Regenerative capacity and factors influencing the management of Mucuna pruriens var. utilis live-mulch

Abstract

The regenerative capacity of Mucuna pruriens var. utilis live-mulch and factors affecting its management were investigated. Six plots of mucuna (each measuring 48 m2) were established at an intra-row spacing of 40 cm and inter-row spacing of 80 cm. The number of days to canopy closure after planting and after the first, second and third trimmings were recorded. The trimming frequency for early-maturing and late-maturing maize varieties and the biomass yield and number of active nodules per plant were determined. Mucuna pruriens attained complete canopy closure 55 days after planting (DAP). The number of days required for complete canopy closure after the first, second and third trimmings were 34, 32 and 26, respectively. The number of trimmings (60 to 90 DAP) varied from 0-1 (for early maturing maize) to 1-2 (for late-maturing maize). The fresh biomass yields at the first, second and third trimmings were 12364, 5941 and 7209 kg ha–1, respectively; while litter yield ranged from 469 to 914 kg ha–1. The effective nodule count per plant varied from 4 (45 DAP) to a maximum of 63 (120 DAP). The N yield (90 days after planting mucuna) was 179 kg ha-1 of which 60 kg ha-1 mineralizable N could be provided for an intercrop. Significant positive relationships were established between biomass yield, N content of mucuna plant, days after planting, and number of effective nodules per plant. The study showed that it would be appropriate to trim M. pruriens two times (at 60 DAP and 34 days after first trimming) during the intercropping of a late maturing maize crop to reduce competition between maize crop and live-mulch for water and plant nutrients in the soil