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

磷（P）是作物和畜牧业生产所需的重要营养素，但作为肥料和饲料来源的磷酸盐岩（PR）的全球储量是有限的关键资源。磷不能用化学方法制造，英国也没有自己的磷储备。因此，英国农业完全依赖化肥、饲料和食品的进口，这些产品的成本越来越不稳定。因此，未来磷的短缺（无论是本地还是全球），或磷进口成本的显着上升，威胁到英国粮食系统的未来安全和弹性，但这种脆弱性以前没有被评估。英国脱欧可能会增加英国对未来磷供应的脆弱性，因为英国被排除在欧盟贸易协定之外。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沃茨，造成营养物污染或富营养化。预计气候变化将加剧这种损失和由此产生的污染。富营养化给社会带来巨大代价，并使许多与水质有关的生态系统服务贬值，包括饮用水、生物多样性和娱乐用水量。控制富营养化的监管标准是基于磷，因此，通过改善整个食物链中磷的管理来提高英国农业的可持续性至关重要。更好地管理P有双重好处：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弹性，其次优化农业集约化，同时最大限度地减少对水质的影响，并增加依赖于水质的生态系统服务的价值。环境和社会经济科学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，集水区和国家规模的农业生产产生影响的阈值。该工作方案将制定并优先考虑可能克服这种脆弱性的适应措施;例如，通过技术创新提高磷的利用效率和磷的二次来源的再利用，以及支持这些措施的必要体制基础设施。与此同时，该项目将查明在集水区内实施更好的磷管理的生物物理、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）。这将通过深入分析影响磷投入如何影响农业、水质和级联生态系统服务的流域异质性，以及评估利益攸关方实施最佳磷管理解决方案的适应能力来实现。一个涉及地方到全球范围利益攸关方的多行为体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磷脆弱性评估，并确定潜在的适应战略，以改善磷管理，以帮助最大限度地提高英国食物链的弹性和可持续性。

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.