Crop Water Productivity of Maize under Koga Irrigation Condition

Abstract

Water is essential for human survival, yet freshwater scarcity threatens growth and food security, making effective water management—particularly deficit irrigation (DI)—crucial. This study examined DI's effects on maize yield, water productivity (WP), and blue water footprint (WF) reduction under different mulches, which apply organic or inorganic materials to soil surfaces to enhance aeration, retain moisture, and curb evaporation. A randomized complete block design (RCBD) with three replications tested three mulches (none, wheat straw, white plastic) and four DI levels: 0% (full irrigation, 100% ETc), 20% (80% ETc), 40% (60% ETc), and 50% (50% ETc), with irrigation scheduled via pan evaporation and data analyzed using ANOVA in R. Results showed significant DI-mulch interactions: 50% ETc DI with plastic mulch minimized consumptive WF reduction and boosted WP by 128.9% over full irrigation without mulch; 80% ETc DI with plastic mulch increased yield by 27.27% over full irrigation without mulch (and 3.17% over 60% ETc with plastic mulch) without significant differences, yielding the highest blue WF (101.433 m³/ton) for full irrigation without mulch. Marginal rates of return were lowest for 60% ETc without mulch, followed by 80% ETc without mulch, with plastic mulch plus DI preferred by 60% of farmers. These findings advocate DI with plastic mulch to optimize maize production, WP, and WF in water-scarce areas.