSS), granule-bound starch synthase (GBSS), and starch branching enzyme (SBE) in grains; the contents of soluble sugar and sucrose in the flag leaves; and the yield, all first increased and then decreased. There is a significant difference between A1 (255 kg·ha−1) and the CK1 (300 kg·ha−1), B1 (210 kg·ha−1), and CK2 (0 kg·ha−1) treatments under the above indicators, with increases of 8–158%, 9–155%, 8–53%, 5–63%, 3–86%, 3–57%, 9–79%, 9–197%, and 9–113%, as well as higher levels of amylose, amylopectin, and total starch content than other treatments by 2–30%, 11–84%, and 8–63%, respectively. Correlation and stepwise regression analyses indicated highly a significant positive correlation between the yield and soluble sugar and sucrose of flag leaves and grains, as well as their key enzymes and starch. Among them, soluble sugar in grains, amylopectin, and sucrose in grains have the greatest impact on the yield of XC37, determining 85% of its yield. SSS, soluble sugars in grains, amylopectin, and SBE have the greatest impact on the yield of XC 6, determining 80% of its yield. The starch showed a highly significant positive correlation with ADPG-PPase, SSS, GBSS, and SBE. There was a significant interaction effect between the nitrogen application rate and variety, with better performance observed in Xinchun 37 compared to Xinchun 6. Under drip irrigation conditions in arid areas, a nitrogen application of 255 kg·ha−1 can effectively regulate the metabolism of sucrose to starch in the flag leaves and grains of spring wheat, which is conducive to the accumulation of starch in grains and the formation of yield.
Soybean (Glycine max L. Merril) is among the key oil seed crops worldwide providing several
benefits from human consumption to the enhancement of soil productivity. The major bottleneck
to the crop’s production in the tropics is the decreasing soil fertility, mainly caused by not only
low nitrogen (N) but also phosphorus (P) levels in the soil. There is a high potential for supplying
N from the atmosphere through biological nitrogen fixation (BNF), a natural process mediated by
the symbiotic bacteria Bradyrhizobia Japonicum, which requires optimum P levels for effective
N fixation. The study focused on assessing the synergistic effect of inoculation and phosphatic
fertilizer application on nodulation, yields, economic returns, P uptake and use efficacy of
Maksoy 5N soybean. The study was conducted at Ngetta Zonal Agricultural Research and
Development Institute (NGEZARDI) located in Lira City, Uganda. The study had the experiment
laid out in RCBD under a split-plot arrangement with the main plots being two inoculation levels
(with or without inoculation) and the sub-plots being phosphatic (TSP) inorganic fertilizer at four
P levels: 0, 7.5, 15, and 45 kg P ha-1
. The treatments were replicated three times. The data
collected included growth and yield parameters, such as the total number of root nodules, number
of effective root nodules, number of seeds per pod, number of pods per plant, biomass yield,
stover weight, grain yield, and 100-grain weight. Production cost and yield data were used to
calculate economic returns. Data collected were subjected to analysis of variance in Genstat
software where the treatment means were further distinguished at a 5% level of probability using
Fishers' least significant difference. The total and effective root nodules increased with
inoculation with a peak in fertilized plots with 15 kg P ha-1
(11.8, 13.3). Under inoculation and P
application, treatments that received 7.5, 15 and 45 kg P ha-1
recorded 9, 30, and 25% higher
yields than the control. The highest net income and benefit: cost ratio were recorded in the
inoculated and fertilized plots with 15 kg P ha-1
(US$ 414.93, 1.87) and (US$ 390.23, 1.76). With
inoculation, P use efficiency based on yield (PUEY) and economic returns (PUEE) decreased with
increasing P levels in the orders of 165 > 73 > 54 > 21 kg grain kg P supplied-1
and 51 > 24 > 20
> 8 US $ kg P supplied-1
for the control, P7.5, P15, and P45 respectively. This study indicated that
for optimal growth, productivity, and economic benefits, soybean ought to be inoculated with
Bradyrhizobium coupled with the application of phosphatic fertilizer at the rate of 15 kg P ha-1
Recent hikes in fertilizer, feed, and food prices threaten the food security of island-dwelling people who rely heavily on imports to sustain food supply and production. The influx of reactive nitrogen (Nr) through imports increases nitrogen load and degrades the environment. To overcome these problems, a robust and sustainable food system must be developed. In this study, we aimed to evaluate the present nitrogen flow in the food system of Ishigaki Island, located in the subtropical zone of Japan, and propose a measure to improve it based on the nitrogen footprint concept. Results showed that the major Nr-loss pathways for agricultural activity on the island were “crop-unused” (37%) and “manure” (43%). In food production, most of the Nr loss to the environment was related to export products, and less than 30% was related to island consumers. To meet the demand of food supply on the island, 5.1 times greater amount of food Nr than that of produced for island consumers was imported from overseas regions, placing the burden of Nr loss on such regions. We found that agricultural activities on the island mainly used chemical fertilizer; less than 13% of cattle manure was reused. To reduce the influx of Nr, we created a scenario in which 30% of chemical fertilizer was replaced by cattle manure. Results indicated 70% of the cattle manure produced on the island was necessary to achieve this scenario. This system could reduce Nr imports and Nr loss on the island by 16% and 17%, respectively. The proposed food system can be extended to other islands to overcome the recent price hikes and conserve the environment. This study is the first to present a detailed nitrogen flow in the food system of a tropical/subtropical island by using the nitrogen footprint concept.
The urban socioeconomic metabolism of multiple flows of resources is highly complex. Our concern is that of moderating the environmental burden and intensity of this metabolism and elevating its “circularity” through technological interventions in the composition of urban infrastructure. The paper addresses present and possible future patterns of the nitrogen (N) metabolism of Suzhou, China, using a Multi-sectoral Systems Analysis (MSA) model of the water, energy, food, forestry, and waste management sectors of the city's infrastructure and economy. Two of the Triple Bottom Lines are employed in the assessment: those of the economic feasibility and the environmental benignity of the technological interventions. Environmental benignity is gauged by three Metabolic Performance Metrics (MPMs). 15 scenarios of these interventions are assessed, each being a different combination of introducing four particular promising technologies. The MPMs allow ranking of the scenarios according to, first, the ratio of incoming resource flows into the city and outgoing socio-economically beneficial products and, second, the rates at which “wastes” of no value are released to the atmosphere (as air pollutants), hydrosphere (water pollutants), and the lithosphere (solid wastes). The economic feasibility of the options can similarly be ranked according to the monetary values of resources (such as clean water or energy) that are saved by lowered urban consumption or that are recovered (such as biofuels or fertilizer) for beneficial re-circulation and re-use. All four candidate technological innovations are associated with the water and waste management sectors of urban infrastructure. We show that the trio of urine-separating technology, cultivation of algal biomass in wastewater treatment, and pyrolysis of animal manure can achieve an expected net annual economic benefit of 1.4B Yuan, together with the potential to recover some 31 Gg N yr−1. Notably, our computational assessment accounts for uncertainty, using Monte Carlo simulation and sensitivity testing. In particular, we examine how uncertainty may significantly undermine the conclusions we may draw about the promise of any given technological innovation vis à vis another alternative.
