Kotchenko S.G., Eremin D.I.

Modern changes in the morphology of integrated and around dark gray forest soils of the forest-steppe zone Trans-Urals

Formed in the forest-steppe of the Trans-Urals, dark gray forest soils have regional morphological features, which complicates their classification when creating soil maps necessary for an adaptive landscape farming system. Long-term use of dark gray forest soils in arable land modifies the morphological characteristics of all genetic horizons. Objective of the research: retrospective analysis of the formation of morphological features of dark gray forest soils and identification of their regional features in virgin and arable land. The studies covered the southern part of the Tyumen region, which is an agricultural area. In 1964 and 2018. 24 full-profile soil sections were laid in virgin and arable lands. It was found that in the forest-steppe zone of the Trans-Urals, dark gray forest soils develop along the sod path with a gradual decrease in the rate of the podzolic process. Over 54 years, the thickness of the humus-accumulative horizon increased by 3 cm, and the upper boundary of the occurrence of calcium carbonate did not change and varied within 90-143 cm. The arable dark gray forest soil is characterized by a lower thickness of the humus horizon compared to the virgin one. Over 54 years, this horizon has decreased from 505 to 478 cm. It was found that in the conditions of the forest-steppe zone of the Trans-Urals, the long-term use of dark gray forest soils in arable land leads to a gradual decrease in the thickness of the illuvial-carbonate horizon. On virgin soil, its thickness in 1964 was 45-55 cm, while on arable land - 35-40 cm. For 54 years on arable land, the thickness of the illuvial-carbonate horizon decreased to 20-25 cm, which indicates modern changes under the influence of agricultural activity. The revealed changes in morphological characteristics (intensification of the leaching process and a decrease in the thickness of the humus layer) justify the shift of the soil-forming process towards podzolization, which, with the existing soil cultivation system, will lead to a deterioration in the fertility of dark gray forest soils

Keywords:LUVIC RETIC GREYZEMIC PHAEOZEMS, MORPHOLOGICAL CHARACTERISTICS, CELINA, HUMUS-ACCUMULATIVE HORIZON, RIPPING LINE, DESCRIPTION OF THE SOIL CUT