Simulating Switchgrass Biomass Yield and N Removal Using Almanac.

An accurate growth model for switchgrass (Panicum virgatum L.) is needed to support decision-making on timing of harvest to predict biomass yield as a function of soil and weather conditions and to maximize resource-use efficiency. The aim is to calibrate ALMANAC model to simulate seasonal changes in biomass yield and incorporate new logic for simulating N removal in harvested biomass for Arkansas conditions. Plots were established in 2008 in Fayetteville, AR, with cv. Alamo and were sampled approximately monthly from early May 2009 to mid-February 2010, and again in 2010-2012. Simulations using ALMANAC will be used to test and improve the predictive ability of the model for biomass yield using a calibration from the 2009 growing season.