Article

Nitrogen fertilizer value of cattle manure applied on soils originating from organic and conventional farming systems

November 2002
Agronomie 22(7)

November 2002
22(7)

DOI:10.1051/agro:2002044

Authors:

Emmanuel Frossard

ETH Zurich

Paul Mäder

Forschungsinstitut für biologischen Landbau

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Nitrogen nutrition of plants in organic farming depends largely on animal manure. In a pot experiment the hypothesis was tested that on a long-term organically managed soil (ORG) characterized by higher soil microbial activity, a greater portion of N applied as cattle manure is mineralized and taken up by plants than on a conventionally managed soil that had received exclusively mineral fertilizers (MIN). Dry matter yields and N uptake by Italian ryegrass were higher by around 20% on ORG than MIN soil. The N utilization of N-15 labeled animal manure components and mineral N differed little between ORG and MIN. The major part of the increased N uptake on ORG compared with MIN was due to a significantly greater N supply from ORG soil. The increased capacity of the ORG soil to supply N to plants became more important at later cuts when N was severely limiting plant growth.

Nitrogen fertiliser replacement values for organic amendments appear to increase with N application rates

Article

Full-text available

Jan 2018
NUTR CYCL AGROECOSYS

Nitrogen (N) supply from organic amendments [such as farmyard manure (FYM), slurries or crop residues] to crops is commonly expressed in the amendment’s Nitrogen Fertiliser Replacement Value (NFRV). Values for NFRV can be determined by comparison of crop yield or N uptake in amended plots against mineral fertiliser-only plots. NFRV is then defined as the amount of mineral fertiliser N saved when using organic amendment-N (kg/kg), while attaining the same crop yield. Factors known to affect NFRV are crop type cultivated, soil type, manuring history and method or time of application. We investigated whether long-term NFRV depends on N application rates. Using data from eight long term experiments in Europe, values of NFRV at low total N supply were compared with values of NFRV at high total N supply. Our findings show that FYM has a significant higher NFRV value at high total N supply than at low total N supply (1.12 vs. 0.53, p = 0.04). For the other amendment types investigated, NFRV was also higher at high total N supply than at low total N supply, but sample sizes were too small or variations too large to detect significant differences. Farmers in Europe usually operate at high rates of total N applied. If fertiliser supplements are based on NFRV of the manure estimated at low total N supply, N fertiliser requirements might be overestimated. This might lead to overuse of N, lower N use efficiency and larger losses of N to the environment.

Apparent long-term fertilizer replacement value of organic amendments depends on mineral fertilizer N range itself

Conference Paper

Full-text available

Jun 2016

N use efficiency in field vegetable production systems – Catch crop strategies and fertilization history effects on organic fertilizer turnover

Thesis

Full-text available

Feb 2012

Leif Nett

The current study dealt with two questions that target potential options to increase the nitrogen (N) use efficiency of agricultural systems and hence avoid environmentally harmful N losses: 1) Does long-term organic fertilization affect the decomposition of recently added organic fertilizers? If so, is this effect relevant to N fertilization practice and hence should be included in fertilizer recommendation systems? The hypothesis was that relevant effects only occur for recalcitrant organic fertilizers while for readily decomposable organic fertilizers, the fertilization history does not play a role. 2) Can the high N balance surpluses in German intensive field vegetable production systems be substantially reduced by cultivation of winter catch crops (CC)? The hypothesis was that the N balance surpluses of the investigated two-year crop rotations can be reduced by a significant amount of more than 30 kg N ha−1. The first hypothesis was tested by applying organic fertilizers to soils that only differed in organic fertilization history. A greenhouse pot experiment with composted farmyard manure and a laboratory incubation experiment with cabbage material, composted farmyard manure, and pine bark as organic fertilizers were conducted. In both experiments, historic and recent fertilization were combined so as to enable the detection of possible “adaptation” effects of the soil biota to a certain fertilizer. In the pot experiment, which lasted 10 weeks, gross N mineralization was estimated by using a balance calculation, including contents of plant N, soil mineral N, and microbial biomass N at the start and end of the experiment. In the incubation experiment, contents of soil mineral N and microbial biomass were determined at five dates while carbon dioxide evolution was monitored continuously over the entire incubation period of five months. Data from the incubation experiment were also used to estimate gross turnover rates of recently added fertilizers by adopting a mechanistic modeling approach. The results of both studies combined indicated that fertilization history had effects on the decomposition of farmyard manure and pine bark, not however on the decomposition of readily decomposable cabbage material. Hence, the hypothesis was accepted in that fertilization history effects depended on the type of fertilizer. However, fertilization history effects showed no consistent trend with respect to increase or decrease in carbon (C) and N mineralization and the effects on net N mineralization were minor in magnitude. Hence, in agricultural practice, fertilization history effects can be neglected for the prediction of N mineralization from recently applied organic fertilizers. The second hypothesis was tested by performing field experiments at three sites in Germany, which differed in edaphic and climatic conditions. Typical intensive vegetable crop rotations were set up, comprising a high input of mineral N fertilizers, a cauliflower crop at the start of the rotation, and a succeeding vegetable crop in the summer of the second year. The experiments were repeatedly performed in two or three consecutive years on new plots at each site to account for variability in weather conditions. Two experimental factors were arranged in a split-plot design: factor “date”, i.e. the cultivation period of cauliflower crop and subsequent sowing of the CC (early, late), and factor “type of CC”, i.e. no CC (control), a cold-hardy CC, or a non-cold-hardy CC over the winter period. To assess the effectiveness of the different crop rotation strategies, N balances were calculated on the basis of fertilizer inputs and measured contents of aboveground plant N, soil mineral N, and crop residue N. The results suggested that the average N balance surplus was 217 kg N ha−1 in the control treatments without a CC. In spite of these high N surpluses, the cultivation of CC reduced the N balance surplus, on average across all sites and experiments, by only 13 kg N ha−1, when compared to the control treatments. In some cases, CC even increased the N balance surplus. The factors date and type of CC only had minor influences on the N balance. Hence, the hypothesis that CC can substantially reduce the N balance surpluses in these systems could not be confirmed. The findings further indicate that the transfer of N taken up by the CC to the succeeding crop is a critical step when adopting this technique. Both approaches to reduce high N losses from agricultural systems that were investigated in the current study were ineffective under the chosen conditions. Other measures to reduce the N balance surpluses in these systems may have greater potential. In particular, approaches that decrease the total N input should come into consideration. In this context, sensor-based precision support tools, which allow a spatially more accurate irrigation and fertilization and thus reduced N input without yield loss, will play a key role.

Unconventional feeds for small ruminants in dry areas have a minor effect on manure nitrogen flow in the soil–plant system

Article

Full-text available

Jan 2013

In dry areas, unconventional feeds are increasingly used for mitigating feed shortages and rangeland degradation. We evaluated how feeding sheep diets containing olive leaves, saltbush leaves and olive cake affects manure quality compared to a barley straw based diet. Soil incubation and plant growth experiments were carried out to measure soil nitrogen (N) mineralization and N uptake by barley plants and to calculate N flow through the feed-animal-soil–plant system. Fresh feces, composts consisting of feces, urine and straw, and ammonium sulfate fertilizer were mixed with soil at rate of 90 mg N kg−1 soil dry matter. Comparisons were made with non-amended soils (control) and soils amended with fresh olive cake applied at 90 and 22.5 mg N kg−1 soil dry matter, respectively. The latter treatment enabled investigation of the effect of passage of olive cake through the digestive tract of sheep on N availability and phenol transformation. Applying fresh olive cake and feces, except the saltbush leaf derived feces, resulted in a net N immobilization. All composts resulted in net N mineralization, although not significantly different from the 0N control soil. Barley growing in soils with amendment that caused N immobilization took up less N than barley growing on the 0N treatment. Reduction in N uptake was most pronounced after amendment with fresh-olive cake. Treatments with net mineralization increased barley N uptake over the 0N treatment with 2–16 % of N applied being taken up. Dietary composition had a minor effect on N fertilizer value of either feces or compost, but feces N alone was not an efficient N source.

Crop/Livestock Integration Effects on Soil Quality, Crop Production, and Soil Nitrogen Dynamics

Article

Full-text available

Dec 2007

Ellen Beth Mallory

Regional integration of potato and dairy farms has developed in Maine through arrangements where manure, feed, and sometimes land, are exchanged between neighboring farms. The effects of integration on soil quality, crop production, nitrogen (N) cycling, and N loss were investigated in field and laboratory studies of contrasting amended (manure, compost, green manure, and supplemental fertilizer) and nonamended (fertilizer only) soil management systems within 2-year potato (Solanum tuberosum L.) rotations in the Maine Potato Cropping Systems Project (MPEP). Additionally, soil quality of 48 integrated and nonintegrated Maine potato and dairy farm fields was assessed. The MPEP’s amended soil system enhanced soil quality and demonstrated aspects of increased resilience for crop production and N cycling. The amended system produced higher and more stable potato yields than the nonamended system by reducing the impact of adverse growing conditions. It also demonstrated the potential to buffer excess N by retaining a greater proportion of net N inputs than the nonamended system. Possible mechanisms to explain increased N retention include better early-season synchrony between N release and crop uptake, as observed in in situ soil monitoring; carbon-enhanced immobilization of excess N, as observed in a laboratory study; increased recalcitrance of N sources; and physical protection. Nitrogen loss, in absolute terms, however, was higher in the amended system due to higher N inputs and a build-up of soil organic N. Soil amendment history had the largest impact on soil N mineralization capacity – fall nitrate levels were higher in the amended system in two of three years, and residual manure N contributed more N than predicted using the standard decay-series model – but it also reduced the availability of recently added N. As currently practiced in Maine, integrated potato systems appear to need greater increases in carbon inputs (preferably as sod crops and trap crops) and reductions in tillage to produce changes in soil carbon that can be detected at a landscape level. Future work should focus on finding balance points for soil organic matter content that enhance soil’s crop production and N cycling functions while avoiding N excesses and loss.

Nitrogen use efficiency of 15 N-labelled sheep manure and mineral fertiliser applied to microplots in long-term organic and conventional cropping systems

Article

Mar 2009

Nitrogen (N) utilisation by crops has to be improved to minimize losses to the environment. We investigated N use efficiency of animal manure and mineral fertiliser and fate of fertiliser N not taken up by crops in a conventional (CONMIN) and a bio-organic (BIOORG) cropping system of a long-term field experiment over three vegetation periods (winter wheat–soybean–maize). Microplots planted with wheat received a single application of 15N-labelled slurries (either urine or faeces labelled) or mineral fertiliser. At the end of each vegetation period we tested whether higher microbial activity and larger microbial biomass in BIOORG than CONMIN soils, and lower long-term N input level in BIOORG, affected use efficiency and fate of fertiliser N not taken up by crops. Recovery of 15N in wheat was 37%, 10% and 47% from urine, faeces and mineral fertiliser, respectively, and decreased strongly in the residual years. In total 41%, 15% and 50% of 15N applied as urine, faeces and mineral fertiliser was recovered by the three crops. 15N recovered from originally applied urine, faeces and mineral fertiliser in the topsoil (0–18 cm) at the end of the third vegetation period was 19%, 25% and 20%, respectively. Of urine-, faeces- and mineral fertiliser-15N, 40%, 61% and 29%, respectively, was not recovered by the three crops and in topsoil suggesting significant transport of 15N-labelled components to deeper soil layers. CONMIN and BIOORG differed neither in fertiliser N use efficiency by crops nor in 15N recovery in soil indicating insignificant difference in the turnover and utilization of the applied manure nitrogen in the conventional and the bio-organic cropping systems.

The rationale for alternative fertilization: Equilibrium isotherm, kinetics and mass transfer analysis for urea-nitrogen adsorption from cow urine

Article

Full-text available

Dec 2015

In an effort to minimize the loss of urea-N through volatilization and concurrently recover urea in a usable form from cow urine, adsorption experiments using bamboo-based activated carbon were performed. Batch studies were undertaken to evaluate the effect of initial concentration, sorption time and temperature on the variation in urea uptake capacity of the prepared carbon. Equilibrium data were tested against various isotherms, kinetics and mass transfer models. The Langmuir monolayer sorption was found to be 146.12 mg.g−1 with nearly 90% urea recovery attained. The process was found to be reversible as seen through regeneration experiments. Thermodynamic parameters indicated that urea sorption was physical, spontaneous and exothermic in nature. Kinetic studies revealed that the rate of urea uptake was limited by both surface adsorption and intra-particle diffusion. It was concluded that the mass transfer of urea molecules over the activated carbon was governed by film diffusion at all concentrations examined.

Article

Full-text available

Apr 2022
NUTR CYCL AGROECOSYS

Targeted use of animal manures as a nitrogen (N) fertilizer is challenging because of their poorly predictable N fertilizer value. An enhanced understanding of their N transformation processes in soil under field conditions is necessary to better synchronize N availability and crop N demand. ¹⁵ N labeled cattle slurry, produced by feeding a heifer with ¹⁵ N labeled ryegrass hay, was used in an on-farm trial on two neighboring fields, cropped with maize or grass-clover, in order to assess crop N uptake and N dynamics in the topsoil. Recovery of applied total N in plant biomass was higher for mineral fertilizer (Min) (45–48%) than for slurry (Slu) (17–22%) when applied at the same rate of mineral N. Also, N derived from fertilizer in plant biomass was higher for Min than for Slu, due to both greater NH 3 emissions and greater initial immobilization of slurry N. Despite initial differences between the two in the relative distribution of residual fertilizer N in soil N pools, already in the following spring the majority (77–89%) of residual N from both fertilizers was found in the non-microbial organic N pool. Of the applied total N, 18–26% remained in the topsoil after the first winter for Min, compared to 32–52% for Slu. Thus, the proportion of fertilizer N not taken up by the first crop after application, enters the soil organic N pool and must be re-mineralized to become plant available.

