Effect of Rhizobial Inoculation on Albizia lebbeck and Its Rhizosphere Activity in Mine Spoils

The evolution of stable and productive mine spoil requires active microbial populations for effective energy flow and nutrient cycling. This can be achieved either by introducing beneficial microorganisms through inoculation or increasing the microbial activity through the incorporation of amendments. Efficient strains of Bradyrhizobium sp. were isolated from mine spoils and used to inoculate seeds of Albizia lebbeck grown in both gypsum and limestone mine spoils. It was observed that nodulation and nitrogenase activity were significantly improved by about 2- and 20-fold respectively with inoculation, along with an enhancement in the growth of 5-month-old seedlings by about 50%. Inoculated plants had higher concentrations of nitrogen and phosphorus, indicating better nutrition. Soil metabolism, as indicated by the activities of dehydrogenase and phosphatases and AM-fungal spores of the mine spoils, was significantly improved with inoculation. The results suggests that the use of efficient strains of Brady...