Effect of irrigation regimes and planting patterns on maize production in humid climates

Abstract

Twin-row planting in maize (Zea mays L.) has potential for reducing plant-crowding stress for optimizing grain yield and resource use. A study was conducted in 2020 and 2021 on a Dundee silt loam in the Lower Mississippi Delta (LMD) region of the United States to evaluate maize grain yield and irrigation water use efficiency (IWUE) in single-row (SR) and twin-row (TR) planting patterns with same seed rate under four irrigation regimes: rainfed (RF), all-furrow irrigation (FI), alternate-furrow irrigation (AFI), and every third-furrow irrigation (TFI). The TR enhanced grain yield by 9.2% in 2020 and 10.9% in 2021 over the SR system. The average final plant density at the reproductive phase was highest under AFI (73,900 ha−1) and lowest under RF (70,480 ha−1). Across all irrigation regimes, the leaf area index was significantly higher in the TR system. Average grain yields under SR were 10.01, 10.44, 9.48 and 9.10 Mg ha−1, respectively, in FI, AFI, TFI and RF; average grain yields under TR were 11.58, 11.32, 10.13 and 9.91 Mg ha−1. The AFI and FI recorded similar grain yields. The IWUE was highest in TR planting (0.028 kg m−3), followed by SR planting (0.024 kg m−3) under AFI. The IWUE of TFI in TR planting was 0.020 kg m−3 and in SR was 0.011 kg m−3. Economic analysis revealed that the TR-FI and TR-AFI had average profits of 446 and 432 US$ ha−1, respectively. The study suggests that maize producers in the LMD can save a significant amount of irrigation water without compromising grain yields by adapting the AFI-TR system.