| With the growth of the population and the development of the economy, the natural resources in the world are being consumed swiftly and the technology of reuse of waste is being attached more importance by many countries. The lack of the natural resources in China is so serious that it has made the research of resources reuse even more important than ever.Since there are high quality of nutrition elements such as organic matter, nitrogen, phosphorus, the agricultural utilization of municipal sludge and lake sediment is become an important topics in nowadays research. However, the heavy metals are the key factor restricting the utilization of municipal sludge and lake sediment in agriculture. Many studies have been made to decrease and reduce the poisonous effect of the heavy metals in municipal sludge and lake sediment, but the characters of system, economy and utility still cannot meet practical demands. Therefore, research on the reasonable utilization of municipal sludge and lake sediment and the avoidance of heavy metals pollution in soil-plant system has a very important significance.The plot experiments and pot experiments were conducted to study the effects of land utilization of municipal sludge and inorganic fertilizer combined and lake sediment and inorganic fertilizer combined in soil-plant system. The effects were on the nutrients contents of soil, the environment quality of soil, the migration of heavy metals in the soil, the nutrients absorption of wheat, the yield of wheat seed, the contents of heavy metals of Cd in wheat seed, the absorption and accumulation of heavy metals of each parts in wheat.The results of plot experiments with different treatments showed that soil nutrients contents could be increased significantly by application of municipal sludge and lake sediment. The soil status could be improved from shortage to enrichment in largest degree respectively. Heavy metals were accumulated in the surface soil layer without migrating downward into deep soil layer after application of municipal sludge and lake sediment. When the municipal sludge application was 150 t/hm2,200 t/hm2 and the lake sediment application was 400 t/hm2, heavy metals(Cd)contents in the surface soil layer exceeded the National Environment Quality StandardⅡfor Soil. With the increasing of application of municipal sludge and lake sediment on soil, the yield of wheat seed and the contents of nutrients, absorbed by wheat, both increased, but the use rate of nutrients not increased, it showed that mass of nutrients accumulated in the soil. The accumulation of heavy metals were in an order: root＞stem＞seed, Cd＞Pb. The ability of plant decreased, absorbed and accumulated heavy metals with the increasing of application of municipal sludge and lake sediment. The contents of heavy metals(Cd,Pb) in wheat seed were not exceeded the National Control Hygienic Standard for Foods. Municipal sludge and lake sediment could be applied 5 years and 6 years on soil continuously, even the amount of application was 100 t/hm2 and 200 t/hm2.The results of pot experiments with different treatments showed that soil nutrients contents could be increased by combined application of municipal sludge and inorganic fertilizer. It was conducted that soil status was infertile, generic, fertile with combined application of municipal sludge and inorganic fertilizer after integrated evaluation on soil fertility. Soil nutrients contents could be also increased by combined application of lake sediment and inorganic fertilizer. The contents of organic matter and tatal nitrogen could not be increased obviously, organic matter and tatal nitrogen could be reached lacking status, available nitrogen could be reached moderate status, The contents of tatal phosphorus and available phosphorus could be increased obviously, tatal phosphorus and available phosphorus could be reached abundant status. The contents of heavy metals(Cd,Pb,Cu,Zn)in soil could be increased after land utilization of municipal sludge and inorganic fertilizer combined and lake sediment and inorganic fertilizer combined. The contents of heavy metals(Pb,Cu,Zn)in soil were not exceeded the National Environment Quality StandardⅡfor Soil with all the treatments, but the contents of heavy metals(Cd)were exceeded it with parts of the treatments. Soil status was clean, much clean and little more polluted with combined application of municipal sludge and inorganic fertilizer after evaluation in synthetic and polluted index method on different treatments, and soil status was clean and much clean with combined application of municipal sludge and inorganic fertilizer. The yield of wheat seed could be increased with combined application of municipal sludge and inorganic fertilizer, lake sediment and inorganic fertilizer. The amount of combined application was the safe and economical, if municipal sludge was 100 t/hm2 and inorganic fertilizer was 150 kg/hm2(CO(NH2)2)+150 kg/hm2((NH4)2HPO4), and lake sediment was 200 t/hm2 and inorganic fertilizer was 150 kg/hm2 (CO(NH2)2)+150 kg/hm2((NH4)2HPO4), the use rate of fertilizer was the largest. The contents of heavy metals(Cd)in wheat seed could be increased with the increasing of application of municipal sludge and lake sediment. The ability decreased, absorbed and accumulated heavy metals of Cd, after increase. The contents of heavy metals of Cd in wheat seed of different treatments were not exceeded the National Control Hygienic Standard for Foods.
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