METHOD OF ESTIMATION OF ORGANIC CARBON AND NITROGEN CHANGE BALANCE IN THE SOIL AND THE RATIO OF THESE ELEMENTS Russian patent published in 1996 - IPC

FIELD: agriculture, analytical chemistry. SUBSTANCE: content of nitrate nitrogen (N_g) is determined in the soil samples. Then the sample is wetted to 40-100% of the total water absorption and incubated in the sealed capsule at t = 65-85 C. At the terminal stage of incubation the content of C-CO₂ and the residual soil carbon C_s were determined in the gaseous medium. The content of total carbon is calculated as a sum of two assays C_s + C - CO₂ = C_vol. Simultaneously, analysis of the total nitrogen (N vol.) and mineralized nitrogen as N-NH₄(N_g) is carried out and nonmineralized nitrogen is measured by difference N_vol-N_g. Then ratio values of different phases of these elements were calculated by the formulas: C-CO₂/N_g; C_s/(N_vol-N_g); (C_s+C-CO₂)/N_vol, and balance change of these elements is estimated as balance value difference during period investigated. Method can be used for prognosis of the soils requirement for organic fertilizers at different ratio of nitrogen and carbon, for anthropogenic effect on balance and dynamics of their forms in the soil. EFFECT: improved method of estimation. 2 dwg