AGROCHEMICAL ASSESSMENT OF AGRICULTURAL LANDS IN THE KHERSON REGION AFFECTED BY FLOODING DUE TO THE DESTRUCTION OF THE KAKHOVKA HYDROELECTRIC STATION

Abstract

The article highlights the impact of long-term flooding of agricultural land as a result of the destruction of the dam of the Kakhovka HPP. The results of experimental studies of the reaction of the soil solution, humus content, mobile compounds of phosphorus and potassium in ten soil samples, silt and silt samples taken in the territory of the Kherson and Beryslav districts of the Kherson region are given. The condition of the soil cover of the flooded land plots was established by comparing the obtained indicators to the background values on the land plots that were not negatively affected and were characterized by the same agro-production group of soils. According to the results of the conducted research, acidification of the soil solution was established in comparison with the background values in 7 areas (from 0.1 to 0.5 units of pH) and alkalinization in 3 areas (from 0.1 to 1.0 units of pH). The selected sludge was characterized by a moderately alkaline reaction (7.8 units of pH), which by 0.7 units. The pH is higher than the background value of the area from which it was taken. The siltation sample, on the contrary, had a lower pH value (7.7) compared to the soil of the area from which it was taken (8.0). Compared to the background values, the content of humus (organic matter) in 5 analyzed soil samples decreased, in 6 it increased. The content of humus in the sludge sample was more than 5.6 times higher than its content in the soil from the site where it was collected. The nitrogen content in terms of nitrification capacity in the selected samples varied from very low (4.7 mg/kg of soil) to very high (26.8 mg/kg of soil). Compared to the background value, in 6 analyzed soil samples, a decrease in nitrogen content was noted – from 1.3 to 87 mg/kg of soil (-7.8 to -85%), in 5 samples – an increase from 4.0 to 17.5 mg/kg of soil (from 35 to 188%). The sludge sample and the soil of the area where it was collected were characterized by high nitrogen content. A significant increase in the content of mobile compounds of phosphorus and potassium in the soil was found on most of the surveyed land plots. The selected samples were characterized by a very high degree of availability of mobile compounds of phosphorus (from 67 to 188 mg/kg of soil) and potassium (from 447 to 2016 mg/kg of soil), and only 1 sample had an elevated content of these indicators. In comparison with the background value, an increase in the content of phosphorus was noted in 10 analyzed soil samples – from 6 to 88 g/kg of soil (from 1.1 to almost 7 times), only in 1 sample was a decrease in the content of the element. The content of mobile phosphorus compounds in the siltation sample (#9) was almost at the level of the background value of the area from which it was taken. The content of phosphorus in the silt was 7 times higher than the content of the element in the area before it was flooded. An increase in the content of mobile potassium compounds was also established in all the studied samples (from 1.04 to 8.4 times).