Large scale biomass production that will permit a significant substitution for fossil fuels will require substantial irrigation water and land. While the southwest U.S. region such as west Texas and southern New Mexico has adequate marginal lands, finding reliable water sources to produce bioenergy crops is the main challenge. This challenge can be met by making marginal quality water (MQW) sources available for bioenergy crops production.
Dr. Yanqi Wu of the Plant and Soil Sciences Department, Oklahoma State University, collaborated with the project leader from Texas A&M University (TAMU), Dr. Girisha Ganjegunte, and other co-leads Drs. Genhua Niu (TAMU), Samuel Zapata (TAMU), Juan Enciso (TAMU), April Ulery (New Mexico State University (NMSU)), and Robert Flynn (NMSU) to evaluate the potential for alternative water sources to produce select biofuel crops on marginal lands.
“We evaluated salt tolerance of various cultivars of energy sorghum, switchgrass, and canola; crop performance and soil property changes under field conditions; and economic feasibility of bioenergy crops production using alternative waters on marginal lands,” Ganjegunte said.
“Our results indicated select cultivars of switchgrass, energy sorghum, and canola are relatively salt tolerant,” Ganjegunte said. “Among the switchgrass cultivars, “Alamo” was the most salt tolerant, while AR91004, DKL 30-42, Summer, and Wichita were the salt tolerant canola cultivars and ES5200 cultivar of energy sorghum,” Wu and Niu added.
“We also observed that biomass and seed yields obtained under saline MQW were comparable to that under freshwater irrigation. Soil salinity increased in saline water irrigation plots, but did not adversely affect the biomass and seed yields,” Ganjegunte said.
“Our economic analyses suggested that energy sorghum is the feedstock with highest probability of economic success followed by canola and switchgrass,” Zapata said. “A positive net return to farmers of $38.85 per acre is expected for energy sorghum,” Zapata added.
The information and best management practices developed as a result of this project should enable interested growers to undertake cultivation of bioenergy suitable for the study region. In addition to crop diversification, enhanced use of MQW can potentially extend the availability of existing freshwater resources in the region.
Funding of this project was provided by the U.S. Department of Agriculture-National Institute of Food and Agriculture (USDA-NIFA) through the South Central Sun Grant Program.