Eddy covariance quantification of corn water use and yield responses to irrigations on farm‐scale fields

Abstract

AbstractFurrow irrigations dominate row‐crop irrigation scenarios in many regions worldwide. In this study, corn (Zea mays L.) yield and evapotranspiration (ET) in an all‐furrow irrigation (FI) were compared against irrigations applied through alternate furrows irrigation (SFI, skip‐furrow irrigation) and rainfed (RF) systems on farm‐scale fields in 2017 and 2019 {corn phases of a soybean [Glycine max (L.) Merr.]–corn rotation} in clay soil in the Lower Mississippi Delta region, United States. Evapotranspiration was monitored using the eddy covariance (EC) method. The average corn yield in the SFI was significantly (12.1 Mg ha−1) higher (4.9%) than in the FI (11.7 Mg ha−1). Corn yield in RF (10.2 Mg ha−1) was significantly lower (10.7%) than in the FI. However, the leaf area index (LAI) in SFI was lower than in FI. Seasonal average ET was 556, 573, and 540 mm in FI, SFI, and RF, respectively. The average water use efficiencies (WUEs) were 0.021, 0.021, and 0.019 Mg ha−1 mm−1, respectively (10.5 % lower in RF than FI and SFI). This investigation revealed that adapting the SFI irrigation regime in the corn cropping system could produce grain yields equal to or higher than corn grown under the conventional FI, saving ∼40% of irrigation water. The farm‐scale studies conducted in this investigation gave better confidence to recommend SFI to replace conventional FI systems in the region for water conservation in corn cropping systems. Further investigations may be needed to evaluate the viability of SFI in other contrasting soils and climates and recommend the system for adoption by the farming community.