The Effect Of Reclaimed Water Irrigation On Soil Performance And The Microorganism

Reclaimed water refers to the urban sewage that after being fully and reliablepurifying treatment, and it meets the standards for the specific use. It has manyadvantages such as a wide range of applications, the low economic cost and so on.Andit is one of the important means to realize the sustainable utilization of water resources.We study two lawn irrigation area in a Beijing recycled water works, and one isirrigated with reclaimed water while the other with tap water. We study the impact ofreclaimed water irrigation area on soil and microbial system with the method ofstatistical and microbial ecology analysis. On this basis, analyse the relationshipbetween soil physicochemical properties and microorganisms of reclaimed irrigationarea, in order to provide a basis for setting a standard for the feasibility and safety of thereclaimed water irrigation.Test11soil physical and chemical indices in reclaimed water irrigation area andanalyse the variation of soil physicochemical properties. Results show that in addition tothe total Phosphorus content, ratio of Carbon and Nitrogen and allavailable Kalium content of the reclaimed water irrigation area is lower than that of tapwater irrigation, the other indexes showed different in different area. The maximumvalue of soil water content, organic matter, organic carbon, total nitrogen, totalpotassium content are at the inlet of reclaimed water irrigation, and higher than tapwater irrigation area. The pH in the aeration tank is largest and higher than the controlarea, the minimum PH is at the inlet. The content of alkali-hydrolyzale nitrogen islargest at the inlet and the value at the outlet and the control area are the same, while theminimum is in the aeration tank. The content of rapid available phosphorus in theaeration tank and the inlet are greater than the control, and the maximum value is at theinlet.As for culturable microorganisms in the soil of reclaimed water irrigation, by usingthe method of dilution coated tablet, we isolated62strains of bacteria,64strains ofactinomycetes,40strains of fungi. Identify the screened bactetia from theirmorphological identification, and according to the eighth edition of the "berger bacteriaidentification manual", the result shows that there are two kinds of dominant spacies: Bacillus and Pseudomona, which accounted for46.97%of the total number ofindividuals; and18frequent groups, which accounted for53.03%of the total number ofindividuals. The research results show that compared with tap water irrigation, somerare species dominance index increased in soil after being watered with reclaimed water,but there are also some species dominance are decreased. The maximum number ofstrains are in the aeration tank while the minimum at the inlet. From three speciesdiversity index, result shows that soil with different physicochemical properties havegreat difference in soil microbial population diversity and lower similar index. Throughcorrelational analysis, diversity index, richness index and evenness index have closerelations, and it’s a consistent reflexion of species and community characteristics.Perform classical correspondence analysis (CCA) with the soil microbialcommunity in reclaimed water irrigation area and physicochemical index such as PH,soil moisture, organic matter (OM), total nitrogen (TN), total phosphorus (TP), totalpotassium (TK), C/N, alkaline hydrolysis nitrogen (AN), available phosphorus (AP),available potassium (AK). The results shows that soil organic matter (OM), totalnitrogen (TN), total phosphorus (TP) these three indicators are main environmentalfactors affecting the soil microbial community structure in reclaimed water irrigationareas.