Elizabeth Stockdale

• National Institute of Agricultural Botany

Soil health metrics with strong links to ecological function and agricultural productivity are needed to ensure that future management of agricultural systems meets sustainability goals. While ecological metrics and crop yields are often considered separately from one another, our work sought to assess the links between the two in an agricultural c...

Abstract Sustainable farming systems provide food for humans while balancing nutrient management. Inclusion or exclusion of livestock has nutrient management implications, as livestock produce food from otherwise inedible crops and their manure is a valuable soil conditioner. However, plant‐based diets are becoming more widespread due to perceived...

A range of chemical, physical and biological processes are important for sustained productivity and environmental quality in agricultural systems. Farmers and scientists share a concern with soil health, and this leads to questions for both measurement and management. An essential step is to define the context and the key functions required of a so...

Soil Quality or Soil Health are terms adopted by the scientific community as a metaphor for the effects of differing land management practices on the properties and functions of soil. Many other terms and metaphors are in use that defy neat quantification: human health, for example. Our challenge is to understand the importance of using such metaph...

The short scoping project (September 2018-March 2019) took an integrated multidisciplinary approach including literature review, interviews and a stakeholder workshop to describe the likely economic, social and environment impacts of the integration of livestock into arable production systems in predominantly arable areas of the UK. • There is no s...

Soil is the basis of all sustainable agricultural production. There are significant elements of our understanding of soils which are common to all of agriculture. These are identified in this chapter which deals with soil in this unifying sense. There are also elements which are of particular importance to organic production, and these are identifi...

The need for sustainable intensification of agricultural production has ushered in a growing awareness of soil health and a requirement to identify with some certainty how changes to land management will affect soil. From an agricultural perspective, the active management of soil health needs to balance the production of a healthy and profitable cr...

The STAR project (Sustainability Trial in Arable Rotations) is a long-term study at Stanaway Farm, Otley, Suffolk, UK on a Beccles/Hanslope Series (heavy) clay soil. Research is delivered through NIAB TAG, supported in part by The Felix Thornley Cobbold Trust (and historically the Chadacre Agricultural Trust) and guided by an independent steering g...

Sustainable agricultural systems must enable profitable production of sufficient high-quality crops to meet human demands while simultaneously minimising off-site impacts. Though simple chemical equilibrium plays a part, nutrient cycling processes in soil are largely the outcome of biochemical processes resulting from the activity and interactions...

More sustainable production of high-quality, nutritious food is of worldwide interest. Increasing nutrient recycling into food systems is a step in this direction. The objective of the present study was to determine nitrogen (N) fertiliser effects of four waste-derived and organic materials in a cropping sequence of broccoli, potato and lettuce gro...

This publication Soil Quality - Constraints to plant production is freely available as a digital book on the iBooks store, with more books to follow soon. Copy link in browser and download free https://books.apple.com/au/book/soil-quality-1-constraints-to-plant-production/id1317079117. Experts from a range of organisations and farmers contributed...

The widespread application of fertilizers has greatly influenced many processes and properties of agroecosystems, and agricultural fertilization is expected to increase even further in the future. To date, most research on fertilizer impacts has used short-term studies, which may be unrepresentative of long-term responses, thus hindering our capaci...

Data on soil and plant properties and hay yield used for the analysis. (XLSX)

Soil pH, organic carbon stocks (SOC), total nitrogen content, soil carbon to nitrogen ratio (C/N), coarse fraction carbon stocks, fine fraction carbon stocks, very fine fraction carbon stocks and exchangeable Al for the O horizon in treatment plots 7 and 11. Values are means (±1 SE), n/a indicates not applicable. (DOCX)

Modelling nitrogen (N) dynamics in agricultural soils can improve our understanding of the nitrogen cycle in rotational systems. NDICEA (Nitrogen Dynamics in Crop rotations in Ecological Agriculture) is a tool to model soil N dynamics for maximum nitrogen use efficiency (NUE) and minimum environmental impacts from agricultural fertilization. In thi...

One approach to decrease the environmental impact of crop production and reduce costs is to optimize agronomic practices and genotypes so that nutrients are used more efficiently. In this study the effects of agronomic practices (rotations, crop protection, fertilization) on yields, nitrogen use efficiency (NUE) and associated parameters were studi...

