Review on Potentials of Rhizobia-Leguminous Plants Symbiotic Nitrogen Fixation for Sustainable Agriculture

Abstract

Agricultural sector throughout the World is facing problem of supplying sufficient amount of food for the increasing human population without affecting the sustainability of the environment. To supply sufficient food, increasing agricultural productivity is required, which in turn need sufficient application of nitrogen fertilizer which has negative effect on human health and on the environment. To overcome, the negative health and environmental effect of chemical nitrogen fertilizer in put in agriculture replacing or supplementing nitrogen inputs from biological nitrogen fixation (BNF) has been in use for more than a century. Form all Biological Nitrogen Fixation (BNF) systems; the symbiotic nitrogen fixation between leguminous plants and rhizobia is the most efficient in supplying fixed nitrogen for the host plant. The use of Biological Nitrogen Fixation (BNF) system to replace and or supplement the chemical nitrogen fertilizer is limited in the developing nations like Ethiopia. In addition, BNF is affected by various environmental factors like soil acidity, salinity, temperature, moisture, and the rhizobial strain(s) used. As a result, rhizobial strain (s) that has been adapted to the prevailing environmental conditions should be sought. In this review paper, the types of rhizobia and their contribution in biological nitrogen fixation, interaction of rhizobia with host plant and factors affecting symbiotic nitrogen fixation were summarized.