Abstract <p>The influence of dump and nondump tillage techniques on the transformation of mobile organic compounds of carbon and nitrogen in the conditions of the forest–steppe zone of Krasnoyarsk krai has been studied. The influence of the ratio of the content of easily mineralized carbon and nitrogen on this process is estimated. The value of the C : N ratio in the soil of the studied variants indicated an average level of nitrogen enrichment of humus. The C : N values for mobile forms of carbon and nitrogen had a broader relationship in the soil treated with the use of waste-free technologies. Strong correlations were found between C_{0.1 NaOH} and the C : N ratio in the soil. Under the conditions of application of dump tillage, an increase in the provision of soil with active organic matter made it possible to stimulate the nitrogen mineralizing ability with the accumulation of ammonium nitrogen compounds. When using nonwaste treatments, similar dependencies were found with the content of nitrate nitrogen compounds. The values of С_mb in С_org (%) indicated a weak biogenicity of the studied soil. There was no differentiation between the layers in terms of the rate of carbon dioxide emission.</p>