Effect of irrigation regimes and planting patterns on corn (Zea mays L.,) water use efficiency and on-farm profitability in humid climates

Authors: PINNAMANENI, SRINIVASA - Oak Ridge Institute For Science And Education (ORISE); Anapalli, Saseendran; Reddy, Krishna

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/15/2022
Publication Date: 4/18/2023
Citation: Pinnamaneni, S.R., Anapalli, S.S., Reddy, K.N. 2023. Effect of irrigation regimes and planting patterns on corn (Zea mays L.,) water use efficiency and on-farm profitability in humid climates. Agronomy Journal. https://doi.org/10.1002/agj2.21221.
DOI: https://doi.org/10.1002/agj2.21221

Interpretive Summary: In recent years, the Mississippi (MS) River Valley Alluvial aquifer has declined considerably due to overdraft of water withdrawals for irrigation incommensurate to its natural recharge levels, threatening the sustainability of irrigated agriculture in the Lower Mississippi Delta. To reduce further decline of this aquifer, crop-irrigation management practices need to be an efficient while sustaining farm productivity and profitability. To address this, scientists with the USDA-ARS Crop Production Systems Research Unit and Sustainable Water Management Research Unit, Stoneville, MS, conducted an experiment by varying corn planting geometry and irrigation regimes during 2020 and 2021. The results of the study indicated that about 10 % yield advantage in grain production by adopting a twin-row compared to single-row planting. Alternate-row irrigation reduced irrigation water consumption significantly without any yield reduction in comparison with every row irrigation. This study demonstrated that corn producers in the lower Mississippi Delta can save a significant amount of irrigation water without compromising grain yields by adapting the twin row and alternate-row irrigation system.

Technical Abstract: Twin-row planting in corn (Zea mays L.) has been proposed for reducing plant-crowding stress for optimizing grain yield and resource use. Experiments for this study were conducted in 2020 and 2021 on a Dundee silt loam in the Lower Mississippi Delta (LMD) region of the USA to evaluate corn grain yields and irrigation water use efficiencies (IWUE) in response to single-row (SR) and twin-row (TR) planting patterns under four irrigation regimes: rainfed (RF), all-furrow (FI), alternate-furrow (AFI) and third-furrow irrigation (TFI). Across two crop seasons and four irrigation regimes, TR enhanced grain yield by 9.2 % in 2020 and 10.9 % in 2021 over the SR system. Averaged across seasons, the final plant stand at the reproductive phase was highest under AFI (73900 ha-1) and lowest under RF (70480 ha-1). Across the four irrigation treatments, the leaf area index (LAI) in the TR system was significantly higher than LAI in SR. The two-season 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; and under TR were 11.58, 11.32, 10.13 and 9.91 Mg ha-1. The differences for grain yields under AFI and FI were non-significant. The highest IWUE was recorded for TR planting (0.021 Mg ha-1 mm-1) followed by SR planting (0.020 Mg ha-1 mm-1) under AFI. The IWUE of TFI in TR planting was 0.011 Mg ha-1 mm-1 and in SR was 0.012 Mg ha-1 mm-1. Economic analysis revealed that the TR- FI and -AFI had an average profit of 446 and 432 USD ha-1, respectively. The study suggests that corn producers in LMD can save a significant amount of irrigation water without compromising grain yields by adapting the AFI - TR system.