Tracing the dynamics of animal excreta N in the soil-plant-atmosphere continuum using 15N enrichment

Chapter

Jan 2019

Abstract The increased demand for organic farm products, and the attendant restrictions on the use of synthetic N fertilizers in both traditional and organic agriculture, has focused attention on the efficacy of organic sources of N, including animal excreta. However, questions arise in regard to the agronomic and environmental benefits of excreta as alternative sources of N. These questions are best addressed through the experimental use of 15N-enriched excreta, which enable the labeled source to be unequivocally traced through the soil-plant-atmosphere continuum, which N difference or N equivalence techniques cannot achieve. In contrast to organic and inorganic N compounds that can be purchased commercially with a specified 15N label on the component N moieties, 15N-enriched excreta must be prepared by the investigator. The methods of production and the uniformity of labeling of the components of 15N-enriched excreta (feces, urine) and their admixture (slurry), the N use efficiencies of excreta in crop pro- duction, and comparisons and interactions of excreta with synthetic N sources are reviewed. Losses of N from excreta-amended soils to the environment and the residual N value of excreta in crop sequences are also examined. It was concluded that while similar agronomic and environmental issues surround the use of both synthetic fertil- izers and excreta as sources of N for plant nutrition, the processes differ in intensity and duration both spatially and temporally.

The Rationale for Alternative Fertilization: Equilibrium isotherm, Kinetics and Mass transfer analysis for Urea-Nitrogen adsorption from Cow Urine

Article

Full-text available

Nov 2015

Influence of Soil Amendment History on Decomposition of Recently Applied Organic Amendments

Article

Full-text available

Jul 2012

Long-term use of organic soil amendments, compared with unamended or mineral fertilized soils, can change soil organic matter content, microbial biomass content, the microbial community structure, and the activity of enzymes involved in organic matter decomposition. It is not clear, however, whether long-term use of organic amendments, by means of these changes, leads to modified decomposition rates of newly added organic amendments. Therefore, this study was used to test the hypothesis that amendment history has an influence only on the decomposition of recalcitrant organic amendments and not on less recalcitrant organic amendments. Soils used for experimentation were taken from a field experiment where contrasting organic amendment regimes of farmyard manure, pine (Pinus sylvestris L.) bark, vegetable crop residues, and an unamended control had been applied for 35 yr. In a full factorial, laboratory-based incubation experiment, each soil was treated with each of these amendments and net C and N mineralization and microbial biomass C contents were monitored during a 147-d period. Collected data were then used to estimate gross turnover rates of newly added amendments with a modeling approach based on the soil organic matter module of the Daisy model. The modeling results suggested that the turnover of farmyard manure and pine bark, not however of crop residues, should be simulated in consideration of an amendment history effect. In contrast, the results of the ANOVA indicated that amendment history had an insignificant effect on net C and N mineralization from recently applied amendment. We concluded that the effects of amendment history on gross turnover rates of recently added organic amendments may depend on the type of amendment but that these effects on net C and N mineralization are minor in magnitude and hence irrelevant to N fertilization practice.

Evaluation of Almond Hull and Shell Amendments across Organic Matter Management of Orchard Soils

Article

Full-text available

May 2024

Hulls and shells are an abundant by-product from almond production with potential as an organic matter amendment (OMA). A combination of incubation study and field research was conducted in 2019–2021 to evaluate the impacts of three practices in combination on orchard soils’ C and N cycling, including a 210-day period of laboratory incubation with hulls and shells, and field sampling of orchard soils with and without historic applications of green waste compost as an OMA; with hulls and shells and with and without off-ground harvest where orchard soils remain undisturbed year round. Hulls and shells increased microbial biomass carbon in the field study by 248 μg g−1 dry soil after one year (p < 0.001) and during incubation, and increased cumulative respiration in soils with and without historic OMA (p < 0.001). Historic OMA resulted in double the total soil organic carbon (SOC) and total nitrogen (TN) compared to soil without resulting in significantly higher respiration and N mineralization when amended with hulls and shells. The decomposition of hull and shell biomass following surface application progressed at similar rates in the laboratory and field (1.7 g kg−1 d−1 during incubation (R2 = 0.84) and 1.3 g kg−1 d−1 in the field trial (R2 = 0.91). Our results highlight the suitability of hulls and shells as a by-product source of OMA for improving soil health in orchards with historic OMA and transitioning to organic matter management.

Nitrogen dynamics after slurry application as affected by anaerobic digestion, biochar and a nitrification inhibitor

Article

Full-text available

Jul 2023

Animal manures are valuable multi‐nutrient fertilisers, but their short‐term nitrogen (N) use efficiency (NUE) by plants is low, bearing the potential of harmful N losses to the environment, such as nitrate (NO 3 ‐ ) leaching. To develop strategies to increase the NUE of cattle slurry, a comprehensive understanding of slurry N dynamics in the soil‐plant system is needed. In a 57‐day microcosm experiment in the greenhouse, we assessed the effect of different slurry treatments on slurry N turnover in the soil and its uptake by ryegrass ( Lolium multiflorum var. Westerwoldicum). Employing a two‐factorial design, ¹⁵ N cattle slurry (SLU), ¹⁵ N anaerobically digested cattle slurry (SLA), and ¹⁵ N anaerobically digested cattle slurry plus biochar (SLA+) were combined with and without the nitrification inhibitor 3,4‐dimethyl‐1H‐pyrazole monophosphate (DMPP). As references, a mineral fertiliser (MIN) and an unfertilised treatment (N0) were included. The ¹⁵ N recovery, hence NUE, in plant biomass was higher for SLA than for SLU, while recovery in soil at 55 days after set‐up showed an opposite trend, with over 45 % of N from SLU still being recovered in soil. DMPP and biochar only marginally affected NUE and fertiliser N recovery in soil. Although ¹⁵ N recovery in soil was highest for SLU, residual N leaching from SLU was low (< 1 % of added N). We attribute this to the limited presence of slurry N in mineral forms at this point of time, with the majority being stored in the non‐microbial organic soil N pool. Leaching of residual N from MIN was significantly higher than for SLU, while SLA and SLA+ ranged in between. Overall, anaerobic digestion appeared suitable for increasing NUE of cattle slurry, but further investigations under field conditions are necessary in order to assess its potential to reduce nitrate leaching in the long‐term.

The prospects of poop: a review of past achievements and future possibilities in faecal isotope analysis

Article

Jul 2023
BIOL REV

What can the stable isotope values of human and animal faeces tell us? This often under-appreciated waste product is gaining recognition across a variety of disciplines. Faecal isotopes provide a means of monitoring diet, resource partitioning, landscape use, tracking nutrient inputs and cycling, and reconstructing past climate and environment. Here, we review what faeces are composed of, their temporal resolution, and how these factors may be impacted by digestive physiology and efficiency. As faeces are often used to explore diet, we clarify how isotopic offsets between diet and faeces can be calculated, as well as some differences among commonly used calculations that can lead to confusion. Generally, faecal carbon isotope (δ13 C) values are lower than those of the diet, while faecal nitrogen isotope values (δ15 N) values are higher than in the diet. However, there is considerable variability both within and among species. We explore the role of study design and how limitations stemming from a variety of factors can affect both the reliability and interpretability of faecal isotope data sets. Finally, we summarise the various ways in which faecal isotopes have been applied to date and provide some suggestions for future research. Despite remaining challenges, faecal isotope data are poised to continue to contribute meaningfully to a variety of fields.

Substrate for cupuaçu plantlets and the influence of cow urine as biofertilizer

Article

Full-text available

Aug 2021
REV BRAS FRUTIC

The use of organic waste as components of substrate to produce fruit plantlets provides alternative materials, easily available and low cost. The aim of this work was to evaluate the effect of substrate and biofertilization with cow urine on the growth of cupuaçu plants (Theobroma grandiflorum) in an organic production system. A factorial experiment was conducted in a completely randomized design with 12 replications including four types of substrates (base mixture; base mixture + coconut fiber; base mixture + cocoa shell and base mixture + sand) with or without biofertilizer application totalizing 96 experimental units. Substrate and biofertilizer influenced the gas exchange and growth of T. grandiflorum plants. The interaction between these two factors significantly affected the dry matter, relative growth rate, net photosynthetic rate, and content of P, K and Mn in the leaves. Each factor, substrate and of cow urine application, independently, influenced the chlorophyll index, the leaf area, diameter, and height of the cupuaçu plants and the contents of N, Ca, Mg, Zn, Fe and Cu in the leaves. The base mixture substrate (composed by soil and organic compost) and fertilization with 1% of cow urine can be indicated to T. grandiflorum plantlets organic production.

Effect of organic and chemical fertilization on the onion crop (Allium cepa L.)

Article

Full-text available

Oct 2020

The bulb onion (Allium cepa L.) is a vegetable widely cultivated and in high demand in national and international markets. Due to the risks that the indiscriminate use of agrochemicals represents for human health and the environment, the present study aimed to make a comparative analysis of the effects of organic vs chemical fertilization currently used in the cropping of red hybrid bulb onion (Eureka). Three organic fertilizers (Zumsil®, ComCat® and EcoFungi®) were compared to three chemical fertilizers (15-15-15®, Muriate of Potash® and Nitrofoska®). The response variables were: plant height at 30 and 60 days after transplanting (DAT), length, diameter and average weight of bulbs, yield in tons per hectare and the relationship between height at 30 and 60 DAT. The experiment was carried out under a completely randomized design with four replicates, seven treatments and 28 experimental units. The statistics used include an analysis of variance and a Canonical Biplot that allowed to obtain groups of variables and to determine their correlation with each one of the treatments. Additionally, a marginal analysis of dominant treatments was performed. Positive response of variables was strongly associated with organic fertilizers. From the economic point of view, the ComCat® organic fertilizer represented an ecological alternative with excellent benefits for the producer. This research is in line with the trends for agrochemical-free foods.

INCREASING NUTRIENT CONTENT OF LIVESTOCK MANURES THROUGH FEEDING AND MANAGEMENT STRATEGIES: A REVIEW

Conference Paper

Full-text available

Mar 2017

N Rawal

Livestock manure has been as asset to crop since the beginning of organized agriculture in Nepal. Animal manure is a nutrient resource containing most of the essential elements required for plant growth and can be a significant source of nutrients in both intensive and subsistence production systems. This paper examines the factors associated with nutrient content in manure from livestock farming illustrating various examples and cases relevant to Nepalese farming practices. The primary factors that affect nutrient composition of manure are livestock species, stage of growth, age and condition of animal, feeding practices and composition, housing and bedding system, moisture content in manure, manure storage condition, time that the manure spends in storage, weather conditions and method of manure application system. All of these factors affect the amounts of nitrogen (N), phosphorus (P), potassium (K) and micronutrients in the manure, as well as its net value. The nutrient contents of stored manures can vary, as often they are mixtures of excreta of different age from animals fed different diets, and possibly come from different animal species. In fact, 55-90% of the N and P content of animal feed is excreted in faeces and urine. The variation in N content in urine is even larger than in FYM. If manure is not properly stored, it may lose 25% of its nitrogen in just one day and 50% in two days as ammonia gas. Appropriate feeding and management strategies are required to optimize the performance, amount and quality of farmyard manure that are valuable source of nutrients for crops when properly applied to soils.

On the role of soil organic matter for crop production in European arable farming

Thesis

Full-text available

Oct 2017

Renske Hijbeek

The aim of this thesis was to improve understanding of the role of organic inputs and soil organic matter (SOM) for crop production in contemporary arable farming in Europe. For this purpose, long-term experiments were analysed on the additional yield effect of organic inputs and savings in mineral fertiliser. In addition, a farm survey was conducted to find drivers and barriers for the use of organic inputs and to assess if arable farmers in Europe perceive a deficiency of SOM. The findings in this thesis suggest that at least on the shorter term, on average, there seems to be no immediate threat from a deficiency of SOM to crop production in arable farming in Europe. The long-term experiments showed that with sufficient use of only mineral fertilisers, on average, similar yields could be attained over multiple years as with the combined use of organic inputs and mineral fertiliser. This was reflected in the farm survey, in which a large majority of farmers indicated not to perceive a deficiency of SOM. Analysis of long-term experiments also showed that more mineral fertiliser N was saved when using farmyard manure at high N rates (with mineral fertiliser application) than at low N rates (without mineral fertiliser application), based on comparisons at equal yield. Specific crops and environments did benefit from organic inputs and more SOM in terms of crop production. Long-term experiments showed that organic inputs give benefit to crop production in wet climates and on sandy soils. In addition, farmers perceived a higher deficiency of SOM on steep slopes, sandy soils, wet and very dry climates. The additional yield effect of organic inputs was significant for potatoes. More in general, farmers who cultivated larger shares of their land with specialized crops (including potatoes, sugar beets, onions and other vegetables) than cereals perceived a higher deficiency of SOM. It seems that while the functions of SOM can be replaced with technical means to a large extent (e.g. tillage, use of mineral fertilisers), there are limits to this technical potential when environmental conditions are more extreme and crops are more demanding. The farm survey revealed that farmers perceive a trade-off between improved soil quality on the one hand and increased pressures from weeds, pests and diseases and financial consequences on the other hand when using organic inputs. If policies aim to stimulate the maintenance or increase of SOM, more insight is needed into the conditions that regulate the pressures of weeds, pests and diseases in response to organic inputs. Financial consequences (at least on the short term) should also be accounted for. More importantly however, benefits from SOM for crop production cannot be taken for granted. Only in specific situations such benefits will exist. If European policies on SOM aim to include benefits for crop production, focus should be on areas with more extreme environmental conditions (very dry or wet climates, steep slopes, sandy soils), or cropping systems with more specialized or horticultural crops rather than cereals.

