Long-term observations of the drained soil of peat-podzolic-gley light loam on ancient alluvial sands state on the example of the meliorative object "Tinky-2" showed that under the influence of agricultural use in the soil, the organic matter mineralization processes are accelerated. During the drainage process, the soil evolutionarily suffered the following changes: the peat layer was compacted, humified and mineralized, which was a reason of the transformation them into the humus horizon. Based on the monitoring studies results it was established that during 21 intensive use years the peat layer thickness was decreased by 74.5% and amounted to 5.51 inch, which in the following 20 years was decreased to a layer of 1.18 inch, and for another 14 years it became a homogeneous humus horizon containing difficulty identifiable plant remains. For half a century, the bulk density increased by 6 times and the total moisture capacity of the soil decreased by 3.6 times. Other indicators were changed significantly. So, the ash content by 2016 increased from 11.2% to 52.7%. It was a reason of the plough-layer decreasing and it mixes with the mineral sand horizon during plowing. It should also be noted that the total nitrogen content in the soil decreased by 1.13%, and total carbon by 15.3% from 1982 to 2016. The dynamics of changes in the soil acidity, phosphorus and potassium content is associated with the introduction of calcareous, organic and mineral fertilizers in the 1980s. The unsystematic exploitation of such soils leads to decrease in the agricultural products productivity and increase in energy costs. When planning these soils usage in agricultural production, it is necessary to develop and implement modern melioration technologies and techniques aimed to increase soil fertility.
