35 years after the Chernobyl accident – do we need rehabilitation measures on agricultural land?

Abstract

The changes in the density of pollution Cs-137 of arable land, hayfields and pastures in the south-west of the Bryansk region are considered. It is noted that the cleansing process is slow, so reha-bilitation measures are the main way to reduce the specific activity of the radionuclide in crop and feed production. The paper presents algorithm of calculation. Economic efficiency of agrotech-nical and agrochemical rehabilitation of arable land is estimated on results of stationary field ex-periments. The most economically expedient rehabilitation measures for various soils and densi-ties of radioactive contamination are established: 1) soil sod-podzolic sand, contamination densi-ty 137Cs 871 kBq/m2 – in crop rotation barley, clover, corn, winter rye, oats application of lime flour in a dose of 2.1 t/ha + NPK; 2) sod-podzolic sandy loam soil, contamination density Cs-137 2516 kBq/m2 – in crop rotation winter rye, potatoes, barley + perennial grasses, clover + timofeevka of the first year of use, clover + timofeevka of the second year of use introduction of phosphorite flour in a dose of 288 kg/ha + NPK; 3) sod-podzolic soil light loamy, contamination density Cs-137 901 kBq/m2 – in crop rotation potatoes, barley, corn, oats + perennial grasses, clover + timofeev-ka of the first year of use, clover + timofeevka of the second year of use, winter rye application of one-and-a-half doses of phosphorus-potassium mineral fertilizer in combination with one dose of nitrogen mineral fertilizer (NP1,5K1,5); 4) sod-podzolic soil is light loamy, contamination density Cs-137 1224 kBq/m2 – in crop rotation potatoes, barley, corn, oats + perennial grasses, clover + timofeevka of the first year of use, clover + timofeevka of the second year of use, application of dolomite flour in a dose of 3 t/ha + manure 120 t/ha + K600. For natural meadows, where rehabili-tation measures are not used, an adaptive method of agroecological use is proposed. With a con-tamination density of Cs-137 of more than 185 kBq/m2, it is advisable to harvest a green mass of canary grass stands in the central parts of the floodpubs, which accumulate less radionuclide, grazing animals along the otava is prohibited in order to protect them from radioactive substanc-es that may enter their body with sod and shallow soil. In “near the river bed” and “near terrace” parts of the waterprays, where grass stands accumulate much more Cs-137, grazing of animals is prohibited.