For urban agglomerations in the bay area, which concentrate multiple environmental elements and intense anthropogenic activities, comprehensive control of nitrogen pollution is particularly challenging due to diverse cross-media migration and transformation forms of nitrogen pollutants. Existing studies on urban nitrogen metabolism mainly focused on quantification of nitrogen flux, without systematic consideration of physiochemical changes of nitrogen between environmental media. This study conducted a dynamic simulation of nitrogen cross-media metabolism in urban agglomeration over 30 consecutive years, and recognized the types, quantities, and trends of cross-media transfer of nitrogen pollution as well as pollution control paths based on ecological network analysis and scenario analysis. Taking the Guangdong-Hong Kong-Macao Greater Bay Area as the case, results show that during its fast-urbanized stage in 1989–2018, more than 25% of the total nitrogen pollution emissions were transferred from other media. The higher degree of imbalance between the socioeconomic system and the soil in the nitrogen metabolic network emphasizes the increased pressure and necessity of pollution control of nitrogen in the solid state with urban development. Promoting fertilizer reduction and sludge land use are priority paths for collaborative control of cross-media nitrogen pollution. The study provides methods to systematically analyze the features of cross-media transfer of nitrogen pollution at the city level, and accordingly propose paths aiming at sustainable urban nitrogen management with multi-media integrity and synergy.
We summarize the recent approaches to macrocycle-based anion extraction, including those based on calix[4]pyrroles, and so-called “Texas-sized” molecular boxes.
Reactive nitrogen (Nr) is an indispensable material for food production. However, it may cause serious environmental problems. The enhancement of nitrogen management in the food supply chain is an effective way to reduce Nr loss and increase Nr use efficiency. While Nr flows in association with the food chain have synergy in a mega-region, in-depth investigations at a cross-regional scale have remained relatively undocumented. This study developed a food-related Nr flow model based on a material flow analysis for the Beijing-Tianjin-Hebei region (BTH) during the years 1978-2017. A multi-regional input-output method was applied to investigate the Nr emissions embodied in the transboundary food supply. The results showed that the total Nr emissions from the food system during the years 1978-2017 in the BTH region increased until 2004 and subsequently decreased gradually. In 2017, Beijing exhibited the lowest Nr emissions per capita (2.3 kg N/cap) and per land use (3089 kg N/km2), while Hebei and Tianjin demonstrated the greatest Nr emissions intensity by capita (13.6 kg N/cap) and by land use (6392 kg N/km2), respectively. While farming and livestock husbandry dominated the regional Nr emissions (i.e., responsible for 90% of the total in 2017), food consumption and waste management have had an increasingly substantial role, as their shared percentage in the total increased by 22% over the study period. Nr emissions resulting from the inner-transboundary food supply chain decreased by 81% between 2012 and 2015 but dramatically increased by 231% between 2015 and 2017. This rebound effect partially resulted from the implementation of coordinated development planning for the BTH region in 2015. This study can facilitate the efficient regulation of regional nitrogen flows and the desired transition of food supply chain.
The Nitrogen Footprint (N-Footprint) is the total amount of reactive nitrogen (Nr) released to the environment as a result of an entity's consumption patterns. N-Footprint assessments have mainly been consumer-oriented and country-sized, although concern has recently focused on single products, especially particular foods.
While traditionally obtained from several software and/or calculators, the N-Footprint is here proposed to be evaluated by combining the Life Cycle (LCA) approach with a specific N based impact assessment modelling, as derived from Intergovernmental Panel on Climate Change guidelines.
The theoretical procedure is then applied to a real livestock case study (the Mora Romagnola pig that provides high quality pork), mainly based on primary data. The total amount of Nr released was about 40 kg per pig (live weight), mainly due to direct components (i.e. manure management ∼ 85%). The results highlight the importance of more comprehensive and systematic quantification of emissions, especially direct ones that are neglected in the classical database and software. The Virtual N-Factor (VNF) was 2.3, which indicates that about 30% of N input by weight is incorporated in the meat, while most of it (∼70%) is dispersed to different environmental compartments (38% atmosphere, 35% soil, 27% water). A comparative analysis to check the reliability of outcomes and the robustness of the accounting procedure is also offered and show that these results are consistent with those reported in the literature for other pork products.
The main benefit of this procedure is that it produces a unique aggregate result of the entity of human pressure on nitrogen cycle. This ensures a high comparability for results, transparency, and reproducibility of the method.
The Environmental Performance Index (EPI) ranks countries’ performance on high-priority environmental issues in two areas: protection of human health and protection of ecosystems. Within these two policy objectives the EPI scores national performance in nine issue areas comprised of more than 20 indicators (see EPI Framework). EPI indicators measure country proximity to meeting internationally established targets or, in the absence of agreed targets, how
nations compare to one another.
Implementation of the Nitrates Directive (NiD) and its environmental impacts were compared for member states in the northwest of the European Union (Ireland, United Kingdom, Denmark, the Netherlands, Belgium, Northern France and Germany). The main sources of data were national reports for the third reporting period for the NiD (2004–2007) and results of the MITERRA-EUROPE model. Implementation of the NiD in the considered member states is fairly comparable regarding restrictions for where and when to apply fertilizer and manure, but very different regarding application limits for N fertilization. Issues of concern and improvement of the implementation of the NiD are accounting for the fertilizer value of nitrogen in manure, and relating application limits for total nitrogen (N) to potential crop yield and N removal. The most significant environmental effect of the implementation of the NiD since 1995 is a major contribution to the decrease of the soil N balance (N surplus), particularly in Belgium, Denmark, Ireland, the Netherlands and the United Kingdom. This decrease is accompanied by a modest decrease of nitrate concentrations since 2000 in fresh surface waters in most countries. This decrease is less prominent for groundwater in view of delayed response of nitrate in deep aquifers. In spite of improved fertilization practices, the southeast of the Netherlands, the Flemish Region and Brittany remain to be regions of major concern in view of a combination of a high nitrogen surplus, high leaching fractions to groundwater and tenacious exceedance of the water quality standards. On average the gross N balance in 2008 for the seven member states in EUROSTAT and in national reports was about 20 kg N ha<sup>−1</sup> yr<sup>−1</sup> lower than by MITERRA. The major cause is higher estimates of N removal in national reports which can amount to more than 50 kg N ha<sup>−1</sup> yr<sup>−1</sup>. Differences between procedures in member states to assess nitrogen balances and water quality and a lack of cross-boundary policy evaluations are handicaps when benchmarking the effectiveness of the NiD. This provides a challenge for the European Commission and its member states, as the NiD remains an important piece of legislation for protecting drinking water quality in regions with many private or small public production facilities and controlling aquatic eutrophication from agricultural sources.
