Response of Corn to Tillage and Delayed Irrigation1
- I. Porro and
- D. K. Cassel2
Irrigation in humid regions is often delayed based on forecasted rainfall or due to labor shortages or equipment problems. The effects of tillage and delayed irrigation on corn (Zea mays L.) were investigated in 1982 and 1983 on a Norfolk loamy sand (Typic Paleudult) with a tillage pan. Irrigation treatments were: optimum irrigation when tensiometer measured soil water pressure at the 25- or 30-cm depth was −40kPa; 2day and 4-day delays after irrigation was needed, and a nonirrigated control. Each irrigation treatment was superimposed on land prepared by two tillage treatments: (i) conventional and (ii) subsoiling and bedding. Delayed irrigation during a wet growing season (1982) had little effect on corn growth. Delayed irrigation during the dry growing season (1983) reduced plant height, leaf area, biomass, and grain yield on conventionally tilled soil but only grain yield on subsoiled plots. With a 4day irrigation delay, grain yields were reduced 29% below the 10.22 Mg ha−1 yield for conventional tillage but only 11% below the maximum of 10.56 Mg ha−1 for subsoiling. Irrigation in 1982 increased mean grain yield of all three delay treatments by 23 and 1% for conventionally tilled and subsoiled treatments, respectively. In 1983, these increases were 314 and l8%, respectively. A 1-yr subsoiling carryover (1983) resulted in a yield of 8.89 Mg ha−1 vs. a current-year subsoiled yield of 10.68 Mg ha−1. A 2-yr carryover (1982) resulted in a yield of 9.60 vs. 10.60 Mg ha−1 from current year subsoiling.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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