Carbon-nitric turnover in agrocnoses of crop rotations

Abstract

The purpose. To determine normative parameters of typification of balance and content of organic carbon Corg in agrocnoses of different crop rotations, as components of methodology of agroecological assessment of their productivity at use of collateral production as organic fertilizers in conditions of modern climatic system of Forest-steppe of Ukraine. Methods. Generalization of results of long-term researches in field stationary experiment, statistical: dispersive, correlation, factorial, claster analysis of parameters of productivity, qualitative and quantitative clauses of balance of nitrogen, carbon. Results. At full leaving of collateral production in 7 – 10-field crop rotations balance of Corg was positive, and the maximal productivity coincided with high values of balance (+1,32 – 2,54 t/hectare) and capacity of balance (3,17 – 3,72 t/hectare). In 3 – 5-field crop rotations balance of Corg was less profitable (+0,56 – + 0,87 t/hectare), but also capacity of balance of Corg increased at the maximal productivity up to 4,01 – 4,12 t/ hectare. Direct correlation is fixed between capacity of balance of Corg and productivity of crop rotations. With growth of productivity of crop rotations proportionally grows both mineralization, and humufication of Corg. Capacity of balance in short crop rotations on the maximal parameters exceeds 4 t/hectare whereas at 7 – 10-field crop rotations the maximal value of capacity of balance is less 4 t/hectare. Conclusions. Ratio Corg to nitrogen in agrocnoses, irrespective of type of crop rotations, is in optimum limits (20 – 30:1), that creates optimum conditions for humifacation of collateral production and formation of humus. It is confirmed by balance calculations of nitrogen and organic carbon.