Changes in physical properties of ordinary chernozems upon their long-term agricultural use

Physical properties of ordinary chemozems differing in duration of agricultural use were studied on experimental plots of the Dokuchaev Institute of Agriculture of the Central Chernozemic Zone (Kamennaya steppe, Voronezh oblast). It was found that during the initial 45-50 years of agricultural use, the quality of plowed chernozems, as compared to long-term fallow, decreases progressively with time: the structure of the plow layer worsens, the bulk density and the solid phase density of the soil increase together with an increase in the content of physical clay (<0.01 mm) particles; the inactive porosity increases, whereas the total porosity decreases, mainly at the expense of a decrease in the amount of air-filled pores. However, soil moisture reserves (that correspond to the main water-physical properties of soils) do not change much. In the subsequent 50 years of agricultural use, physical properties of chernozems remain stable at a sufficiently high level.