Abstract
Modern agriculture has caused extensive nutrient pollution and soil carbon depletion. Policy makers and scientists call for nature-inclusive approaches to improve soil nutrient and carbon management. Overlooked interactions at the interface between plant roots and soil could help achieve these challenges. Through a process called root exudation, plant roots release cocktails of compounds in soil. Root exudates form unique biochemical profiles, which interact with soil microbes, minerals, and organic matter. These plant-soil interactions hold the potential to enhance plant phosphorus and nitrogen acquisition from less available resources and support soil carbon cycling. Yet, scientific knowledge on root exudation mostly focuses on individual plant species and compounds. As a result, the impact of root biochemical profiles on soil processes remains a deep secret. Root ecologists recently proposed a framework that links plant species variation in root traits to different strategies to acquire nutrients. Integrating root exudation into this framework will help reveal the function of root exudates in relation to nitrogen and phosphorus acquisition and improve predictions about plant species effects on soil processes. Therefore, my aim is to investigate how plant species variation in root exudation profiles impacts soil nitrogen, phosphorus and carbon cycling. I will combine methods from plant ecology, soil chemistry and microbiology through three objectives. First, I will connect root exudation to root traits associated with contrasting nutrient acquisition strategies. Second, I will reveal the impact of root exudation profiles on soil nitrogen, phosphorus and carbon cycling. Third, I will use insights from objectives 1-2 to test the effect of soil nutrient levels on root exudation profiles and function This project is novel in using a holistic approach to decipher the multiple functions of root exudation profiles in soil across diverse plant species. By learning from nature, this will generate belowground solutions for a sustainable agriculture.
Netherlands