Impact of Sorghum Induced Land Use Change on Carbon and Energy Balance in Texas High Plains.

According to the United States’ strategic plan, biofuel production will be increased to meet future energy requirements. The Texas High Plains region is one of the regions identified by USDA for biofuel crop production. Sorghum (Sorghum bicolor L) as a potential biofuel crop is already inducing land use change by replacing the conventional cotton (Gossypiumhirsutum L) cropping system in the region. Land use change modifies the soil and other environmental properties, especially carbon dynamics and energy balance closure. Thus, the objective of this study is to compare the impact of cotton, forage sorghum and perennial grassland on the carbon dynamics and energy balance closure of the Texas High Plains region. The study was conducted on three sites planted with cotton, sorghum, and perennial grass (Old World Bluestem, BothriochloaBlashii S.T. Blake). Eddy covariance towers had been installed in each field to measure carbon dioxide and water vapor exchange between the atmosphere and plant canopy. Net radiation, air temperature, relative humidity, soil heat flux, soil moisture, and soil temperature were also measured. Plant measurements included plant height, leaf area index, dry biomass, and yield. Data collected in 2013 indicated greater biomass carbon accumulation by sorghum than cotton and Old World Bluestem.