Aim. To substantiate the agroecological estimation of the performance of a short crop rotation in conditions of intense and organic system of fertilization on the basis of restoring normative parameters of emission and se- questration of С-СО 2 circulation while using by-products as organic fertilizers in conditions of modern climatic system of the Forest-Steppe of Ukraine. Methods. Field, statistical, laboratory. Results of Investigations. The performance of short crop rotations is determined by the capacity of С-СО 2 balance. Strong inverse correla- tion was found between the capacity of N and the ratio between C and N in the agrocenosis, which demon- strated that enhancing the humifi cation processes (ratio constriction) led to the increase in the capacity of С org balance and the decrease in the capacity level of С-СО 2 balance (enhancing mineralization), related to the reduction in the performance of crops in the agrocenosis of a crop rotation compared to the organic system of fertilization. The
capacity of С-СО 2 and С org balance correlates at the medium level of inverse direction, and the yield of the main products, feed units and digestible protein correlates at the level of strong direct correlation. Conclusions. General mineralization of by-products and humus in the agrocenosis and humifi cation processes are antagonists, so extending the ratio between С and N at the intense fertilization system stimulates the in- crease in performance and reducing С to N similar to the organic fertilization system enhances the humifi cation process due to binding of С org into humus and limits mineralization which leads to the reduction in agrocenosis performance at the organic fertilization system.
