Profitability of Beef and Biomass Production from Native Warm-Season Grasses in Tennessee

Native warm-season grasses (NWSGs) have demonstrated potential to reduce summer forage variability, and furthermore, there has been growing interest in the use of NWSGs as lignocellulosic biomass crops. The objective of this research was to determine if there was a difference in net returns for full-season summer grazing beef steers (Bos taurus) on three NWSGs. Additionally, the expected price for biomass that a beef producer would need to break even between using the dual-purpose early-season grazing and biomass system and the full-season grazing system was calculated for these three NWSGs. Weaned beef steers grazed switchgrass (Panicum virgatum L.) (SG), a big bluestem (Andropogon gerardi Vitman) and indiangrass [Sorghastrum nutans (L.) Nash] mixture (BBIG), and eastern gamagrass [Tripsacum dactyloides (L.) L.] at Grand Junction (AP) and Highland Rim (HR), TN, from 2010 to 2012. The dual-purpose grazing occurred for 30 d beginning in early May, with subsequent growth harvested as biomass post-dormancy, and full-season grazing occurred for 90 d beginning in early May. Budgets were developed for each NWSG to calculate net returns, and mixed models were used to determine differences in beef yield and net returns across each NWSG and location. Expected yield and net returns to full-season grazing were not different among NWSGs at AP. However, net returns to full-season grazing were higher for BBIG than SG at HR. A profit-maximizing, risk-neutral individual would increase net returns by grazing any of the NWSGs over marketing calves at weaning. The breakeven biomass prices ranged between US$10 and US$98 Mg-1 depending on the NWSG and location.