1a.Objectives (from AD-416)
The objective of the experiment is to observe and quantify the effects of land conversion from grassland or tilled agricultural land (wheat) to a cellulosic biofuel crop of switchgrass. This project will allow cooperation by multiple institutions and multiple disciplines to study feedstock production of cellulosic biofuels on the Southern Plains.
1b.Approach (from AD-416)
Two sites of Alamo switchgrass will be established: one on the Southern Plains Range Research Station in Woodward, Oklahoma and one at the Southern Plains Experimental Range near Ft. Supply, Oklahoma. The data harvested will be watershed carbon, water, and energy fluxes; soil carbon amount and quality, biomass production, water consumption and runoff, and soil erosion. The information gathered will be used to develop recommendations for efficient biofuels production that mitigate impacts on air and water quality.
Considerable progress has been made for the on-going study of the conversion of pasture and cropland to a grass biofuel. The cropland site was planted to 'Alamo' switchgrass in the spring of 2009, and a good stand was established due to favorable rainfall. Drought conditions in 2010 resulted in considerable thinning of the switchgrass. In the spring of 2011, the cropland seed of 'Blackwell' switchgrass and sand bluestem were planted to enhance stand. Continuing severe drought conditions have prevented germination of these seeds. Existing vegetation in the grassland site was killed in the fall of 2009, and the site was planted to 'Alamo' switchgrass in the spring of 2010. Favorable rainfall conditions resulted in good stand establishment and growth. Equipment to measure the gain or loss of carbon in the form of carbon dioxide was placed on both sites. Carbon dioxide is a greenhouse gas and removal of it from the atmosphere is a desirable goal. In cooperation with colleagues at the Lawrence Berkeley National Laboratory and the University of Nebraska, we have determined that due to the severe drought experience in this area beginning in 2010 and continuing in 2011, the process of converting grassland and cropland has resulted in a slight net loss of carbon to the atmosphere. We will continue to monitor the movement of carbon to determine the response of these systems to changes in climate.
Periodic telephone conversations and emails were conducted to monitor research progress.