Environmental assessment of the state of fallow drained meadow-soddy-gley and brown mountain-forest soils to involve them into a new agricultural turnover (on the example of the Jewish autonomous region)

Abstract

Relevance. In the context of ever-increasing anthropogenic influence, the importance of agricultural land reclamation increases and becomes more complicated. Involvement of new virgin soils in agricultural circulation requires large financial investments and huge labor resources, which the local administration does not have. The secondary return to agricultural circulation of fallow reclaimed lands that are not used in agriculture may be a less costly method of increasing the area of agricultural arable land. Aim. To analyze the changes in vegetation and aggregate composition on drained fallow soils of different ages. Object. Drained fallow meadow-soddy-gley and brown mountain-forest soils of different ages. Methods. Standard geobotanical methods were used to describe the vegetation of the polygons. The granulometric analysis of soils was carried out by the method of dry sieving. Soil density was determined by the cutting cylinder method. Results. The study showed that reclaimed arable land, after being withdrawn from agricultural use, enters into a long process of self-recovery. In the course of a long-term transformation, a noticeable accumulation of humus is observed in fallow brown mountain-forest soils in comparison with adjacent arable lands. In the 20-year-old deposit, the highest content of humus is noted, while there is a decrease in saline and hydrolytic acidity. In fallows, the density of the upper soil horizon decreases, which favorably affects the structure of soils. On brown mountain-forest soils, in a 20-year-old fallow, there is a noticeable increase in the proportion of mesoaggregates (0,25–10 mm), including agronomically valuable ones. The number of micro- (<0,25 mm) and macro-aggregates (>10 mm) decreases, which indicates an improvement in the agronomic properties of fallow soils. The results of dry screening indicate that the fallow period of drained meadow-soddy-gley soils adversely affects their structure.