Grain sorghum and corn comparisons: Yield, economic and environmental responses

Abstract

Grain sorghum (Sorghum bicolor (L.) Moench) is often grown where water stress is expected. But, improved drought tolerance in corn (Zea mays (L.)) hybrids has resulted in increased dryland corn production in preference to grain sorghum. However, grain sorghum may still have a yield advantage over corn in drought prone environments. This study was conducted to determine if grain sorghum has either a yield or economic advantage over corn when drought or temperature stress occurs. . Yield and weather data from crop performance testing programs in Kansas and Nebraska (1992 - 2005) were analyzed. Grain sorghum produced higher yields than corn in environments where corn yields were less than 6.4 Mg ha-1. When net returns ($ ha[superscript]-1) were considered for grain sorghum prices that were set at 70, 87, 100, and 117% of corn prices, grain sorghum net returns were higher than corn net returns when corn yields were equal to or less than 4.4, 6.6, 8.8, and 13.6 Mg ha[superscript]-1, respectively. Both corn and grain sorghum yields were positively correlated to June through August precipitation and negatively correlated to June through August maximum temperatures. The yield difference (grain sorghum minus corn) increased as July and August maximum temperatures increased. Monthly minimum temperatures affected corn yield less than grain sorghum yield. Producers in this region likely can minimize production risks by considering this historical yield information. At locations in this region where corn yields are consistently less than 6.4 Mg ha[superscript]-1, producers should consider producing grain sorghum.