Water Resource Management Integrated Agricultural Systems

Summary: Predictions of forage production derived from site-specific environmental information (e.g., soil type, weather, plant community composition, and management) could help land managers decide on appropriate stocking rates of livestock. This study assessed the applicability of the Great Plains Framework for Agricultural Resource Management (GPFARM) forage growth model for both strategic (long-term) and tactical (within-season) prediction of forage production in northern mixed-grass prairie. An improved version of the model was calibrated for conditions at the USDA–ARS High Plains Grasslands Research Station in Cheyenne, Wyoming. Long-term (1983–2001) simulations of peak standing crop (PSC) were compared to observations. Also, within-season (1983) forecasts of total aboveground biomass made for 1 March onward, 1 April onward, 1 May onward, and 1 June onward were compared to observations. The normal, driest, and wettest weather years on record (1915–1981) were used to simulate expected values, lower bounds, and upper bounds of biomass production, respectively. The forage model explained 66 % of the variability in PSC from 1983 to 2001. The cumulativ