Enhancing resource conservation, soil health and productivity of mustard through green manuring in fallow – mustard cropping sequence

Abstract

A field experiment was conducted at research centre Kota to identify the suitable green manure crop for fallow−mustard sequence to conserve resources, improve soil fertility, enhance productivity and profitability of the fallow−mustard system during 2008−09 to 2010−11. The experiment was laid out in a split plot design with three replications. The main plot involved four green manuring treatments while subplots comprised of four N levels. The three years average data indicated that runoff and soil loss was reduced by 24−43% and 21−42%, respectively over control. An average amount of about 2.0−3.3 t ha–1 dry biomass of green manure crops was incorporated into the soil, which recycled an average amount of 46.6−94.6 kg N ha–1 over three years. Green manuring also enhanced the soil organic carbon (SOC) and available N, P, and K content into the soil. The seed yield of mustard increased by 40%, 52.8% and 75% under in−situ green manuring of cluster bean, sunhemp and sesbania, respectively as compared to without green manuring. A progressive increase in the yield of mustard was also recorded with the increasing N levels and the maximum yield was recorded with 45 kg N ha–1. Similarly, water use efficiency (WUE) was also positively influenced by different green manure treatments and N levels. Green manuring and N application were found economically viable over control in all the three years. Among the three green manure crops, sesbania was found to be most effective in reducing runoff, soil loss, and enhancing soil fertility, crop productivity and profitability in the rainfed region of south−eastern Rajasthan.