Influence of methods of agricultural use of organic soils on leaching biogenic substances into drained waters

Abstract

The purpose of the work is the environmental protection and effective use of drained organic soils of the humid zone in river valleys, which is connected with the development and using the system of sustainable development of agricultural sector, the object of which is the soil, as well as the processes that take place with its participation, especially the degradation of peat soil, leaching of various chemicals into groundwater, which were used in the technologies of growing agricultural crops. In these soils, there is a change in water-air, thermal, nutritional regimes and biological processes, which, due to unreasonable methods of soil use, leads to pollution of river waters, which negatively affect the ecology of the environment in general. The research results showed that the most leached from the soil, regardless of the doses and types of application of mineral fertilizers and weather conditions by year, were the compounds Ca (82–265 mg/l), Mg (33.9–126.0 mg/l), Na (22.1–48.2 mg/l of drainage water), and the lowest — nitrate nitrogen (2.1–29.5 mg/l) and phosphorus (0.4–2.0 mg/l of drainage water). Such dependence is associated with intensive consumption of mobile nitrogen and phosphorus by plants. A lot of Na was leached from the soil (21.2–65.0 mg/l of drainage water). This is due to the significant salt content in the soil, which is considered slightly saline. The most compounds of Ca, Mg, nitrate and ammonia nitrogen are washed out under grasses in spring, and under annual crops in autumn. Leaching mobile compounds of phosphorus and potassium regardless of the type of crop used, and most of them were washed out under grasses and annual crops in autumn; moreover, the amount of washed substances is consistent with the application rate. It was established that the content of almost all biogenic substances in the canals of various purposes did not exceed the MPC for fish farms, based on the use of the content of Mg compounds (MPC — 40 mg/l of water), which in the channels of the floodplain of the Supii River reached 91–126 mg/l of water. At the same time, the introduction of magnesium chemicals in the technological process of growing agricultural crops was not carried out, apparently, its compounds were found in the vivianite layers of the organic soil. The main measures for environmental protection agricultural use of drained organic soils are proposed in accordance with scientifically based methods of their use in the conditions of the humid zone of the Forest-Steppe and Polissia, which will make it possible to regulate and control the ingress of biogenic substances into drainage and river waters.