Organic carbon accumulation in soil under perennial pastures in southern New South Wales, Australia

This thesis tests the following hypotheses, that 1) within a given climate, parent material dominates management in determining OC in soil under perennial pastures because parent material determines the soil properties that influence plant production and OM protection, 2) within a given climate and parent material, there is more OC in soil under introduced compared with native perennial pastures due to higher soil nutrient status associated with soil nutrient management programs and greater OM supply to soil under introduced perennial pastures and 3) for a given soil type, soil with a high OC concentration will continue to accumulate OC in a relatively stable form if both C and nutrient inputs are maintained. Climate, parent material, soil depth and soil fertility significantly influenced the stock of OC in soil, while the type of vegetation (native vs introduced ppastures and crop vs pasture) did not.