Anthropogenic emissions of reactive nitrogen to the atmosphere and water bodies can damage human health and ecosystems1, 2. As a measure of a nation’s contribution to this potential damage, a country’s nitrogen footprint has been defined as the quantity of reactive nitrogen emitted during the production, consumption and transportation of commodities consumed within that country, whether those commodities are produced domestically or internationally3. Here we use global emissions databases4, 5, a global nitrogen cycle model6, and a global input–output database of domestic and international trade7, 8 to calculate the nitrogen footprints for 188 countries as the sum of emissions of ammonia, nitrogen oxides and nitrous oxide to the atmosphere, and of nitrogen potentially exportable to water bodies. Per-capita footprints range from under 7 kg N yr−1 in some developing countries to over 100 kg N yr−1 in some wealthy nations. Consumption in China, India, the United States and Brazil is responsible for 46% of global emissions. Roughly a quarter of the global nitrogen footprint is from commodities that were traded across country borders. The main net exporters have significant agricultural, food and textile exports, and are often developing countries, whereas important net importers are almost exclusively developed economies. We conclude that substantial local nitrogen pollution is driven by demand from consumers in other countries.
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2635.html
The message of this overview is that everyone stands to benefit from nutrients and that everyone can make a contribution to promote sustainable production and use of nutrients. Whether we live in a part of the world with too much or too little nutrients, our daily decisions can make a difference. Without swift and collective action, the next generation will inherit a world where many millions may suffer from food insecurity caused by too few nutrients, where the nutrient pollution threats from too much will become more extreme, and where unsustainable use of nutrients will contribute even more to biodiversity loss and accelerating climate change. Conversely with more sustainable management of nutrients, economies can play a role in a transition to a Green Economy in the context of sustainable development and poverty eradication. The Global Overview develops these essential themes, to prepare societies to take the next steps.
The European Parliament recently called for urgent measures to halve food waste in the EU, where consumers are responsible for a major part of total waste along the food supply chain. Due to a lack of data on national food waste statistics, uncertainty in (consumer) waste quantities (and the resulting associated quantities of natural resources) is very high, but has never been previously assessed in studies for the EU. Here we quantify: (1) EU consumer food waste, and (2) associated natural resources required for its production, in term of water and nitrogen, as well as estimating the uncertainty of these values. Total EU consumer food waste averages 123 (min 55–max 190) kg/capita annually (kg/cap/yr), i.e. 16% (min 7–max 24%) of all food reaching consumers. Almost 80%, i.e. 97 (min 45–max 153) kg/cap/yr is avoidable food waste, which is edible food not consumed. We have calculated the water and nitrogen (N) resources associated with avoidable food waste. The associated blue water footprint (WF) (the consumption of surface and groundwater resources) averages 27 litre per capita per day (min 13–max 40 l/cap/d), which slightly exceeds the total blue consumptive EU municipal water use. The associated green WF (consumptive rainwater use) is 294 (min 127–max 449) l/cap/d, equivalent to the total green consumptive water use for crop production in Spain. The nitrogen (N) contained in avoidable food waste averages 0.68 (min 0.29–max 1.08) kg/cap/yr. The food production N footprint (any remaining N used in the food production process) averages 2.74 (min 1.02–max 4.65) kg/cap/yr, equivalent to the use of mineral fertiliser by the UK and Germany combined. Among all the food product groups wasted, meat accounts for the highest amounts of water and N resources, followed by wasted cereals. The results of this study provide essential insights and information on sustainable consumption and resource efficiency for both EU policies and EU consumers.
Significance
China is the world’s largest producer of reactive nitrogen (Nr), and Nr in the form of synthetic fertilizer has contributed substantially to increased food production there. However, Nr losses from overuse and misuse of fertilizer, combined with industrial emissions, represent a serious and growing cause of air and water pollution. This paper presents a substantially complete and coherent Nr budget for China and for 14 subsystems within China from 1980 to 2010, evaluates human health/longevity and environmental consequences of excess Nr, and explores several scenarios for Nr in China in 2050. These scenarios suggest that reasonable pathways exist whereby excess Nr could be reduced substantially, while at the same time benefitting human well-being and environmental health.
Nitrogen footprints connect entities, such as individuals, with the reactive nitrogen lost to the environment as a result of their activities. Reactive nitrogen contributes to a cascade of environmental and human health problems such as smog, eutrophication, acid rain, and climate change. We present the first institution-level model to estimate the nitrogen footprint of the University of Virginia (UVA), both current and projected to 2025. The model is also used to test scenarios on the most effective ways to decrease the nitrogen (N) footprint of the university. The total nitrogen footprint of the university in 2010 was 492 metric tons (MT) N. Utilities usage (48%) and off-campus food production (37%) were the biggest contributors to the UVA nitrogen footprint. The remaining sectors (food consumption, fertilizer usage, transportation, and research animals) make up the final 15 percent. Of the food production categories, meat (22%) and dairy and eggs (10%) were the largest contributors to the footprint. If the university were to continue with its current activities (i.e., business as usual or BAU), by 2025 the N footprint of the university would increase by 15 percent to 564 MT N. However, scenario testing with the model shows that by 2025, the N footprint could be decreased by 18 percent, relative to BAU, with the implementation of planned and feasible activities, and by an additional 13 percent through further N-reduction strategies. Institutions like the University of Virginia can use a nitrogen footprint tool to improve their sustainability by quantifying and reducing their nitrogen impact.
