Asian Research Journal of Current Science

Soybean production during the post-monsoon season in Myanmar is constrained by moisture stress associated with declining rainfall and fewer rainy days, which limits crop growth and grain yield. Therefore, this study evaluated the effects of different mulch types and application rates on the growth and grain yield of post-monsoon soybean (Glycine max) at the Yezin Agricultural University farm during the 2024–2025 and 2025–2026 growing seasons. The experiment was arranged in a randomised complete block design with four replications. The treatments comprised no mulch (M0), plastic mulch (M1), rice straw mulch at 3 t ha⁻¹ (M2), 6 t ha⁻¹ (M3), and 9 t ha⁻¹ (M4), and maize stover mulch at 3 t ha⁻¹ (M5), 6 t ha⁻¹ (M6), and 9 t ha⁻¹ (M7). Mulching significantly improved soil moisture retention, vegetative growth, yield components, and grain yield compared with no mulch. Plastic mulch promoted faster canopy development during the early growth stage, produced the highest leaf area index (LAI), and generally maintained the greatest soil moisture. Rice straw mulch at 9 t ha⁻¹ produced the highest grain yields of 2456.2 and 3273.1 kg ha⁻¹ in the 2024–2025 and 2025–2026 seasons, respectively. The yields obtained with plastic mulch, rice straw mulch at 6 t ha⁻¹, and maize stover mulch at 9 t ha⁻¹ were not significantly different. The findings indicate that locally available crop residues can serve as effective mulching materials for post-monsoon soybean production under the conditions of the study area.