The role of Phosphorus in the Resilience and Sustainability of the UK food system

磷(P)是作物和牲畜生产所需的必需营养素，但全球磷矿（PR）储量是一种有限的关键资源，磷矿是化肥和饲料的来源。磷不能化学合成，英国也没有自己的PR储备。因此，英国农业完全依赖于化肥、饲料和食品的进口，而这些产品的成本正变得越来越不稳定。因此，未来P的稀缺（无论是本地还是全球），或者P进口成本的显著上升，都会威胁到英国食品系统的未来安全和弹性，但这种脆弱性此前尚未得到评估。由于被排除在欧盟贸易协定之外，英国脱欧可能会增加英国未来P供应的脆弱性。在英国农业中，磷的使用效率也很低，导致大量浪费，磷流失到内陆和沿海水域，造成营养污染或富营养化。预计气候变化将加剧这种损失和由此造成的污染。富营养化对社会的代价非常高昂，并降低了与水质有关的许多生态系统服务，包括饮用水量、生物多样性和娱乐用水。控制富营养化的监管标准是基于磷的，因此，通过改善整个食物链对磷的管理来提高英国农业的可持续性是至关重要的。更好的磷管理有双重好处：首先，它可以通过减少英国对磷进口的依赖来增加英国粮食系统对磷冲击的抵御能力；其次，在对水质影响最小的情况下优化农业集约化，增加依赖水质的生态系统服务的价值。在这个项目中，一个涵盖生物、环境和社会经济科学的跨学科研究团队旨在量化英国农业和英国粮食系统对未来磷短缺的脆弱性，并评估磷短缺可能对农场、流域和国家规模的农业生产产生影响的阈值。工作方案将制定可能克服这一脆弱性的适应措施并确定其优先次序；例如，通过技术创新来提高磷的利用效率和二次磷源的再利用，以及必要的制度基础设施来支持这些。与此同时，该项目将查明在集水区实施改进磷管理的生物物理、技术、社会经济和体制障碍（例如减少使用、增加回收和降低最终用户需求）。这将通过对流域异质性的深入分析来实现，流域异质性会影响磷投入对农业、水质和级联生态系统服务的影响，并评估利益相关者实施最佳磷管理解决方案的适应能力。一个涉及地方到全球范围利益相关者的多参与者平台将确保最终用户的参与和整合，以实现最大的研究影响。该项目将为英国食物链提供第一个P脆弱性评估，并确定改进P管理的潜在适应策略，以帮助最大限度地提高英国食物链的复原力和可持续性。

Phosphorus (P) is an essential nutrient required for crop and livestock production, but the global reserves of phosphate rock (PR) from which fertilisers and feeds are derived are a finite critical resource. Phosphorus cannot be made chemically and the UK has no PR reserves of its own. UK agriculture is therefore entirely dependent on P imports of fertilisers, feeds and foods, which are becoming increasingly volatile in cost. A future scarcity of P (either locally or globally), or a significant rise in the costs of P imports, therefore threaten the future security and resilience of the UK food system, but this vulnerability has not previously been evaluated. Brexit may increase the UK vulnerability to future P supply due to exclusion from EU trade agreements. The use of P within UK agriculture is also very inefficient and leads to large wastage, and loss of P to inland and coastal waters causing nutrient pollution or eutrophication. Such losses and the resulting pollution are expected to be exacerbated by climate change. Eutrophication is very costly to society and devalues many ecosystem services linked to water quality including water quantity for drinking, biodiversity and recreation. Regulatory standards to control eutrophication are based on P, and it is therefore critically important to improve the sustainability of UK farming by improving the management of P across the whole food chain. Better stewardship of P has a double benefit: it can firstly increase the resilience of the UK food system to P shocks by reducing UK reliance on P imports and secondly optimize the intensification of agriculture with minimal impact on water quality and increase the value of the ecosystem services dependent on water quality.In this project, an interdisciplinary research team covering the biological, environmental and socio-economic sciences aims to quantify the vulnerability of UK agriculture and the UK food system to a future P scarcity and assess the thresholds at which P scarcity might impact on agricultural production at farm, catchment and national scale. The work programme will develop and prioritise the adaptations that might overcome this vulnerability; for example through technological innovations to improve P use efficiency and reuse of secondary sources of P and the necessary institutional infrastructure to support these. In parallel, the project will identify the biophysical, technological, socio-economic and institutional barriers to implementing improved P stewardship within catchments (for example by using less, recycling more and lowering end-user demand). This will be achieved through an in-depth analysis of the catchment heterogeneity that influences how P inputs affect agriculture, water quality and cascading ecosystem services and an assessment of the adaptive capacity of stakeholders to implement optimal P stewardship solutions. A multi-actor platform involving stakeholders at local to global scales will ensure end-user engagement and integration for maximum research impact. The project will deliver the first P vulnerability assessment for the UK food chain and identify potential adaptation strategies for improved P stewardship to help maximise the resilience and sustainability of the UK food chain.