| In the last two decades, various industrial and agricultural activities worsen agricultural environments and caused heavy metal pollution of agricultural products, especially vegetable products, which potentially threatened human health. Integrated fertilization with appropriate rate of organic manure and chemical fertilizers is one important feature of fertilizing systems in China, and can enhance soil fertility and nutrient recycling, which takes up important situation in the construction of sustainable agriculture. Pollution risk of organic manuring is depended on the sources of organic manure. Ecological risk of swedge sludge used as soil amendments was well assessed. However, the environmental risk of application of commercial organic manure made from feces of domestic animals is still unclear. Identification of the effects of integrated fertilization with chemical fertilizers and organic manure on crop yield and quality of agricultural products as well as environment is significant to agricultural food safety.With a series of field experiments and chemical analysis, the effects of integrated fertilization with chemical fertilizers and commercial organic manure on market yields of crops (including rice, rape, tomato, radish, and greens) and quality of agricultural products as well as on environmental impacts were studied. Meanwhile, heavy metal balance in the important soil-crop systems was also discussed. The results obtained were summarizes as follows:1. Under equal N, P2O5, and K2O rates, the differences of shoot biomass and grain yieldof rice plants among treatments were not significant (p<0.05), and high rate of organic manure treatments (T3, T4) could significantly (p<0.05) reduce shoot biomass and grain yield of rape plants. In the located experiment with the tomato-radish-greens rotation, integrated fertilization with chemical fertilizers and organic manure could significantly (p<0.05) reduce fruit yield of tomato plants as the first season crop, yet it could increase radish and greengs yield as the following crops.2. In general, N, P, K contents of test crops (except K content in husks and N content in stalks of rape plants, N and K contents in leaves and K content in stalks of tomato plants) with integrated fertilization with chemical fertilizers and organic manure were obviously or significantly higher than these of chemical fertilizer treatment (Tl). Under the appropriate nutrient supply conditions, both of integrated fertilization with chemical fertilizers and organic manure and application of chemical fertilizers alone could preferably meet the nutrient demand of test crops.3. Integrated fertilization with chemical fertilizers and commercial organic manure could effectively reduce concentrations and accumulation of heavy metals (Cu, Zn, Cd and Pb) in test crops. Copper, zinc, cadimium, lead concentrations in harvesting parts of test crops of all treatments were lower than the limit of these heavy metals in foods (GB18406.1—2001). It was noticed that cadmium concentration in brown rice increased trendly with the increase in the rate of organic manure applied. Healthy risk existed as Cd concentration in brown rice of treatments with medium and high rate of organic manure were as high as the limit (0.2 mg/kg) in cereals.4. Integrated fertilization with chemical fertilizers and commercial organic manure could obviously or significantly reduce NH4+-N (except treatment T4 in the radish experiment), NCV-N, total P content in runoff or drainage water. Comparison with the quality standards surface water (grade III), only total P contents in drainage water of treatment Tl, T2, and T3 in rice experiment were higher than the criteria. Integrated fertilization with chemical fertilizers and commercial organic manure could obviously reduce the excessive ratios of NH/-N, NCV-N, total P in runoff water from rape experiment. The excessive ratios of NH4 -N, NCV-N, total P in runoff water from the vegetable cropping system were high at large, but which were lower in integrated fertilization treatment with chemical fertilizers and commercial organic manure. The above results implied that integrated fertilization with chemical fertilizers and commercial organic manure could effectively improve the quality of runoff or drainage water from agricultural fields, reduce N, P losses and ratios of N, P losses to N, P supply, and minimize the pollution risk of N, P losses.5. Heavy metal concentrations in runoff or drainage water of different treatments were quite lower, and heavy metal losses were also quite limited. The impacts of different fertilization on available concentrations of heavy metals in soil were not obvious. Under the normal doses of nutrient supply, application of chemical fertilizers and/or commercial organic manure can't induce heavy metal pollution in soils and surface water.6. Heavy metal balance in the important soil-crop systems was different as a result of different fertilization. It was also found that zinc and copper deficits in the soil-crop systems occur easily in treatments with no organic manure or lower rate of organic manure. Integrated fertilization with appropriate rate of organic manure and chemical fertilizers (T3) could remain the balance of zinc and copper as micronutrients. Application of chemical fertilizers and commercial organic manure could mostly result in cadmium and lead accumulation in soils. Lead accumulation in soils decreased trendly with the increase in the rate of organic manure, and cadmium accumulation in soils increased trendly with the increase in the rate of organic manure. Since the criteria of Cd pollution in soil is low as 0.5 mg-kg"1 soil, excessive organic manuring probably increase cadimium pollution risk in soils. These results suggested that integrated fertilization with appropriate rate of organic manure and chemical fertilizers could not only remain the balance of zinc and copper as micronutrients and prevent soil degradation lead by excessive heavy metal accumulation, but also achieve nutrient circle and recycle, which can be regarded as an effective manner for the construction of sustainable agriculture.
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