Determining the impact of climate and soil variability on switchgrass (Panicum virgatum L.) production in the south‐eastern USA; a simulation study

Abstract

AbstractSwitchgrass (Panicum virgatum L.) is a perennial warm‐season grass native to North America. The species is currently being evaluated as a potential feedstock for bioenergy. Growth and yield of switchgrass vary substantially due to weather and soil conditions. The objective of this study was to determine the impact and implications of weather, climate, and soil variability on switchgrass production in the south‐eastern USA using a crop simulation model. We simulated switchgrass growth and yield as a function of weather, soil, and crop management with the Agricultural Land Management Alternative with Numerical Assessment Criteria (ALMANAC) model. The model was first evaluated with switchgrass data from five field experiments conducted throughout Alabama. Subsequently, switchgrass growth and yield were simulated for climate and soil conditions representing the Tennessee River Valley region of northern Alabama and Georgia. Based on the simulations, we evaluated switchgrass production potential in this region under different climate and land‐use scenarios. Weather data from the 1950s, 1960s, and 1980s were included to account for the climate variability during the twentieth century. The average annual simulated switchgrass yield across the region was significantly (P < 0.05) higher for the 1950s (13 740 kg d.m. ha−1) and the 1980s' climate (14 162 kg d.m. ha−1) than for the 1960s' climate (12 492 kg d.m. ha−1). The annual production potential for the region ranged from 64 977 and 83 915 metric t due to spatial variability in climate and soil conditions. Using results and implementing the approach from this study can help plan switchgrass‐based bioenergy systems. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd