Jo Smith

University of Aberdeen | ABDN

Gully erosion can be combatted in severely affected regions like sub-Saharan Africa by a range of low-cost interventions that are accessible to affected farmers. However, for successful implementation, biophysical evidence of the effectiveness of interventions needs to be combined with buy-in and input from local communities. Working with farmers i...

Anaerobic digestate is proposed as an alternative to inorganic fertilisers, but a better understanding of how anaerobic digestates impact the soil and how plant growth is influenced is needed for wider acceptance. In this study, a series of pot experiments were conducted growing spring barley (Hordeum vulgare L.) in a range of soils with the applic...

Peatlands are a globally important carbon store, but peatland ecosystems from high latitudes to the tropics are highly degraded due to increasingly intensive anthropogenic activity, making them significant greenhouse gas (GHG) sources. Peatland restoration and conservation have been proposed as a nature-based solution to climate change, by restorin...

The potential for biogas provision through household-scale anaerobic digestion in rural sub-Saharan Africa is limited due to perceived water shortages. The most common substrate is animal dung diluted 1:1 with water. Two experimental methods tested the potential of reducing water demand. The first experiment compared the chemical oxygen demand (COD...

Agriculture is essential for providing food and maintaining food security while concurrently delivering multiple other ecosystem services. However, agricultural systems are generally a net source of greenhouse gases and ammonia. They, therefore, need to substantively contribute to climate change mitigation and net zero ambitions. It is widely ackno...

The volume of municipal solid waste produced in many cities in low to middle income countries exceeds the capacity of handling facilities causing environmental and health risks. This study provides the most comprehensive analysis to date of municipal solid waste to energy options for Abuja, Nigeria. We use most recently available data on waste gene...

AIM This study aimed to simulate deactivation of E. coli in soils amended with cattle manure after burning, anaerobic digestion, composting or without treatment. METHOD AND RESULTS The Weibull survival function was used to describe deactivation of E. coli. Parameters for each treatment were determined using E. coli measurements from manure-amended...

Salt-affected soil reclamation provides opportunities for crop production and carbon se-questration. In arid regions such as Pakistan, limited studies have been reported involving soil reclamation and crop production under wheat-maize rotation, but no study has reported predictions on long-term carbon sequestration in reclaimed soils for the treatm...

The aim of this paper is to quantify the impact of incorporating biochar into soils on net nitrogen waste from farming systems in India. It assumes only crop residues that are currently burnt in the fields are used to produce biochar. It accounts for losses of nitrogen occuring during pyrolysis, and the potential savings due to capture of reactive...

Soil organic carbon is one of the most commonly used indicators of soil health, as it plays a vital role in maintaining fertility and combating global warming. Understanding the vertical distribution and controlling factors of organic carbon in the entire regolith, rather than just the routinely defined upper 1 m portion of the soil, is crucial for...

Our study measured heterotrophic carbon dioxide (CO2) emissions in a drained peatland under potato cultivation in south-western Uganda. Soil carbon losses have not previously been reported for this land use, and our study set out to capture the range and temporal variation in emissions, as well as investigate relationships with key environmental va...

The objectives of this study across the highlands of Ethiopia were: (i) to characterize the association between soil organic carbon (SOC) stocks and biophysical variables and (ii) to model and map attainable SOC sequestration associated with five improved land management practices. The spatial distribution of the SOC stock was studied using a multi...

Context Climate change can impact greatly on poorer and vulnerable communities, increasing the risk of natural disasters, and affecting agricultural production. Aims This study aims to explore the potential impacts of climate smart agricultural practices (CSAP) on working farms in Karnal, Haryana, India. Methods Practices studied included zero till...

Community-led watershed development activities, including the establishment of exclosures (areas where both livestock and farming activities are excluded) on degraded communal grazing land, have become a common practice in Ethiopia since the 1990s. However, it is not yet fully understood how these exclosures change soil organic carbon and total soi...

Scots pine bog edge woodland is a type of habitat typical on raised bogs where trees cohabitate with bog vegetation to form a low-density stand. Even though nowadays this habitat does not cover large areas, in a future scenario it is possible that this environment will expand, either naturally (drier climate) or anthropogenically, as the result of...

