Influence of nitrogen and potash fertilizers on the accumulation of <sup>137</sup>Cs by perennial legume-cereal and cereal grasses on peat soils
It has been established that on peat shallow soil, the use of P60K240 (K180 for the first grass cutting and K60 for the second grass cutting) under perennial legume-cereal grasses reduces the 137Cs content in hay by 2.2-3.0 times. The use of nitrogen fertilizers in total rates from 30 to 90 kg/ha against the background of P90K180 reduces the concentration of 137Cs in the hay of the first cut by an average of 1.7-2.0 times, in the hay of the second cut by 1.5-1.9 times. On peaty-gley soil, phosphorus and potash fertilizers in rates of P90K90 reduce the transfer of 137Cs into perennial grasses of the first cut by 27-28 %. When K120 is introduced for the first cut, a decrease in 137Cs input from the soil into plants is observed. Top dressing of grasses of the second cut with potassium at a dose of 30 kg/ha against the background of P90K90 provides a 50 % decrease in the coefficient of radionuclide conversion into hay. The introduction of cereal grasses N60 and N80 for the first cut does not significantly increase the 137Cs intake into plants. The second nitrogen fertilization of grasses leads to a slight increase in the accumulation of 137Cs in the hay of the grasses of the second cut. The intake of 137Cs in hay at increased doses of nitrogen fertilizers (N120-140) decreases against a high background of potassium use.