Effects of Deer Dung and Microbial Fertilizer on the Bioavailability of Pb and Zn in Vegetable Soil

The influence of different dosage of deer dung and microbial fertilizer on the content of DTPA-Pb and DTPA-Zn in vegetable soil and the content of Pb and Zn in Brassica campestris was studied through the pot experiment. Results show that the addition of deer dung and microbial fertilizer could significantly decrease the contents of DTPA-Pb and DTPA-Zn in vegetable soil. The content of DTPA-Pb was decreased significantly by 25.81% (P < 0.05) with 5% deer dung addition and the content of DTPA-Pb was decreased significantly by 26.48% (P < 0.05) with 10% microbial fertilizer addition. Application of deer dung and microbial fertilizer colud promote the transformation of acid-extractable Pb, reducible Pb and oxidation state of Pb to residual Pb. Compared with the blank experiment, the content of Pb and Zn in the Brassica campestris among the six treatment groups decreased significantly, 5% deer dung treatment group was the most effective on the decrease of the content of Pb in the plant by 48.50%. 10% microbial fertilizer treatment group was most effective on the decrease of the content of Zn in the plant by 32.51%. The content of Pb and Zn in Brassica campestris were most significantly and positively correlated with the content of DTPA-Pb and Zn in soil (P < 0.01).