Accumulation of heavy metals in the four years' continual swine manure-applied greenhouse soils

Greenhouse soils which were applied with swine manure for 0～4 years respectively and where vegetable samples were collected in a vegetable base. The total concentrations of Cu, Zn, Pb, Mn, Cr, Cd, Ni and As in soils and vegetable samples and the bioavailability concentrations of Cu, Zn, Pb, Mn, Cd and As in soils were measured, respectively. The measured data were tested using Fisher small sample non-parameter randomization. The aim was to study accumulation and bioavailability concentration changes of heavy metals in the four years continual swine manure-applied greenhouse soils and the impact of heavy metals on vegetable. Results show that after four years' continual swine manure applied in soils, Cu and Zn could be accumulated in soil, and As could be accumulated to some degree, and Pb, Cd, Ni and Cr were not accumulated in the short-term, Mn was not accumulated obviously, but Pb, Cd, Ni and Cr could be accumulated in soils if long-term and large quantity swine manure was applied. The pH value of the soil would decrease. The bioavailability concentrations of Cu, Zn were increased and had positive relation with the total concentrations of Cu, Zn(p<0.05) and negative relation with pH value (p<0.01), respectively, and Pb, Mn and Cd in soil were increased and had negative relation with pH value (p<0.05), and the bioavailability concentration of As which was not related to pH value (p>0.05) was increased too. The contents of As in some tomato and cucumber samples which were collected in four years continual swine manure applied soils exceeded the concerned standard. The total concentrations of Cu and Zn in soils could exceed the second rank of the national farmland soil environmental standard after 10 and 15 years continual swine manure-applied with the 150 m³/(hm²·a) quantity, respectively.