Agricultural Academy

Abstract . Effects of heavy metals from polluted soils on the roots and nodules formation. Bulg. J. Agric. Sci., Intensive development of transport in suburban areas contributes to excessive accumulation of heavy metals in cultivable soils. The negative effect of heavy metals on legumes becomes apparent in specifi c concentrations in the soils, hence it is not always possible to determine direct harm of environment to the growth of plants root system. The aim of the research was to evaluate the impact of soil conditions on root system weight, weight and number of root nodules in different legumes species; fi eld pea (Pisum sativum) and spring vetch (Vicia sativa). Additionally, we assess the degree of metals accumulation in roots dry mass. Research studies have shown that an increase in heavy metals content in agricultural soils in an urbanized area results in a decrease in microbiological activity of soils, their fertility, and in consequence a decrease in plants productivity. Metals pollution of soils resulted in deterioration of biometrical parameters of the root system and deterioration of effi ciency of the symbiotic system. Field pea showed little sensitivity to the presence of heavy metals in the soil. Spring vetch was more sensitive to soil pollution, developing lesser root mass. Field pea was less sensitive to the cultivation station, the effect of which was a lower level of zinc, chromium and nickel accumulation. Moreover, fi eld pea showed high detoxifi cation capacity, accumulating a large amount of lead in the roots