Effects of Soil Moisture–Based Irrigation Controllers, Mowing Height, and Trinexapac-Ethyl on Tall Fescue Irrigation Amounts and Mowing Requirements

Conservation of water and other resources used for turfgrass management is increasingly important as environmental concerns and maintenance costs rise. Irrigation strategy, mowing height, and plant growth regulators may affect irrigation amounts, mowing frequency, and associated energy and labor expenditures. Our objectives were to evaluate (i) the water-conservation potential of using soil moisture sensor (SMS)–based irrigation controllers in turfgrass grown on a fine-textured soil and (ii) potential reductions in mowing frequency based on irrigation strategy, mowing height, and applications of trinexapac-ethyl (TE). A 2-yr field study was conducted on a Chase silty clay loam soil near Manhattan, KS. Treatments of traditional frequency-based and SMS-based irrigation were assigned to whole plots of tall fescue (Festuca arundinacea Schreb.). Subplot treatments included mowing at 5.1 or 8.9 cm with or without monthly applications of TE. Using SMS-based irrigation resulted in application of 31 to 70% less water than frequency-based irrigation, but irrigation treatment did not influence mowing frequency. In plots mowed at 5.1 cm, mowing was reduced by 33% when treated with TE, but at 8.9 cm mowing was reduced by only 13% when treated with TE. Main effects revealed that mowing at 8.9 vs. 5.1 cm or using TE vs. untreated turf reduced mowing frequency by 9%. Results indicate SMS-based irrigation conserves water compared with frequency-based irrigation on tall fescue grown on a fine-textured soil and mowing higher or applying TE reduced mowing frequency; TE applications were more beneficial in turfgrass mowed at lower heights.