Estimating Water Used by Irrigated Corn in West Central Minnesota
1980
Dylla, A. S. | Timmons, D. R. | Shull, H.
Irrigation development in Minnesota is expanding rapidly on the sandy and droughty soils of which there is considerable area. Construction of suitable wells into underlying gravel aquifers has facilitated the rapid growth. The objective of this study was to measure water use by irrigated corn in west central Minnesota for comparing with current estimating methods for irrigation scheduling. Lysimeters, 1.75 m diam by 1.22 m deep, located in irrigated corn (Zea mays L.) plots were used to measure water use or evapotranspiration (ET) amounts. Four years of comparisons were made of measured ET to amounts calculated with the standard and refined Jensen-Haise potential ET equations and corn crop coefficients from southeastern North Dakota data. Measured ET was also compared with ET estimates determined by the Lundstrom-Stegman “checkbook method,” and by crop coefficients with pan evaporation. Crop coefficients with pan evaporation provided the better ET estimates, however, the “checkbook method” was the simplest and was about as accurate for estimating ET as the Jensen-Haise potential ET equation with southeastern North Dakota crop coefficients.
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