Effects of Soil Sterilization and Fungicide on the Growth, Cadmium and Lead Accumulation of Vicia faba

Purpose To investigate the effects of soil microorganisms on the heavy metals accumulation of Vicia faba grown on the heavy metals polluted farmland.

Method The V. faba was cultivated on the heavy metals-polluted soils from a farmland in a lead-zinc mining area of Huize County, Yunnan Province under a greenhouse condition. The growth, mineral nutrient, cadmium (Cd) and lead (Pb) content and accumulation of V. faba were investigated under treatments of soil sterilization and fungicide (benomyl).

Result The fungicide treatment significantly increased the contents of alkaline hydrolysis nitrogen (N) in soils and N in shoots, decreased the phosphorus (P) and potassium (K) content in roots, but had no significant effects on the plant height and biomass of V. faba; reduced the Cd content in shoots, Cd accumulation in plant, and the enrichment coefficient and transport coefficient of Cd in V. faba. The soil sterilization significantly decreased the contents of available K in soils and K in roots, the plant height and biomass of V. faba; increased the Cd and Pb content in plant and the Pb accumulation in roots, but reduced the Cd accumulation in roots and Pb accumulation in shoots; increased the enrichment coefficient of Cd and Pb and transport coefficient of Cd, while decreased the transport coefficient and biological transport factor of Pb.

Conclusion The elimination of microorganisms and fungi resulted in changes on the mineral nutrition, content and accumulation characteristics of Cd and Pb in V. faba, and influenced the plant growth. These results indicated that soil microorganisms played an important role in the tolerance and accumulation of heavy metals in V. faba.