Produce a farmers guide on cover crops species selection, establishment, and termination

覆盖作物是未来农业政策的基石，也是新兴的“再生农业”方法的关键组成部分，有望共同提供自然资本和人类营养。虽然它们可以带来多种农艺和环境效益，从通过建立土壤健康和恢复力来提高产量到减少农场排放/投入和增加碳捕获和生物多样性，但它们这样做的能力取决于具体情况，依赖于选择能够在播种地特定条件下发挥作用的物种。种子选择建议可以通过供应商获得，但到2020年，大约有150种商业混合物上市（Mills等，2020），在这个市场上导航是具有挑战性的。适当的种子选择也只是覆盖作物成功的几个关键因素之一，有关建立、管理和终止技术的决策同样重要，特别是在存在实施障碍的情况下（例如，在无法使用草甘膦进行终止的有机系统中，或在覆盖作物生长窗口通常减少的北方气候中）。因此，尽管覆盖作物被纳入elm / sfi，并作为新兴碳交易平台的农场选择，但农民在采用覆盖作物时面临着巨大的不确定性/风险，没有单一的“最佳实践”建议来源，包括种子选择、播种、农艺和终止。在覆盖作物生产过程的任何阶段做出的错误决定都可能导致作物歉收，浪费时间，经济损失，以及错过充分利用覆盖作物潜力的机会。在极端情况下，甚至可能导致“生态系统损害”，例如，一种选择不当的覆盖作物为随后的经济作物的病虫害提供了“绿色桥梁”。因此，我们有机会更好地支持农民种植覆盖作物，并从中获得农艺、环境和社会经济收益。为了实现这一机会，我们建议开发一种可获取的、独立的、由农民主导和科学支持的“农民覆盖作物选择、建立和终止指南”，为希望利用覆盖作物的农民提供信心，在所有阶段降低决策过程的风险，减少不可预见的成本，并提高覆盖作物在农场的成功和吸收。重要的是，本指南将纳入在一系列最终用户情景（例如，土壤成分和区域气候）中管理覆盖种植成功的外部因素，影响如何设计覆盖作物以获得最佳效果的内部驱动因素（例如，作物轮作计划和期望覆盖作物可交付成果的平衡），以及可用于部署覆盖作物的工具，包括在具有挑战性的环境中。

Cover crops are cornerstones of future farming policy and critical components of emerging 'regenerative agriculture' approaches that promise co-delivery of natural capital and human nutrition. While they can deliver multiple agronomic and environmental benefits, from increasing yields by building soil health and resilience to reducing on-farm emissions/inputs and increasing carbon capture and biodiversity, their ability to do so is context-dependant and reliant on selecting species that can perform under conditions specific to the field in which they are sown. Seed selection advice is available through suppliers, but with ~150 commercial mixes marketed in 2020 (Mills et al, 2020), navigating this marketplace is challenging. Appropriate seed selection is also just one of several key factors governing cover crop success, with decisions regarding establishment, management and termination techniques being equally important, especially where barriers to implementation exist (e.g. in organic systems where glyphosate is unavailable for termination, or in northern climates where windows for cover crop growth are typically reduced).Consequently, despite their inclusion in ELMs/SFIs, and as on-farm options in emerging carbon-trading platforms, farmers are exposed to significant uncertainty/risk when adopting cover crops, with no single source of 'best practice' advice covering seed selection, sowing, agronomy and termination. A poor decision made at any stage in the cover crop production process can result in a failed crop, wasted time, financial loss, and a missed opportunity to leverage a cover crop's full potential. In extreme cases, 'ecosystem disservices' can even result, for example where an ill-chosen cover crop provides a 'green bridge' for pests and diseases of the subsequent cash crop.Opportunity therefore exists to better support farmers to engage with cover crops and the agronomic, environmental, and socio-economic gains that can flow from them. To realise this opportunity, we propose development of an accessible, independent, farmer-led and scientifically-supported '_Farmer's guide to cover crop selection, establishment, and termination_' to provide confidence to farmers wishing to utilise cover crops, de-risking the decision-making process at all stages, reducing unforeseen costs, and improving the success and uptake of cover crops on-farm. Importantly, this guide will embed external factors that govern successful cover cropping across a range of end-user scenarios (e.g. soil compositions and regional climates), internal drivers that influence how cover crops are designed to best effect (e.g. crop rotation plans and the balance of desired cover crop deliverables), and the tools that can be used to deploy them, including in challenging circumstances.