Rhizobium Biofertilizer Technology for Southern Rajasthan of India

Abstract

The symbiotic systems are a major source of N in most legumes with an average of 80% of N derived from biological N-fixation (BNF). Besides N -fixation, rhizobia have been increasingly associated with secretion of 2 plant growth promoting substances, solubilization of organic and inorganic phosphate and antagonistic action against pathogen. For the establishment of an effective symbiosis two main classes of bacterial symbiosis genes are essential: nodulation and symbiosis genes. A fully functional symbiosis requires successful survival ability of bacteria even under adverse environmental conditions. The survival, growth and persistence of rhizobia largely depend on edaphic, biotic and abiotic factors. Soil acidity complex of arable land provides an array of constrains for size and effectiveness of rhizobial population owing to excess availability of Al and Mn to toxic levels and characterized by deficiency and poor availability of P, Ca, Mg and Mo. About 60% of the Rajasthan state falls under desert region and covers largest area of hot arid regions of the Indian Desert. Hence, the selection of effective, efficient and compatible stress tolerant rhizobial strains with multiple plant growth promoting activities are need of the hour that could help in ecological rehabilitation of degraded soils and increase soil fertility thereby improve the growth as well as production of leguminous crops.