Effects of irrigation frequency and mulching on maize growth and yield in a high-altitude semi-arid environment of Daykundi, Afghanistan

Water scarcity is a major constraint to maize production in the high-altitude semi-arid regions of Afghanistan. This study investigated the combined effects of irrigation interval and mulch type on the growth, yield components and grain yield of the local maize cultivar Logari under high-altitude semi-arid conditions in Daikundi, Afghanistan. A split-plot randomised complete block design (RCBD) was implemented with three irrigation intervals (7, 10 and 14 days) as main plots and four mulch treatments (green plastic, transparent plastic, organic straw and no-mulch) as subplots, replicated three times (n = 36 plots). Plant growth traits, yield components and grain yield were analysed using GLM split-plot ANOVA followed by LSD mean separation. Results demonstrated that mulch type significantly influenced all measured traits (p < 0.01), whereas irrigation interval affected grain yield only (p < 0.05). Green and transparent plastic mulches produced the highest grain yield (6.46 t ha-1), approximately 40 % greater than organic mulch and no-mulch treatments (4.42–4.66 t ha-1). Maize under 7- and 10-day irrigation intervals also produced significantly higher grain yield than the 14-day interval. Although the irrigation × mulch interaction was not statistically significant, plastic mulch treatments maintained numerically higher yields under extended irrigation intervals. These findings indicate that plastic mulching can improve maize productivity and irrigation water productivity under semi-arid conditions. However, soil moisture, soil temperature and evapotranspiration were not directly measured. Further studies incorporating direct soil-water monitoring and biodegradable mulch alternatives are recommended.