Humans increase the amount of reactive nitrogen (all N species except N2) in the environment through a number of processes, primarily food and energy production. Once in the environment, excess reactive nitrogen may cause a host of various environmental problems. Understanding and controlling individual nitrogen footprints is important for preserving environmental and human health. In this paper we present the per capita nitrogen footprint of Japan. We considered the effect of the international trade of food and feed, and the impact of dietary preferences among different consumer age groups. Our results indicate that the current average per capita N footprint in Japan considering trade is 28.1 kg N capita−1 yr−1. This footprint is dominated by food (25.6 kg N capita−1 yr−1), with the remainder coming from the housing, transportation, and goods and services sectors. The difference in food choices and intake between age groups strongly affected the food N footprint. Younger age groups tend to consume more meat and less fish, which leads to a larger food N footprint (e.g., 27.5 kg N capita−1 yr−1 for ages 20 to 29) than for older age groups (e.g., 23.0 kg N capita−1 yr−1 for ages over 70). The consideration of food and feed imports to Japan reduced the per capita N footprint from 37.0 kg N capita−1 yr−1 to 28.1 kg N capita−1 yr−1. The majority of the imported food had lower virtual N factors (i.e., Nr loss factors for food production), indicating that less N is released to the environment during the respective food production processes. Since Japan relies on imported food (ca. 61%) more than food produced domestically, much of the N losses associated with the food products is released in exporting countries.
The planetary boundaries framework defines a safe operating space for humanity based on the intrinsic biophysical processes
that regulate the stability of the Earth system. Here, we revise and update the planetary boundary framework, with a focus
on the underpinning biophysical science, based on targeted input from expert research communities and on more general scientific
advances over the past 5 years. Several of the boundaries now have a two-tier approach, reflecting the importance of cross-scale
interactions and the regional-level heterogeneity of the processes that underpin the boundaries. Two core boundaries—climate
change and biosphere integrity—have been identified, each of which has the potential on its own to drive the Earth system
into a new state should they be substantially and persistently transgressed.
With more than 60% of the land farmed, with vulnerable freshwater and marine environments, and with one of the most intensive, export-oriented livestock sectors in the world, the nitrogen (N) pollution pressure from Danish agriculture is severe. Consequently, a series of policy action plans have been implemented since the mid 1980s with significant effects on the surplus, efficiency and environmental loadings of N. This paper reviews the policies and actions taken and their ability to mitigate effects of reactive N (Nr) while maintaining agricultural production. In summary, the average N-surplus has been reduced from approximately 170 kg N ha−1 yr−1 to below 100 kg N ha−1 yr−1 during the past 30 yrs, while the overall N-efficiency for the agricultural sector (crop + livestock farming) has increased from around 20–30% to 40–45%, the N-leaching from the field root zone has been halved, and N losses to the aquatic and atmospheric environment have been significantly reduced. This has been achieved through a combination of approaches and measures (ranging from command and control legislation, over market-based regulation and governmental expenditure to information and voluntary action), with specific measures addressing the whole N cascade, in order to improve the quality of ground- and surface waters, and to reduce the deposition to terrestrial natural ecosystems. However, there is still a major challenge in complying with the EU Water Framework and Habitats Directives, calling for new approaches, measures and technologies to mitigate agricultural N losses and control N flows.
We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, N-neutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66 kg N. A total of US$ 3050 was collected from the participants and used to offset the conference's N footprint by supporting the UN Millennium Village cluster Ruhiira in South-Western Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates.
The human alteration of the nitrogen cycle has evolved from minimal in the mid-19th century to extensive in the present time. The consequences to human and environmental health are significant. While much attention has been given to the extent and impacts of the alteration, little attention has been given to those entities (i.e., consumers, institutions) that use the resources that result in extensive reactive nitrogen (Nr) creation. One strategy for assessment is the use of nitrogen footprint tools. A nitrogen footprint is generally defined as the total amount of Nr released to the environment as a result of an entity's consumption patterns. This paper reviews a number of nitrogen footprint tools (N-Calculator, N-Institution, N-Label, N-Neutrality, N-Indicator) that are designed to provide that attention. It reviews N-footprint tools for consumers as a function of the country that they live in (N-Calculator, N-Indicator) and the products they buy (N-Label), for the institutions that people work in and are educated in (N-Institution), and for events and decision-making regarding offsets (N-Neutrality). N footprint tools provide a framework for people to make decisions about their resource use and show them how offsets can be coupled with behavior change to decrease consumer/institution contributions to N-related problems.
Reactive nitrogen (Nr) is an indispensable nutrient for agricultural production and human alimentation. Simultaneously, agriculture is the largest contributor to Nr pollution, causing severe damages to human health and ecosystem services. The trade-off between food availability and Nr pollution can be attenuated by several key mitigation options, including Nr efficiency improvements in crop and animal production systems, food waste reduction in households and lower consumption of Nr-intensive animal products. However, their quantitative mitigation potential remains unclear, especially under the added pressure of population growth and changes in food consumption. Here we show by model simulations, that under baseline conditions, Nr pollution in 2050 can be expected to rise to 102-156% of the 2010 value. Only under ambitious mitigation, does pollution possibly decrease to 36-76% of the 2010 value. Air, water and atmospheric Nr pollution go far beyond critical environmental thresholds without mitigation actions. Even under ambitious mitigation, the risk remains that thresholds are exceeded.
Western diets are characterised by a high intake of meat, dairy products and eggs, causing an intake of saturated fat and red meat in quantities that exceed dietary recommendations. The associated livestock production requires large areas of land and lead to high nitrogen and greenhouse gas emission levels. Although several studies have examined the potential impact of dietary changes on greenhouse gas emissions and land use, those on health, the agricultural system and other environmental aspects (such as nitrogen emissions) have only been studied to a limited extent. By using biophysical models and methods, we examined the large-scale consequences in the European Union of replacing 25–50% of animal-derived foods with plant-based foods on a dietary energy basis, assuming corresponding changes in production. We tested the effects of these alternative diets and found that halving the consumption of meat, dairy products and eggs in the European Union would achieve a 40% reduction in nitrogen emissions, 25–40% reduction in greenhouse gas emissions and 23% per capita less use of cropland for food production. In addition, the dietary changes would also lower health risks. The European Union would become a net exporter of cereals, while the use of soymeal would be reduced by 75%. The nitrogen use efficiency (NUE) of the food system would increase from the current 18% to between 41% and 47%, depending on choices made regarding land use. As agriculture is the major source of nitrogen pollution, this is expected to result in a significant improvement in both air and water quality in the EU. The resulting 40% reduction in the intake of saturated fat would lead to a reduction in cardiovascular mortality. These diet-led changes in food production patterns would have a large economic impact on livestock farmers and associated supply-chain actors, such as the feed industry and meat-processing sector.