Does organic farming (OF) work in favour of protecting the natural environment? A case study from Poland

Article

Jul 2017
LAND USE POLICY

Organic farming (OF) is a management system that is closely linked with the quality of the natural environment since it should, besides producing organic food, constitutes a protective factor for all components of that natural environment. Therefore, the objective of this paper was to answer the following question: Does organic farming (OF) protect the natural environment? In order to achieve this goal it was essential to determine what kinds of natural and non-environmental factors have the largest influence on the development of OF in Poland, and to assess the significance of these factors in the spatial diversification of the regional density of organic farms. The analysis was carried out on the basis of data from 2012 comprising 2074 communes, including both rural communes (1563) and urban-rural ones (511). The research results indicated the weaknesses of the organic farming policy (OFP) with respect to the functioning of OF in Poland in the years 2007–2013. The results also show that the development of OF in Poland mainly depends on the system of financial support, i.e. one that either encourages farmers to change the manner of production to a more environmentally friendly one, or one that has an impact on their decision to resign from production using ecological methods. Moreover, as our research has proved, OF is not always developed in places where it should be a priority because of the suitable conditions of the natural environment.

Sustainability of organic horticulture

Article

Jan 2010

Michael Raviv

The elusive role of soil quality in nutrient cycling: a review

Article

Full-text available

Sep 2016
SOIL USE MANAGE

Cycling of nutrients, including nitrogen and phosphorus, is one of the ecosystem services we expect agricultural soils to deliver. Nutrient cycling incorporates the reuse of agricultural, industrial and municipal organic residues that, misleadingly, are often referred to as ‘wastes’. The present review disentangles the processes underlying the cycling of nutrients to better understand which soil properties determine the performance of that function. Four processes are identified (i) the capacity to receive nutrients, (ii) the capacity to make and keep nutrients available to crops, (iii) the capacity to support the uptake of nutrients by crops and (iv) the capacity to support their successful removal in harvested crop. Soil properties matter but it is imperative that, as constituents of ‘soil quality’, they should be evaluated in the context of management options and climate and not as ends in their own right. The effect of a soil property may vary depending on the prevailing climatic and hydrologic conditions and on other soil properties. We recognize that individual soil properties may be enhancing one of the processes underlying the cycling of nutrients but simultaneously weakening others. Competing demands on soil properties are even more obvious when considering other soil functions such as primary production, purification and flow regulation of water, climate modification and habitat provision, as shown by examples. Consequently, evaluations of soil properties and management actions need to be site-specific, taking account of local aspects of their suitability and potential challenges.

Agroecological Intelligence Needed to Prepare Agriculture for Climate Change

Chapter

Full-text available

Mar 2013

P.S. Bindraban

Production of 15N-Labelled Liquid Organic Fertilisers Based on Manure and Crop Residue for Use in Fertigation Studies

Article

Full-text available

Mar 2016
PLOS ONE

Large quantities of crop residue and animal manure from agricultural and livestock activities are annually produced worldwide. With proper management, these residues are potentially valuable sources of plant nutrients, mainly N. Recycling such subproducts in sustainably-based agricultural systems can minimise the use of mineral fertilisers, and hence reduce the potential risk of surface and groundwater pollution. Therefore, the purpose of this study was to obtain (small scale) two liquid labelled-organic fertilisers, an animal- and a vegetal-based organic (AO and VO, respectively) fertiliser, to be used as organic N sources in subsequent fertigation studies. Forage maize (Zea mays L.) grown under 15N-labelled fertiliser supply was used as raw material for VO fertiliser production, and also as 15N-labelled sheep feed to obtain 15N-labelled manure. The labelled faeces fraction was used as raw material for the AO fertiliser. The VO fertiliser was obtained after an acidic and an enzyme-driven hydrolysis. The AO fertiliser was obtained after acidic hydrolysis. The VO liquid fertiliser presented an N concentration of 330 mg·L-1, 85% of total N was organic, while ammonium and nitrate N accounted for 55% and 45% of the mineral nitrogen fraction, respectively. This fertiliser also exhibited high K, Ca and S concentrations and notable values for the remaining macro- and micronutrients. The AO liquid fertiliser had a similar total N concentration (496 mg·L-1, 82% of total N in an organic form) to that of VO, but its mineral N fraction significantly differed, which came in a predominantly (95%) ammonia form. It also had a high content of N, P, K and other macronutrients, and sufficient Fe, Zn, Mn, Cu and B levels, which suggests its suitability as a potential fertiliser. The percentage of 15N enrichment in both VO and AO liquid fertilisers exceeded 2% 15N atom excess, which enabled their use in subsequent assays run to assess nitrogen uptake efficiency.

The DOK experiment (Switzerland)

Chapter

Jan 2006

Options for Ammonia Mitigation: Guidance from the UNECE Task Force on Reactive Nitrogen

Book

Full-text available

Jan 2014

This document represents the culmination of a major effort to synthesize and update available knowledge on the control of ammonia emissions from agriculture to the atmosphere. The Ammonia Guidance Document is meant as a state-of-the-art reference document for preventing and abating ammonia emissions from agricultural sources, to be used primarily by policy makers, those in industry and scientists. It shows the various possible measures in the whole ‘animal feeding – animal housing – manure management chain’. It discusses the effectiveness of the measures as well as the economic cost of the measures.

Global Warming: Role of Livestock

Article

Full-text available

Jan 2015

This chapter provides an overview of the current state of knowledge concerning global warming with special reference to contribution from livestock resources. Global warming pertains to the effect of natural greenhouse gases (GHGs) such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and halogenated compounds on the environment. These GHGs are generated by humans and human-related activities. Carbon dioxide, CH4, and N2O are the principal sources of radiative forcing (Fifth IPCC Report of 2013). Interestingly, livestock contributes to climate change through emissions of CO2, CH4, and N2O into the atmosphere. Globally, the livestock sector directly and indirectly contributes 18 % (7.1 billion tonnes CO2equivalent) of GHG emissions. While direct GHG emissions from livestock refer to emissions from enteric fermentations in livestock, urine excretion, and microbial activities in manures, indirect GHG emissions are those not directly derived from livestock activities but from manure applications on farm crops, production of fertilizer for growing crops used for animal feed production, and processing and transportation of refrigerated livestock products. Other indirect emissions include deforestation, desertification, and release of carbons from cultivated soils due to expansion of livestock husbandry. According to FAO’s Global Livestock Environmental Assessment Model (GLEAM), the GHG emission from livestock-related activities was estimated to be around 7.1 gigatonnes CO2-eq. per annum, representing 14.5 % of human-induced emissions. This clearly indicates the significant role for livestock contributions to climate change.

The Position of Mineral Nitrogen Fertilizer in Efficient Use of Nitrogen and Land: A Review

Article

Full-text available

Jan 2014

Jaap Jan Schröder

Our attitude towards mineral nitrogen (N) fertilizers is ambivalent. N fertilizers have on one hand increased our supply of food, feed and other bio-based raw materials tremendously and also improved the use efficiency of land and labor, but have on the other hand a negative impact on the quality of the environment and contributed to the depletion of fossil fuel reserves. This awareness has resulted in strong pleas to spend much more attention to the recycling of N containing downstream “wastes”. It is, however, naive to assume that even perfect recycling suffices to offer the same number of people the same diet without inputs of “new” N, as inevitable losses of N make compensations indispensable. “New” N can be derived from either biological N fixation (“legumes”) or from industrially fixed N (“fertilizer”). The existing literature provides no evidence that the use of N fertilizers is per se unsustainable, as these fertilizers can also be made from renewable forms of energy. Besides, soil health and human health appear sensitive for the dosage but not for the form of N. It is yet imperative to reduce the input of “new” N as much as possible, so as to minimize adverse environmental effects. Measures to this end are a more precise assessment of crop N requirements, a better timing and positioning of N inputs, and any measure supporting the acceptance of “wastes” by farmers. The present paper elaborates the above aspects.

Influence of Herbicide and Soil Amendments on Soil Nitrogen Dynamics, Microbial Biomass, and Crop Yield in Tropical Dryland Agroecosystems

Article

Full-text available

Nov 2012

Nitrogen (N) dynamics is the key factor for designing management strategies to achieve sustained crop productivity. A 2-yr field experiment was performed to examine the influence of herbicide (butachlor [2-chloro 2'6' diethyl-n-butoxy-methylacetanilide]; HC) alone or in combination with soil amendments on N dynamics involving N mineralization rate (N-min), inorganic N pool, N uptake (N-up) by plants, soil microbial biomass N, and crop yield in tropical dryland agroecosystems. The N-min rate showed distinct seasonal patterns which decreased from rice period to summer fallow except herbicide + animal manure (farmyard manure; HC + AM) and herbicide + crop residue (wheat [Triticum aestivum L.] straw; HC + CR) treatments. The annual rate of N-min, inorganic N pool, and crop yield were higher in HC + AM, herbicide + chemical fertilizer (NPK; HC + CF), herbicide + green manure {dhaincha [Sesbania aculeata (Willd.) Pers.] shoots; HC + GM} while comparable in HC + CR and HC treatments relative to control (CO). Soil moisture content better predicted variation in N-min rate compared to soil temperature. Plant N-up and crop yield relative to CO was higher in HC + CF, HC + GM, and HC + AM, comparable in HC + CR while lower in the HC treatment. Annual N-min rate explained a significant part of variations in annual soil microbial biomass N, inorganic N pool, plant N-up, and crop yield. Results indicate that combined application of HC + AM result in relatively sustained availability of inorganic N and higher crop yield throughout the annual cycle.

SPECIAL TOPICS -- Mitigation of methane and nitrous oxide emissions from animal operations: II. A review of manure management mitigation options

Article

Full-text available

Nov 2013
J ANIM SCI

This review analyzes published data on manure management practices used to mitigate methane (CH4) and nitrous oxide (N2O) emissions from animal operations. Reducing excreted nitrogen (N) and degradable organic carbon by diet manipulation to improve the balance of nutrient inputs with production is an effective practice to reduce CH4 and N2O emissions. Most CH4 is produced during manure storage; therefore, reducing storage time, lowering manure temperature by storing during colder seasons, and capturing and combusting the CH4 produced during storage are effective practices to reduce CH4 emission. Anaerobic digestion with combustion of the gas produced is effective in reducing CH4 emission and organic carbon content of manure; this increases readily available carbon and N for microbial processes creating little CH4 and increased N2O emission following land application. Nitrous oxide emission occurs following land application as a byproduct of nitrification and dentrification processes in the soil, but these processes may also occur in compost, biofilter materials, and permeable storage covers. These microbial processes depend on temperature, moisture content, availability of easily degradable organic carbon, and oxidation status of the environment, which make N2O emissions and mitigation results highly variable. Managing the fate of ammoniacal N is essential to the success of N2O and CH4 mitigation because ammonia is an important component in the cycling of N through manure, soil, crops, and animal feeds. Manure application techniques like subsurface injection reduce ammonia and CH4 emissions but can result in increased N2O emissions. Injection works well when combined with anaerobic digestion and solids separation by improving infiltration. Additives such as urease and nitrification inhibitors that inhibit microbial processes have mixed results, but are generally effective in controlling N2O emission from intensive grazing systems. Matching nutrient requirements with manure fertilization, managing grazing intensity, and using cover crops are effective practices to increase plant N uptake and reduce N2O emissions. Due to system interactions, mitigation practices that reduce emissions in one stage may increase emissions elsewhere, so mitigation practices must be evaluated at the whole farm level.

The Need for Agro-Ecological Intelligence to Preparing Agriculture for Climate Change

Article

Full-text available

May 2012
J Crop Improv

P.S. Bindraban

Gratefully, the quality of life for billions of people will improve drastically during the coming decades. This implies that the production of virtually every commodity will have to increase dramatically. Agriculture-related activities ought to provide food, feed, and non-edible plant-based products. The availability of natural resources per person will, however, continue to decline. Resource degradation like erosion, soil fertility decline, and water pollution further constrain production increases. Hence, the use efficiency of natural resources will have to be boosted drastically, while variability should be curtailed through enhanced buffering capacity of the production base to prevent shock in food systems. These changes in agricultural strategies also call for interdisciplinary research groups to seek for synergies between production factors. This paper provides an overview of the challenges to meet the above mentioned production conditions and stresses the need for agro-ecological intelligence in choosing agricultural development strategies and, therefore, in designing agro-ecosystems. Plant production is taken as a starting point where global change, including climate, are considered in an integral manner.

