Abstract
Four Experiments were conducted to evaluate the efficacy of indigenous mulches on maize-pulse (mungbean and pea) association at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur. Quality protein maize (Pozarica) was intercropped with mungbean (BARI mug-5) and pea (IPSA-1). The experiments were conducted in rabi season (2002-2003), early kharif season (2003), late kharif season (2003) and rabi season (2003-2004). Water hyacinth, rice straw, rice husk and ash were used as mulching materials each at the rate of 10 ton/ha. Variations of morpho-physiological and yield contributing characters were studied together with microclimatic parameters. The highest soil moisture was observed under rice straw (8.16% to 19.42%) followed by water hyacinth (6.94% to 18.79%) and the lowest in control treatment (3.15% to 17.90%) at 5 cm depth. The highest amount of photosynthetically active radiation (PAR) was intercepted by maize canopy grown under water hyacinth and rice straw treated plots and the lowest amount was recorded in the control plots. Fluctuation of soil temperature under water hyacinth and rice straw was less than the control treatment. The highest and the lowest temperature in control treatments were in between 12 noon to 4 pm and between 2 am to 7 am respectively. Mulched soils though extracted greater amount of nutrients (N, P, K, Ca, Mg and Na) during developmental stages yet it was comparable to the initial stages and the final harvest. Superior morphological performances were observed in case of water hyacinth and rice straw treated maize, whereas such performances were observed in case of rice husk treated mungbean. Mungbean did not grow well in winter season. Higher leaf area indces (LAIS) of maize were exhibited in water hyacinth and rice straw treated plots. The taller plants with better growth and greater amount of dry matter were found in the water hyacinth and rice straw treated maize plants. The mean days required for tasseling was 91, 69, 48 and 92 DAS respectively for the first rabi, early kharif, late kharif and the second rabi grown maize crops. Days to first flowering and maturity for mungbean also reduced gradually in consecutive three seasons. In case of pea they were 37 and 70 DAS. The highest maize yields, as observed with water hyacinth mulch were 7484, 8852, 5920 kg/ha in three seasons and 5812 kg/ha in second rabi season followed by rice straw treated plots. The lowest maize yield in different crop seasons were observed in case of control and rice husk treated plots. The highest yield of mungbean was observed in late kharif season (1099 kg/ha) in rice husk treated plots while the highest yield (1539 kg/ha) of pea was observed in water hyacinth treated plots in rabi season. The lower amount of weed growth was recorded under rice straw and water hyacinth mulches. Overall results indicate that water hyacinth and rice straw were quite effective in conserving soil moisture and soil fertility and consequently for obtaining higher yield of maize. Maize in association with mungbean was found better in early kharif and late kharif seasons while pea grew better in rabi season.