Effect of Soil Moisture and Temperature on Soil Carbon Flux from a Conventional Cotton Cropping System.

In intensively managed agroecosystems, management practices such as tillage, fertilization and irrigation during the growing season can result in major changes in the soil environment and these changes can potentially lead to levels of carbon dioxide emissions that are several orders of magnitude above the typical undisturbed background rates. In addition to the type of crop and management practices, surface hydrological conditions play an important role in determining the rate and evolution of these emissions. This loss of soil C is a major factor in determining the source–sink relationships of agroecosystems. Although irrigated cotton (Gossypium hirsutum L.) in the semiarid Texas High Plains is a major cropping system in the region, the C exchange processes and their contribution to regional C balance has not been adequately studied. This study focuses on estimation of soil carbon dioxide flux from a conventional cotton cropping system in the Texas High Plains and its relation to soil temperature and soil moisture conditions.