Maximizing Stomatal Control and Root System to Optimize Water-Use Efficiency in Soybeans.

摘要

Soybean and grain sorghum roots have been studied in relation to rate of root extention,rooting depth,dry matter distribution in the soil profile,soil water use and flux,and physiological stages of development under irrigated and nonirrigated conditions. Soybean roots reached a depth of 160cm in a barrier-free soil 15 1/2weeks after planting date in both irrigated and nonirrigated treatments. Sorghum roots reach maximum depth (150cm) much quicker than soybean roots (7weeks after planting date). Soil moisture inventories showed that sorghum conserves soil moisture early in the season, a phenomenon related to stomatal resistance. Stomatal resistance may be useful for scheduling irrigations in soybeans and sorghum.