Linking nutrient acquisition strategies and plant performance to resource gradients for improved agroecology

与土壤退化、土地稀缺、水污染和气候变化相关的当前和未来农业管理挑战将对农业实践产生重大影响，对生产力、生态系统服务和粮食安全产生深远影响。这些挑战可以通过将多种物种纳入农业景观和审查在不同生产系统中运作的主要机制来解决。尽管如此，目前，在混合农业（作物-作物）和农林（树木-作物）系统中，养分有效性、光资源和作物性能之间的动态关系仍有很多未知。这项工作位于生物学、地球科学和农业管理的界面，目的是通过使用新的稳定同位素和根际技术将作物生长与适当的营养供应联系起来。为此，我的研究项目将研究多物种热带和温带农业系统中现有的养分循环、养分转移和作物反应。具体目标是1)确定最佳的多物种种植设计和农业生态系统管理，以实现最大产量；2)确定最有利的植物-土壤和植物-植物相互作用；3)比较和对比热带和温带地区的农业生态系统动态。在当前的地缘政治背景下，面对难以获得或不受欢迎的肥料使用，农业节育做法的发展正在增加。与此同时，全球也在呼吁改善农业多样性和粮食安全。通过将生态原则应用于农业景观，这项工作将产生可持续的、可实现的做法，提高养分循环和植物-土壤相互作用的效率，从而提高产量并加强环境服务。该研究项目的研究结果将为高价值热带系统以及加拿大农业环境的健全农业管理处方提供重要信息。

Current and future agricultural management challenges associated with soil degradation, land scarcity, water contamination and climate change will have significant impacts on agricultural practices with far reaching consequences for productivity, ecosystem services and food security. Such challenges can be met by integrating multiple species into the agricultural landscape and by examining dominant mechanisms operating in diverse production systems. Despite this, presently, there is still a great deal unknown regarding the dynamic relationships between nutrient availability, light resources and crop performance in mixed agricultural (crop-crop) and agroforestry (tree-crop) systems. The aim of this work, which lies at the interface of biology, geosciences and agrarian management, is to link crop growth to appropriate nutrient supply by using novel stable isotope and rhizosphere techniques. To do this, my research program will examine existing nutrient cycles, nutrient transfer and crop response in multi-species tropical and temperate agricultural systems. Specific objectives are to 1) determine optimal multi-species planting design and agroecosystem management for maximum yields, 2) identify the most advantageous plant-soil and plant-plant interactions, and 3) compare and contrast agroecosystem dynamics in tropical and temperate regions. In the current geopolitical context, the development of nutrient-conserving practices for agriculture in the face of inaccessible or undesirable fertilizer use is on the rise. This is paralleled with a global call for improved agro-diversity and food security. By applying ecological principles to agricultural landscapes, this work will result in sustainable yet attainable practices that improve the efficiency of nutrient cycles and plant-soil interactions in order to increase yields as well as enhance environmental services. Findings from this research program will provide significant information for sound agricultural management prescriptions in high-value tropical systems as well as in the agrarian environment of Canada.