Study On The Risk Of Vegetable Soil Environment By Combined Application Of Fertilizer And Manure In Rural Toilets

With the advancement of the"toilet revolution"in rural my country,three-compartment septic tank toilets have become the current mainstream promotion type,but the problem that comes with it is how to efficiently treat the large amount of manure produced by three-compartment septic tank toilets in rural areas.Since most rural areas in my country have the tradition of using human feces and urine as fertilizers for vegetable cultivation,with the increase of people’s awareness of hygiene and the promotion of chemical synthetic fertilizers,this resource-based method has been gradually rejected,and toilet feces can only be treated.Relying on the urban sewage treatment system has caused unnecessary waste of resources in this process,increased the cost of manure treatment by rural households,and also increased the risk of secondary pollution to the environment during the process of manure transportation.At present,there is no relevant research on the effect of returning manure liquid from the third compartment of a three-compartment septic tank on the soil environment and plants.Therefore,this study selects the manure and acidity and alkalinity of the third compartment of a typical rural three-compartment septic tank.Two types of soils with large differences were used as the research objects.Through pot experiment,five fertilization treatments were set for each soil:blank（CK）,manure only（F）,chemical fertilizer only（CF）,and manure:chemical fertilizer=1:2（P1）,manure:chemical fertilizer=2:1（P2）,plant water spinach and Chinese cabbage in two seasons,explore the effects of different fertilization treatments on different soil environments for planting water spinach and Chinese cabbage,and fertilization the effect of treatment on the yield and quality of vegetables.The main results of this study are as follows:（1）The combined application of manure and chemical fertilizers（P1 and P2）changed the properties of soil nutrients,especially the available phosphorus（AP）,available potassium（AK）,soil p H and electrical conductivity（P<0.05）.P1 and P2 can increase the content of AP（766.32%,100.01%;327.10%,69.96%）and AK（111.84%,160.49%;91.88%,97.91%）of sierozem and fluvo-aquic soil for planting vegetables,and increase electrical conductivity,F or combined application of manure and chemical fertilizers can reduce soil p H.（2）The application of manure（F,P1 and P2）can increase the sierozem urease activity（S-UE）of water spinach planting,and P1 will reduce the sierozem hydrogen peroxide for planting water spinach enzyme activity（S-CAT）and fluvo-aquic soil invertase activity（S-SC）;P1 and P2 can reduce the S-UE of the fluvo-aquic soil for growing Chinese cabbage and increase the alkaline phosphatase activity of sierozem（S-ALP）,F can increase acid phosphatase activity（S-ACP）of fluvo-aquic soil,P1 will reduce sierozem S-CAT,P2 combined application will increase the S-SC of the fluvo-aquic soil（P<0.05）（3）Combined application of manure and chemical fertilizers will inhibit soil microbial activity.P1and P2 can reduce the abundance of fungal communities in the fluvo-aquic soil where water spinach is grown,and P2 can increase the diversity and abundance of bacterial communities in the fluvo-aquic soil;P1 and P2 can reduce the diversity and richness of bacterial communities in the sierozem where cabbage is grown,and reduce the abundance of fungal communities in the fluvo-aquic soil.P1 will reduce the fungi in sierozem community diversity,the application of manure will reduce the diversity and abundance of bacterial communities in the fluvo-aquic soil where Chinese cabbage is grown（P<0.05）;after the application of manure,the dominant bacteria such as Arthrobacter,Blastococcus,Chloroflexi and Acidothermus and pathogenic bacteria such as Fusarium in the soil relative abundance increased.（4）Combined application of manure and chemical fertilizers can increase the yield of vegetables grown on sierozem and fluvo-aquic soil;increase vegetable nitrate content;F and P2 can reduce sierozem the soluble sugar content of water spinach grown on soil,the application of manure can increase the soluble sugar content of Chinese cabbage grown on sierozem,and the combined application can increase the soluble sugar content of Chinese cabbage grown on fluvo-aquic soil.F reduces the soluble sugar content of Chinese cabbage grown on fluvo-aquic soil;the vitamin C content of water spinach grown on sierozem was increased,and the application of manure can increase the vitamin C content of Chinese cabbage grown on sierozem（P<0.05）（5）Correlation analysis results show that the key environmental factors that affect soil enzyme activity are AK,EC and p H;the soil microbial activities that affect water spinach planting are TC,NH₄⁺-N and p H,and the soil microbial activities that affect water cabbage planting are AP,AK,p H and EC;it is AP,AK,NO₃^--N,p H and EC that affect the yield and quality of vegetables.