The alteration of the global nitrogen (N) cycle is creating severe environmental impacts. This paper analyses the increasing importance of the international trade of food and feed in the alteration of the N cycle at the global scale in two ways. First, using the information on food and feed trade across world countries, and assuming that N constitutes 16 % of proteins, we quantified the N annually traded in the period 1961–2010. We observed that in that period, the amount of N traded between countries has increased eightfold (from 3 to 24 TgN) and now concerns one-third of the total N in world crop production, with the largest part corresponding to animal feed. Secondly, we divided the world into 12 regions and studied the N transfer among them in two reference years: 1986 and 2009. The N flow among these regions has dramatically intensified during this period not only due to an increase in the population but also in the proportion of animal protein in the diet of some countries. Nowadays, in terms of proteins and N, a small number of countries (e.g., USA, Argentina and Brazil) are feeding the rest of the world. At the global scale the system is becoming less efficient because of the disconnection between crop and livestock production across specialised regions, increasing the environmental impacts. As human diet is an additional clear driver of the observed changes, the solutions must rely not only on the producers, but also on the consumers. The results of our study provide new insights into the food dependency relationships between the different regions of the world as well as the growing importance of international food and feed trade in the global N cycle.
The global nitrogen (N) cycle has been transformed by human use of reactive N as a consequence of increased demand for food and energy. Given the considerable impact of humans on the N cycle, it is essential that we raise awareness amongst the public and policy makers as this is the first step in providing individuals and governments the opportunity to reduce their impact on the N cycle and reduce the environmental and health consequences of N pollution. Here we describe an N footprint tool for the UK developed as part of the N-PRINT program. The current per capita N footprint in the UK is 27.1 kg N per capita per year with food production constituting the largest proportion of the footprint (18.0 kg N per capita per year). Calculating an N footprint for 1971 (26.0 kg N per capita per year) demonstrates that per capita N footprints have increased slightly. The average UK footprint is smaller than that found in the USA but is higher than the Netherlands and Germany. Scenario analysis demonstrates that reducing food protein consumption to the levels recommended by the FAO and World Health Organization reduces the overall N footprint by 33%. Consuming a vegetarian diet and consuming only sustainable food both decreased the N footprint by 15% but changes in energy use have a much smaller impact.
Human activities affect the impact of the nitrogen cycle on both the environment and climate. The rate of anthropogenic nitrogen fixation from atmospheric N2 may serve as an indicator to the magnitude of this impact, acknowledging that relationship to be effect-dependent and non-linear. Building on the set of Representative Concentration Pathway (RCP) scenarios developed for climate change research, we estimate anthropogenic industrial nitrogen fixation throughout the 21st century. Assigning characteristic key drivers to the four underlying scenarios we arrive at nitrogen fixation rates for agricultural use of 80 to 172 Tg N/yr by 2100, which is slightly less to almost twice as much compared with the fixation rate for the year 2000. We use the following key drivers of change, varying between scenarios: population growth, consumption of animal protein, agricultural efficiency improvement and additional biofuel production. Further anthropogenic nitrogen fixation for production of materials such as explosives or plastics and from combustion are projected to remain considerably smaller than that related to agriculture. While variation among the four scenarios is considerable, our interpretation of scenarios constrains the option space: several of the factors enhancing the anthropogenic impact on the nitrogen cycle may occur concurrently, but never all of them. A scenario that is specifically targeted towards limiting greenhouse gas emissions ends up as the potentially largest contributor to nitrogen fixation, as a result of large amounts of biofuels required and the fertilizer used to produce it. Other published data on nitrogen fixation towards 2100 indicate that our high estimates based on the RCP approach are rather conservative. Even the most optimistic scenario estimates that nitrogen fixation rate will remain substantially in excess of an estimate of sustainable boundaries by 2100.
Haber-Bosch nitrogen (N) has been increasingly used in industrial products, e.g., nylon, besides fertilizer. Massive numbers of species of industrial reactive N (Nr) have emerged and produced definite consequences but receive little notice. Based on a comprehensive inventory, we show that (1) the industrial N flux has increased globally from 2.5 to 25.4 Tg N yr(-1) from 1960 through 2008, comparable to the NOx emissions from fossil fuel combustion; (2) more than 25% of industrial products (primarily structural forms, e.g., nylon) tend to accumulate in human settlements due to their long service lives; (3) emerging Nr species define new N-assimilation and decomposition pathways and change the way that Nr is released to the environment; and (4) the loss of these Nr species to the environment has significant negative human and ecosystem impacts. Incorporating industrial Nr into urban environmental and biogeochemical models could help to advance urban ecology and environmental sciences.
On 13 October 1908, Fritz Haber filed his patent on the ``synthesis of ammonia from its elements'' for which he was later awarded the 1918 Nobel Prize in Chemistry. A hundred years on we live in a world transformed by and highly dependent upon Haber-Bosch nitrogen.
Global nitrogen fixation contributes 413 Tg of reactive nitrogen (Nr) to terrestrial and marine ecosystems annually of which anthropogenic activities are responsible for half, 210 Tg N. The majority of the transformations of anthropogenic Nr are on land (240 Tg N yr(-1)) within soils and vegetation where reduced Nr contributes most of the input through the use of fertilizer nitrogen in agriculture. Leakages from the use of fertilizer Nr contribute to nitrate (NO3(-)) in drainage waters from agricultural land and emissions of trace Nr compounds to the atmosphere. Emissions, mainly of ammonia (NH3) from land together with combustion related emissions of nitrogen oxides (NOx), contribute 100 Tg N yr(-1) to the atmosphere, which are transported between countries and processed within the atmosphere, generating secondary pollutants, including ozone and other photochemical oxidants and aerosols, especially ammonium nitrate (NH4NO3) and ammonium sulfate (NH4)2SO4. Leaching and riverine transport of NO3 contribute 40-70 Tg N yr(-1) to coastal waters and the open ocean, which together with the 30 Tg input to oceans from atmospheric deposition combine with marine biological nitrogen fixation (140 Tg N yr(-1)) to double the ocean processing of Nr. Some of the marine Nr is buried in sediments, the remainder being denitrified back to the atmosphere as N2 or N2O. The marine processing is of a similar magnitude to that in terrestrial soils and vegetation, but has a larger fraction of natural origin. The lifetime of Nr in the atmosphere, with the exception of N2O, is only a few weeks, while in terrestrial ecosystems, with the exception of peatlands (where it can be 10(2)-10(3) years), the lifetime is a few decades. In the ocean, the lifetime of Nr is less well known but seems to be longer than in terrestrial ecosystems and may represent an important long-term source of N2O that will respond very slowly to control measures on the sources of Nr from which it is produced.
