Application Of Products Derived From Sewage Sludge To Farm Land And Evaluation Of Their Organic Matter Quality

With the development of economy, the yield of sewage sludge has been increased gradually in recent years and the impact of sludge on the environment has become more and more serious. Many researchers from home and abroad have done much work for the treatment and utilization of sewage sludge, but from China's specific conditions, land use is the most feasible and most realistic way to treat sewage sludge. However, in terms of the fertilizer efficiency and environmental effects, agriculture utilization as organic fertilizer, organic-inorganic compound fertilizer and substrate after composting is the best way for treatment and disposal of sewage sludge. However, little information on the subject and studies about how to assess the fertilizer efficiency of organic manure is available. In this paper, the fertilizer efficiency and environmental effect of sludge substrate and sludge organic-inorganic compound fertilizer on the cultivation of garden flowers, food crops such as wheat, rice and economic crops such as cotton and rape were systematically investigated. Moreover, the evaluation of organic matter quality was also, studied in detail.By screening through the matrix, it was found that physical and chemical properties of 50%, 60% and 70%, 80% of the compost matrix sawdust are good. Compared to the traditional matrix, The above products had higher nutrient content, lower prices. Applied to garden flowers, they can increase the yield and quality of flowers. Enhancing effects were various on different flowers. The matrix remained rich total P and N, available N, P, K, after harvest of flowers.Pot experiments of three different proportions of organic and inorganic fertilizer were performed. The results show that they have significantly increased the wheat and rice yield in both soils, and improved the nutritional quality of rice. The content of special treatment sludge in organic and inorganic fertilizer should not be too high, otherwise it is bad for increasing the yield. Organic and inorganic fertilizer made of sludge, sewage sludge and alkalinized sludge can escalate the yield of rape and cotton, increase the contents of total N, microdiffuse N and available P, the overall effect of organic and inorganic compound fertilizer made of sludge is superior to municipal sludge and alkalinized sludge.Wheat and rice grain yield, straw yield and the total biological production were significantly increased in the treatments with organic and inorganic compound fertilizer, sludge and alkalinized sludge. .The N conversion efficiency in plant was accelerated in the treatment with organic and inorganic compound fertilizer. On the normal application levels, sludge will not cause heavy metal pollution in soils. The effect of yield increase is the best in the treatments with organic and inorganic compound fertiliuzer made of sludge. On the whole sludge best organic and inorganic fertilizer, Yield increase treated with 80 percent of the applied amount of compound fertilizer made of sludge was comparative to that treated with chemical fertilizers. The application of compound fertilizer, sewage sludge and alkalinized sludge can reduce the leaching of N and P in soils. It is helpful to reduce the risk of eutrophication in water. There is a significant positive correlation between organic C determined with 0.02N potassium permanganate oxidation technique and biomass C. Hence, organic C measured with 0.02N potassium permanganate oxidation method is denoted the quality of compound fertilizer made of sludge and organic matter. If organic C content analyzed with 0.02N potassium permanganate oxidation method is more than or equal to 0.30%, and organic matter content measured with the existing national standard GB18877-2002 approach is >20%, the quality of the tested organic and inorganic fertilizer or organic matter sample is qualified.