Mechanisms of whole-profile C and N cycling – Yui Osanai
Title: Mechanisms of whole-profile C and N cycling under rotational cotton in Australia.
Project Description
Previous research within the cotton industry has demonstrated the potential of some systems (e.g. cotton-maize) to increase C and N contents, particularly in the deep soil profile. This has considerable significance for C and N cycling and nutrient supply for cotton production. A comprehensive understanding of the quantities and mechanisms of C and N distribution, mineralisation and turnover through the whole-profile under cotton-maize and comparable cotton rotations will enable these cycles to be fully predicted and managed, with added benefit of quantifying the potential contribution to and mitigation of greenhouse gas emissions. Together, these will enable us to identify the best management practice that maximises resource use efficiency while reducing environmental footprints, thereby ensuring the economic and environmental sustainability of the cotton industry under more stringent carbon-accounting regulations.
Approach
This project aims to characterise the quantity, distribution and mechanisms of soil C and N turnover under contrasting cotton farming systems, utilising existing ACRI sites where cotton-cereal rotations and cotton-maize rotations have been applied over the years. Using a range of conventional and novel techniques, we will investigate:
- the quantity and depth distribution of organic C and N,
- physical and biological drivers of C and N distribution in the profile,
- mineralisation, turnover and rates of C and N cycling down the profile.
Outcome
The information generated will contribute to the mechanistic understanding of the whole-profile C and N cycling under various cotton rotations to identify the best management practice to maximise long-term C and N capture for improved nutrient management and climate mitigation.
Users
Researchers, Policy makers, Land managers.
