Effects of Irrigation and Row Spacing on Evapotranspiration and Microclimate of a Sorghum Field.

摘要

An evapotranspiration model was tested over the 1973growing season at Manhattan,Kansas. The model predicted daily evapotranspiration rates that were within one to two mm of lysimetric estimates. Evaporation accounted for 22percent of the seasonal evapotranspiration. Energy balance over wide and narrow row sorghum indicated within row advection early in the growing season and large scale advection at near maturity. Advection was greater in the wide-row sorghum. Seasonal evapotranspiration rates were 54and 52cm for the narrow and wide row sorghum,respectively. Hourly net carbon dioxide exchange rates were determined for wheat,sorghum and soybean. Sorghum canopy had nearly twice the net carbon dioxide exchange of the wheat and soybean canopies.