Maximizing soybean productivity and profitability by transitioning from flood to furrow irrigation on clay-textured soils

Abstract

The type of irrigation delivery system used in the mid-southern United States can have an effect on crop–water relationships and withdrawal from the Mississippi River Valley Alluvial Aquifer. This study was conducted to determine whether converting from flood irrigation to an optimized furrow irrigation delivery system improves soybean [Glycine max (L.) Merr.] grain yield, net returns, and irrigation water use efficiency (IWUE). The effects of flood and optimized furrow irrigation on soybean grain yield, net returns above specified costs, irrigation water applied, and IWUE were investigated from 2016 to 2018 on 24 paired fields with the same soil type, cultivar, planting date, and management practices in the Delta region of Mississippi. Transitioning from flood irrigation to an optimized furrow irrigation system increased soybean grain yield by 7% and net returns above specified costs by 18% but had no effect on consumptive water use or IWUE. Our data indicate that mid-southern US soybean producers should convert from flood to optimized furrow irrigation systems to maximize soybean grain yield and net returns; however, switching between irrigation delivery systems will have no effect on aquifer decline.