INFLUENCE OF ORGANIC CARBON ACCUMULATION IN LONG-TERM EXPERIENCES FOLLOWING SYSTEMATIC APPLYING OF MINERAL AND ORGANIC FERTILIZERS

Abstract

In long-term experiences in our country assessments of changes to the content of C - organic, humus and N-organic show that the systematic application of nitrogen fertilizer at the economic optimum but also of those with N, P, K in long-term experiments in several localities ensures in time (3-4 decades) an increase of organic components in the soil, even a positive humic balance, although these technologies, in the first years of experimentation and application may cause some reduction of humus content (Borlan and Hera, 1984; Kurtinecz and Rusu, 2007). Obviously, these data, essentially contradictory led to attempts to quantify the negative or positive processes in this area and it was even concluded that changes of C - organic, humus and N - organic in the soil following systematic application of fertilizers are determined by the nature and dosage of fertilizer applied to the crops, by the level of harvests obtained, by the remaining biomass or biomass removed from the soil, by coefficients of recovery of plants concerning nutrients, by crop rotation, by soil microbiological activity etc. This paper presents the influence of accumulation of C - organic in long-term experiences following the systematic application of mineral and organic fertilizers.