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

英国可耕地农业的经济和环境可持续性正面临危机，部分原因是由于持续的集约化耕作造成的土壤退化。使用翻耕和短期轮作，即少量作物（特别是小麦和油菜）频繁种植，高度依赖化肥、杀虫剂和除草剂的投入，导致土壤有机质流失、压实、蓄水能力降低，土壤侵蚀和农用化学品造成水污染的风险增加，并降低了农场的盈利能力。在这些短期轮作中，小麦中越来越难对付的抗除草剂杂草（如黑种草）和油菜中越来越难对付的抗杀虫剂昆虫（如跳甲）的积累加剧了这一问题。为了解决这些问题，一些农民开始回归混合农业，将含有草和三叶草的牧草重新引入到可耕地轮作中，希望这将改善土壤质量，减少杂草和疾病并提高利润，但没有指导这些决策的关键证据。我们的多学科提案直接解决了这一行业主导的研究需求。我们认识到迫切需要确定如何最好地恢复土壤质量，并通过全面评估这些系统的成本和效益来实现良好的畜牧生产和经济回报。我们的目标是提供第一个全面的行业知情，农民参与的土壤质量，环境和经济成本效益，农民的动机和障碍重新引入羊到耕地轮作，重点是我们最密集的英格兰东部地区的评估。我们的方法是比较传统的放牧草三叶草和传统的作物种植，创新的管理系统，持有更好的回报，包括结合新的物种丰富的草药leys，割草和免耕直接钻的作物的承诺。这项工作分为五个工作包：1.农民参与研究网络：我们正在建立一个可耕地农民网络，他们已经在进行初步试验，将草三叶草和物种丰富的草药、绵羊和免耕引入可耕地轮作。我们将与参与的农民以及那些没有做出这些改变的农民举办研讨会，并进行大规模的农民调查，以了解采用这些替代系统的动机和障碍。我们将确定农民在这些方法中取得成功的地方，以及是什么使他们取得成功。2.土壤质量恢复和绵羊生产：我们将与一组参与性的农民进行田间试验，比较在绵羊放牧和割草的情况下，富含草药的牧草和传统草三叶草牧草对土壤质量（有机质、结构、对水储存和渗透的影响、养分循环、蚯蚓和与绵羊粪便有关的生物）的影响。我们将评估绵羊生产（活体重增加和肠道病原体）和leys的生物量生产。3减少耕作的影响：确定直接钻孔是否比圆盘或犁式耕作对随后的可耕地作物产量和土壤质量有好处。（包括产量、养分利用效率、杂草、疾病和害虫的评估）。4农场规模的成本效益分析：评估环境和经济成本效益，使羊和草三叶草与草药leys到耕地轮作，割草，和使用直接钻孔与目前的耕地耕作方法相比-评估成本和农场的产出价值，以及不同方法的养分利用效率。5升级和政策影响：景观规模效应，包括对洪水和污染风险的影响，并考虑有针对性的农业付款，以鼓励最有益的做法

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