We explore poor farmers' incentives to adopt production systems that increase soil carbon sequestration, focusing on the impact of risk. A dynamic optimization model of conservation agriculture adoption is presented, where farmers optimize over expected utility of profits from agriculture and carbon sequestration. Adoption impacts on agricultural productivity are modeled as a combination of the technological effects of the new system, and productivity effects of changes in soil carbon on agricultural output. Comparative static results indicate increases in soil carbon sequestration price and the discount rate have unambiguous impacts on equilibrium soil carbon levels; the former leading to higher, and the latter to lower, carbon levels. Increases in the price of agricultural output and risk aversion have ambiguous impacts, depending on the relative strength of the productivity and technology effects. The paper concludes with a discussion of designing soil carbon payment mechanisms to benefit low income farmers.