Interactive effects of sowing windows, sowing depths and moisture management practices on yield parameters of soybean [Glycine max (L.) Merrill] under rainfed conditions

A field experiment was conducted during Kharif 2024 at the MARS, UAS Dharwad, to investigate the interactive effects of sowing windows, sowing depths, and moisture management practices on yield of soybean [Glycine max (L.) Merrill] under rainfed conditions. The study was laid out in a factorial RCBD with three sowing windows (10 July, 5 August, 9 September), two depths (5 cm and 10 cm), and two moisture regimes (with and without mulch). Soil temperature and moisture dynamics varied significantly across treatments. Early sowing on 10 July maintained higher soil temperature (25.1°C) and favorable moisture (22.4%), which facilitated better germination, crop establishment, and root development. Sowing at 5 cm depth ensured quicker germination and higher vigor due to warmer soils, whereas 10 cm depth favored moisture conservation, supporting later growth. Mulching increased soil temperature but reduced soil moisture, while without mulch preserved higher moisture during reproductive stages. Yield attributes were strongly influenced by treatments. July 10 sowing consistently outperformed later dates, recording maximum pods per plant (40.33), seed yield (2199 kg ha⁻¹), and haulm yield (2578 kg ha⁻¹). Interaction effects revealed that July 10 sowing at 5 cm depth with mulch produced the highest pod number (44.67), seed yield (2413 kg ha⁻¹), and haulm yield (2651 kg ha⁻¹). Delayed sowing in September reduced yield drastically due to shortened season and lower soil temperature. Overall, early sowing, shallow depth, and suitable moisture management optimized the soil environment and enhanced soybean yield under rainfed conditions.