NOTE ON EFFECTS OF A MUCUNA-PRURIENS VAR UTILIS CROP ON THE GROWTH OFMAIZE (ZEA-MAYS) ON AN ACID ULTISOL IN SOUTHEASTERN NIGERIA

An experiment was conducted with the aim of quantifying the effect of a previous crop of Mucuna (Mucuna pruriens var. utilis); velvet bean o n growth of maize (Zea mays). The experiment was located on a highly d egraded ultisol in southeastern Nigeria (4 degrees 51' N; 7 degrees 03 ' E). Maize was sown after a Mucuna crop and a natural grass fallow (w ith or without 40 kg N ha(-1) as urea). Leaf area, height, biomass, an d yield of maize varied in the order: fallow regrowth + mea > Mucuna f allow > fallow regrowth without urea. The proportion of leaf to total dry matter of maize shifted from 70% to 30% between the period 6 to 10 weeks after sowing. Grain yield was significantly correlated to ear-l eaf N (r = 0.91*), Ca (r = 0.81**), Mg (r = 0.71*) and K (r = 0.65*) contents. Grains constituted 27%, 20% and 15% of maize biomass on urea , Mucuna, and fallow regrowth plots, respectively. Sowing Mucuna pruri ens var. utilis as a relay cover crop may reduce the need to apply syn thetic N-fertilizer.