Restoring soil quality through re-integration of leys and sheep into arable rotations

The economic and environmental sustainability of UK arable farming is facing a crisis, caused in part by soil degradation as a result of continuous intensive cultivation. The use of ploughing and short rotations in which a small number of crops (especially wheat and oilseed rape) are grown with very high frequency with high reliance on inputs of fertilizers, pesticides, herbicides has led to loss of soil organic matter, compaction, reduced water-storage capacity and increased risks of water pollution from soil erosion and agro-chemicals, and reduced farm profitability. This has been compounded by the build-up of increasingly intractable herbicide- resistant weeds in wheat such as blackgrass, and pesticide- resistant insects such as flea beetle in oilseed rape in these short rotations.
To address these problems, some farmers are starting to return to mixed farming, reintroducing leys containing grass and clover, grazed by sheep, into arable rotations hoping this will improve soil quality, reduce weeds and diseases and boost profits, but without the critical evidence they need to guide these decisions.
Our multidisciplinary proposal directly addresses this industry-led research need. We recognize the urgent requirement to determine how best to restore soil quality, and achieve good livestock production and economic returns through a comprehensive evaluation of the costs and benefits of such systems. Our goal is to provide the first comprehensive industry-informed, farmer-participatory assessment of soil quality, environmental and economic cost-benefits, farmer motivations and barriers to reintroducing sheep into arable rotations, focused on our most intensively cultivated areas of eastern England.
Our approach is to compare traditional grazed grass-clover leys and conventional crop cultivation, with innovative management systems that hold the promise of better returns involving combining novel species-rich herbal leys, mowing and no-tillage direct drilling of the crops. The work is divided into five work packages.
1.Farmer-participatory research network: We are building a network of arable farmers who are already conducting initial trials into introducing grass-clover and species-rich herbal leys, sheep and no- tillage, into arable rotations. We will run workshops with participant farmers, as well as those who have not made these changes, and conduct a large-scale farmer-survey to understand the motivations for, and barriers to, incorporating these alternative systems. We will identify where farmers have had success with these approaches and what has made them successful.
2.Soil quality restoration and sheep production: We will set up field experiments with a participatory group of farmers to compare the effects of herb-rich leys with traditional grass-clover leys under sheep grazing versus mowing, on soil quality, (organic matter, structure, effects on water storage and infiltration, nutrient cycling, earthworms and organisms associated with sheep faeces. We will assess sheep production (live weight gain, and intestinal pathogens) and the biomass production of the leys.
3 Effects of reducing tillage: Determine whether direct drilling offers benefits over disc or plough-based tillage on subsequent arable crop production and soil quality following leys (including assessment of yield, nutrient use efficiency, weeds, diseases and pests) in our participatory farm-based trials.
4 Farm-scale cost-benefit analysis: Evaluate the environmental and economic cost-benefits of bringing sheep and grass-clover versus herbal leys into arable rotations, mowing, and use of direct drilling compared to current arable tillage practices - assessing the costs and output values to farms, and nutrient use efficiency of the different approaches.
5 Upscaling and policy implications: Landscape-scale effects including impacts on flood and pollution risk and consider targeted farm payments to encourage the most beneficial practices

This multidisciplinary research project will, for the first time, evaluate the environmental and economic cost-benefits of reintroducing leys and sheep into arable rotations to improve soil quality in our most intensively cropped areas of eastern England. The project will deliver the evidence-base needed to guide how to use these systems to increase soil organic matter content and improve soil structure and associated hydrological functioning and soil water and nutrient storage. These changes are required to reduce the problems of water pollution, and establish more sustainable crop and livestock production systems. The research is focused on experiments to be conducted with 5 arable farmers in participatory research. We will evaluate the potential benefits of innovative approaches that combine new types of ley and tillage methods. We will study the effects of traditional grass clover-leys, versus new species-rich herbal leys, grazing versus mowing, and conventional tillage versus direct drilling, as tools that in novel combination are hypothesized to be more effective in restoring physical, chemical and biological soil quality than the traditional approaches, and predicted to deliver greater economic and environmental benefits. The research builds on, and extends, current trials supported by the AHDB and National Sheep Association. It will provide a the most comprehensive assessment of soil quality changes from these systems, through detailed sampling and analyseis of soil structure and hydrological functioning, organic carbon and nutrients, together with data on herbage, sheep and crop production, economic and environmental cost-benefits. The project is multiscale from plot-to-field-to-farm-to-catchment-to-landscape and will deploy a range of upscaling modelling tools that will allow the wider effects of reintroducing sheep into arable rotations to be determined to guide policymaking on farm payments for environmental goods and services.

We have developed a set of pathways to deliver impact from this research to address the industry-challenge- how best to reintroduce livestock into arable rotations to improve soil quality.
The research findings will be directly communicated to SARIC industry club members through written reports, and oral presentations at the annual SARIC meetings. Our proposal has been developed in consultation with leaders of existing AHDB work in this area and we will fully engage with existing AHDB mechanisms for dissemination of our research findings. The research is especially important for the industry club members Anglia Water, and NRM Cawood Scientific with whom we will be collaborating in the development of their soil testing service.
The core outcomes of the project will directly influence a) Farmers, farm managers: benefit through understanding benefits of leys and sheep grazing to restore soil quality under different management practices and soil types; b) seed companies (Cotswold Seeds, Kings) Statutory agencies involved in water and soil conservation (e.g. Natural England, Environment Agency); c) Utility companies involved in water supply, nitrate pollution and management of stormwater and associated sediment discharges e.g. Yorkshire Water; d) households in flood-risk areas where the risks have been increased by loss of arable soil water infiltration and storage capacity; e) Game and Wildlife Conservation, f) The Sustainable Soils Alliance and other organizations such as the Global Soils Partnership seeking to protect soils, g) Government policy makers (DEFRA).
MECHANISMS OF ENGAGEMENT AND IMPACT GENERATION
On-farm demonstrations: The project launch event to which industry-club members, collaborators and farmers will be invited will be run at NIAB Innovation Farm including a visit to the experimental leys to be set up by NIAB in 2018
Knowledge exchange workshops: We will conduct these with farmers at the start (2019), middle (2020) and end (2022) of the project.
Linking Farmers and Environmental Agencies: In Spring 2022 we will run a one day outreach meeting at the GWCT Allerton Project Visitor Center to demonstrate research outcomes, visit ongoing studies of sheep in arable rotations (see LoS) and communicate findings to farmers and farm managers and agencies involved in water and soil conservation.
Sheep Producers: We will publicize our findings to sheep producers through in-kind support of the National Sheep Association publishing articles in their bi-monthly magazine and contributing to their seminar programmes at key NSA events.
Arable Farmers: We will present summary information on finding of the research at NIAB-TAG stand at the annual Cereals Event in the summer of 2022 and at annual June NIAB Open days.
Academics: Submission of manuscripts for publication in high impact and open access peer reviewed journals, associated press releases and conference presentations.
Policymakers. We will communicate through established links with Defra in Demonstration Test Catchments (See letter of support from Defra, who would be willing to consider provision of translational funds in the final year of the project to draw together the results in a policy relevant format in order to maximise the impact of the work). In addition we have a pathway to policy-influence via the Sustainable Soils Alliance and policy briefing notes.
The Public: We will engage with the public through press releases in relation to publication of results; at annual International Science open days and the annual NIAB Festival of Plants events and through the project website and Twitter.
End of Project Knowledge Translation Event: The final project meeting in Autumn 2022 at NIAB innovation Farm will be focused on translation of the project discoveries into practical applications with collaborators and industry club members.