THE CONTRIBUTION OF RHIZOBIUM-MELILOTI TO SOIL DENITRIFICATION

The ability of Rhizobium meliloti cells to denitrify in soils under se veral conditions was tested. All the strains tested were able to remov e large amounts of N-NO3- from soils. Both water filled pore space abo ve 36% and temperatures above 20-degrees-C greatly increased nitrogen losses. However, even with optimal conditions for denitrification and the highest rhizobial populations found in agricultural soils. the con tribution of Rhizobium to the total denitrification was virtually negl igible as compared to other soil microorganisms.