| A field experiment was conducted to investigate effects of chicken manure application on bioavailability of
heavy metals Cd, Pb and As in soil and vegetable growth. On the treatment sites Malabar spinach (Gynura cusimbua), eggplant
(Solanum melongena) and no vegetable were planted respectively with different amounts of chicken manure fertilization. All the
responses of total heavy metal contents (Cd, Pb and As) and their availability in soil, heavy metal uptake by vegetables and their
growth were measured. The results showed that contents of Cd and As were high in chicken manure, which increased or kept the
total heavy metal contents in soil. Also, the heavy metal Pb with relatively low contents in chicken manure could accumulate in
soil after planting vegetables. With no chicken manure fertilizer, the total content of As in soil decreased significantly after
planting vegetables. When the chicken manure amount was 12 000 kg/hm2, the Cd bioavailability in the soil with vegetable
planting increased most than other treatments. And when the chicken manure amounts were 8 000, 12 000 and 16 000 kg/hm2,
the As bioavailability in soil with three different planting treatments all decreased. The Cd and Pb contents in Malabar spinach
first decreased and then increased, while As content displayed contrary tendency. Besides, the yields of Malabar spinach first
increased and then decreased with the chicken manure fertilizer increasing. But the fertilizer amount had no significant effect on
the yield and biomass of eggplant. |
