Parametrization of changes in organic carbon content depending on the fertilizer system

Abstract

Goal. To determine the parameters of changes in the content of organic carbon in typical chernozem depending on the long-term use of different fertilizer systems for field crop rotation in the High Forest-Steppe of the Left Bank of Ukraine. Methods. Field — to determine the impact of fertilizer application systems on the humus state of typical chernozem, laboratory — to determine the content of organic carbon in the soil, calculation — to calculate the reserves of organic carbon and humus, mathematical — to assess the reliability of the data. Results. It was determined that before the establishment of a stationary field experiment, the content of organic carbon (Corg) in the arable soil layer averaged 2.89%. The coefficient of variation of the parameters of this indicator was 8%, but the scope of variation of the obtained results was 1.03 abs. %. It was established that for 28 years of application of mineral and organic fertilizers there was a slow deposition of Corg. Under the mineral fertilizer system with the introduction of single and double doses of complete fertilizer, the Corg content increased from 2.94–2.96 to 3.09–3.10%. Under the organic system, which provided the periodic application of manure under row crops, the Corg content increased from 2.80 to 3.09%, while the combined application of manure and mineral fertilizers caused an increase in Corg from 2.71–2.79 to 3.09–3.16%. Corg reserves increased from 5 for the mineral to 10 and 13 t/ha for organic and organomineral fertilizer systems, respectively. Conclusions. An increase in the Corg content in typical chernozem was established with the introduction of fertilizer systems in a row: mineral — +0.14–0.15 abs.%, organic — +0.29, organomineral — +0.37–0.38 abs.%. The systematic application of mineral and periodic of organic fertilizers contributes the most to carbon deposition in soils.