Ureolytic and nitrifying bacterial heterotrophs from acid soils

Nitrification following ureolysis in soil samples from tea growing soils (pH 4.5–5.5) was found to be chiefly due to the activity of heterotrophic bacteria belonging to generaBacillus, Arthrobacter, Sporosarcina, Micrococcus, Clostridium, Pseudomonas andProteus. A correlation between the intensity of ureolytic activity of organisms in a given soil sample and the yield levels of tea was observed. In culture media the increase in the quantity of NH ₄ ⁺ -N indicating ureolysis was not accompanied by proportional increase in biomass. Ureolysis and nitrification in sterile soil sample inoculated with the isolates improved through amendment of organic carbon to the soil.