The ability of plants to compete effectively for nitrogen (N) resources is critical to plant survival. However, controversy surrounds the importance of organic and inorganic sources of N in plant nutrition because of our poor ability to visualize and understand processes happening at the root–microbial–soil interface. Using high-resolution nano-sc...

Fig S1 Amount of held on the soil’s solid phase as a function of solution concentration. Fig S2 Total amount of present in soil solution and held on the soil’s cation exchange phase in Triticum aestivum planted and unplanted microcosms. Fig S3 Time-dependent mineralization of 14C-labelled glutamate in soil in the presence and absence of wheat (Trit...

Introduction Concepts of soil fertility Plant–soil interactions determining soil fertility Assessing soil fertility Managing soil fertility References

Phosphorus (P) availability to crops in organic systems can be a major issue, with the use of readily available forms often restricted. One product that can be used in organically managed systems, that is also relatively easily accessible to growers, is phosphate rock, although its solubility and therefore crop availability is often poor. One possi...

Accurate characterization of dissolved organic matter (DOM) in soil is vital for understanding its functional significance. In this study, we used ultrafiltration to determine the molecular weight (MW) distribution of dissolved organic C (DOC), N (DON), and phenolics in two contrasting agricultural grassland soils. This MW fractionation (>100, 10-1...

The quantity and/or quality of soil organic matter (SOM) and its fractions regulate microbial community composition and associated function. In this study an established, replicated agricultural systems trial in a semi-arid environment was used to test: (i) whether agricultural systems which have increased plant residue inputs increase the amount o...

The rapid expansion of organic farming systems means that it is timely to consider their responses to climate change. The overall value of ecosystem services delivered is higher and the energy use of organic farms is lower than conventional comparators, whether assessed per unit area or per tonne of product. Increases in the amount of carbon stored...

Phosphorus (P) availability to crops in organic systems can be a major issue, with the use of readily available forms often restricted. One product that can be used in organically managed systems, that is also relatively easily accessible to growers, is phosphate rock, although its solu-bility and therefore crop availability is often poor. One poss...

Since 1970, measurement of the soil microbial biomass (SMB) has been widely adopted as a relatively simple means of assessing the impact of environmental and anthropogenic change on soil microorganisms. The SMB is living and dynamic, and its activity is responsible for the regulation of organic matter transformations and associated energy and nutri...

The sustainable use of nutrients in agricultural food production represents a major emphasis for international research, and evidence that clearly demonstrates the imbalance between nutrient inputs and outputs exists. Nutrient surpluses exist and are most commonly associated with intensive livestock production and present a particular range of envi...

Imaging resource flow in soil-plant systems remains central to understanding plant development and interactions with the environment. Typically, subcellular resolution is required to fully elucidate the compartmentation, behavior, and mode of action of organic compounds and mineral elements within plants. For many situations this has been limited b...

The health of the soil, recognized by its active role in the linked processes of decomposition and nutrient supply, is considered as the foundation of agriculture by the organic farming movement. Nutrient management in organically managed soils is fundamentally different from that of conventional agricultural systems. Crop rotations are designed wi...

Farmers who manage systems organically have limited options available to optimise soil P status, particularly if not linked to the readily available sources of P from livestock enterprises. In such cases, phosphate rock (PR) can be applied under the discretion of the organic certification body. However, the solubility of P from this source is unpre...

Plant roots and microorganisms interact and compete for nutrients within the rhizosphere, which is considered one of the most biologically complex systems on Earth. Unraveling the nitrogen (N) cycle is key to understanding and managing nutrient flows in terrestrial ecosystems, yet to date it has proved impossible to analyze and image N transfer in...

This paper describes integration of IL as a thread running through the environmental sciences curriculum at Newcastle University. A variety of IL activities, including skills development, reflection and assessment, were piloted within existing modules between 2005 and 2008. Discussion groups and learning logs were used to draw out student perceptio...

Effective nutrient management is essential in organic farming systems. Processed soluble fertilisers such as ammonium nitrate, which feed the plant directly and are thought to bypass the natural processes of the soil, are not generally acceptable. Nutrient supply to crop plants is supported through recycling, the management of biologically-related...

