Abstract

                                Field experiments were conducted at Tamil Nadu Agricultural University during the NEM season of 1993-94 and SWM season of 1994 to study the effect of different spacings and phosphorus application on biomass production and nitrogen (N) accumulation of three green manure crops. pillipesara, sunnhemp and velvet beans, Velvet beans produced the highest hiomass of 27.6 the in the SWM season followed by Sunnhernp and pillipesara. Biomass production and N accumulation were higher at closer spacing (30x20cm). Application of 50 kg P20ha significantly increased the growth of all the three crops. Interaction between spacing and P levels was significant and highest hiomass (10.0, 11.2 and 35.9 t/ha for pillipesara, sunnhemp and velvet beans respectively) was achieved in the treatment combination of 50 kg P:Os/ha and closer spacing (30 x 20 cm). Velvet beans and sunnhemp produced higher biomass in SWM season (27.6 and 101 t/ha) while NEM season was more favourable for pillipesara (8.5 ha)

Key words : Velvet heans, sunnhemp, pillipesara, biomass, N accumulation