Comparison of agrophysical parameters and humus content in the soil of virgin and arable land

Topicality. Currently, there is an urgent need to address the following challenges: loss of soil humus content, deterioration of soil agrophysical properties, reduction of the impact of soil agrophysical degradation, restoration and preservation of fertility. Purpose. Comparison of agrophysical parameters and humus content in the soil of virgin and arable lands and development of scientific recommendations on the formation of favourable agrophysical properties and regimes of chernozems to suspend the development of degradation processes in the soil and preserve fertility. Material and Methods. The study of ordinary chernozem was carried out in the virgin lands and experimental plots of the Erastivka Research Station of the Institute of Grain Crops of NAAS of Ukraine during 2010–2016. We studied: total humus content; structural and aggregate composition of the soil; soil structure coefficient; soil density; water resistance of agronomically valuable structural aggregates. In May, soil samples were selected at equilibrium density after mechanical tillage. Sampling was carried out from the soil profile at intervals of 5 cm, to a depth of 0–200 cm in quadruplicate according to DSTU 4287. Results. It was found that deterioration of agrophysical properties (structural and aggregate state, density, water resistance) and reduction of humus content and thickness in the humus horizon in comparison with virgin soil occurred as a result of long-term cultivation of ordinary chernozem. Conclusions. When comparing the properties of ordinary chernozem of arable land with virgin soil, we find that they are significantly degraded. Significant loss of humus and structure degradation leads to an increasing soil density and a partial loss of the ability to resist degradation. To preserve and sustainably use arable chernozems, an improved farming system should be implemented, with scientifically based crop rotations, the latest soil protection technologies, and the proper amount of organic and mineral fertilisers to increase the humus content as its main components. Key words: ordinary chernozem, soil degradation, humus content, structural and aggregate state, density, water resistance