Carbon sequestration under subtropical perennial pastures II: Carbon dynamics

Here we take advantage of the stable carbon isotope shift that occurs when a C4 plant is sown into a soil previously dominated by C3 vegetation, to explore the movement and fate of newly sequestered soil organic carbon (SOC) following establishment of subtropical perennial pastures in temperate regions of Australia. In kikuyu-based pastures up to 33 years of age, SOC accumulated exclusively in the coarse size fraction (>50μm) in the sandy soils of southern Western Australia. In South Australian loams, regardless of pasture age, new SOC was found to accumulate in both the coarse and fine (