ABSTRACT

Micro-Organisms ...........................................................................................431 33.1.2 ‘Rhizosphere effect’ and Microbial Populations in Agroecsoystems .... 434 33.2 Biological Nitrogen Fixation .........................................................................436 33.2.1 Legume-Rhizobium Symbiosis and Soil Microbes .........................436 33.2.2 Associative Nitrogen Fixing Organisms ..........................................438 33.3 Phosphate Solubilizing Bacteria ....................................................................439 33.4 Mycorrhizas ...................................................................................................440 33.5 Plant Growth Promoting Rhizobacteria .........................................................442 32.6 Azolla and Blue Green Algae ........................................................................443 Keywords .................................................................................................................444 References ................................................................................................................444 Exercise ....................................................................................................................447 Further Reading .......................................................................................................447 Useful Websites ........................................................................................................447

33.1 MICROBES IN SOIL