Cutting Frequency Effects on Yield and Nutritive Values of Alfalfa.

Alfalfa is harvested five times a year in southwest Kansas under irrigation. Alfalfa hay is a very important feed for both dairy and beef. Proper harvest management is essential for profitable alfalfa production, particularly manipulation of forage quality and yield. Within reason, fewer cuttings per season generally result in higher yield per season, but at the expense of forage quality. Producing more tonnage of alfalfa forage may be more important for producers’ profitability than higher forage quality with lower alfalfa yield. Also, with cost of fuel continually increasing, this study may help reduce fuel usage by harvesting less frequently than typical five cuttings per year. The objectives of this research are: 1) to assess how cutting frequency affects dry matter yield, nutritive value of alfalfa production in southwest Kansas; and 2) to determine the optimum cutting frequency that improves water use efficiency, reduces input costs (fuel, labor) and maintains alfalfa forage yield and forage quality. Based on one year data in 2013, the highest alfalfa yield (4.27 dry tons per acre) occurred at cutting four times a year at mid-bloom stage. On average, harvesting more frequently such as cutting alfalfa five times a year had the highest crude protein contents than other cutting treatments and no difference in crude protein was found between early – and mid-bloom stages in four cutting treatment. Total digestible nutrients (TDN) and relative feed value (RFV) values were increased as the cutting interval was decreased. When considering both dry matter yield and forage nutritive values, cutting alfalfa four times a year at mid-bloom stage appears to be better practice than cutting alfalfa 3 times, 4 times at early bloom stage, and 5 times a year in Garden City, KS.