Assessment of the content of mobile phosphates and phosphatase activity in agricultural land soils of the Donetsk People’s Republic

The article presents the results of studies of the content of mobile forms of phosphates and the activity of the phosphatase in the soils of agricultural lands of the Donetsk People’s Republic. It was revealed that the lowest content of mobile forms of phosphorus was noted in sites with the cultivation of grain crops (1.27-2.17 mg /100 g of soil), where this indicator did not exceed 42% compared to the control. When cultivating vegetable crops, the maximum supply of phosphates (3.44-4.59 mg / 100 g of soil) was characterized by the plot under tomatoes, while the content of mobile phosphorus in the A horizon of the fields under onions and eggplants was 36-38% lower compared to the control indicators. All underlying horizons had a reduced content of mobile phosphates and activity of the phosphatase compared to arable ones, which is typical of the chernozem type of soil formation. The removal of phosphorus with commercial agricultural crops led to a decrease in the content of mobile phosphates in the soil of all sites after harvesting. The most significant decrease of this indicator was noted in the arable horizon of plots under grain crops, amounting to more than 65% compared to the control. During the period of active formation of vegetative mass, the maximum phosphatase activity was observed in plots under grain crops and amounted to 70-86% relative to the control. The assessment of phosphatase activity in the soil according to the Gaponyuk and Malakhov scale showed that sites under grain crops is characterized by a high degree, and all other sites are of medium degree. A strong negative correlation was established between the content of mobile phosphates and phosphatase activity (r from -0.83 to -0.92).