COMPARATIVE GROWTH, NODULATION AND TOTAL NITROGEN CONTENT OF SIX TREE LEGUME SPECIES GROWN IN IRON MINE WASTE SOIL

Abstract

Six tree legume species, namely Sesbania grandiflora, Leucaena leucocephala, Acacia nilotica, Acacia auriculiformis,Prosopis juliflora and Albizia lebbeck, were grown in iron mine waste soil to study their comparative growth, nodulation and total nitrogen contents with a view to select suitable plant species to be used for reclamation of mine waste soils. Growth responses of plants as determined from shoot length, root length, fresh and dry weights were found to be highest in S. grandiflora, followed by L. leucocephala and A. nilotica. Although nodule number per plant was highest in S. grandiflora, A. nilotica showed better rooting and nodulation capacity with larger nodule size and dry weight per nodule over others. Total nitrogen content of plant was highest in L. leucocephala. From the overall performance from all parameters L. leucocephala, S. grandiflora and A. nilotica were seen to be the best responding plants in iron mine waste soils. However, S. grandiflora was unsuitable for reclamation purpose because of its high water demand, softwood and lower hardiness. Hence, the other two tree legumes, L. leucocephala and A. nilotica, were found to be most suitable for growing in iron mine areas.