Nitrogen over the ages! It was discovered in the eighteenth century. The following century, its importance in agriculture was documented and the basic components of its cycle were elucidated. In the twentieth century, a process to provide an inexhaustible supply of reactive N (Nr; all N species except N2) for agricultural, industrial and military uses was invented. This discovery and the extensive burning of fossil fuels meant that by the beginning of the twenty-first century, anthropogenic sources of newly created Nr were two to three times that of natural terrestrial sources. This caused a fundamental change in the nitrogen cycle; for the first time, there was the potential for enough food to sustain growing populations and changing dietary patterns. However, most Nr created by humans is lost to the environment, resulting in a cascade of negative earth systems impacts-including enhanced acid rain, smog, eutrophication, greenhouse effect and stratospheric ozone depletion, with associated impacts on human and ecosystem health. The impacts continue and will be magnified, as Nr is lost to the environment at an even greater rate. Thus, the challenge for the current century is how to optimize the uses of N while minimizing the negative impacts.
New techniques have identified a wide range of organisms with the capacity to carry out biological nitrogen fixation (BNF)-greatly expanding our appreciation of the diversity and ubiquity of N fixers-but our understanding of the rates and controls of BNF at ecosystem and global scales has not advanced at the same pace. Nevertheless, determining rates and controls of BNF is crucial to placing anthropogenic changes to the N cycle in context, and to understanding, predicting and managing many aspects of global environmental change. Here, we estimate terrestrial BNF for a pre-industrial world by combining information on N fluxes with (15)N relative abundance data for terrestrial ecosystems. Our estimate is that pre-industrial N fixation was 58 (range of 40-100) Tg N fixed yr(-1); adding conservative assumptions for geological N reduces our best estimate to 44 Tg N yr(-1). This approach yields substantially lower estimates than most recent calculations; it suggests that the magnitude of human alternation of the N cycle is substantially larger than has been assumed.
The demand for more food is increasing fertilizer and land use, and the demand for more energy is increasing fossil fuel combustion, leading to enhanced losses of reactive nitrogen (Nr) to the environment. Many thresholds for human and ecosystem health have been exceeded owing to Nr pollution, including those for drinking water (nitrates), air quality (smog, particulate matter, ground-level ozone), freshwater eutrophication, biodiversity loss, stratospheric ozone depletion, climate change and coastal ecosystems (dead zones). Each of these environmental effects can be magnified by the 'nitrogen cascade': a single atom of Nr can trigger a cascade of negative environmental impacts in sequence. Here, we provide an overview of the impact of Nr on the environment and human health, including an assessment of the magnitude of different environmental problems, and the relative importance of Nr as a contributor to each problem. In some cases, Nr loss to the environment is the key driver of effects (e.g. terrestrial and coastal eutrophication, nitrous oxide emissions), whereas in some other situations nitrogen represents a key contributor exacerbating a wider problem (e.g. freshwater pollution, biodiversity loss). In this way, the central role of nitrogen can remain hidden, even though it actually underpins many trans-boundary pollution problems.
The livestock sector contributes considerably to global greenhouse gas emissions (GHG). Here, for the year 2007 we examined GHG emissions in the EU27 livestock sector and estimated GHG emissions from production and consumption of livestock products; including imports, exports and wastage. We also reviewed available mitigation options and estimated their potential. The focus of this review is on the beef and dairy sector since these contribute 60% of all livestock production emissions. Particular attention is paid to the role of land use and land use change (LULUC) and carbon sequestration in grasslands. GHG emissions of all livestock products amount to between 630 and 863 Mt CO2 e, or 12-17% of total EU27 GHG emissions in 2007. The highest emissions aside from production, originate from LULUC, followed by emissions from wasted food. The total GHG mitigation potential from the livestock sector in Europe is between 101 and 377 Mt CO2 e equivalent to between 12 and 61% of total EU27 livestock sector emissions in 2007. A reduction in food waste and consumption of livestock products linked with reduced production, are the most effective mitigation options, and if encouraged, would also deliver environmental and human health benefits. Production of beef and dairy on grassland, as opposed to intensive grain fed production, can be associated with a reduction in GHG emissions depending on actual LULUC emissions. This could be promoted on rough grazing land where appropriate.
This paper contrasts the natural and anthropogenic controls on the conversion of unreactive N2 to more reactive forms of nitrogen (Nr). A variety of data sets are used to construct global N budgets for 1860 and the early 1990s and to make projections for the global N budget in 2050. Regional N budgets for Asia, North America, and other major regions for the early 1990s, as well as the marine N budget, are presented to Highlight the dominant fluxes of nitrogen in each region. Important findings are that human activities increasingly dominate the N budget at the global and at most regional scales, the terrestrial and open ocean N budgets are essentially disconnected, and the fixed forms of N are accumulating in most environmental reservoirs. The largest uncertainties in our understanding of the N budget at most scales are the rates of natural biological nitrogen fixation, the amount of Nr storage in most environmental reservoirs, and the production rates of N2 by denitrification.
Curbing nitrogen emissions is a central environmental challenge for the
twenty-first century, argue Mark Sutton and his colleagues.
The Netherlands is "well known" for its nitrogen problems; it has one of the highest reactive nitrogen (Nr) emission densities in the world. It is a small country at the delta of several large European rivers. Ever since the industrial revolution, there has been a growing excess of nutrients and related emissions into the atmosphere (ammonia, nitrogen oxides and nitrous oxide) and into groundwater and surface water (nitrate), leading to a large range of cascading environmental impacts. Vehicular traffic, sewage and animal husbandry are the main sources of oxidized and reduced forms of Nr. This paper provides an overview of the origin and fate of nitrogen in the Netherlands, the various reported impacts of nitrogen, the Dutch and European policies to reduce nitrogen emissions and related impacts. In addition, ways are presented to go forward to potentially solve the problems in a European perspective. Solutions include the improvement of nitrogen efficiencies in different systems, technological options and education.
Identifying and quantifying planetary boundaries that must not be transgressed could help prevent human activities from causing unacceptable environmental change, argue Johan Rockström and colleagues.