This book is the result of a Workshop. The objective of this Workshop was to address three key issues: the quantifiable effects of organic in comparison with conventionally produced food on human health; the environment impact on these possible health benefits; and how the public perceives these benefits. To address these issues, the Workshop exami...

The maintenance of soil fertility is a key tenet of organic farming and can be broadly defined as theability of the soil to support the productivity of the system. The central concept of soil fertility inthese systems is the use of legume-based multi-annual rotations together with the judicious useof on-farm manures. Rotations provide the opportunit...

A large body of published research now exists on economic, social, technical and policy related aspects of organic production. The dramatic increase in published research over the last 20 years reflects not only the existence of policy support for organic farming in some countries but also the availability of government funding for research on orga...

The availability of soil management advice to UK farmers was evaluated in the context of the Single Payment Scheme through expert consultation supported by a questionnaire survey. Feedback from service providers indicated that the highest current priority was provision of advice to meet cross compliance obligations. Gaps were identified in the info...

Improved understanding of the seasonal dynamics of C and N cycling in soils, and the main controls on these fluctuations, is needed to improve management strategies and to better match soil N supply to crop N demand. Although the C and N cycles in soil are usually considered to be closely linked, few data exist where both C and N pools and gross N...

The basis of organic farming is that it is environmentally, socially and economically sustainable, and it aims, wherever possible, to use renewable resources in the production system and avoid waste. Thus this review considers the use of nutrient, energy and water within the farming systems, and indices that are used to evaluate the use of these re...

Microorganisms (e.g. bacteria, fungi, actinomycetes, microalgae) play a key role in organic matter decomposition, nutrient cycling and other chemical transformations in soil. In fact general measurements of microbial activity in soil are synonymous with the breakdown of organic matter. Decomposition of organic matter is usually controlled by hetero...

The term 'sustainable agriculture' is used widely and has embraced a diverse range of issues and objectives, including animal welfare, greater protection of the environment, and the need for farming to support other sectors of the economy such as tourism. Where the principles of sustainable development are applied to agriculture, then farming syste...

Soils are structurally heterogeneous across a wide range of spatio-temporal scales. Consequently, external environmental conditions do not have a uniform effect throughout the soil, resulting in a large diversity of micro-habitats. It has been suggested that soil function can be studied without explicit consideration of such fine detail, but recent...

We conducted a laboratory incubation of forest (Scots pine (Pinus sylvestris) or beech (Fagus sylvatica)), grassland (Trifolium repens/Lolium perenne) and arable (organic and conventional) soils at 5 and 25 1C. We aimed to clarify the mechanisms of short-term (2-weeks) nitrogen (N) cycling processes and microbial community composition in relation t...

The understanding of nitrogen mineralization is central to providing good advice to ensure that nitrogen (N), from whatever source, is utilized by crops as efficiently as possible to minimize pollution. We have reviewed how mineralization is accounted for in current advice. It is clear that there is at least a qualitative understanding of the effec...

The spatial location of microorganisms and their activity within the soil matrix have major impacts on biological processes such as nutrient cycling. However, characterizing the biophysical interface in soils is hampered by a lack of techniques at relevant scales. A novel method for studying the distribution of microorganisms that have incorporated...

In organic farming systems, fertilizing materials can be used when potassium (K) deficiency is shown, but such systems are dominantly nitrogen (N) limited and this is likely to affect crop utilization of K. The supply of K to grass/clover from a range of mineral and organically based K fertilizers and its interaction with N supply were studied in a...

A balanced use of resources within organic farming systems is required to maintain sustainable systems. Hence, it is essential to have tools that can assess the use of resources within the farming system and their impact on the environment. The range of tools that have been developed include those assessing local farm-scale issues together with tho...

Phosphorus (P) is an essential plant nutrient that needs to be managed carefully in organic systems so that crop yield and quality remain sustainable without contributing to environmental damage, particularly that associated with eutrophication. Under organic regulations, minimally processed rock phosphate (PR) can be used to amend low P fertility...

