Water Use by Dryland Corn as Affected by Maturity Class and Plant Spacing
1976
Alessi, J. | Power, J. F.
Very early maturing hybrids of corn (Zea mays L.) have become available recently and appear to be adapted to semiarid regions. Water use information is needed for these hybrids. The purpose of this study, at Mandan, N.D., was to evaluate the effects of maturity class of corn hybrid and of plant spacing on water utilization under dryland cropping. In each of 3 years, 68 and 85-day relative maturity class hybrids were grown at plant populations of 20, 30, 40, 60, and 74 thousand plants/ha in 50 and 100-cm rows on Temvik silt loam (Typic haploboroll). The 20, 40, and 74 thousand plant populations were monitored for changes in soil water content by the neutron method both in the row and midway between rows. Neither row spacing nor location of the access tube in respect to the row had an appreciable effect upon soil water content at any sampling date. Water withdrawal by corn was generally confined to the upper 90-cm soil depth, regardless of treatment. Increased population usually increased water use during vegetative growth, leaving less water for reproductive growth. Hybrids and row spacings had less effect upon water use. Except for dry matter production by the 85-RM hybrid at the highest population, water use efficiency (WUE) was greatest at a population of 40,000 plants. While the early maturing hybrid was efficient in using water for grain production, the later maturing hybrid used water more efficiently for forage production. Results of regression analysis between yields and water use suggest that the earlier maturing hybrid would be less affected by severe drought than would the later hybrid.
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