Symbiotic N 2 fixation by soybean in organic and conventional cropping systems estimated by 15 N dilution and 15 N natural abundance

Article

Jan 2007

Nitrogen (N) is often the most limiting nutrient in organic cropping systems. N2 fixing crops present an important option to improve N supply and to maintain soil fertility. In a field experiment, we investigated whether the lower N fertilization level and higher soil microbial activity in organic than conventional systems affected symbiotic N2 fixation by soybean (Glycine max, var. Maple Arrow) growing in 2004 in plots that were since 1978 under the following systems: bio-dynamic (DYN); bio-organic (ORG); conventional with organic and mineral fertilizers (CON); CON with exclusively mineral fertilizers (MIN); non-fertilized control (NON). We estimated the percentage of legume N derived from the atmosphere (%Ndfa) by the natural abundance (NA) method. For ORG and MIN we additionally applied the enriched 15N isotope dilution method (ID) based on residual mineral and organic 15N labeled fertilizers that were applied in 2003 in microplots installed in ORG and MIN plots. These different enrichment treatments resulted in equal %Ndfa values. The %Ndfa obtained by NA for ORG and MIN was confirmed by the ID method, with similar variation. However, as plant growth was restricted by the microplot frames the NA technique provided more accurate estimates of the quantities of symbiotically fixed N2 (Nfix). At maturity of soybean the %Ndfa ranged from 24 to 54%. It decreased in the order ORG > CON > DYN > NON > MIN, with significantly lowest value for MIN. Corresponding Nfix in above ground plant material ranged from 15 to 26 g N m-2, with a decreasing trend in the order DYN = ORG > CON > MIN > NON. For all treatments, the N withdrawal by harvested grains was greater than Nfix. This shows that at the low to medium %Ndfa, soybeans did not improve the N supply to any system but removed significant amounts of soil N. High-soil N mineralization and/or low-soil P availability may have limited symbiotic N2 fixation.

Simulating residual effects of animal manures using 15 N isotopes

Article

Jan 2007

An estimation of the residual nitrogen effects of animal manure is important when optimizing crop rotations and fertiliser applications. The residual effect of animal manure was studied with the dynamic simulation model FASSET. The model was tested on experiments with 15N-labelled animal manures, where the fate of labelled manure N had been studied. Three field experiments differing in animal manure type, the labelled fraction of the manure, soil type and application techniques were analysed. The duration of the experiments varied between one and three years. In general, the model simulations agreed well with the observations. At the end of the experimental periods, the model captured 74% of the observed variation in soil 15N, whereas some systematic difference was found between measured and simulated plant uptake of 15N. The model was used to evaluate the impact of soil types, soil fertility, manure type, climate and crop type on the 15N residual effect of animal manure. These scenarios showed that wet climates, sandy soils and crops with a short growing season reduce the residual effects of animal manures. The type of the manure also influenced the residual effect of the manure such that the residual effect increased from pig slurry and cattle slurry to deep litter. The soil organic matter level had little influence on the 15N residual effect of the manure.

Organic Amendment History and Crop Rotation Effects on Soil Nitrogen Mineralization Potential and Soil Nitrogen Supply in a Potato Cropping System

Article

Full-text available

Nov 2008
AGRON J

Crop management practices infl uence readily and potentially available N in soil. In this study, we evaluated the eff ects of organic amendment history and crop rotation on potentially mineralizable N (N 0 ), mineralizable N pools, and fi eld estimates of soil N supply in potato (Solanum tuberosum L.) production, and evaluated a suite of N availability measures to detect changes in these parameters. Preplant soil samples (top 15-cm) were collected from the potato year of a rotation trial in Maine during 2004 and 2005. Treatments included three crop rotations, with and without a history of organic amendment (solid beef (Bos taurus) manure) application: PB, potato-barley (Hordeum vulgare L.); PSPB, potato-soybean (Glycine max (L.) Merr.)-potato-barley; and PSBA/T, potato-soybean-barley-alfalfa (Medicago sativa L.)/timothy (Phleum pratense L.). Th e N 0 and mineralizable N pools were determined by aerobic incubation at 25°C and periodic leaching for 24 wk with a fi xed-k approach. On average, his- torically amended soil had 35% higher values of N 0 , and an 8% higher proportion of mineralizable N partitioned to the stable mineralizable N pool, compared with nonamended soil. Lower values of N 0 , mineralizable N pools and some measures of N avail- ability were measured in PSBA/T compared with PB and PSPB rotations. All tested measures of N availability detected manage- ment-induced changes in N 0 and mineralizable N pools. Th e preplant nitrate, UV absorbance of 0.01 M NaHCO 3 extract at 205 nm and particulate organic matter (POM)-N were the best predictors of fi eld-based indices of soil N supply (r 2 = 0.50 to 0.73). Management-induced changes in the size and quality of mineralizable N should be considered in developing best N management programs through organic amendment application and crop rotations.

Interactions between soil organic matter level and soil tillage in a growing crop: N mineralization and yield response

Article

May 2006
SOIL USE MANAGE

Four levels of soil organic matter (SOM) had been established on a coarse sandy loam after application of four combinations of mineral fertilizer, animal manure, straw incorporation and catch crops for 12 years. Soil tillage was carried out in a growing spring barley crop (Hordeum vulgare) to examine the potential for improving the synchrony between soil N mineralization and crop N demand. Tillage raised soil nitrate concentrations temporarily but did not influence barley dry matter (DM) yield. At maturity, both grain DM yield and N uptake were largest on soil with the highest OM level. The previous OM applications had a pronounced influence on crop development and N availability, but soil tillage did not significantly improve the synchrony between soil N mineralization and crop N demand.

Exploring the Benefits of Organic Nutrient Sources for Crop Production and Soil Quality

Article

Full-text available

Oct 2007

ADDITIONAL INDEX WORDS. organic, nutrient sources, soil quality, health benefits, environment SUMMARY. Consumer demand for organically grown produce has increased dra-matically over the past decade, most likely because of the perceived benefits to the environment and human health. A major component of organic production is providing organic sources of nutrients to promote plant growth as well as sustain soil quality. Organic nutrition of plants can present opportunities and challenges to the grower. The primary objective of this article is to review scientifically based information dealing with the effects of organic nutrient sources on crop yields and quality, soil properties, and environmental risks. Effects of organic nutrient sources are often evaluated by comparison with conventional production, but this approach can be problematic because nutrient source may be confounded with many other cropping system components. Despite these drawbacks, a careful examination of the literature suggests the following conclusions. Soil quality is generally improved with application of organic nutrient sources, but careful management is required to avoid environmental risks of nitrate (NO 3) leaching and phosphorus accumulation. Provided that nutrient supply is equal, yields with organic sources tend to be similar to those with inorganic sources. However, lack of available nitrogen (N) that is synchronous with plant demand often limits yields in organic cropping systems. Limited N availability and varied supply of other nutrients from organic sources may contribute to the differences sometimes observed in dry matter content, tissue NO 3 and mineral concentration, vitamin C and other phytochemicals, and taste. Phytonutrient content also may be affected by differences in pest control strategies among cropping systems regardless of nutrient source. There is a slight, but significantly, increased risk of produce contamination by Escherichia coli and other enteric bacteria contamination on produce when organic nutrient sources are used, but if proper guidelines are followed, contamination with the lethal serotype O157:H7 does not appear to be a major concern. Appropriate management of organic inputs is critical to achieving potential benefits for crop production and soil quality. T he use of organic farming tech-niques to grow crops has gained in popularity in recent years as a result of both an increase in consumer demand for organically grown produce and a genuine desire on the part of many growers to sus-tain or improve the soil (Dimitri and Greene, 2002). Now, organic produce generally commands a higher price than conventional produce (Oberholtzer et al., 2005), prompt-ing producers to grow crops organi-cally. The increased consumer demand appears to be driven primarily by the perception that organically grown produce is safer and more nutri-tious to eat than produce grown con-ventionally (Lockie et al., 2002; Williams and Hammitt, 2001). Ever since mainstream agricul-ture switched from more natural nutrient sources such as manure or compost to chemically manufactured synthetic fertilizers over the past 60 to 70 years, there has been much debate about the effect that these nutrient sources have on crop and soil quality. In a review over 30 years ago on this subject, Barker (1975) concluded that both organic and synthetic fertil-izers have a role in agriculture and the good points of each should be acknowledged. Before and since that time, many studies have been con-ducted in an attempt to quantify dif-ferences in crop and soil attributes resulting from conventional and organic production methods.

Relevance of soil and terrain information in studies of major global issues

Conference Paper

Full-text available

Aug 2010

European food and agricultural strategy for 21st century

Article

Full-text available

May 2011

Production ecological analyses reveal great differences in food production potential and food requirement between global regions, which implies the need for redistribution of food between surplus and deficit regions. The surplus production potential, current production and trade volumes of Europe along with the desires of its society for non-food functions from its land, favours a dual agricultural path for Europe. It can continue to guarantee its own food provision through a food-oriented path of intensive agriculture, while cherishing a socially-oriented pathway to meet non-food desires. Europe can assume an active role in world food security by using its surplus potential to supplement the deficit region Asia and by using its agricultural insight to facilitate processes towards sustainable agriculture in Latin America and to support overall agricultural development in Africa. The prospects for the coming decades for European agriculture are so favourable that there is little need to introduce agro-energy or heavy subsidy measures to stimulate or revitalise agricultural development within its territory.

Organic management and soil health promote nutrient use efficiency

Article

Full-text available

Jul 2023

Introduction Nitrogen is a key nutrient for plants. Often less than 50% of the applied nitrogen fertilisers is acquired by crops and nitrogen can be easily lost into the environment causing environmental pollution. Thus, to make agriculture more sustainable, it is important to investigate which factors determine nitrogen use efficiency (NUE). We investigated whether NUE was higher in organically managed soils compared to conventionally managed soils. Materials and Methods To test this, we carried out a pot experiment in a greenhouse using soils from 16 fields. The soils were collected from conventionally (eight fields) or organically managed fields (eight fields). In addition, plants received two different ¹⁵ N enriched N sources (mineral ¹⁵ N or an organic fertiliser source, namely ¹⁵ N enriched plant litter). Plants were harvested at three time points, and growth and nitrogen uptake were assessed at each time point. Results NUE depended on management type and harvest time and the higher NUE of organically managed soils became more evident towards the second and third harvest. The average NUE at the end of the experiment was 93% and 55% for mineral fertiliser and litter application, respectively. This indicated that mineral fertilisers were immediately acquired by the plants, while nutrients in organic amendments had a lower availability and probably would be supplied later but steadier. Further, NUE was positively linked to microbial biomass, soil organic carbon content, and aggregate size, indicating that enhanced soil quality and soil health leads to a more efficient use of fertilisers. Conclusion Our results indicate that organic management and soil health promote a more efficient use of nutrients and contribute to a more sustainable agriculture.

Leached nitrate under fertilised loamy soil originates mainly from mineralisation of soil organic N

Article

Oct 2022
AGR ECOSYST ENVIRON

Animal manures are suspected to be a major source of nitrate leaching due to their low nitrogen use efficiency (NUE) by crops. However, actual measurements of nitrate leaching from animal manure under field conditions are scarce. In an on-farm field trial in Switzerland over 2.5 years, we used ¹⁵N labelling to trace the fate of N from cattle slurry in the soil-plant system and to test whether more nitrate was leached from slurry than from mineral fertiliser. The experiment was conducted on two neighbouring fields with loamy soil in an agricultural area of the Swiss midlands, where nitrate levels in the groundwater are persistently high. Both fields followed the same crop rotation (silage maize – winter wheat – grass-clover), but shifted by one year. We compared three fertiliser treatments: Control (Con), ¹⁵N mineral fertiliser (Min), and ¹⁵N cattle slurry (Slu). In order to provide a comprehensive fertiliser N balance over several years, we traced the labelled fertilisers into crop biomass, soil, and leached nitrate. In the year of application, ¹⁵N recovery in crops was 45–47% for Min, but only 19–23% for Slu. Complementary to this finding, recoveries in soil were greater for Slu than for Min, despite greater NH3 emissions from Slu. Fertiliser recovery in the succeeding crops was small (< 4.6% of the originally applied fertiliser N in the first residual year and < 2.4% in the second) and similar for both fertilisers. Depth translocation of fertiliser N was marginal, with the majority of ¹⁵N in soil still in the top 0.3 m after 2.5 years. Along with higher recoveries in soil for Slu, we found significantly more slurry N than mineral fertiliser N lost through leaching. However, less than 5% of cumulated amounts of nitrate leaching over the three crops, which reached up to 205 kg nitrate-N ha⁻¹, originated from direct leaching of the labelled fertilisers. Our findings suggest that most nitrate leaching originated from the mineralisation of soil N.

Different agricultural practices specify bacterial community compositions in the soil rhizosphere and root zone

Article

Full-text available

Oct 2020

We are only beginning to understand the influence of agricultural practices, together with soil properties and geographic factors, affect bacterial communities and their influence on the soil processes. Here, we quantify how typical agro-practices, i.e., no-tillage, ridge tillage, continuous corn cropping, and crop rotation with corn and bean, and the corresponding soil physicochemical characteristics affect bacterial diversity and community compositions of the rhizosphere and root zone soils. Results show that species richness in the rhizosphere was significantly higher than that in the root zone soils (p < 0.05), typically with more abundant Crenarchaeota and Firmicutes populations that are active members for C and N cycling. Specifically, crop rotation compared to other agro-practices was able to mediate soil pH value and the available P and thereby control the bacterial diversity pattern in the rhizosphere (p < 0.05), while tillage practices regulated the relative abundance of bacterial populations in root zone soils by varying the soil available N (p < 0.05). Analysis of biomarker patterns suggests that the observed differences in bacterial functional capabilities (e.g., nutrient cycling) are strongly related to the physicochemical properties of surrounding soils. Our results highlight the importance of soil-plant interaction in shaping soil bacterial community structure typically in the rhizosphere and root zone soils and also illustrates the challenges in linking soil ecosystem function to microbial processes.

