Effect of wastewater sludge on agri-environmental indicators of soil

The chemical composition of sewage sludge (WWS), depending on entering the treatment plants for industrial and municipal wastewater, as well as methods for determining and varies over a wide range. WWS characterized by a wide range of macro- and microelements, including heavy metals. The WWS contains 1,00-1,34% total nitrogen, total phosphorus 0,21-0,23%, 0,32-0,36% of potassium at pH - 4.8-5.0. The aim of the work was to determine the effect of waste products in the form of WWS on the environment and agri-environmental indicators of soil. In the course of the research were taken into account reserves of nutrients in the soil, their distribution in the profile, space-time variation in the soil and available to plants. Indicators: soil acidity, digestible form of nitrogen, phosphorus, potassium, trace elements, the reaction medium, the content of absorbed bases and humus. Thus, in terms of the object overlap and fertile layer of OSV leads to the accumulation in the fertile layer of soil nitrate and, ultimately, in crop production. In the area of overlap of the fertile layer WWS showed a reduction of humus content of 31.1%, mobile forms of phosphorus by 14.3%, 26.1% potassium, and increases soil acidity by 2.9% compared with the control. Study on the WWS storage site led to a sharp accumulation of soil nitrate in excess of the MPC from 18.2% to 218.0%, with an average to 244.5%.