Agriculture is the largest anthropogenic source of methane (CH 4 ), emitting 145 Tg CH 4 y ⁻¹ to the atmosphere in 2017. The main sources are enteric fermentation, manure management, rice cultivation and residue burning. There is significant potential to reduce CH 4 from these sources, with bottom-up mitigation potentials of approximately 10.6, 10,...

This special issue provides an assessment of the contribution of soils to Nature's Contributions to People (NCP). Here, we combine this assessment and previously published relationships between NCP and delivery on the UN Sustainable Development Goals (SDGs) to infer contributions of soils to the SDGs. We show that in addition to contributing positi...

Soils have both direct and indirect impacts on available energy, but energy provision, in itself, has direct and indirect impacts on soils. Burning peats provides only approximately 0.02% of global energy supply yet emits approximately 0.7–0.8% of carbon losses from land-use change and forestry (LUCF). Bioenergy crops provide approximately 0.3% of...

This study assessed the potential contributions of improved cookstoves in increasing organic fertilizer availability for application to farmland, greenhouse gas emission mitigation and improvement of household finances using the Kitchen Performance Test, Controlled Cooking Test, household survey and focus group discussions. Substitution of a three-...

Soil properties are often assumed to be static over time in hydrological studies,especially in hydrological modelling. Although it is well appreciated that soil structure and its impact on hydraulic properties are time-variable, particularly on cultivated land, very few studies have focused on quantifying the influence of such changes on soil hydro...

Aim: This study investigated impacts of different organic waste treatment methods on reduction and spread of faecal indicator organisms to food crops in a developing country. Methods and results: Fresh cattle manure was subjected to three different treatments; anaerobic digestion, burning and composting. E. coli, coliforms and nitrogen content o...

In the last six decades, the consumption of reactive nitrogen (Nr) in the form of fertilizer in India has been growing rapidly, whilst the nitrogen use efficiency (NUE) of cropping systems has been decreasing. These trends have led to increasing environmental losses of Nr, threatening the quality of air, soils, and fresh waters, and thereby endange...

Biogas digester programmes have been rolled out across many countries in sub-Saharan Africa over the past decade with varying levels of success. In Ethiopia, reported success rates have been low, despite high levels of interaction between non-governmental organisations and various levels of government, plus the establishment of practical eligibilit...

Scotland is continuing to afforest land in order to combat climate change, but the long-term capacity for carbon sequestration in forest soils is still uncertain. Here we present measurements that provide comparative estimates of soil organic carbon in grassland and forestry sites at steady state. We develop a new approach to interpret these values...

Replacement of forest by agricultural systems is a major factor accelerating the emissions of greenhouse gases; however, related field studies in the tropics are very scarce. To evaluate the impact of forest transition to plantations on soil methane (CH4) and respiration (CO2) fluxes, we conducted measurements in an undisturbed forest, a disturbed...

It is important, prior to application of organic wastes to land, that pathogen loads are reduced sufficiently to minimize dissemination to the wider environment. Anaerobic digestion for biogas production is a low-cost method to reduce pathogens in agricultural wastes that provides the added benefits of energy generation. There have been claims of p...

Northern peatlands play an important role in the regulation of the atmospheric greenhouse gas (GHG) balance, functioning as a net carbon sink with low rates of organic decomposition. However, perturbations such as drainage increase peat oxidation, which may lead to enhanced gaseous release of carbon. For this reason, the number of restoration proje...

We present a new systems model that encompasses both environmental and socioeconomic outcomes to simulate impacts of organic resource use on livelihoods of smallholder farmers in low to middle income countries. It includes impacts on soils, which in many countries are degrading with long term loss of organic matter. Many farmers have easy access to...

Under current trends, 60% of India’s population (>10% of people on Earth) will experience severe food deficiencies by 2050. Increased production is urgently needed, but high costs and volatile prices are driving farmers into debt. Zero budget natural farming (ZBNF) is a grassroots movement that aims to improve farm viability by reducing costs. In A...

A simple soil water budget model is introduced and evaluated against data collected at four sites at Gourdie, near Dundee, Scotland, during 2000, using both short-term (2000-only) and long-term (1961–2011) averaged climate data. The performance of the model is compared using five different pedotransfer function sets to derive parameters for cool te...

