Nutrient use and carbon sequestration in the plant-soil environment : novel application of spectral data to inform and optimise agroecosystem management

Abstract

Variation in plant traits such as growth rate and nutrient use determine individual plant requirements for nitrogen (N) and phosphorus (P), and ecological stoichiometry underpins the distribution of the elements carbon (C), N and P in ecosystems. Compared with natural systems, plant trait variation and plasticity has been relatively understudied in agroecosystems. The overarching objectives of research presented in this thesis were 1) to understand plant trait variation and identify interspecific competition for resources in the context of the stoichiometry of nutrient limitation, 2) to provide understanding of how carbon and nutrients become distributed in the plant-soil agroecosystem, and 3) to develop the use of spectral analysis techniques to achieve the aforementioned objectives. The research presented in this thesis established that intraspecific trait plasticity, whilst perhaps not as extreme or diverse as that which exists in natural systems, did exist in an agricultural context and that understanding trait diversity can assist in the development of sustainable agricultural management. Further, the development of spectral technologies that quantify plant trait variation (high throughput phenotyping) and can measure the flow on effects of differential management in the soil environment (IRS) are invaluable to advance the field of agricultural research.

Date of Award	2021
Original language	English