Effect Of Municipal Sewage Sludge On Mongolian Pine Growth And Soil Nutirent Status

With the urbanization becoming more and more obvious, the quantity of sewdgesludge is increasing, how to deal with that safely and effectively has become anurgent city environmental economic problem, currently, land utilization of sewagesludge is considered to be the most promising disposal method. It can not only solvethe problem of sludge disposal can also improve soil fertility, improve soil structureand increase the productivity of land. The sludge sand use has important practicalsignificance to reduce desertification and secondary pollution.The desertification area of China is2620000square kilometers, accounted for27.33%. Desertification is ecological disaster, hindering economic development,worsen living environment, climate changing, affecting the progress of socialcivilization. Mongolian Pine（Pinussylvestris var. mongolica）, as the pine trees, is oneof the main afforestation tree species in North China.This paper focuses on the study of the sewage sludge used in sand soil to makean organic combination to realize the resource utilization of the sludge and Pinussylvestris var.mongolica seedlings for breeding purposes, it can take economicbenefits and environmental benefits for the local. Take the sewage sludge of sewagetreatment plant in the North of Shenyang and sandy soil in Zhanggutai ZhangwuFuxin as the research object, to explore the effect of municipal sewage sludge on thebiomass and nutrition influence of Mongolian pine （Pinus sylvestris var. mongolica）in the soil and provide scientific basis for sewage sludge using and sand soil fertilityimprovement.The results are summarized as follows:Different treatments on Pinus sylvestris var. mongolica make diffrent influence.Through the observation we can see that, S2, S3grow best, and S4from the start,with the increase of sewage sludge volume, the growth status of Pinus sylvestris var.mongolica is decreased. From the aspect of plant height, net increase in the amount ofS2, S3is the highest, while S4, S5, S6three treatments with increasing amount ofsludge, the plant height was significantly decreased. Effect of different dosage of Pinus sylvestris stems are larger. S5, S6stems were significantly lower than othertreatments, S3is the most robust.Different sludge treatment effects on the indexes of ecological photosyntheticphysiology of Pinus sylvestris var. mongolica is obvious. Photosynthetic rate （Pn）increased with the amount of sludge applied photosynthetic rate increased, S3peakand the stomatal conductance and transpiration rate （Tr） generally similar to the curve,showed a single peak curve. Peak but the stomatal conductance and transpiration rateappeared in S4treatment. Diurnal variation curve of CO₂concentration and on thecontrary, S3net photosynthetic rate, the lowest CO₂concentration of S6, netphotosynthetic rate, respiration intensity, CO₂concentration was highest.Different sludge treatment effects on nutrient content in roots and leaves ofPinus sylvestris var. mongolica significantly. The nitrogen content of leaf of Pinussylvestris roots is increased with the amount of sludge applied and rising, rising stem> root> leaf nitrogen content, from the view was leaf> root> stem. The phosphoruscontent in rhizome and leaf of Pinus sylvestris var. mongolica is increased with theamount of sludge applied and rise, rise was root> stem> leaf, from phosphoruscontent was root> leaf> stem. The content of each organ of Pinus sylvestris var.mongolica rhizome and leaf potassium overall was first increased and then decreasedwith nitrogen, phosphorus content, the different. The content of potassium in differentorgans was leaf> stem> root.Different sludge treatment has obvious influence on the pine rhizosphere andnon-rhizosphere soil nutrient content. On the whole, rhizosphere and non-rhizospheresoil, total nitrogen, hydrolyzable nitrogen, total phosphorus, available phosphoruscontent are increased with the increase in the amount of sludge applied. The contentof hydrolyzed in the rhizosphere soil, nitrogen and available phosphorus increasemost significantly. Therefore, sewage sludge has a significant effect on soilimprovement.