The influence of soil composition on the productivity of phytocenoses

Federal Research Centre of Biological Systems and Agrotechnologies of the Russian Academy of Sciences, 29, 9 Yanvarya St., Orenburg, 460000, Russia

^* Corresponding author: vtn1972@mail.ru

Abstract

Soil factors play a decisive role in the formation of the species composition of plant communities in the steppe zone. The purposeof the research work was: a comprehensive assessment of the productivity of natural lands and agrocenoses. Field research was carried out in the Orenburg Urals region. It was established that the productivity of above-ground phytomass decreases from steppe areas - 2.38 t/ha to agrocenoses - 0.38 t/ha. In the steppe area, 89 plant species from 27 families were noted; in the forest belt - 59 species from 22 families; fallows - 28 species from 10 families, the agrocenosis is represented by 5 species from 4 families. When assessing soil fertility, the quantitative content of humus and basic plant nutrients: nitrate nitrogen, mobile phosphorus and exchangeable potassium, were important. The amount of humus in the soils of the steppe area at a depth of (0 -10 cm) is 0.77% and (30-40 cm) is 1.4%. The smallest amount of humus in the soils of the agrocenosis is at a depth of (0-10 cm) - 0.32% and (30-40 cm) - 0.36%. The heterogeneity of the content of mobile phosphorus was revealed, high values were noted in the soils of the agrocenosis at a depth (0-10 cm) - 51 mg/kg and the lowest values in the soils of the steppe area at a depth (30-40 cm) - 17.16 mg/kg. A significant content of mobile forms of potassium was noted in the forest belt at a soil depth (0-10 cm) - 761.1 mg/kg, the minimum parameters of the steppe area at a soil depth (30-40 cm) - 106.4 mg/kg. Microclimate, the amount of nutrients in the soil, and anthropogenic impact are the main indicators of the productivity formation of the phytocenosis of a particular tract.