Influence Of Reclaimed Water Irrigation On Turf

This research on reclaimed water irrigation of urban turf, consisting of two parts: plot experiment and investigation, is a part of "National 863 Programs" for "Integtation and Demonstration of Water-saving Irrigation Technology for Urban Green Space of Semi-arid Area in Northern China" and Beijing Olympic Scientic Research Programs " Research on Reclaimed Water Supply Technology and It's Environmental Security" .This research conducts a series of studies, including: study of water quality for irrigation; influence of reclaimed water on turf soil chemical property, on turf soil microorganism, on turf leaf mineral content, and on turf growth & resistance ability against environmental adversity. The whole conclusion of this research is written below:1. Reclaimed water includes secondary effluent and more advanced treated wastewater. The study of water quality for irrigation suggests that: all of the quality indexes of reclaimed water, except Kjeldahl Nitrogen, are higher than National Standard of Water Quality for Field Irrigation. Tertiary effluent of Gao-beidian is a kind of traditional tertiary wastewater treatment, UF and MF are more advanced, RO is the deepestly treated water, whose quality is near to distilled water.2. Nutrient content and heavy metals content of secondary effluent (SE) is higher, but the study shows that threaten of heavy metals over-accumulation is little after SE irrigation. Nutrient content of Tertiary effluent of Gao-beidian, MF and UF are near to SE, but their heavy metals content is near to Tap Water, thus, they have irrigation advantage, but the following study show that the redundant residual CL" in MF water may somehow take off this advantage. RO is not suitable for a irrigation water source.3. For both short-termed and Long-termed reclaimed water irrigation, there is no significant impact on soil heavy metal content, after 10 years reclaimed water irrigation, heavy metals in turf soil is near to common background, far below to pollution standard.4. There is no significant impact on soil pH for both short-termed and long-termed reclaimed water irrigation. The soil EC is significantly higher than the Tap Water irrigated turf after Long-termed common tertiary water and secondary effluent irrigation, but is only 1/9 of Alert, and has no bad effect on turf growth.5. Comparing with Tap Water irrigation, the short-termed plot experiment shows that, except MF, reclaimed water irrigation has no significant effect on turf nutrient factors. After irrigated MF, the OM of turf reduces sharply, and NH4+,NO2- elevated significantly.The situation of influence of long-termed common tertiary water and secondary effluent irrigation on soil nutrient content is more complicated, the N level is a little lower than Tap Water irrigated area, but the content of effective P is apparently higher than Tap Water irrigated turf soil.6. Investigation of long-termed common tertiary water and secondary effluent irrigation shows that, comparing with Tap Water irrigation, there is no significant change in soil Bacteria biomass, Actinomycete Biomass and Eumycete biomass. Short-termed plot experiment shows that UF and RO irrigation can significantly increase soil Bacteria biomass; MF irrigation can significantly increase soil Actinomycete biomass. In the case of Eumycete biomass, all irrigation waters have no significant difference.7. Comparing with Tap Water irrigation, turf leaf heavy metals, Ca, Cl- and Na+ content are apparently higher after long-termed common tertiary water and secondary effluent irrigation, but there is no bad effect on turf growth.There is no significant impact on turf leaf N,P content after both long-term and short-term reclaimed water irrigation.8. Comparing with Tap Water irrigation, there is no significant impact on turf resistance ability against adversity after both long-term and short-term reclaimed water irrigation.9. Comparing with Tap Water irrigation, long-termed common tertiary water and secondary effluent irrigation can increase turf mowing weight, and increase Kentucky Bluegrass's C...