Water storage and flow in shallow subsurface drives runoff generation, vegetation water use and nutrient cycling. Modelling these processes under non-steady state conditions is challenging, particularly in regions like the subtropics that experience extreme wet and dry periods. At the catchment-scale, physically-based equations (e.g., Richards equa...

The use of limited organic resources to build resilience to drought in semi-arid regions was investigated using systems modelling. The study focussed on Halaba in Ethiopia, drawing on biophysical and socioeconomic data obtained from a survey of farms before, during and after the 2015/16 El Niño event. Using a simplified weather dataset to remove no...

We present the methodological development of a surveying and accounting tool created in response to a lack of appropriate data for modelling ecosystem services in tropical wetlands in East Africa. The survey provides a practical field methodology for quickly characterising the environmental, vegetation, soil and hydrological properties of a wetland...

Background: Understanding stakeholders' perceptions is crucial to the development and implementation of any intervention. However, a structured approach to eliciting stakeholder insights into complex, multisector issues of food security, household environment and health is lacking in many low and middle-income countries. This qualitative, workshop...

The use of limited organic resources to build resilience to drought in semi-arid regions was investigated using systems modelling. The study focussed on Halaba in Ethiopia, drawing on biophysical and socio-economic data obtained from a survey of farms before, during and after the 2015/16 El Niño event. Using a simplified weather dataset to remove n...

Low applications of inorganic fertilizer and decline in soil organic matter often contribute to loss of production in Sub-Saharan Africa. A trial was conducted on integrated soil fertility management of teff (Eragrostis tef) in Southern Ethiopia during the main cropping season of 2015. Treatments were based on recommended rates of inorganic fertili...

East African wetlands are hotspots of ecosystem services, particularly for climate regulation, water provision and food production. We review the ability of current approaches to ecosystem service assessments to capture important social-ecological dynamics to provide insight for wetland management and human wellbeing. We synthesise evidence of huma...

Available online xxxx Biogas technology, as a pro-poor renewable energy source, has been promoted in Uganda through the use of fixed dome and floating drum digester designs. However, these designs have proved to be too expensive for the average Ugandan household to afford. A cheaper flexible balloon digester has been proposed to increase uptake. Ho...

Biogas technology, as a pro-poor renewable energy source, has been promoted in Uganda since the 1980s by the government and NGOs. However, many of the biogas designs promoted have proved to be too expensive for the average Ugandan to afford. A cheaper flexible balloon digester has been proposed, but there have been lack of evidence on the economic...

Human activities have massively altered the global nitrogen (N) cycle, doubling annual production of reactive N (Nr) compounds from atmospheric dinitrogen (N2). The use of 120 Mt year⁻¹ fertilizer N, with a global terrestrial/atmospheric N fixation of 285Mtyear⁻¹, has provided huge benefits for global food production. However, nitrogen use efficien...

Field experiments were conducted at Gujjar Seed and Nursery Farm, Haripur, Pakistan to investigate impact of incorporating differently treated of organic manures using different tillage systems on soil carbon. Maximum increase in soil carbon was observed when the required nitrogen was applied as bioslurry produced from cattle manure by anaerobic di...

Soil amendment with organic wastes in the Highlands of Ethiopia has been greatly reduced by widespread use of dung cakes and crop residues as fuels. This study assessed the interaction between household energy and recycling of nutrients and carbon to the soil using household survey, focus group discussions, key informant interviews, direct observat...

The study analyses dis-adoption of biogas technologies in Central Uganda. Biogas technology makes use of livestock waste, crop material and food waste to produce a flammable gas that can be used for cooking and lighting. Use of biogas technology has multiple benefits for the households since it reduces the need for fuelwood for cooking and also pro...

This paper aims to evaluate the suitability of the ECOSSE model to estimate soil heterotrophic respiration (Rh) from arable land and short rotation coppices of poplar and willow. Between 2011 and 2013, we measured Rh with automatic closed dynamic chambers on root exclusion plots at one site in the UK (willow, mixed commercial genotypes of Salix spp...

The Welsh Government is committed to reduce greenhouse gas (GHG) emissions from agricultural systems and combat the effects of future climate change. In this study, the ECOSSE model was applied spatially to estimate GHG and soil organic carbon (SOC) fluxes from three major land uses (grass, arable and forest) in Wales. The aims of the simulations w...