Human activities create more reactive nitrogen than is created through natural processes every year. The excess reactive nitrogen in the environment causes various negative effects including eutrophication, climate change, acidification, and human health problems. The sources of the excess nitrogen are mainly fertilizers and animal and human waste generated by food production and consumption. Therefore, our food choices have major effects on the nitrogen load to the environment. To quantify the load, a consumption-based accounting tool, called the nitrogen footprint, has been recently developed. In current nitrogen footprint models, seafood is calculated as a single category using the same simple assumptions as livestock. However, there is a variety of types and methods of production of seafood. In addition, world per capita consumption of seafood is projected to continue expanding. In this paper, we propose a new nitrogen footprint model to evaluate the impact of seafood in detail, present the results of the model applied to Japan as a case study, and explain the important parameters that are needed to accurately evaluate the load of seafood consumption. Our model tracks the feeding steps in detail, considering differences among fed aquacultured seafood, non-fed aquacultured seafood (mainly bivalves and filter-feeding carp), and captured seafood. Our model evaluates the Japanese food nitrogen footprint of fed aquacultured seafood as 0.7 kg-N/capita/year, ca. 45% of that of all seafood, whereas the previous model evaluates it as 3.36 kg-N/capita/year. Our results demonstrate that the key factors for assessing the nitrogen load of seafood are the proportions of fed aquaculture and of plant protein in feed. In order to enable food choices that will effectively reduce nitrogen release, we provide the virtual N factors (per intake nitrogen release during production) for different seafood as 0.2 (non-fed aquacultured and captured), 4.8 (freshwater and diadromous fish), 3.9 (demersal fish), 3.4 (pelagic fish and other marine fish), and 8.2 (crustaceans). Our results show that eating more non-fed aquacultured and captured seafood and less fed-aquacultured shrimps and prawns could reduce our nitrogen load from food consumption as effectively as choosing poultry instead of beef. Although its evaluation is limited to nitrogen load related to food itself and not including the load from energy use, etc., our detailed nitrogen footprint model for different seafood categories and production sources can quantify the effectiveness of policies and actions that link sustainable consumption and sustainable fisheries and aquaculture, contributing toward the Aichi Biodiversity Targets.
http://www.sciencedirect.com/science/article/pii/S1470160X15004719
In OECD countries, agriculture uses on average over 40% of land and water resources, and thus has significant affect on the environment. This report provides the latest and most comprehensive data and analysis on the environmental performance of agriculture in OECD countries since 1990. It covers key environmental themes including soil, water, air and biodiversity and looks at recent policy developments in all 30 countries.
Over recent years the environmental performance of agriculture has improved in many countries, largely due to consumer pressure and changing public opinion. Many OECD countries are now tracking the environmental performance of agriculture, which is informing policy makers and society on the trends in agri-environmental conditions, and can provide a valuable aid to policy analysis. The indicators in this report provide crucial information to monitor and analyse the wide range of policy measures used in agriculture today, and how they are affecting the environment.
Did You Know? In OECD countries, agriculture uses on average 40% of land and water resources.
Secure and nutritious food supplies are the foundation of human health and development, and of stable societies. Yet food production also poses signi½cant threats to the environment through greenhouse gas emissions, pollution from fertilizers and pesticides, and the loss of biodiversity and ecosystem services from the conversion of vast amounts of natural ecosystems into croplands and pastures. Global agricultural production is on a trajectory to double by 2050 because of both increases in the global population and the dietary changes associated with growing incomes. Here we examine the environmental problems that would result from these dietary shifts toward greater meat and calorie consumption and from the increase in agricultural production needed to provide this food. Several solutions, all of which are possible with current knowledge and technology, could substantially reduce agriculture’s environmental impacts on greenhouse gas emissions, land clearing, and threats to biodiversity. In particular, the adoption of healthier diets and investment in increasing crop yields in developing nations would greatly reduce the environmental impacts of agriculture, lead to greater global health, and provide a path toward a secure and nutritious food supply for developing nations.
Nitrogen (N) is an essential element for plants and animals. Due to large inputs of mineral fertilizer, crop yields and livestock production in Europe have increased markedly over the last century, but as a consequence losses of reactive N to air, soil and water have intensified as well. Two different models (CAPRI and MITERRA) were used to quantify the N flows in agriculture in the European Union (EU27), at country-level and for EU27 agriculture as a whole, differentiated into 12 main food categories. The results showed that the N footprint, defined as the total N losses to the environment per unit of product, varies widely between different food categories, with substantially higher values for livestock products and the highest values for beef (c. 500 g N/kg beef), as compared to vegetable products. The lowest N footprint of c. 2 g N/kg product was calculated for sugar beet, fruits and vegetables, and potatoes. The losses of reactive N were dominated by N leaching and run-off, and ammonia volatilization, with 0·83 and 0·88 due to consumption of livestock products. The N investment factors, defined as the quantity of new reactive N required to produce one unit of N in the product varied between 1·2 kg N/kg N in product for pulses to 15–20 kg N for beef.
In this paper we use nitrogen (N) footprints as indicators of potential environmental impacts of food production in Austria. These footprints trace the losses of reactive nitrogen (Nr), i.e. N compounds that are generally accessible to biota, in connection to the chain of food production and consumption. While necessary for food production, Nr is known for its negative environmental impacts. The N footprints presented here describe Nr losses but do not link to effects directly. In deriving N footprints, Nr lost along the production chain needs to be quantified, expressed as “virtual nitrogen factors” (VNF). We calculated specific VNF for Austrian production conditions for a set of eight broad food categories (poultry, pork, beef, milk, vegetables & fruit, potatoes, legumes, cereals). The life-cycle oriented nitrogen footprints for the respective food groups were replenished by assessing Nr losses related to energy needs and to food consumption. The results demonstrate that in general, animal based products are less nitrogen-efficient than plant based products. For meat, footprints range from 64 g N per kg (pork) to 134 g N per kg (beef). For vegetable products, footprints are between 5 g N per kg (potatoes) and 22 g N per kg (legumes). The detailed ranking of food products is different when relating nitrogen footprints to either simple mass of food, or protein content. Vegetables & fruit cause only 9 g N per kg, but 740 g N per kg protein, which is even higher than pork (616 g N per kg protein) or poultry (449 g N per kg protein). These differences clearly show that taking into account protein and other aspects of food quality may be crucial for a proper assessment of dietary choices. The total N footprint per Austrian inhabitant is dominated by food production and consumption (85%) but also includes other activities linked to fixing nitrogen from the atmosphere (notably combustion). The average N footprint is 19.8 kg N per year per Austrian inhabitant, which is on the lower end of a range of industrialized countries.
