Biological Systems Engineering


Date of this Version



Published in APPLIED ENGINEERING in AGRICULTURE Vol. 5(3):September 1989. Copyright © 1989 American Society of Agricultural Engineers. Used by permission.


Irrigated soybean production in Nebraska spans a region with diverse soils and climates. Irrigators can easily adopt irrigation scheduling using a stage of growth for timing applications. However, simplifying assumptions, including soil water holding capacity, rainfall, stored soil water, and adequate irrigation system capacity, are implicit in the development of stage of growth irrigation scheduling recommendations. Reliance on these can lead to misapplication of irrigation water.
This project tested irrigation scheduling techniques for indeterminate soybean production in Nebraska, with stage of growth indicating the initiation of irrigation. The range of soils and climate in the study area gave a range of irrigation scheduling recommendations. In the semi-arid, west-central Nebraska, full-season irrigation to meet evapotranspiration demand has been recommended. In sub-humid, south-central and eastern Nebraska, irrigation can be delayed until flowering on deep medium to fine textured soils if the potential root zone is filled at planting time.