| The reclaimed water and its effect on plant growth, soil fertility and environments were studied. Pot experiment were studies in Lanzhou University sewage treatment center, Field experiment were studies in Lanzhou Arming sewage treatment factory. Perennial ryegrass (Lolium perenne cv. Premier and Panterra), Tall fescue(Festuca arundinacea cv. Barlexas and Easy Care), Kentucky bluegrass (Poa pratensis cv. Barvictor and Barrister), alfalfa (Medicago saliva cv. Algonquin) and white clover (Trifolium repens cv. Nanouk) were selected for the experiment. The impact of irrigation on plant growth and physiological response with reclaimed water was studied in this paper, and the soil characteristic were studied systematically. It will provide theoretical and experimental bases for the utilization and demonstration of reclaimed water irrigation in Lanzhou area. The conclusions reached include the following:(1) The Short term irrigation with reclaimed water can promote the growth of green plants.The results show that reclaimed water irrigation can to some extent improve lawn texture but remarkably raise the leaf width of turf grass. Besides, the grass chlorophyll content under the irrigation test of reclaimed water is significantly higher than that under running water irrigation, with no significant difference in the leaf cell membrane permeability and root activity. We do a pot experiment that reclaimed water was used in greenbelt irrigation test of white clover and alfalfa. The results showed that reclaimed water irrigation can improve photosynthetic indices in a certain period of time and some extent, in the late of reclaimed water for white clover irrigation, the photosynthetic rate (Pn), transpiration rate (Tr), conductance to H2O (Gs) and CO2concentration (Ci) under the irrigation test of reclaimed water is significantly higher than that under running water irrigation. Two plants species’ changes of Tr, Pn, intercellular Ci is closely related with Gs. There have no significant difference in photochemical efficiency (Fv/Fm) and chlorophyll content between running water and reclaimed water. In short, reclaimed water irrigation is not caused damaged to greenbelt plants and has a certain role in promoting.(2) Reclaimed water rich nutrition elements, so it can significantly improve soil available nutrient supply. Short-term reclaimed water irrigation can significantly increase soil organic matter, potassium, available nitrogen content, and total nutrient content have increased to some extent; pH value there is a slightreduced, but did not change significantly. At the same time reclaimed water’salt ions to accumulate in the soil, in order to the total salt content was increased significantly in the soil, but lower than the0.1%threshold, which is still non-salinization of soil, not harm in the short-term irrigation on plant growth.(3) Long-term reclaimed water irrigation field survey test found that reclaimed water irrigation soil organic matter, nitrogen and potassium were higher than the water control was significantly (P<0.05).Long-term renewable water irrigation,soil total potassium and total phosphorus content was significantly higher than tap water, total sodium content not occur significant change;Under long-term reclaimed water irrigation the soil salt did not change significantly, perennial ryegrass,tall fescue, Kentucky bluegrass the soil salt were0.043%,0.036%,0.035%. It did not cause soil salinization for six years of irrigation with reclaimed water.It was feasible to irrigate greenbelt by reclaimed water, the reasonable reclaimed water irrigation enhanced growth of plants, increased soil nutritional components.As long as we control strictly the number of harmful chemical substance and pathogenic microorganism in reclaimed water quality. Irrigation with reclaimed water is safe and it could be widely extension and application. |
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