Potential production and environmental effects of switchgrass and traditional crops under current and greenhouse-altered climate in the central United States: a simulation study

Abstract

If, as many climate change analysts * speculate, industrial and other emissions of CO 2 can be offset by substitution of biofuels, large areas of land, including agricultural land, may be converted to the production of biomass feedstocks. This paper explores the feasibility for the Missouri-Iowa-Nebraska-Kansas (MINK) region of the US of converting some agricultural land to the production of switchgrass (Panicum virgatum L.), a perennial warm season grass, as a biomass energy crop. The erosion productivity impact calculator (EPIC) crop growth model simulated production of corn (Zea mays L.), sorghum (Sorghum bicolor (L.) Moench), soybean (Glycine max L.), winter wheat (Triticum aestivum L.) and switchgrass at 302 sites within the MINK region. The analysis is done for both current climatic conditions and a regional climate model-based scenario of possible climate change. Daily climate records from 1983 to 1993 served as baseline and the NCAR-RegCM2 model (RegCM hereafter) nested within the CSIRO general circulation model (GCM) provided the climate change scenario. Crop production was simulated at two atmospheric CO 2 concentrations ([CO 2 ]) at 365 and 560 ppm to consider the CO 2 -fertilization effect. Simulated yields of the perennial switchgrass increased at all sites with a mean yield increase of 5.0 Mg ha −1 under the RegCM climate change scenario. Switchgrass yields benefited from temperature increases of 3.0-8.0 • C, which extended the growing season and reduced the incidence of cold stress. Conversely, the higher temperatures under the RegCM scenario decreased yields of corn, soybean, sorghum and winter wheat due to increased heat stress and a speeding of crop maturity. With no CO 2 -fertilization effect, EPIC simulated maximum decreases from baseline of 1.5 Mg ha −1 for corn, 1.0 Mg ha −1 for sorghum, 0.8 Mg ha −1 for soybean and 0.5 Mg ha −1 for winter wheat. Simulated yields increased for all crops under the RegCM scenario with CO 2 set to 560 ppm. Yields increased above baseline for 34% of the soybean and 37% of the winter wheat farms under RegCM/[CO 2 ] = 560 ppm scenario. Water use increased for all crops under the higher temperatures of the CSIRO scenario. Precipitation increases resulted in greater runoff from the traditional crops but not from switchgrass due to the crop's increased growth and longer growing season. Simulated soil erosion rates under switchgrass and wheat cultivation * Corresponding author. Tel.: +1-202-646-5204; fax: +1-202-646-5233. E-mail address: robbie.brown@pnl.gov (R.A. Brown).0167-8809/00/$ -see front matter ©2000 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 7 -8 8 0 9 ( 9 9 ) 0 0 1 1 5 -2 32 R. A. Brown et al. / Agriculture, Ecosystems and Environment 78 (2000) [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] were less severe than under corn management. However, simulated erosion under switchgrass was considerable in eastern Iowa during the period of crop establishment because of strong winds at that time.

Midwest vision for sustainable fuel production

“…This region encompasses a high concentration of prime cropland and benefits from a humid continental climate. Annual precipitation varies to some extent in an east-west gradient across the region, but is generally sufficient for dryland crop production [4]. More pronounced are seasonal temperature gradients that occur along a north-south axis and influence the length of the growing season and severity of winter.…”

Resistance and Resilience of A Stream Salamander To Supraseasonal Drought

“…Bioenergy crops are projected to compete successfully for agricultural acreage at a price of US$33/10 6 g, or about US$1.83/10 9 joules (Walsh et al, 2003). Warming and precipitation increases are expected to allow the bioenergy crop, switchgrass, to compete effectively with traditional crops in the central USA (based on the RegCM2 model and doubled CO 2 concentration) (Brown et al, 2000). [WGII 14.4.8] …”

Stress-Tolerant Feedstocks for Sustainable Bioenergy Production on Marginal Land

“…At the whole-plant level, synthesis of HSPs increases tolerance of temperatures that could otherwise be lethal [29,210]. Although HSPs protect cells against damage, the heat shock response increases the rate of maturation in crops and can decrease yields [211]. Further, the heat shock In addition, several varieties ("Alpha," "India," "Owasco," "Tully Champion," and "01X-268-015") showed no reduction in growth with severe salinity (EC(e)≤8.0 dS/m) [176].…”

“…Even though plant height and total biomass decreased under heat stress [249], a climate modeling paper shows that Panicum virgatum yields could increase under warmer climate scenarios (3 to 8°C), due to extended growing season and limited cold stress [211].…”