What happens when traditional cotton country is converted to grow bioenergy crops?
That’s what a team of Texas AgriLife Research scientists will determine in a new U.S. Department of Agriculture National Institute of Food and Agriculture-funded project. The team, led by Dr. Nithya Rajan, AgriLife Research agronomist in Vernon, has been awarded a $500,000 Agriculture and Food Research Initiative bioenergy grant.
In the study, Rajan says they will help analyze how a change from the traditional cotton in the southwestern Cotton Belt to a switchgrass or biomass sorghum would affect the carbon balance, hydrologic cycle and greenhouse gas emissions.
The bioenergy grants are being offered to help ensure the U.S. can reach the goal outlined in the Energy Independence and Security Act of 2007. The act requires the U.S. to produce 36 billion gallons per year of biofuels by 2022, according to the USDA.
As outlined by USDA, the sustainable bioenergy initiative supports development of regional production systems that contribute significantly to reducing dependence on foreign oil, have net positive social, environmental and rural economic impacts, and are compatible with existing agricultural systems.
The overall goal of Rajan’s study is to investigate the energy, water, carbon and greenhouse gas fluxes associated with the change in agricultural land use to a biofuels-dominated cropping system in the semi-arid southwestern Cotton Belt region. She also will be assessing the implications of these changes on hydrological and biogeochemical processes.
The thought is that the second-generation biofuel feedstock systems will reduce the negative environmental effects associated with the conventional, intensively managed cropping systems currently in the region, Rajan said.
This would lead to a more environmentally sound system of agriculture that can promote agricultural sustainability while supporting the goals of the Biofuels Strategic Production Report, she said.
Rajan said the majority of land-use change studies previously conducted in semi-arid regions have involved the transitions from natural to agricultural systems or the return of agricultural systems to natural ones.
“Our study will build on the established, documented methodologies for investigating such land-use changes, but we will apply them to purely agroecosystems,” she said.
The study is designed to answer questions related to the transition to farming systems that “can expand our capacity to produce environment-friendly fuels in a manner that does not compete with primary food and fiber production and benefits the environment through the conservation of existing resources,” Rajan said.
“Through our research efforts, we expect to provide a comparison of the environmental impacts associated with land-use change to second generation biofuel feedstocks,” she said.
Through their modeling efforts, Rajan says they will be able to provide regional assessments of the sustainability of the second-generation biofuel cropping systems under current and possible future climate conditions.
Other research team members include Dr. Srinivasulu Ale, AgriLife Research hydrologist at Vernon, and Dr. Ken Casey, AgriLife Research air quality scientist in Amarillo.
The AgriLife Research team is collaborating with Dr. Stephen Maas, an agricultural micrometeorologist at Texas Tech University, in establishing flux towers in selected cotton, perennial grass and biomass sorghum fields to monitor carbon dioxide and water fluxes in the individual fields.
The team will then tie field data with satellite remote-sensing based upscaling methods and modeling for regional scale assessments, Rajan said. The study will require taking these flux measurements continuously for the next three years.