Modeling of Alfalfa Growth Under Different Cutting Management Systems.

Alfalfa is very important forage as a cash crop in southwest Kansas and harvested five times a year 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. This study was conducted to do crop modeling of alfalfa growth under four different cutting management systems such as harvesting three times, four times at early bloom stage, four times at mid-bloom stage, and five times a year. Parameters used in this crop modeling include air temperature, precipitation, solar radiation, soil temperature, and evapotranspiration. Correlations between alfalfa growth and these variables will be discussed to explain how weather variables affect the alfalfa yield accumulation during a growing season.