Reclaimed Water Irrigation for the Production of Kentucky Bluegrass (Poa pratensis L.) Sod and Its Impact on the Environment; a Greenhouse Study.

There is growing concern about the use of municipal water sources in sod production, especially during times of reduced water supply.  An alternative to municipal potable water sources is the use of reclaimed water. However, in Ontario sod production using reclaimed water for irrigation is not commonly practiced.  Therefore, there is limited research on the effects reclaimed water has on soil, turf health and leaching in the province.  A greenhouse study was conducted to examine the use of reclaimed water for irrigation during the initial establishment of a sod system using soil column lysimeters.  Four different types of reclaimed water were used for irrigation over a 90 day period: tertiary municipal wastewater, secondary municipal wastewater, industrial wastewater, and storm water.  Irrigation was applied to three cultivars of Kentucky Bluegrass (Avalanche, Barrister, and Moonlight SLT) and one blend made of the three.  The soil was assessed for changes in the total eubacterial community structure using 16S rDNA fingerprinting, and the nitrifying and denitrifying bacteria were quantified using RT-PCR for the amoA, nirS, and nirK functional genes.  Turf health was assessed by NTEP ratings and clipping weights.  Soil was monitored for changes in ammonium, nitrate, as well as salt accumulation. Leachate collected from the soil column lysimeters was tested for nitrate to determine the potential risk of unsafe levels leaching into the ground water.  Results indicated that irrigating with the different types of reclaimed water had a significant treatment effect.