Research has suggested that carbon can be captured through changes in farming practices, thereby helping California reach its greenhouse gas emission reduction goals as put forward under the California Global Warming Solutions Act of 2006, Assembly Bill 32, (Nunez, Chapter 488, Statutes of 2006). This study assessed the potential and economic feasibility of soil carbon sequestration and reduction of trace gas emissions in California agricultural soils. To accomplish this, the researchers integrated databases that include geographic data on environmental factors and land use data with ecosystem simulation models and economic analyses. The resulting assessment tool analyzes land use and management impacts on carbon stocks and associated greenhouse gas fluxes between California agricultural soils and the atmosphere. The study found that adjusting farming practices could reduce greenhouse gas emissions by about 0.5 to 3 megagrams of carbon dioxide equivalent per hectare per year. The variation in this number is mainly on the type of farming practice used. This potential increased in the following order: low nitrogen fertilizer input, reduced tillage, manure application, and winter cover cropping. Even higher potentials could be reached when these single management options are combined. However, the uncertainty around the carbon reduction potentials of a single field remains large. More research is needed to reduce this uncertainty.
