Premium
Evapotranspiration and Water Use Efficiency by Soybean Lines Differing in Growth Habit 1
Author(s) -
Singh B. P.,
Whitson E. N.
Publication year - 1976
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1976.00021962006800050042x
Subject(s) - evapotranspiration , canopy , water use efficiency , environmental science , water use , agronomy , leaf area index , botany , biology , ecology , irrigation
Determinate and indeterminate soybeans [ Glycine max (L.) Merr.] differ in canopy morphology due to a difference in their growth habits. Canopy morphology may affect receipt and loss of radiation, air circulation, and eddy turbulence. These factors may in turn influence heat and water vapor transfer, thereby possibly influencing plant water use. The objective of this study was to determine the effects of soybean growth habits on evapotranspiration and water use efficiency. The daily evapotranspiration rate for both lines was maximum at the early reproductive stage. Water extraction by both lines extended to a l22cm soil depth, the lowest depth measured. The total evapotranspiration by the determinate line was 41.2 cm as compared to 39.2 cm for the indeterminate line. The difference in evapotranspiration as a result of the difference in growth habits amounted to only a small fraction of the total evapotranspiration. The determinate line produced 24.9% more main than the indeterminate line by utilizing only 5.6% more water. This accounted for an 18.1% greater water use efficiency of the determinate line. These values suggest that growth habits affect water use efficiency primarily by controlling grain yield.