Biomass Accumulation, Soil Fertility and Energy Use in Seed Crop Systems of Velvet Bean (Mucuna Pruriens L.)

Abstract

Seed crop production systems of velvet bean (Mucuna pruriens L.) were assessed in two field studies for ecosystem services. At flowering stage, long duration genotype Arka Shubra was significantly superior in biomass accumulation (14.61 t ha−1), while 100% recommended NPK + 15 t FYM ha−1 registered significantly higher biomass production (11.74 t ha−1). Biomass availability at harvest was higher in long duration genotypes (7.48–7.75 t ha−1) and the average biomass availability of 6.45 t ha−1 at harvest gives scope for including velvet bean as component crop in cropping systems/fallows. The average soil carbon stocks were estimated at 22.8 t ha−1 at the end of 2 yrs and 12.4 t ha−1 at the end of one crop season. Soil nutrient availability was optimum except for soil test P in pre-, standing and post crop growth periods. Highly significant relations (R2 = 0.949) were observed between nodule number and available N at harvest. The N availability was more in long duration genotypes (209–215 kg N ha−1) over pre-experimental status. Nutrient addition improved the available N status by 40–185 kg ha−1 over pre-experimental status and control. The nutrient uptake was 4–10% higher in Arka Shubra over other long duration genotypes and 100–200% higher over medium/short duration genotypes at flowering. The recyclable biomass and uptake of NPK are more in long duration genotypes implying huge nutrient recycling potential of the system. Overall, seed crop systems of velvet bean are efficient in resource use and energy use (>2.5 EUE) and ideal components for sustainable land management.