Nitrate Leaching from Irrigation with Tailored Water during Turfgrass Establishment.

Treated effluent has become an important water source of turfgrass irrigation. In addition to helping in conserving potable irrigation water, it also provides nutrients for plant growth. Membrane bioreactors are used for decentralized water treatment facilities and offer the opportunity to adjust for constituents in the effluent water (tailored water). However, excessive concentrations of nutrients in recycled water may result in surface and groundwater contamination. Three greenhouse studies were conducted at New Mexico State University using tailored water which consisted of treated effluent  with an electrical conductivity (EC) of 2.3 dSm^-1, sodium adsorption ratio (SAR) of 12.7, and a NO₃-N content of 15 ppm to establish bermudagrass [Cynodon dactylon (L.) cv. ‘Princess77’ , tall fescue [Festuca arundinacea (Schreb.)] cv. ‘Pennington ATF1258’', and buffalograss [Buchloe dactyloides (Natt.) Eng.] cv. ‘SWI 2000' from seed and sod. Control columns were irrigated with potable water and received amounts of granular Ca(NO₃)₂ fertilizer to match the total N applied to containers irrigated with tailored water. Leachate and soil samples were collected at three depths (10, 20, and 50 cm) and analyzed for NO₃-N, EC, and SAR. Turf cover was assessed weekly by means of digital image analysis and plant tissue was analysed to determine the nutritional status of the grasses. Nitrate concentrations in leachate did not differ between propagation types. Grasses established with tailored water exhibited greater coverage at the end of the study. Nitrate-N in leachate of containers irrigated with tailored water differed between species and was higher in buffalograss compared to bermudagrass. Leaf tissue N and P concentrations of turfgrasses did not differ between tailored and potable irrigation. Overall, turfgrasses irrigated with tailored water established faster but nitrate in the leachate was not different from potable irrigation and granular fertilization.