Background Although linkages have been found between agricultural interventions and nutritional health, and the development of clean fuels and improved solid fuel stoves in reducing household air pollution and adverse health effects, the extent of the potential of combined household interventions to improve health, nutrition and the environment has...

Biogas could provide a more sustainable energy source than woodfuels for rural households in Sub-Saharan African. However, functioning of biogas digesters can be limited in areas of low water availability. The water required is approximately 50 dm3 day−1 for each cow and 10 dm3 day−1 for each pig providing manure to the digester, or 25 (±6) dm3 day...

In Europe, carbon sequestration potential has previously been estimated using data from the Global Change and Terrestrial Ecosystems Soil Organic Matter Network (GCTE-SOMNET). Linear relationships between management practices and yearly changes in soil organic carbon were developed and used to estimate changes in the total carbon stock of European...

Increasing oil palm (OP) plantation establishment on tropical peatlands over the last few decades has major implications for the global carbon (C) budget. This study quantified total and heterotrophic soil carbon dioxide (CO2) emissions in an industrial OP plantation (7 year old, 149 trees ha− 1) on peat located in the eastern coast of the Sumatra...

We implemented a spatial application of a previously evaluated model of soil GHG emissions, ECOSSE, in the United Kingdom to examine the impacts to 2050 of land-use transitions from existing land use, rotational cropland, permanent grassland or woodland, to six bioenergy crops; three ‘first-generation’ energy crops: oilseed rape, wheat and sugar be...

Models are approximations of real systems. Although, in theory, there is no limit to the refinement and detail of a mathematical model, with greater refinement allowing more detailed representation of the physical system, there is a practical limit in terms of the model outputs, which is, in part, defined by the intended end use. This chapter descr...

This paper reviews use of organic resources in rural Sub-Saharan Africa (SSA), impacts on household energy, and interactions with provision of food and water. Wood, charcoal and dung supply over 70% of household energy in SSA, but with improvements in energy technologies, crop-residues and human excreta could also contribute. Improving cookstoves i...

The residual effects of bioslurry and composted poultry manure on soil properties and subsequent crop productivity have not yet been studied in detail under humid subtropical conditions of Pakistan. Therefore, field studies were conducted at Gujjar Seed and Nursery Farm, Haripur, Pakistan, during 2012-2013 to determine the residual effects of diffe...

Tillage systems (minimum, conventional and deep) with different sources of nitrogen (bioslurry, poultry manure and chemical fertilizer) were studied through field experiments at Gujjar Seed and Nursery Farm, Haripur, Khyber-Pakhtunkhwa, Pakistan, for two consecutive years (2012-2013) in a randomized-complete-block-design with split plots and four r...

This book contains 31 chapters, grouped into 7 parts, which provides a link between the complexity of the scientific knowledge on soil carbon, and how this knowledge can be applied for multiple benefits, and the complexity of the policy and practice arenas where soil and land management impact many sectors: environment, farming, energy, water, econ...

In March 2013, 40 leading experts from across the world gathered at a workshop, hosted by the European Commission, Directorate General Joint Research Centre, Italy, to discuss the multiple benefits of soil carbon as part of a Rapid Assessment Process (RAP) project commissioned by SCOPE (Scientific Committee on Problems of the Environment). This col...

In this study, we simulated heterotrophic CO2 (Rh) fluxes at six European peatland sites using the ECOSSE model and compared them to estimates of Rh made from eddy covariance (EC) measurements. The sites are spread over four countries with different climates, vegetation and management. Annual Rh from the different sites ranged from 110 to 540 g C m...

www.snh.org.uk/pdfs/publications/commissioned_reports/562.pdf

Holistic farming systems provide designs for the whole farm that make long term sustainable use of nutrients, water, labour, finances and energy. In using organic residues to produce energy, and safely recycling the digested residues back into the farming system, a biogas digester could be a central component of many holistic systems. This paper di...

Indoor combustion of solid biomass fuels such as wood and charcoal is common in large parts of the world and has been demonstrated to lead to high levels of exposure to fine particulate matter and gases such as carbon monoxide. Such exposures have been shown to be linked to increased risk of respiratory and cardiovascular illness and may contribute...

