Grain sorghum growth, water use, and yield in contrasting soils

Abstract

Soil characteristics and the climate in which they occur help control crop growth and yield. We conducted a study to determine the influence of contrasting soils on grain sorghum ( Sorghum bicolor Moench) growth, water use, and yield. In 1992 and 1993, grain sorghum (‘DK-46’) was grown in 0.75-m rows with 16 plants m −2 at Bushland, TX in lysimeters containing monolithic soil cores of silty clay loam, silt loam, and fine sandy loam. The 1992 irrigation treatments were well-watered (WW) and no applied early season irrigation to achieve a pre-anthesis water stress. The 1993 irrigation treatments were WW with limited irrigation during late vegetative and reproductive growth stages to achieve a post-anthesis water stress. The crop in the silt loam soil produced lower grain yield in 1993 under high soil water conditions, but greater grain yield, total biomass, and seed number under reduced irrigation compared with the crop on the clay loam. The crop in the sandy loam consistently produced the lowest leaf areas and yield components in all irrigation treatments, possibly due to high soil bulk densities which may have restricted rooting. The 1993 crop in the silt loam had the highest water use in all treatments, and extracted water uniformly throughout the profile in both years. High strength silty clay and clay horizons and possibly a calcic horizon in the silty clay loam may have delayed or limited rooting, and affected crop growth and yield. The crop in the sandy loam consistently produced the lowest yield components in all irrigation treatments, possibly due to restricted rooting resulting from high bulk densities and also low water holding capacity.