Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Agricultural Engineering

First Advisor

Darrell W. DeBoer


Water balance and economic analyses of a five-year tillage and irrigation study in South Dakota were performed. Three primary tillage, preplant, operations (Plow, Disk and Till-Plant), two secondary tillage, post-emergence, operations (Inter-Row Tillage and a Control), and four sprinklers operating at pressures of 41 to 344 kPa were studied. Surface runoff, soil water storage and evapotranspiration values were 8, -8 and 100% of total water input values during a study period from late June to mid-August. Evapotranspiration values averaged 7.1 mm/day for the study period. Deep percolation loss was calculated to be zero. The Inter-Row Tillage treatment produced less surface runoff and more soil water storage than the Control treatment. Pumping and til1age costs were used in the economic analysis, with pumping cost being the dominant parameter. The Disk primary tillage treatment and Inter-Row secondary tillage treatment were economically superior to the other tillage treatments. One of the research goals was to obtain field data concerning the fate of water inputs for irrigated corn in central South Dakota. Of particular interest was daily evapotranspiration demand, because it is a primary parameter used in irrigation scheduling procedures. Field evapotranspiration data are limited for South Dakota conditions. Another research goal was to use the water data set as a basis for economic evaluation of the tillage/sprinkler combinations and to determine feasible management alternatives for irrigators.

Library of Congress Subject Headings

Conservation tillage

Water conservation

Irrigation efficiency

Corn -- Irrigation



Number of Pages



South Dakota State University