Utilization of Sparingly Soluble Phosphate by Red Cloverin Association with Glomus mosseae andBacillus megaterium

A pot experiment was conducted to investigate the mobilization of sparingly soluble inorganic andorganic sources of phosphorus (P) by red clover (Trghlium pmtense L.) whose roots were colonized by thearbuscular mycorrhizal (AM) fungus Glomus mosseae and in association with the phosphate-solubilizing(PS) bacterium Bacillus megaterium ACCC10010. Phosphate-solubilizing bacteria and rock phosphate hada synergistic effect on the colonization of plant roots by the AM fungus. There was a positive interactionbetween the PS bacterium and the AM fungus in mobilization of rock phosphate, leading to improved plantP nutrition. In dual inoculation with the AM fungus and the PS bacterium, the main contribution to plantP nutrition was made by the AM fungus. Application of P to the low P soil increased phosphatase activityin the rhizosphere. Alkaline phosphatase activity was significantly promoted by inoculation with either thePS bacterium or the AM fungus.