Summary Phosphorus (P) is an essential plant nutrient that needs to be managed carefully in organic systems so that crop yield and quality remain sustainable without contributing to environmental damage, particularly that associated with eutrophication. Under organic regulations, minimally processed rock phosphate (PR) can be used to amend low P fe...

The aim of this study was to assess the influence of season, farm management (organic, biodynamic, integrated, and conventional), and soil chemical, physical, and biological properties on gross nitrogen (N) fluxes and bacterial community structure in the semi-arid region of Western Australia. Moisture availability was the dominant factor mediating...

Summary Maintaining ecosystem function is a key issue for sustainable farming systems which contribute broadly to global ecosystem health. A focus simply on the diversity of below- ground organisms is not suffi cient and there is a need to consider the contribution of below-ground biological processes to the maintenance and enhancement of soil func...

Effective use and recycling of manures together with occasional and judicious use of supplementary fertilizing materials forms the basis for management of phosphorus (P) and potassium (K) within organic farming systems. Replicated field trials were established at three sites across the UK to compare the supply of P and K to grass–clover swards cut...

The aims of this study were to: (i) assess the impact of hay and fertilizer application on organic matter (OM) fractions (dissolved organic matter (DOM), light fraction organic matter (LFOM, !1.0 g cmK3), heavy fraction OM (HFOM, !1.7 g cmK3)), carbon (C) and nitrogen (N) cycling processes and microbial community size and structure, and (ii) quanti...

The aims of this study were to: (i) assess the impact of hay and fertilizer application on organic matter (OM) fractions (dissolved organic matter (DOM), light fraction organic matter (LFOM, !1.0 g cmK3), heavy fraction OM (HFOM, !1.7 g cmK3)), carbon (C) and nitrogen (N) cycling processes and microbial community size and structure, and (ii) quanti...

Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and mana...

Isotopic pool dilution using 15N is proving to be a valuable tool for increasing our understanding of gross N cycling processes and our ability to both model these processes and link them to microbial function. However, not all applications are appropriate. Many of the questions asked by agronomists and soil scientists can often be addressed by sim...

Nitrogen (N), phosphorus (P) and potassium (K) budgets were calculated for nine organic farms in the UK. The farms were situated on sandy loams, silty clay loams and silty loams over chalk with stockless farming systems and cattle, pig and poultry enterprises with a significant proportion of arable cropping. A soil surface nutrient budget was calcu...

The relative dominance of the competing pathways for ammonium, namely, the microbial processes of nitrification (N) and immobilisation (I), has been suggested as a major factor in controlling nitrogen losses from soils. In this paper we bring together data from four studies in arable and grassland soils to establish whether the ratio N/I is correla...

On organic farms, where the importation of materials to build/maintain soil fertility is restricted, it is important that a balance between inputs and outputs of nutrients is achieved to ensure both short-term productivity and long-term sustainability. This paper considers different approaches to nutrient budgeting on organic farms and evaluates th...

An earlier paper (Macdonald et al., 1997; J. Agric. Sci. (Cambridge) 129, 125) presented data from a series of field experiments in which 15N-labelled fertilizers were applied in spring to winter wheat, winter oilseed rape, potatoes, sugar beet and spring beans grown on four different soils in SE England. Part of this N was retained in the soil and...

Soil fertility is de®ned as the ability of a soil to provide the conditions required for plant growth. It is a result of the physical, chemical and biological processes that act together to provide nutrients, water, aeration and stability to the plant, as well as freedom from any substances that may inhibit growth. Within this de®nition, it is usef...

OrgPlan is a computer programme aimed at farmers and advisors assisting with the planning of an organic conversion. The programme is divided into technical modules, supported by a standard enterprise database, a report builder and an advisory section. Through the farm profile builder, rotation, cropping and livestock planner, conversion scenarios o...

On organic farms, where the importation of materials to build/maintain soil fertility is restricted, it is important that a balance between inputs and outputs of nutrients is achieved to ensure both short-term productivity and long-term sustainability. This paper considers different approaches to nutrient budgeting on organic farms and evaluates th...

