Impact of mulching and nutrients on soil water balance and actual evapotranspiration of irrigated winter cabbage (Brassica oleracea var. capitata L.)

An optimal nutrient prescription along with favorable water management through mulching is key to high horticultural productivity, efficient water use, and minimizing soil nutrient loss. A field experiment was conducted in the Balindi Research Complex, Bidhan Chandra Krishi Viswavidyalaya in the Indo-Gangetic Plains of India, to evaluate the impact of mulching and balanced fertilization on actual evapotranspiration (ETa), crop coefficients (Kc), yield and yield attributes of cabbage (Brassica oleracea var. capitata L. cv. Green Express) during the winter seasons of 2018–2019 and 2019–2020 in the cabbage-fallow upland system under surface irrigated conditions. The experiment was laid out in a factorial strip plot design where no mulch (M1), live mulch [M2, Egyptian clover (Trifolium alexandrinum L.)], and paddy straw mulch (M3) were in strips with cabbage. Each treatment contained nutrient levels of 75% (N1), 100% (N2), and 125% (N3) of the recommended dose of an NPK fertilizer (RDF) with 200 N:100 P2O5:100 K2O. Higher soil water conservation under M3 incited 60% and 46% lower profile water change than M1 and M2 treatments, respectively. Paddy straw mulch produced 10.1% and 22.3% more yield and achieved 29.5% and 15.1% higher water productivity (WP) as compared to M1 and M2, respectively. Treatment N3 produced the highest yield and the least partial factor productivity of fertilizer (PFPf) compared to N2 and N1 treatments. Maximum ETa loss was from the M1N3 treatment (226.30 mm) and the highest yield (25,695 kg ha−1), yield attributes, and WP (120.1 kg ha−1 mm−1) were obtained from the M3N3 combination. The average estimated Kc values were 0.5 for initial, 1.0 for crop development, and 1.2 for mid-season, and 0.6 for maturity stages. The results suggest that the application of straw mulch with 125% RDF of chemical fertilizer under surface irrigated conditions improved cabbage yield, water productivity and soil fertility, however, living mulch achieved a higher economic return to the Indo-Gangetic alluvial clay loam Inceptisol of India.