CO2 PRODUCTION BY THE SOIL AND ITS RELEASE DURING THE MINERALIZATION OF SUBSTANCES CONTAINING NITROGEN

Fertilizer tagged with N-15 was used in a pot experiment to determine net mineralization of N-14 in Leached Chernozem, Gray Forest, and Sod- Podzolic soils, and the release of CO2 carbon was measured at the same time using membrane samplers and glass isolators. It was demonstrated that net mineralization of soil nitrogen is associated with cumulativ e release of CO:! carbon from the soil in amounts equal to 4-8 times t he amount of nitrogen mineralized according to data compiled with the use of insulators and 40-80 times the amount of nitrogen mineralized b ased on membrane sampler data. The amount of nitrogen mineralized was correlated with the reserves of nitrogen contained in the microbial bi omass.