The Australian government has identified soil carbon sequestration on agricultural lands as a potential strategy to offset greenhouse gas emissions. Industry and government claim providing positive incentives for farmers to change their land management will be cost can result in significant carbon sequestration in agricultural soils. There is, however, little information about the costs or benefits of agricultural soil carbon sequestration to test these claims. The objective of this study is to assess the costs of alternative land-use and land practises that will increase soil carbon sequestration, for a case study of the WA Wheat belt. The analysis integrates biophysical modelling of carbon sequestration with whole-farm economic modelling, to evaluate the cost-effectiveness of alternative carbon storage practices. Preliminary results suggest that, even under low commodity price scenarios, the opportunit sequestering carbon are considerable. We discuss the implications of our findings for policy development.