Scientific publications

The paper takes the Kuibyshev and Nizhnekamsk storage reservoirs within the Republic of Tatarstan as case studies of complex man-altered lowland water systems in European Russia under modern natural and anthropogenic changes. We present a quantification of the diffuse nutrient load from agricultural activities in the catchments of the Kuibyshev and Nizhnekamsk reservoirs within the borders of the Republic of Tatarstan for the 2001–2019 period. Having studied the dynamics of organic and mineral nitrogen (N) and phosphorus (P) fertilizer use in crop production in the catchments, we revealed a trend for their reduced application, amounting to 72.2 thousand tons N/year and 28.5 thousand tons P/year. Livestock numbers in animal farms of all categories was studied. During the study period, the numbers of cattle, sheep, goats, pigs, and horses tended to decrease while poultry numbers increased in farms of all categories in the catchments of the Kuibyshev and Nizhnekamsk reservoirs within the Republic of Tatarstan. The N and P load caused by livestock production was estimated. The average input to the catchments during the study period amounted to 51.9 thousand tons N/year and 26.4 thousand tons P/year. Estimation of the contributions of the main types of animal husbandry to the total N and P load in the catchments of the Kuibyshev and Nizhnekamsk reservoirs within Tatarstan showed that the main contributor was cattle farming (82 % for N and 81 % for P).