Studies On The Effects Of Vegetable Yield And Safty Soil Security Capacity After Application Biogas Fertilizer

The paper studied the effects of the biogas fertilizer on the yield and content of nitrate and heavy metal in different vegetables. Sdudies the soil security capacity after application of biogas fertilizer. In the experiment, cabbage, lettuce and scallion were chosen as materials, livestock manures was treated by using anaerobic fermentation technology. The research is hoping to find the best and the most security capacity of vegetable and soil security after application of biogas fertilizer.The rusult showed that: along with fertilizer application increasing, the yield of vegetables increased differently. The output of cabbage is 3672—4233kg/mu, increased by 5.1—12.5% than the comparison, significantly higher than control. Compared to the control, the output of scallion is -0.3—12.4%, the output of lettuce is 22.7—34.2%,the yield reached significant level. It illustrated that fertilizer application can increase the output, and the increase sequences are lettuce>cabbage>scallion. Different vegetables are different to the N,P,K absorption effect. Proper fertilizer application would promote absorption of the nutritionorgan. The more fertilizer applied, the more absorption of N, P and K. In general, the content of N, P, K in cabbage showed the tendency of rising. Increased by 21.8—28.5%,3.3%—13.3% and 2.0%—8.8% than the comparison. Compared to the control, the content of N, P, K of scallion increased by -2.9%—16.3%,7.7%—19.2%,27.3%—71.8%. The content of potassium in scallion significantly higher than control. It showed that applying organic fertilizer can promote plant to absorb potassium. Content of P in lettuce increased first and decreased afterwards. Different nutrients were demanded and absorbed in different kinds of vegetable crops.Applying organic fertilizer has some safety, In the destructive tests, the yield of all treatments were significantly higher than CK, increased by 2.8—32.0%. The content of Cd and Cr in cabbage with excessive fertilization was not significant between the treatment and the control, the other kinds of heavy metal were significantly lower than CK. The content of Pb, Hg, Cr, Cd in lettuce and scallion was lower or significant lower than CK. The content of Pb, Hg, Cr, As in cabbage was significantly lower than CK, but Zn and Cu had a rise trend, by -9.3—12.3% and -4.2—12.5%, respectively. It indicates that people need to balance the relation between increasing fertilization and controlling environmental pollution. In general, amount of biogas fertilizer applied, pesticide and heavy metal in vegetable and soil were both lower than limit standards.Nitrogen content were same in soil which had plant the lettuce, scallion and cabbage. The content of P, K in soil which had planted scallion and lettuce is significant difference to contrast. This difference perhaps relate to different nutrition absorption in different vegetables. The content of nitrate and heavy metal of vegetables are safety according to the limite. And soil bearing capacity is beyond the application amount, so further studies need to be carried out in the future to find the best fertilization method.