The productivity of coppice stands of Sesbania sesban (Linn. ) Merrill has been evaluated under high density planting on marginal (alkali) lands. Better sprouting, increase in height, greater canopy spread and larger diameter of the main stem were observed to be mainly responsible for greater energy fixation at the level of 25,000 plants per hectare as compared with higher densities of 50,000 or 75,000 plants per hectare.