Furrow irrigation spacing effects on corn production in vertisols of the Mississippi Delta

The majority of soils in the Mississippi Delta are vertisols, whose shrink–swell behavior makes them prone to waterlogging when subjected to excessive infiltration amounts from conventional management of furrow irrigation. The goal of this investigation was to examine if corn (Zea mays L.) grain yield and quality (test weight, kernel composition, and kernel weight) can be improved in vertisols of this region by widening furrow irrigation spacing while increasing furrow inflow rate proportionally to reduce waterlogging. A research station study at the National Center for Alluvial Aquifer Research and an on-farm study near Glen Allan, Mississippi, were conducted from 2021 to 2023. Furrow irrigation spacing treatments in the research station study included 3.3 ft, 6.7 ft, 13.3 ft, and 26.7 ft. The on-farm study included 10 ft, 20 ft, and “tractor track” (alternating between 10 and 30 ft furrow irrigation spacing) treatments. The three years of the research station study showed that the 26.7-ft treatment yielded 8.5% higher than the narrower treatments at the top position of the field (50–100 ft from the topographically higher end of 500 ft furrows). Higher grain protein and kernel weight were observed halfway between two irrigated furrows of the 13.3-ft and 26.7-ft treatments than adjacent to irrigated furrows of any treatment. Corn grain yield in the on-farm study was not significantly different among furrow irrigation spacing treatments. This research demonstrates that furrow irrigation spacing can be widened to at least 26.7 ft in vertisols of the Mississippi Delta without decreasing corn grain yield and quality.