Gross and per unit agricultural land area nitrogen balance (NB
G and NB
A, respectively) in agricultural areas were estimated with a nitrogen-flow model for 13 Asian countries, for regions within a country, and for individual grid cells, from 1970 to 2005. Country- and regional-level estimates showed that NB
A is higher in Japan and South Korea than in other Asian countries, but has recently been stable or decreasing. The contribution of inorganic fertilizer to the nitrogen input is decreasing, whereas that of livestock manure is increasing in these countries. In many other countries, the primary nitrogen source is inorganic fertilizer and its input rate and NB
A have increased sharply since the 1980s. NB
A of some Chinese provinces and Indian states were as high as those of Japan and South Korea. The results suggest that regional-scale estimation is necessary because of the large spatial variability in nitrogen flows within a country. Based on the NB
G estimated for each 0.5° × 0.5° grid cell, nitrogen outflow from agriculture into major river basins was evaluated. About 20 % of the nitrogen balance flowed into China’s Changjiang River basin, versus 10 % into the Ganges River basin. Uncertainties in the basic data and estimation results, and the use of an alternative measure of a country’s environmental performance were discussed.
The human use of reactive nitrogen (Nr) in the environment has profound beneficial and detrimental impacts on all people. Its beneficial impacts result from food production and industrial application. The detrimental impacts occur because most of the Nr used in food production and the entire amount of Nr formed during fossil fuel combustion are lost to the environment where it causes a cascade of environmental changes that negatively impact both people and ecosystems. We developed a tool called N-Calculator, a nitrogen footprint model that provides information on how individual and collective action can result in the loss of Nr to the environment. The N-Calculator focuses on food and energy consumption, using average per capita data for a country. When an individual uses the N-Calculator, the country average is scaled based on the individual's answers to questions about resource consumption. N footprints were calculated for the United States and the Netherlands, which were found to be 41 kg N/capita/yr and 24 kg N/capita/yr, respectively. For both countries, the food portion of the footprint is the largest, and the food production N footprints are greater than the food consumption N footprints. The overarching message from the N-Calculator is that our lifestyle choices, and especially our food consumption, have major impacts on the Nr losses to the environment. Communicating this message to all of the stakeholders (the public, policymakers, and governments) through tools like the N-Calculator will help reduce Nr losses to the environment.
Human production of food and energy is the dominant continental process that breaks the triple bond in molecular nitrogen
(N2) and creates reactive nitrogen (Nr) species. Circulation of anthropogenic Nr in Earth’s atmosphere, hydrosphere, and biosphere
has a wide variety of consequences, which are magnified with time as Nr moves along its biogeochemical pathway. The same atom
of Nr can cause multiple effects in the atmosphere, in terrestrial ecosystems, in freshwater and marine systems, and on human
health. We call this sequence of effects the nitrogen cascade. As the cascade progresses, the origin of Nr becomes unimportant.
Reactive nitrogen does not cascade at the same rate through all environmental systems; some systems have the ability to accumulate
Nr, which leads to lag times in the continuation of the cascade. These lags slow the cascade and result in Nr accumulation
in certain reservoirs, which in turn can enhance the effects of Nr on that environment. The only way to eliminate Nr accumulation
and stop the cascade is to convert Nr back to nonreactive N2.
The Nitrogen (N) and phosphorus (P) costs of food production have increased greatly in China during the last 30 years, leading to eutrophication of surface waters, nitrate leaching to ground water, and greenhouse gas emissions. Here, we present the results of scenario analyses in which possible changes in food production - consumption in China for the year 2030 were explored. Changes in food chain structure, improvements in technology and management, and combinations of these on food supply and environmental quality were analyzed with the NUFER model. In the business as usual scenario, N and P fertilizer consumption in 2030 will be driven by population growth and diet changes, and will both increase by 25%. N and P losses will increase by 44 and 73%, respectively, relative to the reference year 2005. Scenarios with increased import of animal products and feed instead of domestic production, and with changes in the human diet indicate reductions in fertilizer consumption and N and P losses relative to the business as usual scenario. Implementation of a package of integrated nutrient management measures may roughly nullify the increases in losses in the business as usual scenario, and may greatly increase the efficiency of N and P throughout the whole food chain.
Reactive nitrogen in the environment is a current and future major policy issue. Nitrogen pollution and its emissions are difficult to control, because they are associated with two of the most important human needs i.e. food and energy. In the Netherlands, several measures have been taken to decrease emissions with varying success. So far policy has been focussed on individual environmental issues related to specific sources. This paper summarises the results of a study to analyse the nitrogen problem in the Netherlands in an integrated way All relevant aspects are taken into account simultaneously. This was done by deriving regional agricultural nitrogen production ceilings, including all relevant nitrogen flows in agriculture and most relevant effects, i.e. protection of ground and surface water from nitrate pollution and N-eutrophication, controlling NH3 volatilisation in view of impacts on terrestrial ecosystems and reducing NOx and N2O emissions in view of climate change policies. For agriculture, nitrogen ceilings provide a good basis for regulating nitrogen through fertiliser use and feed import. Results show that reactive nitrogen production in the Netherlands should be decreased by 50–70␒n order to reach the ceilings necessary to protect the environment against nitrogen pollution from agriculture
This paper discusses governmental policies and measures that regulate the use of animal manure in the European Union (EU-15). Systematic intervention by governments with European agriculture in general started at the end of the 19th century. Major changes in governmental policies on agriculture followed after the establishment of the EU and its Common Agricultural Policy (CAP) in 1957. Environmental side effects of the large-scale intensification of agricultural production were addressed following the reform of the CAP and the implementation of various environmental regulations and directives from the beginning of the 1990s. The Nitrate Directive approved in 1991 has exerted, as yet, the strongest influence on intensive livestock production systems. This directive regulates the use of N in agriculture, especially through its mandatory measures to designate areas vulnerable to nitrate leaching and to establish action programs and codes of good agricultural practice for these areas. These measures have to ensure that for each farm the amount of N applied via livestock manure shall not exceed 170 kg x ha(-1) x yr(-1). These measures have large consequences, especially for countries with intensive animal agriculture, including The Netherlands, Belgium, Denmark, and Ireland. The mean livestock density in these countries is between 1.5 and 4 livestock units/ha, and the average amounts of N in animal manure range from 100 to 300 kg/ha of agricultural land. More than 10 yr after approval of the Nitrate Directive, there appears to be a delay in the implementation and enforcement in many member states, which reflects in part the major complications that arise from this directive for intensive livestock farming. It also reflects the fact that environmental policies in agriculture have economic consequences. The slow progress in the enforcement of environmental legislations in agriculture combined with the increasing public awareness of food safety, animal welfare, and landscape maintenance call for a more fundamental change in EU agriculture.