Physiology, growth, and yield of sweet corn as affected by growth stage-based irrigation management and biochar application

Abstract

Water deficits are among major agricultural issues in semi-arid West Texas and require water-saving agricultural practices like growth stage-based irrigation management and biochar. A 2-year (2021 and 2022) field experiment was conducted in a split-plot design with irrigation based on crop evapotranspiration (ETc) as a main plot factor with four levels (I1 [100% ETc for whole growing season], I2 [80% ETc stress at vegetative stage followed by 60% ETc stress at reproductive stage], I3 [60% ETc stress at vegetative stage followed by 80% ETc stress at reproductive stage], I4 [40% ETc stress for whole growing season]) and biochar as a subplot factor with three rates (0, 15, and 20 t/ha) with four replications. Among the irrigation levels, I3 maintained plant height, leaf area index, leaf water potential, and higher cobs number and yield comparable to I1, despite some reduction in biomass. The yield penalty averaged across 2 years under I2, I3, and I4 was 29%, 9%, and 50%, respectively, compared to I1. Irrigation treatment I3 maintained 3% and 12% higher water productivity values in 2021 and 2022, respectively, compared to I1, with a saving of 24% water in irrigation across 2 years. Thus, I3 can be adopted as an alternative to full irrigation to save water with a minimal yield penalty for sweet corn (Zea mays L. var. rugosa) production in the West Texas region. Biochar had marginal effect on plant physiological and growth response. A long-term study could explore more on the integrated effect of irrigation and biochar on sweet corn productivity.