The objective of this research was to investigate ways to increase the amount of C transferred to the stable SOM (humus) pool following crop residue retention. The central hypothesis was that humus has a constant stoichiometry of CNPS reflecting its largely microbial origin, and that sequestration of C-rich crop residue material into the humus pool could be improved by adding supplementary nutrients to the residues to achieve these ratios. A review of the literature and measurement of 59 Australian soils confirmed that soil humus had a near constant C:N:P:S ratio. A series of microcosm experiments were then conducted using wheat straw incubated with or without supplementary nutrients (N, P and S) to investigate the impact on C sequestration into the humus pool.
|Qualification||Doctor of Philosophy|
|Award date||01 Dec 2011|
|Place of Publication||Australia|
|Publication status||Published - 2011|