Soil organic matter storage in a perennial rotation pasture in north-central Nova Scotia from 2007 to 2015

Article

Mar 2018
CAN J SOIL SCI

Repeated analysis of soil organic matter (SOM) in the top 0.3 m of a perennial rotation pasture with legumes in Nova Scotia showed a significant increase of SOM from 2007 to 2015 (paired t test; n = 24; P < 0.001). This suggests perennial pastures in cool-humid biomes enhance ecosystem services of dairy farms through SOM storage.

Soil microbial biomass, functional diversity and crop yields following application of cattle manure, hog manure and inorganic fertilizers

Article

May 2005
CAN J SOIL SCI

Soil biological properties can be significantly impacted by land management. Cattle manure, hog manure or inorganic fertilizers were applied annually or triennially in field trials conducted at two sites over 3 yr. A control treatment without manure or fertilizer was also included. Canola (Brassica napus) was grown in year 1, hulless barley (Hordeum vulgare) in year 2, and wheat (Triticum aestivum) in year 3. Where effects were significant, cattle manure increased soil microbial biomass C (MBC) by 26% to three-fold, hog manure by 31% to two-fold, and inorganic fertilizers reduced MBC by 20-64%. Similar effects, except the reduction by inorganic fertilizers, were observed for functional diversity of soil bacteria (Shannon index, H′). At one site, where crop yields were recorded for 3 yr, hog manure produced greater grain yields (75% increase over the control) than the rest of the treatments (49% increase by cattle manure) in year 1, but cattle manure out-yielded other treatments thereafter, when it increased yields by 25-50%. Cattle manure out-yielded other treatments even when nutrient uptake from inorganic fertilizers was the highest, implying that other factors also influenced crop yields. At the other site, crop yields were recorded only in year 1, and all soil amendments increased canola yields about three-fold relative to the control. Frequency of application usually had no effects on MBC or H′, but the triennial application rate of inorganic fertilizers or hog manure produced lower crop yields than annual applications in year 1.

Ammonia emissions from cattle slurries applied to grassland: Should application techniques be reconsidered?

Article

Sep 2015
SOIL USE MANAGE

Ammonia is easily lost after land spreading of livestock slurries. Low-emission techniques entailing injection and trailing shoes have therefore become compulsory in the Netherlands on grassland. There is an argument that the emission of ammonia after surface application is overestimated and that the emission of various other nitrogen (N) compounds, following the prescribed low-emission techniques, is underestimated. Opponents also claim that injection in particular decreases grassland yields due to its negative effect on soil quality and biodiversity. They state that a similar reduction in ammonia emissions could be realized via low-protein dairy cow diets and slurry spreading under favourable weather conditions. This study evaluates these claims and concludes that low-emission techniques reduce the loss of ammonia effectively and increase the availability of N to grassland. There are no indications that low-emission techniques per se have negative effects on soil quality, the productivity of crops and biodiversity. It has also been demonstrated that the efficacy of proposed alternatives is limited.

Options for Ammonia Mitigation: Guidance from the UNECE Task Force on Reactive Nitrogen, Centre for Ecology and Hydrology, Edinburgh, UK

Technical Report

Jan 2014

B. Wade contributed to: Chapter 8: Fertilizer application………………………………………………………………………41 Misselbrook, T., Webb, J., Pallière, C., Sutton, M.A., Lukin, S. & Wade, B.

Tillage in the growing season is ineffective as a tool of increased soil N mineralization

Article

Apr 2004

Naudanlihantuotannon ympäristövaikutukset - kirjallisuusselvitys

Book

Full-text available

Nov 2014

Production of Nitrogen15-Labeled Pig Manure for Nitrogen Cycling Studies

Article

Sep 2005
SOIL SCI SOC AM J

Nitrogen-15 labeled pig (Sus scrofa) manure was produced to study the homogeneity of labeled pig manure prepared for soil N cycling studies. Growing pigs were fed with a diet consisting of mainly N-15-labeled barley (Hordeum vulgare L.) and peas (Pisum sativum L.) during a period of 11 d. Labeled feces and urine were collected separately. The N-15 enrichment of urine N was lower than that of fecal N except for the first 2 d of the N-15 feeding period. After 11 d of N-15 feeding, the N-15 enrichment of fecal N was 7% lower and urine N 28% lower than the enrichment of feed N. The homogeneity of N-15-labeling of feces N, sampled at different times during the N-15 feeding, was tested by an incubation test in quartz sand and soil. After 12 wk in soil at 20 degrees C, 25 to 27% of the feces N was in inorganic form, and the N mineralization rate declined after this period. The test indicated that the N-15-labeled pig feces had a satisfactory labeling homogeneity even though the feed ingredients had variable N-15 enrichments. We recommend the collection of urine and feces separately and the use of labeled feces in combination with unlabeled urine and vice versa in studies of the fate of pig manure N in agroecosystems. If feces and urine with a similar N-15 enrichment can be obtained the two components can be mixed in the same manure.

A meta-analysis of the differences in environmental impacts between organic and conventional farming

Article

Full-text available

Sep 2009
BRIT FOOD J

Purpose: This paper aims at comparing the environmental impacts of organic and conventional farming and linking these to differences in management practises. The studied environmental impacts are related to land use efficiency, organic matter content in the soil, nitrate and phosphate leaching to the water system, greenhouse gas emissions and biodiversity. Design / Methodology / Approach: The theoretic framework uses the driver-state-response framework and literature data were analysed using meta-analysis methodology. Meta-analysis is the statistical analysis of multiple study results. Data were obtained by screening peer reviewed literature. Findings: From our meta-analysis we can conclude that soils in organic farming systems have on average a higher content of organic matter. We can also conclude that organic farming contributes positively to agro-biodiversity (breeds used by the farmers) and natural biodiversity (wild life). Concerning the impact of the organic farming system on nitrate and phosphorous leaching and greenhouse gas emissions the result of our analysis is not that straightforward. When expressed per production area organic farming scores better than conventional farming for these items. However, given the lower land use efficiency of organic farming in developed countries, this positive effect expressed per unit product is less pronounced or not present at all. Original value: Given the recent growth of organic farming and the general perception that organic farming is more environment friendly than its conventional counterpart, it is interesting to explore whether it meets the alleged benefits. By combining several studies in one analysis, the technique of meta-analysis is powerful and may allow to generate more nuanced findings and to generalise findings to a wider scope.

Yield and flour quality of spring wheat as affected by soil tillage and animal manure

Article

Sep 2008
J SCI FOOD AGR

BACKGROUND: Yield and quality of organic bread wheat may be improved by adjusting tillage and type of manure. We tested two different tillage strategies (rotovation plus ploughing or ploughing only) before sowing spring wheat ( Triticum aestivum L.) on a coarse loamy sand. The tillage strategies were combined with four nitrogen (N) rates of animal manure supplied in either slurry or liquid manure. RESULTS: Rotovation before ploughing had only a negligible influence on soil inorganic N content in the spring and on wheat biomass development. Liquid manure gave a higher protein and gluten content than slurry, probably due to its higher proportion of inorganic N. At low N rates, gluten from wheat supplied with slurry was softer than from wheat given liquid manure and responded differently to baking tests than expected from their gluten and protein content. At higher N rates, loaf volume corresponded well with the gluten and protein content. CONCLUSION: Soil tillage intensity did not have a major influence on soil N mineralisation patterns and manure N availability. Except at low N rates, the response of wheat flour to different types of animal manure is mainly determined by the amount of inorganic N supplied. Copyright © 2008 Society of Chemical Industry

Sustainability of Organic Horticulture

Chapter

Jan 2010

Michael Raviv

Storage and Handling Can Alter the Mineralization Characteristics of Manure

Article

Full-text available

Nov 1999

In vitro incubations of manure-amended soil are frequently used to evaluate manure N and C availability. Manures are typically frozen, refrigerated, or dried prior to analysis. An experiment was designed to evaluate the effects of these manure storage methods on C and N mineralization characteristics. Two dairy slurries were collected and seven treatments, fresh, frozen (4 or 5 wk), refrigerated (1 d, 1 wk, 4 wk), freeze-dried or oven-dried, were compared. Rates and extents of N and C mineralization were determined by aerobic incubation of slurry-amended soil at 25°C. Slurry was added at a rate equivalent to 265 kg N ha-1 incorporated into the upper 15 cm of soil. The appearance of NH4/+ and NO3/- and the production of CO2 were monitored during 16 wk. Refrigeration or freezing had no effect on slurry N content; however, freeze drying and oven drying resulted in N losses of 30% or more. CO2-C production followed first-order kinetics during 9 wk for all treatments with approximately 18 to 26% of the slurry C mineralized. Net mineralization of organic N was minimal in all treatments and was not affected by freezing or refrigerating the slurries. With oven-dried and freeze-dried slurries, however, there was a greater immobilization of N when compared with fresh manure. Results indicate that oven drying and freeze drying are unsuitable methods of storage, but the mineralization characteristics of manure are not affected by refrigeration or freezing.

Impact of agricultural practices on the size and activity of the microbial biomass in a long-term field experiment

Article

Full-text available

Jan 1995

The Dehrain long-term field experiment was initiated in 1875 to study the impact of fertilization on a wheat-sugarbeet rotation. In 1987, the rotation was stopped to be replaced by continuous maize. Crop residues were soil-incorporated and the mineral fertilization was doubled in some plots. The impact of those changes on the microbial biomass and activity are presented. In spring 1987, the soil was still in a steady-state condition corresponding to the rotation. The microbial biomass was correlated with total organic C and decreased in the order farmyard manure>mineral NPK>unfertilized control. Microbial specific respiratory activity was higher in the unfertilized treatments. The soil biomass was closely related to soil N plant uptake. In 1989, after 2 years of maize and crop residue incorporation, the steady-state condition corresponding to the previous agricultural practices disappeared. So did the relationship between the biomass and total organic C, and the soil N plant uptake. Biomass specific respiratory activity increased because of low efficiency in the use of maize residues by microbes under N stress.

Phosphorus budget and phosphorus availability in soils under organic and conventional farming

Article

Full-text available

Jan 2002

The aim of this work was to assess to which extent organic farming practices would affect the accumulation of total and available phosphorus (P) in a cropped soil in comparison to conventional practices. In order to achieve this, soil samples were taken from a long-term field trial comparing a non-fertilised control (NON), two conventionally cultivated treatments (MIN, CON), and two organically cultivated treatments (ORG, DYN). Soil samples were taken from each treatment at two depths (0-20 and 30-50 cm) before starting the field trial (1977) and at the end of every three crop rotations (1984, 1991 and 1998). They were then analysed for total P (Pt), total inorganic P (Pi), total organic P (Po) and isotopically exchangeable Pi. After 21 years, the average P input-output budget reached -20.9 kg P ha–1 a–1 for NON, -7.8 for DYN, -5.7 for ORG, -5.0 for MIN and +3.8 for CON. Total P, Pi as well as the amount of Pi isotopically exchangeable within 1 minute (E1) were positively correlated to the P budget. Comparison between P budget and Pt in the top- and subsoils of the fertilised treatments suggested a net transfer of P from the 0–20 to the 30–50 cm layers between 13 and 26 kg P ha–1 a–1during the first rotation and between 3 and 12 kg P ha–1 a–1during the second rotation. During the third rotation a net upward movement of P from the subsurface to the topsoil ranging between 3.7 and 10.5 kg P ha–1 a–1was estimated. In the topsoil, E1decreased from an initial value of 12 mg P kg–1 to 11 in CON, 8 in MIN, 6 in ORG, 5 in DYN and 2 in NON after 21 years. In the subsoil, E1 increased from an initial value of 2 mg P kg–1 to 4 in MIN, ORG, DYN and NON and to 6 in CON. These results show that, with the exception of NON, all treatments had still an adequate level of available P after 21 years of trial and that, in this low to moderately P sorbing soil, an equilibrated input-output budget allows to maintain P availability at a constant level. In the organic systems, yields have so far partly been attained at the expense of soil reserves or residual P from earlier fertiliser applications.

A rapid procedure for estimating nitrogen mineralization in manured soil

Article

Full-text available

Feb 2001

A routine soil testing procedure for soil N mineralization is needed that is rapid and precise. Not accounting for N mineralization can result in the over-application of N, especially in soils with a history of manure application. Our objectives were to compare results from a recently proposed rapid laboratory procedure with: (1) long-term N mineralization under standard laboratory conditions, and (2) actual forage N uptake from soil receiving dairy cattle (Bos taurus) manure in a 2-year field study. The rapid procedure is based on the quantity of CO2-C evolved during 24 h under optimum laboratory conditions following the rewetting of dried soil. Dairy cattle manure was surface applied beginning in 1992 at annual rates of 0, 112, 224, or 448 kg N ha–1 to field plots on a Windthorst fine sandy loam soil (fine, mixed, thermic Udic Paleustalf) near Stephenville, Texas (32°N, 98°W). Results of the one-day CO2 procedure were highly correlated with soil N mineralized from samples collected in March of 1995 (P=0.004) and 1996 (P<0.001) and with forage N uptake (P<0.001) both years of the study. Residual inorganic N in the same soil samples was poorly correlated with soil N mineralization and forage N uptake.

