The transformation and balance of nitrogen in fluoride-polluted agroecosystems on gray forest soils of the Baikal region

In years with different hydrothermic conditions, the impact of fluorides on the nitrogen cycle in gray forest soils under agroecosystems was investigated in field experiments with the N-15 isotope. The content of fluorides in the soil at a level three times higher than the maximum permissible concentration caused neither a decrease in the yield of spring wheat nor a pronounced accumulation of fluorine in the grain. However, the negative effect of pollution manifested itself in the intensification of nitrogen mineralization processes. The net mineralization of nitrogen increased, whereas nitrogen immobilization decreased. This resulted in a considerable nitrogen deficiency, which was three to five times higher in the polluted soil compared to the control plots.