Effect of soil conditioners on some biological properties of sandy soil and the diversity of microbes involved in their biodegradation

ABSTRACT

The application of bitumen and ureaformaldehyde at the two low application rates stimulated the total bacterial, fungal and Azotobacter counts in sandy soil. The higher rate of conditioners applications, however, delayed the proliferation of soil microorganisms for 60 days. The application of bitumen and ureaformaldehyde to sandy soil planting with peanut inoculated with Rhizobium spp. Induced insignificant increase in nodulation, dry matter yield and N accumulation except the higher application rate which resulted in slight decrease in nodulation. Generally, no marked retardation of nodulation or N2 fixation was noted as a consequence to the conditioner application. The bacterial genera contributing to the biodegradation of bitumen and ureaformaldehyde in the sandy soil are Bacillus, Micrococcus, Pseudomonas, Flavobacterium, and Streptomyces. Bacillus was the most dominant genus for both soil conditioners