| Irrigation scheduling is an essential component for developing best management practices for turfgrass. This study investigated the effects of three irrigation scheduling methods on water use, leachate quantity, and leachate quality for creeping bentgrass (Agrostis stolinifera L.) grown on a sand-based putting green. Data measured by this study include: irrigation volumes, irrigation frequency, leachate volumes, nitrate loading, phosphorus loading, rooting depth, and root mass. Annual irrigation volumes for 2010 show the 80% daily potential evapotranspiration (PET) treatment required the lowest volume (284.7 mm) while rooting depth adjusted irrigation (RDAI) and soil moisture dependent irrigation (TDR) required 340.7 mm and 421.9 mm, respectively. The TDR irrigation treatment resulted in the greatest annual leachate volumes in 2010 (397.9 mm) and 2011 (410.8 mm). The TDR irrigation treatment resulted in the greatest annual nitrate loading in 2011 (1.36 kg NO3- ha -1) compared to the RDAI (0.32 kg NO3- ha -1) and 80% daily PET (0.11 kg NO3- ha -1) treatments. Annual phosphorus loading totals were significant (p ≤ 0.05) in 2010 and 2011 with the TDR (0.091, 0.100 kg NO3- ha-1) treatment resulting in three times more P loading than the 80% daily PET (0.017, 0.036 kg NO 3- ha-1) and RDAI (0.032, 0.032 kg NO 3- ha-1) treatments. Data show that reduced irrigation volumes along with more frequent applications during dry months minimizes the environmental impact of turfgrass by conserving water and reducing nutrient losses. However, utilizing a deep and infrequent irrigation method would save water during months that receive regular precipitation by allowing precipitation to supply moisture rather than irrigation. Deep and infrequent irrigation results in an extended interval allowing for a greater chance to receive precipitation between irrigation applications. |
