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

与土壤退化、土地稀缺、水污染和气候变化有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整合到农业景观中并通过检查在不同生产系统中运行的主导机制来应对。尽管如此，目前关于农业(作物-作物)和农林(树-作物)混合系统中养分可获得性、光照资源和作物表现之间的动态关系仍有许多未知之处。这项工作的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养分供应联系起来，这项工作位于生物学、地学和农业管理的交界处。为了做到这一点，我的研究计划将研究热带和温带多物种农业系统中现有的营养循环、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，以及3)比较和对比热带和温带地区的农业生态系统动态。在目前的地缘政治背景下，在难以获得或不受欢迎的化肥使用情况下，为农业制定养分保护做法的情况正在增加。这与改善农业多样性和粮食安全的全球呼声相呼应。通过将生态学原理应用于农业景观，这项工作将产生可持续但可实现的做法，提高养分循环和植物-土壤相互作用的效率，以增加产量和加强环境服务。这项研究计划的发现将为高价值热带系统以及加拿大农业环境中合理的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.