Kinetics of microbial P uptake in cultivated soils

Article

Full-text available

Jan 2001

Knowledge about the role of microorganisms in P cycling at conditions of constant soil respiration rates and constant size of microbially bound P is lacking. To study the kinetics of microbial P uptake and cycling under such conditions, soils differing in biological activity were 33PO4 labelled by introducing a carrier-free tracer solution and incubated for 56 days. The 33PO4 incorporation into the fraction of microbial P releasable by chloroform treatment (Pchl) was assessed and the isotopic composition [=specific activity (SA); SA=33PO4/31PO4] of Pchl and soil solution P compared. Soils were taken from a 20-year-old field experiment including a non-fertilised control (NON), a minerally fertilised conventional (MIN) and two organic farming systems [bio-organic (ORG); bio-dynamic (DYN)]. Tracer P incorporation continuously increased during incubation in DYN, ORG and MIN soils. It decreased in the order DYN>ORG>MIN, with differences in 33PO4 uptake between the farming systems being higher than suggested by the differences in the amount of Pchl. In the P-deficient NON soil, the highest initial incorporation of tracer P was found, but no additional uptake could be detected thereafter. In all soils, the SA of Pchl converged to the SA of the soil solution with increasing time. Since Pchl remained almost constant during the experiment, the findings suggest an intensive uptake of P from the soil solution into Pchl and concomitant release of P back to the soil solution and, thus, a rapid cycling through Pchl. Intensive P cycling between Pchl and the soil solution was confirmed in an additional experiment where microbial activity was stimulated by glucose and N additions.

An Extraction Method for Measuring Soil Microbial Biomass C

Article

Full-text available

Jan 1987
SOIL BIOL BIOCHEM

The effects of fumigation on organic C extractable by 0.5 M K2SO4 were examined in a contrasting range of soils. EC (the difference between organic C extracted by 0.5 M K2SO4 from fumigated and non-fumigated soil) was about 70% of FC (the flush of CO2-C caused by fumigation during a 10 day incubation), meaned for ten soils. There was a close relationship between microbial biomass C, measured by fumigation-incubation (from the relationship Biomass C = FC/0.45) and EC given by the equation: Biomass C = (2.64 ± 0.060) EC that accounted for 99.2% of the variance in the data. This relationship held over a wide range of soil pH (3.9–8.0).ATP and microbial biomass N concentrations were measured in four of the soils. The ratios were very similar in the four soils, suggesting that both ATP and the organic C rendered decomposable by CHCl3 came from the soil microbial biomass. The C:N ratio of the biomass in a strongly acid (pH 4.2) soil was greater (9.4) than in the three less-acid soils (mean C:N ratio 5.1).We propose that the organic C rendered extractable to 0.5 m K2SO4 after a 24 h CHCl3-fumigation (EC) comes from the cells of the microbial biomass and can be used to estimate soil microbial biomass C in both neutral and acid soils.

Nitrogen-15 Labeling of Dairy Feces and Urine for Nutrient Cycling Studies

Article

Full-text available

Sep 1999
AGRON J

Estimates of the availability of dairy manure nutrients to crops rely on indirect measurements and can vary greatly. More accurate estimates of manure nutrient availability are needed to improve manure management. The objective of this study was to enrich dairy feces and urine in (15)N to study nutrient flow in the feed-animal-manure-soil and crop-environment continuum. Ammonium sulfate (12.3 or 10 atom % (15)N)) was applied to soil to enrich alfalfa (Medicago sativa L.) and corn (Zea mays L.) plants during growth. Alfalfa hay contained from 2.386 to 3.980 atom % (15)N in three harvests and corn silage contained 8.162 atom % (15)N. A feed mixture containing 55% alfalfa hay and 45% corn silage (4.026 atom % (15)N) was fed to two mature nonlactating cows (Bos taurus) for 36 h. The pattern of (15)N excretion in urine and feces was similar for both cows. The (15)N appeared in urine by 8 h and in feces by 24 h, and peaked by 30 h in urine (1.642 atom % (15)N) and by 54 h in feces (2.341 atom % (15)N). Enrichment approached basal levels at 132 h after initial feeding for both urine and feces. Of the total (15)N fed, 60% was recovered: 31% from urine and 29% from feces. Approximately 60 to 70% of the total N excreted in dairy feces was endogenous N and 30 to 40% was undigested feed N. Combining feces excreted during the 16- to 122-h period after initial feeding of (15)N-enriched feed would produce feces having uniformly labeled N components. The various (15)N-enrichment levels of urine and feces collected during different times after feeding offer possibilities for studying differential (15)N use in short- and long-term nutrient cycling studies.

Microbial biomass and size-density fractions differ between soils of organic and conventional agricultural systems

Article

Full-text available

Jun 2000
SOIL BIOL BIOCHEM

Agricultural production systems have to combine management practices in order to sustain soil quality and also pro®tability. We investigated microbial biomass and size-density fractions of soils from a long-term field trial set up in 1978 at Therwil, Switzerland. It compares the economic and ecological performance of organic and conventional agricultural systems. Main differences of the systems were the amount and form of fertiliser as well as the plant protection strategy, whilst crop rotation and soil tillage were the same. Microbial biomass C and N as well as their ratios to the total and light fraction C and N pools in soils of the organic systems were higher than in conventional systems. This is interpreted as an enhanced decomposition of the easily available light fraction pool of soil organic matter (SOM) with increasing amounts of microbial biomass. The role of microbial biomass as a regulator and light fraction organic matter as an indicator of decomposition is discussed. The presented results indicate that labile pools of SOM are distinctly affected by long-term management practices.

Quantitative Effects of Feed Protein Reduction and Methionine on Nitrogen Use by Cows and Nitrogen Emission from Slurry

Article

Full-text available

Jan 2001

The effects on N use and N volatilization from slurry were investigated in 24 early-lactation Brown Swiss cows (32 kg/d milk) fed four diets with 128, 124, 147 and 175 g/kg DM of crude protein (CP). All diets were supplemented with 0.75 g/kg of rumen-protected Met except for one of the low-protein rations (128 g/kg of CP). The unsupplemented low-protein ration was calculated to be deficient in Met by approximately 20%. No significant treatment effects on performance, water intake and excretion, and slurry quantities were observed. Differences in N intake were closely reflected in the daily excretions of total and urea N via urine, and in urine N as a proportion of total excretory N. These values were higher for the unsupplemented low-protein ration than for the Met-supplemented low-protein ration. The treatment effects on fecal N excretion were generally smaller, and milk N excretion and N balance were not affected. Feed N utilization for milk N excretion increased with decreasing CP content from 27% for the high-protein group to about 35% for the two low-protein groups. Comparing the Met supplemented rations only, ammonia N emission from fresh slurry (excreta:water = 1:0.5) decreased from 231 to 160 and 55 microg/s per square meter of surface with 175, 147 and 124 g/kg of CP, respectively, and the corresponding total N losses during 7 wk of slurry storage declined from 89 to 57 and 25 g/d per cow. Regression analysis demonstrated the basic suitability of milk urea N excretion to estimate urine N excretion and, consequently, potential N emissions.

Soil Quality and Financial Performance of Biodynamic and Conventional Farms in New Zealand

Article

Full-text available

May 1993

Biodynamic farming practices and systems show promise in mitigating some of the detrimental effects of chemical-dependent, conventional agriculture on the environment. The physical, biological, and chemical soil properties and economic profitability of adjacent, commercial biodynamic and conventional farms (16 total) in New Zealand were compared. The biodynamic farms in the study had better soil quality than the neighboring conventional farms and were just as financially viable on a per hectare basis.

DOK-Versuch: Vergleichende langzeit-untersuchungen in den drei anbausystemen biologischdynamisch, organisch-biologisch und konventionell

Article

Jan 1993

DOK-Versuch: vergleichende Langzeit-Untersuchungen in den drei Anbausystemen biologisch-dynamisch, organisch-biologisch und konventionell. III. Boden: Chemische Untersuchungen, 1 und 2. Fruchtfolgeperiode

Article

Jan 1993

Wirkungsvergleich organischer Dünger mittels 15N‐Tracer

Article

Jan 1982

H. Peschke

DOK-Versuch: Vergleichende Langzeituntersuchungen in den drei Anbausystemen biologisch-Dynamisch, Organisch-biologisch und Konventionell

Article

Jan 1991

Mikrobielle Umsetzungen im Enddarm von Sauen bei intracaecaler Infusion hoher Mengen an verschiedenen reinen Substraten

Article

Jan 1989

SHORT COMMUNICATION : Soil microbial biomass C, N mineralization, and N uptake by corn in dairy cattle slurry- and urea-amended soils

Article

Nov 1996
CAN J SOIL SCI

A spring application of dairy cattle slurry (300 kg total N ha-1) on high- and low-fertility sites resulted in higher microbial biomass C during the growing season than on a control soil or a soil receiving 100 kg N ha-1 as urea. Microbial biomass C was also significantly higher on the high- fertility site and was reflected in greater N mineralization and N uptake by corn. There was no greater net N mineralization in the manured soil than in the control or fertilized soil as would be expected as a result of higher microbial biomass C and significant organic N contribution from the manure.

Availability of Nitrogen in 15N-Labeled Ruminant Manure Components to Successively Grown Crops

Article

Mar 1999

To improve crop N use efficiency of animal manures, the availability of N in individual manure components must be better understood. This microplot field study quantifies crop offtakes of N in four similar batches of ruminant manure containing 15N-labeled urine, feces, or straw, or unlabeled components only. The urine and feces were from a sheep first fed unlabeled hay and then 15N-labeled hay. Manures (≃19 g total N m-2) were incorporated into two coarse-textured soils before planting to spring barley (Hordeum vulgare L.) undersown with perennial ryegrass (Lolium perenne L.). Manures with one 15N-labeled component were supplemented with unlabeled NH4NO3 (7.3 g N m-2), while unlabeled manure was given 15NH415NO3. Labeled and unlabeled N were determined in the spring barley at maturity and in six cuts of ryegrass taken during the succeeding 2.5 yr. The homogeneity of feces and urine 15N-labeling was high. Dry matter yields and crop N offtakes were similar in all treatments. Barley (grain and straw) recovered 40, 26, 10, and 6%, respectively of 15N added with mineral fertilizer, urine, straw, and feces. Weighted mean recovery of the combined manure and fertilizer dressing was 22% of the added 15N. Crop recovery of urine and feces 15N was smaller and that of straw 15N higher than reported in previous studies on individual components, indicating that the N mineralization-immobilization turnover (MIT) of the manure components interacted. In the second and third growth seasons, 2.7 to 4.4% and 1.1 to 2.0% of the 15N was recovered in grass cuts, respectively. Total recovery ranged from 84 to 95% of the added 15N, suggesting small N losses from this cropping system.

Gezielte 15N-Anreicherung von organischen Dungemitteln fur Versuchszwecke: 2. Mitt.: Herstellung von 15N-markierter Gulle

Article

Jan 1982

H. Peschke

Durch Verfütterung N-markierter Futtermittel mit durchschnittlich 15,26 Atom-% Überschuβ in zwei Portionen als eine Tagesration an ein laktierendes Rind werden Höchstwerte im Harn von 5,31 und im Kot von 7,30 Atom-% N-Überschuβ erreicht. Die Hauptmasse des N wird am 2. bis 4. Versuchstag ausgeschieden. Es werden drei Möglichkeiten der Güllebereitung diskutiert und mehrere Güllemuster mit unterschiedlichen Parametern vorgestellt. Die Schluβfolgerungen beziehen sich auf die Gewinnung und Anwendung von N-Gülle.

Zum Einfluß von Stärkeart und -menge in der Ration auf scheinbare und wahre Verdaulichkeit des Stickstoffs und auf die N-Bilanz beim Schaf

Article

Oct 1985
Arch Anim Nutr

The fumigation-extraction method to estimate soil microbial biomass: Calibration of the K EC value

Article

Jan 1996
SOIL BIOL BIOCHEM

The kEN value (= extractable part of microbial biomass N after fumigation) of the fumigation-extraction method was assessed using the C-to-N ratio of the organic matter which was rendered extractable by CHCl3 fumigation. The data for this calibration approach was obtained from 51 arable and 23 grassland soils. The second calibration approach was to compare the relationship between N rendered extractable by CHCl3 fumigation and the C-to-N ratio measured in the flush of the fumigation-incubation method by recalculating data obtained from the literature. On the basis of these two approaches, we recommend using a kEN value of 0.54 as originally proposed by Brookes et al. (Soil Biology & Biochemistry17, 837–842, 1985).

