Abstract
A field experiment was conducted to examine the role of intercropping different legumes (Alysicarpus rugosus, Atylosia scarabaeoides, Centrosema pubescens, Clitoria tematea, Glycine javanica, Macroptilium lathyroides, M. atropurpureum, Stylosanthes guianensis, S. hamata and Vigna luteola) in the nitrogen economy, biomass productivity and protein enrichment of a Chrysopogon fulvus pasture maintained for four years (1979-1981) under rainfed conditions. Results clearly demonstrated that the pasture legumes have sufficient capacity to improve the soil-N which may serve as a ready source of N-assimilation process in the grass up to 177 kg N ha-1 in a 4-year crop stand. The effects of Macroptilium atropurpureum, Atylosia scarabaeoides and Glycine javanica on Chrysopogon fulvus were evident among the pasture legumes in terms of N-equivalent values, ranging 152-177 kg N ha-1. They improved the process leading to high biomass production, in addition to enriching the protein status of C. fulvus (5.14-6.28%). Macroptilium atropurpureum and Clitoria tematea almost doubled the biomass production of grass+ legume (6.5-6.6 t ha-1) over monoculture (3.52 t ha-1) in the first year. During the second year (1980), Glycine javanica and Macroptilium lathyroides increased biomass production (7.5-9.2 t ha-1) 3-4 fold over the control (2.42 t ha-1). On the basis of the 4-year average, Glycine javanica (6.37 t ha-1) and Atylosia scarabaeoides (5.65 t ha-1) also gave high biomass and protein yields of C. fulvus compared with the control (2.8 t ha-1) and a 40 kg N ha-1 treatment (5.39 t ha-1). The legumes would act as an excellent substitute of nitrogen fertilizer in the economy of grassland management.
