MICROFLORA OF SOIL: A REVIEW.

Abstract

Microflora of soil is an integral part of soil Organic Matter. Soil bacteria and fungi are the start of the soil food web that supports other organisms. Bacteria constitute the most abundant groups of microorganisms in soil and the fungal population of soils constitutes a very heterogenous group of organisms. The bacterial genera Nocardia, Streptomyces and Micromonospora belong to order actinomycetes (aerobic and heterotrophic) are capable of degrading many complex organic substances and consequently play an important role in building soil fertility. The soil food web is interconnected matrix of invisible (fungi, bacteria, protozoa, nematodes) and visible (earthworms, beetles, arthopods) creatures that have a whole host of functions which creates a healthy ecosystem for plant growth. Various microorganisms were isolated from different soil samples collected. Thus the population of total bacteria in rhizosphere was reported to be highest as compared as to non-rhizosphere. The majority of the bacteria were reported to be Bacillus and Micrococcus Species. The total fungal population densities were also decreased in non-rhizosphere while the highest fungal population was observed in rhizosphere. The majority of fungi were reported to be Aspergillus niger, Aspergillus fumigatus, Penicillum species and Fusarium species. A number of diazotrophs bacteria have abilities to fix Nitrogen, some strains may relieve deficiencies where there is an inadequate application of N fertilizers. Many heterotrophic bacteria live in the soil and fix significant levels of Nitrogen including Azotobacter, Azospirillum and Rhizobium. N fixing microorganisms are globally noteworthy due to the fact as they provide only natural biological source of fixed N in the biosphere. The population count of Azotobacter was also more in rhizosphere than non-rhizosphere sites.