Effects of Polymicrobial Bioinoculant on Yield, Quality and In Situ Digestibility of Sorghum Sudangrass in South Mississippi

With rising input costs, beef cattle producers are forced to make decisions based upon the return on investment. Chemical fertilizer application is a common used method by beef cattle producers in the southeastern United States to improve pasture yield and quality [1]. Application of 80 kg N/ha to smooth bromegrass pastures resulted in an increase of crude protein by two percentage points, and resulted in greater bodyweight gain per ha [2]. However, Mosier [3] noted that application of commercial fertilizer is often in excess of plant uptake, with the plant only fully utilizing 17-50%. With recent changes regarding commodity and fertilizer prices, the practice of fertilizer application falls under closer scrutiny. One potential method to help increase the utilization of N fertilizer may be the use of bioinocoulants. Bioincoulants are microbes that will work in conjunction with plants to increase nutrient uptake and in theory, increase yield or reduce fertilizer input. In a review, Kennedy [4] determined that certain bioincoulants could be used to crop production systems to reduce N use and enhance farm output. Hein [5] examined the use of a bioincoulant on production of rice in Vietnam, and determined that the addition of bioinoculant resulted in increases in yield of grain. In addition to the increased yield, Cong and Dung [6] demonstrated that the use of bioincoulants maintained yield with decreased fertilizer. Most of the data that exist, involve vegetables, and grains, however, it is unclear to what extent this product might enhance pasture productivity, since productivity (yield and quality) and affect animal performance [7,8]. Thus, our objective was to evaluate the effectiveness of this novel bioinoculant on DM yield, forage quality characteristics and digestibility of sorghum sudangrass.