Onshore wind energy is a key component of the renewable energies used by governments to reduce carbon emissions from electricity production, but will carbon emissions be reduced when wind farms are located on carbon-rich peatands? Wind farms are often located in uplands because most are of low agricultural value, are distant from residential areas,...

Soil acidity is an important parameter that can regulate ecosystem structure and function. However, a quantitative understanding of the relationships between soil pH and environmental factors remains unavailable. In this study, relationships of soil pH with both climatic and edaphic factors in alpine grasslands on the Tibetan Plateau, China were qu...

Land use change on Indonesian peatlands contributes to global anthropogenic greenhouse gas (GHG) emissions. Accessible predictive tools are required to estimate likely soil carbon (C) losses and carbon dioxide (CO 2) emissions from peat soils under this land use change. Research and modelling efforts in tropical peatlands are limited, restricting t...

This paper derives an algebraic solution (the Geometric Series Solution; GSS) to replace iterative runs of soil organic matter (SOM) models for initialisation of SOM pools. The method requires steady-state/long-term-average series of plant input and soil climate driving data. It calculates the values of SOM pools as if SOM models are iterated for a...

Land use change can have a strong impact on soil carbon dynamics and carbon stocks in urban areas. Due to rapid urbanization, large areas of land have been paved, and other areas have undergone rapid land use change. Evaluation of the impact of urbanization on carbon dynamics and carbon stock (30 cm) has become an issue of urgent concern. The soil...

Saline soils cover 3.1% (397 million hectare) of the total land area of the world. The stock of soil organic carbon (SOC) reflects the balance between carbon (C) inputs from plants, and losses through decomposition, leaching and erosion. Soil salinity decreases plant productivity and hence C inputs to the soil, but also microbial activity and there...

We use a soil carbon (C) model (RothC), driven by a range of climate models for a range of climate scenarios to examine the impacts of future climate on global soil organic carbon (SOC) stocks. The results suggest an overall global increase in SOC stocks by 2100 under all scenarios, but with a different extent of increase among the climate model an...

We use a soil carbon (C) model (RothC), driven by a range of climate models for a range of climate scenarios to examine the impacts of future climate on global soil organic carbon (SOC) stocks. The results suggest an overall global increase in SOC stocks by 2100 under all scenarios, but with a different extent of increase among the climate model an...

The challenge of collecting field measurements of soil carbon dioxide (CO2) efflux and soil carbon (C) in tropical peatlands creates an opportunity for the use of SOC models for predicting local and regional impacts of land use and climate change on these soils, offering a way of translating this limited data into tangible results. Previously, no s...

The global warming potential of nitrous oxide (N2O) and its long atmospheric lifetime mean its presence in the atmosphere is of major concern, and that methods are required to measure and reduce emissions. Large spatial and temporal variations means, however, that simple extrapolation of measured data is inappropriate, and that other methods of qua...

Systems approaches have great potential for application in predictive ecology. In this paper, we present a range of examples, where systems approaches are being developed and applied at a range of scales in the field of global change and biogeochemical cycling. Systems approaches range from Bayesian calibration techniques at plot scale, through dat...

Soil organic carbon (SOC) models are used to predict changes in SOC stocks and carbon dioxide (CO(2)) emissions from soils, and have been successfully validated for non-saline soils. However, SOC models have not been developed to simulate SOC turnover in saline soils. Due to the large extent of salt-affected areas in the world, it is important to c...

Agriculture and associated land-use changes contribute a significant portion to global greenhouse gas (GHG) emissions; mainly as N2O, CO2 and CH4. Improved modelling of soil processes will greatly enhance the value of national inventories, both in terms of more accurate reporting and better mitigation policy options. In Ireland, Agriculture and Lan...

Interest in the use of small scale biogas digesters for household energy generation and treatment and utilization of organic wastes in rural areas of Sub-Saharan Africa (SSA) has been increasing with numerous organisations promoting their adoption for both socioeconomic and environmental benefits. In this paper, we review energy production using sm...

Modelling greenhouse gas (GHG) emissions from tropical peatlands is of crucial importance in determining GHG emission rates under global change. Modelling efforts to date have been restricted by the lack of available data for parameterisation, input and validation of simulation models, due to the complex and often inaccessible nature of tropical pe...