1. Management Practices of Sweet Sorghum forOptimal Production and Water Use Efficiency in Texas
W. D. Rosenthal, W. Harman, J. Blumenthal, and B. Bean. Texas Agricultural Experiment Station—Temple, Texas and Texas A&M University
40-Yr. Simulations
Introduction
Plant Config.
Calibration
Sweet sorghum (Sorghum bicolor L. Moench) has received increased interest as a potential crop to produce ethanol for fuel in the U.S. Other countries already produce sweet sorghum for ethanol (Gnansounou et al., 2005; FAO, 2002) With ethanol plants being built through the Great Plains and Texas, the crop ahs potential possibilities for markets. However nitrogen and irrigation management practices need to be determined for different production areas of Texas. This poster summarizess field and simulation (WinEPIC) (Williams, et al., 1984) production results and potential production of sugar for ethanol in south-central Texas.
College Station – Irrigated 2006
Planting—April 10
1st harvest—July 10
2nd harvest—October 3
Fertilizer—100 # N, 60 # P at planting
--100 #N at end of 1st harvest
Irrigations—2 first crop
3 second crop
Amarillo – Irrigated 2006
Planting—May 25
Harvest—November
Irrigation—31.5 cm
College Station – Irrigated 2006
Observed Simulated
First Crop T/ha T/ha
Ratoon Crop T/ha T/ha
Ethanol produced
first crop 366 L/ha --
second crop 245 L/ha --
Amarillo – Irrigated 2006
First Crop T/ha
Crop Parameters
Methods
Default New
Biomass energy ratio
Biomass energy decline
rate
Fract. of growing season
LA declines
LAI decline factor
Lower limit of HI
Max. root depth (ft)
Base T (oF)
Optimum T (oF)
Summary
Use the EPIC (Erosion Productivity Impact Calculator) (Williams et al. 1984) model to simulate
Conventional grain sorghum yields
Calibrate forage yields to observed data
Simulate potential forage yields for first and
ratoon crops in south-central Texas and Amarillo
a.dryland and irrigated (3 inches per irrigation)
b. 200 and 300 # N (planting and end of
first harvest)
c.flexible and fixed harvest dates
Hypothesis
Flexible harvests for ratoon crops can vary more than 1 month (Sept. 20-Nov 20)
Improved nitrogen and irrigation management can increase yields by approximately 10%
Increased growth temperature regimes influences production
Forage sweet sorghum can be grown as first and ratoon crops in south-central and panhandle ofTexas
Objective
References
Determine nitrogen and irrigation management practices for sweet sorghum in south-central and panhandle of Texas
Williams, J. R., C. A. Jones, P. T. Dyke A modeling approach to determining the relationship between erosion and soil productivity. Trans. ASAE 27:
FAO Sweet sorghum in China. IN: World Food Summit, 5 Years later. Agricul. Dept. Food & Agric. Org. of the United Nations (FAO).
Gnansounoou, E. A. Dauriat, and C. E. Wyman Refining sweet sorghum to ethanol and sugar: economic trade-offs in the center of North China. Georesource Technology 96: