CONTENT OF HEAVY METALS IN AGRICULTURAL SOILS OF PRIMORSKIY KRAI
The article presents data on the content of heavy metals (Mn, Zn, Cu, Cr, Ni, Co, Pb) in agricultural soils of Primorskiy krai under rice crops, vegetable crops, and on virgin lands. The content of heavy metals in soils is shown on the example of the Khasanskiy and Spasskiy districts of Primorskiy krai. The content of mobile forms of metals was determined in soil samples by the atomic absorption method. The influence of agricultural methods, intensive chemicalization on the content of heavy metals in soils when growing rice, soybeans and vegetable crops is considered. Attention was paid to the results obtained from fields leased by Chinese farmers. The levels of metal concentrations were compared with concentrations in virgin and fallow areas, along with agricultural land cultivated by local farmers using traditional agricultural methods peculiar to our region. The index of total soil pollution with Zc was calculated. The concentrations of heavy metals in agricultural soils, soils of virgin and fallow plots have been differentiated. The total indicator of chemical soil pollution with Zc showed the acceptable degree of pollution. The sanitary and hygienic assessment of soils indicates a relatively favorable situation against the background of dehumification, acidification and disturbance of the balance of exchangeable cations in the soils of the studied areas leased by Chinese farmers. The further prospects for the use of soils of Primorskiy krai in agriculture were estimated. It has been shown that excessive chemicalization of soils leads to their degradation and can contribute to excessive accumulation of heavy metals in soils. In this connection, the regular monitoring of agrochemical indicators of the ecological state of agricultural soils is necessary in the agricultural regions of Primorskiy krai.