Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)


Agricultural Engineering

First Advisor

D.W. DeBoer


A computer model using available weather data was developed to estimate the irrigation requirement, in terms of rate and depth, for east-central South Dakota. The model simulated corn and alfalfa production under center pivot irrigation for various soil types and water management practices. Management Method I applied 25.4 mm when 39.1 mm was depleted from the root zone, thus forming a 12.3 mm buffer for precipitation. Management Method II applied an irrigation when the percent soil water reached depletion levels which varied through the season to conserve water. Net irrigation capacities of 6 mm/day were adequate for maximum corn and alfalfa production. Under Management Method I, net seasonal irrigation depths of 400 mm to 440 mm and 525 mm were required for corn and alfalfa respectively. Management Method II reduced net seasonal irrigation 50 mm to 160 mm for corn and 120 mm to 200 mm for alfalfa. However, additional yield reductions of 3.5% to 7.5% and 6.0% to 10.0% could be expected for corn and alfalfa using the water conservation approach of Management Method II when compared to Management Method I.

Library of Congress Subject Headings

Irrigation -- South Dakota
Crops -- Water requirements -- South Dakota



Number of Pages



South Dakota State University


No Copyright - United State