Volume 70 contains six excellent treatises dealing with two of the leitmotifs in the plant and soil sciences - environmental quality and crop improvement. Chapter 1 is a comprehensive treatment of the role of carbon sequestration in affecting climate change. Issues of science, monitoring, and degraded lands are fully discussed. Chapter 2 deals with...

This book is divided into 6 sections: organic matter and sustainability; modelling soil organic matter dynamics - global challenges; soil organic matter management - the roles of residue quality in C sequestration and N supply; the role of soil organic matter and manures in sustainable nutrient cycling; implications of soil biodiversity for sustain...

 The existence of soluble organic forms of N in rain and drainage waters has been known for many years, but these have not been generally regarded as significant pools of N in agricultural soils. We review the size and function of both soluble organic N extracted from soils (SON) and dissolved organic N present in soil solution and drainage waters...

Soluble organic nitrogen (SON) is not generally considered to be a significant pool of nitrogen (N) in agricultural soils. Given the importance of SON in forest and natural systems, this view is challenged with examples from current research. Methods to collect and measure SON are described and possible roles for SON in N transformations are discus...

The aim of this article is to set the background for the discussion of the prediction of nitrate losses and the use of such predictions in decision making. The article discusses measurements and models used to predict water flow and nitrate supply, before drawing both together to consider prediction of nitrate loss. The difficulties and advantages...

Soil-plant N dynamics lie at the heart of some of the questions being asked of researchers by farmers, environmentalists and policy makers. Our aim in this paper is to highlight areas in which research is needed to address these questions. Although we have a general understanding of many processes, fundamental understanding of the processes of the...

Field trials were carried out to study the fate of 15N-labelled urea applied to summer maize and winter wheat in loess soils in Shaanxi Province, northwest China. In the maize experiment, nitrogen was applied at rates of 0 or 210 kg N ha-1, either as a surface application, mixed uniformly with the top 0.15 m of soil, or placed in holes 0.1 in deep...

Soils form a major repository of nitrogen (N) within both natural and agricultural terrestrial ecosystems, containing, on a global basis, an estimated 2.4 x 10¹¹ tons of N. The soil receives N inputs through fertilizer additions and from the atmosphere in precipitation and dry deposition or via biological fixation; inputs are also made in plant and...

Field trials were carried out to study the fate of15N-labelled urea applied to summer maize and winter wheat in loess soils in Shaanxi Province, north-west China. In the maize experiment, nitrogen was applied at rates of 0 or 210 kg N ha–1, either as a surface application, mixed uniformly with the top 0.15 m of soil, or placed in holes 0.1 m deep a...

Plant N uptake and mineralisation were studied in a pot experiment using two soils of contrasting textures with a range of N-labelled manures: poultry manure, cattle slurry, fresh swine manure, composted cattle manure, sewage sludge, straw, cabbage residues, pea residues and grass-clover turf. A range of manure and soil properties were determined b...

Field methods used to measure nitrogen mineralization are reviewed. The relative importance of net and gross measures of mineralization are considered in relation to field studies. Some of the problems with in situ core incubations are discussed, particularly that of the disruption of plant roots, and immobilization of mineralized N. A technique ap...

Experiments were carried out to investigate relationships between a number of nitrogen availability indices and biomass nitrogen, in a wide range of Scottish soils, and to establish the source of the nitrogen released. In one experiment, three soils were incubated for a week with high enrichment (99.2 atom %) (15NH4)2SO4 to label the soil biomass....

Various management strategies aimed at maximising N supply for organic crops were studied. The N released from manures in the first year was shown to be derived mainly from the pool of mineral N added in the manure. The availability of this pool was controlled by the supply of soluble carbon also added in manures, which stimulates the growth of the...

The N uptake patterns and efficiency of the use of N from heap-composted cattle manure by spring barley and maincrop potatoes were compared, together with the incidence of pests and diseases under different N levels. The incidence of fungal diseases was so low that differences between treatments were not apparent. However, some evidence was obtaine...

On organic farms it is important that a balance between inputs and outputs of nutrients is achieved. This paper collates nutrient budgets collated at the farm scale for 88 farms in 9 temperate countries. The majority of budgets were compiled for dairy farms (56). All the nitrogen budgets showed an N surplus (average 83 kg N ha -1 year-1). The phosp...