The fate of fresh and stored 15 N-labelled sheep urine and urea applied to a sandy and a sandy loam soil using different application strategies

Article

Sep 1996

The fate of nitrogen from 15N-labelled sheep urine and urea applied to two soils was studied under field conditions. Labelled and stored urine equivalent to 204 kg N ha−1 was either incorporated in soil or applied to the soil surface prior to sowing of Italian ryegrass (Lolium multiflorum L.), or it was applied to ryegrass one month after sowing. In a sandy loam soil, 62% of the incorporated urine N and 78% of the incorporated urea N was recovered in three cuts of herbage after 5 months. In a sandy soil, 51–53% of the labelled N was recovered in the herbage and the distribution of labelled N in plant and soil was not significantly different for incorporated urine and urea. Almost all the supplied labelled N was accounted for in soil and herbage in the sandy loam soil, whereas 33–34% of the labelled N was unaccounted for in the sandy soil. When the stored urine was applied to the soil surface, 20–24% less labelled N was recovered in herbage plus soil compared to the treatments where urine or urea were incorporated, irrespective of soil type. After a simulated urination on grass, 69% of the labelled urine N was recovered in herbage and 15% of the labelled N was unaccounted for. The labelled N unaccounted for was probably mainly lost by ammonia volatilization. Significantly more urine- than urea-derived N (36 and 19%, respectively) was immobilized in the sandy loam soil, whereas the immobilization of N from urea and urine was similar in the sandy soil (13–16%). The distribution of urine N, whether incorporated or applied to the soil surface prior to sowing, did not influence the immobilization of labelled urine N in soil. The immobilization of urine-derived N was also similar whether the urine was applied alone or in an animal slurry consisting of labelled urine and unlabelled faecal N. When urine was applied to growing ryegrass at the sandy loam soil, the immobilization of urine-derived N was significantly reduced compared to application prior to sowing. The results indicated that the net mineralization of urine N was similar to that of urea in the sandy soil, but only about 75% of the urine N was net mineralized in the sandy loam soil, when urine was applied prior to sowing. Thus, the fertilizer effect of urine N may be significantly lower than that of urea N on fine-textured soils, even when gaseous losses of urine N are negligible.

The fate of 15 N-labelled organic nitrogen in sheep manure applied to soils of different texture under field conditions

Article

May 1994

The fate of nitrogen from15N-labelled sheep manure and ammonium sulfate in small lysimeters and plots in the field was studied during two growth seasons. In April 1991,15N-labelled sheep faeces (87 kg N ha-1) plus unlabelled (NH4)2SO4 (90 kg N ha-1), and (15NH4)2SO4 (90 kg N ha-1) were each applied to three soils; soil 1 (100% soil + 0% quartz sand), soil 2 (50% soil + 50% quartz sand) and soil 3 (25% soil + 75% quartz sand). The lysimeters were cropped with spring barley (Hordeum vulgare L.) and undersown ryegrass (Lolium perenne L.). The barley crop recovered 16–17% of the labelled manure N and 56% of the labelled (NH4)2SO4-N. After 18 months 30% of the labelled manure N and 65% of the labelled (NH4)2SO4-N were accumulated in barley, the succeeding ryegrass crop and in leachate collected below 45 cm of soil, irrespective of the soil-sand mixture. Calculating the barley uptake of manure N by difference of N uptake between manured and unmanured soils, indicated that 4%, 10% and 14% of the applied manure N was recovered in barley grown on soil-sand mixtures with 16%, 8% and 4% clay, respectively. The results indicated that the mineralization of labelled manure N was similar in the three soil-sand mixtures, but that the manure caused a higher immobilization of unlabelled ammonium-N in the soil with the highest clay content. Some of the immobilized N apparently was remineralized during the autumn and the subsequent growth season. After 18 months, 11–19% of the labelled manure N was found in the subsoil (10–45 cm) of the lysimeters, most of this labelled N probably transported to depth as organic forms by leaching or through the activities of soil fauna. In unplanted soils 67–74% of the labelled manure N was recovered in organic form in the 0–10 cm soil layer after 4 months, declining to 55–64% after 18 months. The lowest recovery of labelled N in top-soil was found in the soil-sand mixture with the lowest clay content. The mass balance of15N showed that the total recovery of labelled N was close to 100%. Thus, no significant gaseous losses of labelled N occurred during the experiment.

Labelling of animal manure nitrogen with 15 N

Article

May 1994

A sheep was fed on15N-labelled ryegrass hay during a period of 9 days in order to obtain15N-labelled manure. After 9 days of feeding, the total N in faeces contained 3.70 atom %15N excess, which was equivalent to 82% of the15N enrichment of the hay N. The easily-decomposable fraction of the faecal N was less labelled (2.89 atom %15N excess) than the slowly-decomposable fraction. The15N enrichment of mineralized faecal N did not change significantly during 32 weeks of incubation in sand. About 25% of the faecal N was water-soluble. This N had a higher15N enrichment than the total faecal N, indicating that a part of the water-soluble N was indigestible feed N. The faeces contained only small amounts of NH4+-N, which had a15N enrichment similar to the15N enrichment of N mineralized during incubation in sand. It is suggested that the labelled faecal N obtained after a few days of feeding on labelled feed could be divided in two N pools: A decomposable N fraction (about 60%) with a15N enrichment similar to the enrichment of N mineralized in sand (2.89 ± 0.09 atom %15N excess), and a very slowly-decomposable N fraction (about 40%) with a15N enrichment similar to that of the feed (4.52 atom %15N excess).

Some observations on the distribution and origin of nitrogen in sheep faeces

Article

Aug 1969
J AGR SCI

V C Mason

1. Three methods, based on treatment with neutral detergent or acid detergent, or involving ultrasonic disintegration, are described and compared for the direct estimation of undigested dietary nitrogen in individual samples of sheep faeces. Estimates of the true digestibility of the nitrogen in several sheep diets derived from analyses performed with these methods agreed well with each other, and were in accord with published estimates, derived by extrapolation techniques. Two other methods, based on treatment with phenol–acetic acid–water, and lysozyme–trypsin, respectively, were found to be unsuitable for such estimates. 2. The quantitative distribution of nitrogen between undigested dietary residues, bacterial residues, endogenous debris residues and the water soluble fraction was determined chemically. It was concluded that 57–81% of the non-dietary faecal nitrogen was associated with bacterial material. 3. Indirect evidence suggested that most of the bacterial nitrogen in faeces originated in the rumen.

Animal manure slurries as a source of nitrogen for cereals; Effect of application time on efficiency

Article

Jan 2007
SOIL USE MANAGE

Field experiments undertaken at 14 sites, on a range of soil types, in lowland England, during the cropping years 1989–1993, tested the effectiveness of cattle or pig slurry as a source of nitrogen for cereal cropping. Slurry was applied in autumn, winter and spring, to autumn and spring sown cereal crops. Assessments included slurry nitrogen efficiency relative to N in spring applied fertilizer in terms of both grain yield and grain protein production, apparent crop recovery and content of mineral nitrogen in soil profiles. Crop response to nitrogen was poor at seven sites where high residues of soil mineral nitrogen (SMN) were present. On the seven responsive sites, spring slurry applications proved more efficient (mean 40%) as a source of N than autumn (mean 24%) or winter applications (mean 32%). These differences were smaller than reported in a number of other studies, probably as a result of relatively low excess winter rainfall, resulting in less nitrate leaching during the period of the investigation. Rapid incorporation into the topsoil of slurry applied in autumn, increased (28 kgN/ha) the SMN of samples taken early in the winter. However this increase did not lead to a consistent improvement in crop N uptake. Slurry dressings, whenever applied, can be expected to make a significant contribution to the N requirement of the succeeding crop and need to be taken into account when calculating the appropriate spring fertilizer application.

Nitrogen interactions and crop uptake from fresh and composted 15N‐labelled poultry manure

Article

Jul 2006
EUR J SOIL SCI

Holger Kirchmann

SUMMARY15N-labelled poultry excrement was obtained by feeding chickens with 15N-labelled barley grain. The excrement produced was tested for uniformity of 15N-labelling; only small variations in the 15N content were found, indicating uniform labelling. The excrement was mixed with straw to produce manures which were used in a pot experiment measuring uptake of labelled and unlabelled N by ryegrass from the mixture in both a fresh form and after a period of composting. Interactions of N pools differed between the two materials. Addition of composted manure to soil caused a larger uptake of unlabelled N by ryegrass, whereas fresh manure caused a smaller plant uptake of unlabelled N. The proportion of plant N coming from labelled N from fresh manure was 25.7% and from composted manure 3.8%. However, the contributions of the two manures to plant uptake of total N were 15.5% and 13.8%, respectively. The fresh manure, being a mixture of excrement and straw, is considered as a two-component material, whereas composted manure is considered as a single component. It was concluded that the increase or decrease in the quantity of unlabelled, soil-derived N in plants after manure addition was related to the amount of energy available in the different manures.

Crop uptake and leaching of 15N applied in ruminant slurry with selectively labelled faeces and urine fractions

Article

Dec 1997

Two animal slurries either labelled with 15N in the urine or in the faeces fraction, were produced by feeding a sheep with unlabelled and 15N-labelled hay and collecting faeces and urine separately. The slurries were applied (12 g total N -2) to a coarse sand and a sandy loam soil confined in lysimeters and growing spring barley (Hordeum vulgare L). Reference lysimeters without slurry were supplied with15 NH4 15NO3 corresponding to the inorganic N applied with the slurries (6 g N m-2). In the second year, all lysimeters received unlabelled mineral fertilizer (6 g N m-2) and grew spring barley. N harvested in the two crops (grain + straw) and the loss of nitrate by leaching were determined. 15N in the urine fraction was less available for crop uptake than mineral fertilizer 15N. The first barley crop on the sandy loam removed 49% of the 15N applied in mineral fertilizer and 36% of that applied with urine. The availability of fertilizer 15N (36%) and urine15 N (32%) differed less on the coarse sand. Of the15 N added with the faeces fraction, 12–14% was taken up by the barley crop on the two soils. N mineralized from faeces compensated for the reduced availability of urine N providing a similar or higher crop N uptake in manured lysimeters compared with mineral fertilized ones.About half of the total N uptake in the first crop originated from the N applied either as slurry or mineral fertilizer. The remaining N was derived from the soil N pool. Substantially smaller but similar proportions of15 N from faeces, urine and fertilizer were found in the second crop. The similar recoveries indicated a slow mineralization rate of the residual faeces N since more faeces was left in the soil after the first crop.More N was lost by leaching from manured lysimeters but as a percentage of N applied, losses were similar to those from mineral fertilizer. During the first and second winter, 3–5% and 1–3%, respectively, of the 15N in slurry and mineral fertilizer was leached as nitrate. Thus slurry N applied in spring just before sowing did not appear to be more prone to loss by nitrate leaching than N given in mineral fertilizer. Slurry N accounted for a higher proportion of the N leached, however, because more N was added in this treatment.

Modelling the change in soil organic C and N in response to applications of slurry manure

Article

Jan 1996

A computer simulation model of the turnover of organic matter in soil was adapted to simulate the change in soil organic C and N contents of soil during several years following annual additions of farm slurry to maize fields. The model proved successful in estimating the build-up of both C and N in soil and the leaching of N to ground-water in response to applications of slurry ranging from 50 to 300 tons per hectare per year. The model was then used to estimate the build-up of organic matter in soil under crops of fodder maize that were grown using the excess of manure produced during the last 20 years in the Netherlands. The build-up of organic matter from these applications was estimated to lead to about 70 kg extra nitrogen mineralized ha-1 yr-1. As a result of legislation manure applications have decreased and are expected to decrease further in the immediate future. Calculations suggest that after 10 years of manure applied at rates no longer exceeding the amount needed to replace the phosphorus removed by crops, the extra mineralization of N will still be between 45 and 60 kg ha-1 yr-1. If manure applications cease altogether then the extra mineralization will be about 25–30 kg N ha-1 yr-1.

Soil microbial biomass and mineralization of carbon and nitrogen in ecological, integrated and conventional forage and arable cropping systems

Article

Dec 1999

In a cropping systems experiment in southeastern Norway, ecological (ECO), integrated (INT) and conventional (CON) forage (FORAGE) and arable (ARABLE) model farms were compared. After 5 experimental years, topsoil was sampled in spring from spring grain plots and incubated for 449 days at controlled temperature (15 °C) and moisture content (50% water-holding capacity). There were no detectable differences between model farms in terms of total soil C or N. For INT and CON, however, values of microbial biomass C and N, microbial quotient (Cmic/Corg), and C and N mineralization were, or tended to be, higher for FORAGE than for ARABLE. For the ECO treatment, values were similar for FORAGE and ARABLE and did not differ significantly from that of CON-FORAGE. For INT and CON, the metabolic quotient (qCO2) was lower for FORAGE than for ARABLE. Again, for the ECO treatment, values were similar for FORAGE and ARABLE and did not differ significantly from that of CON-FORAGE. We estimated the sizes of conceptual soil organic matter pools by fitting a decomposition model to biomass and mineralization data. This resulted in a 48% larger estimate for CON-FORAGE than for CON-ARABLE of physically protected biomass C. For physically protected organic C the difference was 42%. Moreover, the stability of soil aggregates against artificial rainfall was substantially greater for CON-FORAGE than for CON-ARABLE. On this basis, we hypothesized that the lower qCO2 values in the FORAGE soils were mainly caused by a smaller proportion of active biomass due to enclosure of microorganisms within aggregates. Altogether, our results indicated a poorer inherent soil fertility in ARABLE than in FORAGE rotations, but the difference was small or absent in the ECO system, probably owing to the use of animal and green manures and reduced tillage intensity in the ECO-ARABLE rotation.

