PHYTO-RECLAMATION DOMESTICATION OF SOLONETZ SOILS OF BARABA AND ITS EFFECT ON THE BIOLOGICAL ACTIVITY OF SOIL

Abstract

Results are given from investigations carried out at the established experimental plot of the Siberian Research Institute of Fodder Crops on fine- and medium-textured solonetz soils in the eight phyto-reclamation crop rotations during the four rotations. As annual phyto-ameliorants were used millet, oats, Sudan grass, peas; perennial ameliorants were melilot, alfalfa, awnless brome. It has been found that the long-term phyto-reclamation of solonetz soils, as compared with raw land, significantly improves soil fertility characteristics: decreases soil acidity from 8.2-8.0 to 7.6-7.0; reduces the content of water-soluble salts in the 1 m soil layer by 11-41% on medium solonetz soils, and by 51-52% on fine ones; increases the content of mineral nitrogen. The phyto-reclamation increases aeration of soil, and contributes to increasing the number of soil microorganisms involved in the mineralization processes and humus synthesis, these are bacteria assimilating organic and mineral nitrogen, nitrifying agents, and nitrogen fixers. It has been found that by the end of the forth rotation of fodder phyto-reclamation crop rotations the upper soil layers of fine- and medium-textured solonetz soils approach zonal chernozem soils as to the index of total biological activity. As to chemical characteristics, the solonetz soils studied go over to the category of residual solonetz-like soils.