Organic matter of sod-podzolic soil after transition to a fallow state

Soil plays a crucial role in carbon sequestration in terrestrial ecosystems. It is known that the strengthening of carbon sequestration processes occurs with a decrease in the intensity of soil treatments. The study of changes in organic matter and physical properties of sod-podzolic soil 16 years after the transition from arable soils to a fallow state against the background of weak water erosion was carried out. A significant increase in the content and reserves of total carbon in fallow soil compared to arable soil was found, mainly due to carbon of the light fraction. On arable soil, the content of the light fraction in the lower part of the field was significantly higher than in the upper part, due to the washing away of light particles as a result of erosion, these differences were smoothed out on fallow soil. There are no significant changes in the density, density of the solid phase and total porosity in fallow soil at this stage of succession, compared with arable soil. In fallow soil, the content of macro-aggregates (including water-bearing ones) was noticeably higher, and the share of micro-aggregates was lower than in arable soil.