Does organic agriculture reduce soil erodibility? The results of a long-term field study on loess in Switzerland

Article

Jul 1998
AGR ECOSYST ENVIRON

In a long-term field trial in northwestern Switzerland, the effects of organic and conventional land-use management on earthworm populations and on soil erodibility were investigated. A silt loam soil which had developed in deep deposits of alluvial loess characterised the study site. Three methods were applied to analyse soil erodibility, at three different periods between autumn 1992 and 1993: aggregate stability (measured in the laboratory by a high energy rainfall simulation and by percolation) and soil particle detachment (measured in the field by splash erosion). Earthworm biomass and density, as well as the population diversity, were significantly greater on the organic plots than on the conventional plots. Likewise, the aggregate stability of the organic plots, when determined by means of percolation, was significantly better. Therefore, erosion susceptibility is greater on plots farmed conventionally. On the other hand, splash erosion monitoring and simulated rainfall experiments only partially highlight differences in erodibility between the two main land-management methods. Future comparisons between the farming systems should also include farmer managed fields with greater differentiation in crop rotations and cultural practices like tillage, fertilisation and pesticide use.

Size of the soil microbial biomass in a long-term field experiment as affected by different N-fertilizers and organic manures

Article

Jun 1993
SOIL BIOL BIOCHEM

The size of the soil microbial biomass was measured in a more than 30 yr old field experiment, whose treatments included different N fertilizers and organic manures. The size of the microbial biomass was measured as biomass C and N by the chloroform fumigation-incubation technique, as K2SO4 extractable ninhydrin-reactive N released upon fumigation and as the soil's ATP content. There was a high degree of correlation (r > 0.88) between the fumigation-based methods and the ATP determinations. Compared with the biomass estimate by ATP, biomass C was underestimated in the ammonium sulphate fertilized soil (pH 4.4), the peat-amended soils, and the sewage sludge amended soil. Biomass N was only underestimated in the ammonium sulphate and peat-amended soil, whereas there was a good correlation between the ninhydrin assay and the ATP assay for all soils. Between three successive years biomass C showed larger, statistically significant, variations than the size of the biomass measured by the ninhydrin assay.There was a high degree of correlation (r > 0.90) between both the rate of base respiration and the size of the microbial biomass and the soil's carbon content. These relationships generally held independent of whether carbon was derived from stabilized soil organic matter (in the fallow soil), from crop residues, or from organic manures such as straw, green manure, farmyard manure, or sawdust.Relative to the soil's carbon content the microbial biomass was smaller than expected in the peat amended-soils, the ammonium sulphate fertilized, and the sewage sludge-amended soil. The rate of base respiration was only lower than expected in the sewage sludge treated soil. The size of the biomass was negatively affected by a low soil pH, but the rate of base respiration was not. Liming some of the soils indicated that other factors than low pH restricted the size of the biomass in the peat and sewage-sludge amended soils, but not in the ammonium sulphate fertilized soils.

Dynamics of soil microbial biomass and activity in conventional and organic farming systems

Article

Jun 1998
SOIL BIOL BIOCHEM

Dynamics of microbial communities during two growing seasons were compared in soils under tomatoes managed by conventional (2- and 4-y rotations), low input, or organic practices. Fumigation extractable carbon (FEC) and nitrogen (FEN), potentially mineralizable N, arginine ammonification and substrate induced respiration (SIR) were significantly higher in organic and low input than conventional systems on most sample dates. Microbial variables were significantly negatively correlated with amounts of soil mineral N in the conventional 4 y system, whereas they were positively correlated with mineral N in the organic system. The C-to-N ratios of material released after fumigation extraction were significantly higher in the conventional than organic soils. In all farming systems, soil moisture was positively correlated with FEC or FEN, but negatively correlated with the C-to-N ratio of the microbial biomass and SIR. Soil temperature was negatively correlated with FEC and FEN, but positively correlated with the C-to-N ratio of microbial biomass.

The fumigation-extraction method to estimate soil microbial biomass: Calibration of the KEC value

Article

Jan 1996
SOIL BIOL BIOCHEM

Rainer Georg Joergensen

The kEC value (=extractable part of microbial biomass C) of the fumigation-extraction (FE) method was assessed on the basis of 153 soils (94 arable, 46 grassland and 13 forest soils) by indirect calibration using the fumigation-incubation (FI) method. Sixty-six soils were investigated for the first time and the data on a further 87 soils were obtained from the literature. The single kEC values ranged from 0.23 to 0.84. A split according to the form of land use resulted in a significantly (Scheffé, P = 0.05) lower kEC value for the arable soils (0.42; n = 94) in comparison to those for the grassland (0.49; n = 46) and the forest soils (0.51; n = 13). This difference is mainly due to the significant effects of the respiration rate measured in non-fumigated control samples of the FI method which was used for calibration of the kEC value. For that reason, I investigated the effects of incubation temperature (22°, 25° and 28°C) on biomass C data obtained by the FI method, and thus on the kEC value of the FE method, and discuss further problems of direct and indirect calibration. Based on experimental and literature data, I conclude that the kEC values of Vance et al. (Soil Biology & Biochemistry19, 703–707, 1987) and Wu et al. (Soil Biology & Biochemistry22, 1167–1169, 1990) remain valid. A kEC value of 0.38 can be recommended for C analysis by dichromate consumption and a kEC value of 0.45 for that by UV-persulfate or oven oxidation.

Le phosphore assimilable des sols : sa représentation par un modèle fonctionnel à plusieurs compartiments

Article

Jan 1993

J.C. Fardeau

L'analyse compartimentale des cinétiques d'échange isotopique des ions phosphate permet de démontrer que le phosphore (P) biodisponible des sols est un ensemble hétérogène contenant des ions phosphate liés à la matrice du sol, mais susceptibles de gagner la solution du sol en des temps très variables. Le P biodisponible est donc un système à plusieurs compartiments. En partant de considérations sur les conditions de fonctionnement des racines et des systèmes racinaires, le P assimilable a été découpé en 5 compartiments différenciés par la durée nécessaire à leur transfert dans la solution du sol. Le pool central, P L, est celui des ions libres pour lesquels le temps de transfert de la phase solide à la solution du sol est inférieur à 15 s. Les 4 autres pools, B, C, D et F, sont tous directement reliés au pool central. Ils contiennent les ions dont le temps de transfert vers la solution du sol est compris, dans ce système en état stationnaire, entre 1 m et 1 j (pool B), 1 j et 3 mois (pool C), 3 mois et 1 an (pool D) et est supérieur à 1 an pour le pool F. Ce modèle ne prend pas en considération le P organique dont la transformation vers la forme biodisponible suit des processus différents. Pour favoriser la comparaison visuelle rapide des caractéristiques essentielles du P biodisponible présent dans les échantillons issus de prélèvements différents, une représentation schématique de ce modèle global a été mise au point. À titre d'exemple, on montre que des prélèvements répétitifs ou des fertilisations excédentaires de phosphore modifient tous les compartiments. Cette représentation permet d'illustrer l'existence de 2 types de pouvoir tampon du sol pour les ions phosphate : l'un est qualifié de «pouvoir tampon instantané», l'autre de «pouvoir tampon retard»; ce dernier assure le renouvellement des ions phosphate dans la solution en fonction du temps et de la quantité prélevée ou ajoutée. Available soil phosphate: its representation by a functional multiple compartment model. Analysis of the isotopic exchange kinetics of phosphate ions which occurs in a soil-solution system maintained in steady-state shows that the available soil phosphate is a heterogeneous system that lends itself to compartmentalization. Available soil P has been subdivided into 5 pools in relation to the functioning of roots and root systems. The central and most important pool for P uptake by crops is the pool PL of free phosphate ions: this pool contains ions which can be transferred into the soil solution in < 15 s. The 4 other pools, B, C, D and F, branch directly off the central pool. In this system studied in steady-state, the pool B contains ions which can exchange with the phosphate ions of the soil solution in between 1 min and 1 d. The pool C contains the ions able to enter the solution in steady-state between 1 d and 3 months. The pool D contains ions which can exchange with phosphate ions in the solution in 3 months to 1 yr. The pool F contains phosphate ions exchangeable after > 1 yr. This model concerns only inorganic P, organic P following other rules of transformation, such as those of microbial mineralization. A schematic functional model has been developed to summarize this information. The model applied to various soil samples taken from 2 long-term field experiments showed that repeated fertilization or exhaustive cropping can modify all the pools. This scheme shows 2 kinds of phosphate buffering capacity (PBC) for soils. The first kind, which depends on the PL pool, is called 'instantaneous PBC'; the second kind, which depends on the 4 other pools, is called 'delayed PBC': its effect on the maintenance of phosphate ion concentration in the soil solution is time-dependent.

Methods for Dietary Fiber, Neutral Detergent Fiber, And Nonstarch Polysaccharides In Relation To Animal Nutrition

Article

Nov 1991

There is a need to standardize the NDF procedure. Procedures have varied because of the use of different amylases in attempts to remove starch interference. The original Bacillus subtilis enzyme Type IIIA (XIA) no longer is available and has been replaced by a less effective enzyme. For fiber work, a new enzyme has received AOAC approval and is rapidly displacing other amylases in analytical work. This enzyme is available from Sigma (Number A3306; Sigma Chemical Co., St. Louis, MO). The original publications for NDF and ADF (43, 53) and the Agricultural Handbook 379 (14) are obsolete and of historical interest only. Up to date procedures should be followed. Triethylene glycol has replaced 2-ethoxyethanol because of reported toxicity. Considerable development in regard to fiber methods has occurred over the past 5 yr because of a redefinition of dietary fiber for man and monogastric animals that includes lignin and all polysaccharides resistant to mammalian digestive enzymes. In addition to NDF, new improved methods for total dietary fiber and nonstarch polysaccharides including pectin and beta-glucans now are available. The latter are also of interest in rumen fermentation. Unlike starch, their fermentations are like that of cellulose but faster and yield no lactic acid. Physical and biological properties of carbohydrate fractions are more important than their intrinsic composition.

[Effect of type of starch and quantity in rations on apparent and true digestibility of nitrogen and nitrogen balance in sheep]

Article

Nov 1985
Arch Anim Nutr

In a digestibility trial 5 semisynthetic rations were fed in 3 periods to 10 male sheep to examine the effects on N balance, components of faecal nitrogen and N digestibility. The rations contained constant amounts of nitrogen but different contents of cellulose and two different types of starch (untreated and steamflaked). Content and type of starch did not show any noticeable effect neither on excretion of undigested dietary nitrogen nor on true digestibility. There could not be noticed any effects on the apparent N digestibility by changing contents of cellulose or untreated starch. If the rations contained steamflaked corn starch, the animals excreted more faecal nitrogen and therefore showed a lower apparent N digestibility. Especially the water soluble N fraction of the faecal nitrogen was clearly higher. Compensation took place through a lower N excretion with the urine. The reason for increased faecal N excretion may be higher microbial protein synthesis in the rumen. This was accented by the allantoin excretion with the urine.

Entstehung, visuelle und analytische Diagnose

Jan 1988

W Bergmann
Ernährungsstörungen Bei Kulturpflanzen

Bergmann W., Ernährungsstörungen bei Kulturpflanzen. Entstehung, visuelle und analytische Diagnose, Gustav Fischer Verlag, Stuttgart Germany and New York USA, 1988.

Use of tracers for soil and fertilizer nitrogen research

Jan 1976
ADV AGRON
219-266

R D Hauck
J M Bremner

Hauck R.D., Bremner J.M., Use of tracers for soil and fertilizer nitrogen research, Adv. Agron. 28 (1976) 219-266.

Einfluss der Bewirtschaftungs-Verfahren des DOK-Versuchs auf die Mineralisierung und Verfügbarkeit von Stickstoff im Boden

Jan 1997

S A Meyre

Meyre S.A., Einfluss der Bewirtschaftungs-Verfahren des DOK-Versuchs auf die Mineralisierung und Verfügbarkeit von Stickstoff im Boden, Ph.D. thesis No. 12405, ETH Zurich, Switzerland, 1997.

Ausnutzung des Güllestickstoffs durch Klee-Gras-Gemenge

Jan 1999
AGRARFORSCHUNG
425-428

F X Schubiger
H R Bosshard
H Briner
J Lehmann

Schubiger F.X., Bosshard H.R., Briner H., Lehmann J. Ausnutzung des Güllestickstoffs durch Klee-Gras-Gemenge, Agrarforschung 6 (1999) 425-428.

Aufwand und Ertrag: Nährstoffbilanzen, 1. und 2. Fruchtfolgeperiode

Jan 1993
565-579

Aufwand und Ertrag: Nährstoffbilanzen, 1. und 2. Fruchtfolgeperiode, Schweiz. Landw. Forsch. 32 (1993) 565-579.

Quantifizierung der Wirkung organischer und mineralischer Stickstoffdünger auf Pflanze und Boden unter besonderer Berücksichtigung 15 N-markierter tierischer Exkremente

Jan 1973
907-916

K Rauhe
E Fichtner
F Fichtner
E Knappe
W Drauschke

Rauhe K., Fichtner E., Fichtner F., Knappe E., Drauschke W., Quantifizierung der Wirkung organischer und mineralischer Stickstoffdünger auf Pflanze und Boden unter besonderer Berücksichtigung 15 N-markierter tierischer Exkremente, Arch. Acker-Pflanzenbau Bodenkd. 17 (1973) 907-916.

Nitrogen fertilizer value of cattle manure applied on soils originating from organic and conventional farming systems

Abstract

No full-text available

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