Effects of cutting frequencies on the yield and quality of Longdong alfalfa in the Loess Plateau

A unicast experiment was conducted in the Loess Plateau from 2012 to 2013 in order to explore the rational utilization of Longdong alfalfa (Medicago sativa ‘Longdong’) grassland. This experiment was divided into two utilization modes, i.e., multiple mowing and one mowing. The results showed that plant height accumulation, branch number accumulation, total yield, crude protein (CP), crude fat (EE) and crude ash (Ash) yields of Longdong alfalfa under multiple cutting condition were significantly higher than those under one cutting condition after two years experiment. However, the content of neutral detergent fiber (NDF) and acid detergent fiber (ADF) under multiple cutting condition were significantly lower than those under one cutting conditions The correlation analysis showed that the yield was positively correlated with plant height, number of branches, CP, Ash, NDF and ADF content under one cutting condition (P < 0.05). Under multiple cutting condition, the yield was positively correlated with plant height, branch number, CP, and EE content (P < 0.01) and negatively correlated with NDF and ADF content (P < 0.01). In conclusion, multiple cutting can increase alfalfa hay yield and yield more nutrients than that by one cutting, which is a suitable management measure for Longdong alfalfa grassland in the Loess Plateau.