Tuesday, November 6, 2007
171-11

Scheduling Turfgrass Subsurface Drip Irrigation for Uniform Surface Wetting and Turfgrass Establishment.

Michael Schaaf, Ryan Goss, and Gabriel Ludwig. Plant and Environmental Sciences, New Mexico State University, P.O. Box 30003 MSC 3Q, Las Cruces, NM 88003-8003

Areas such as the arid southwest are looking for ways to conserve water while still maintaining acceptable turfgrass quality. Subsurface drip irrigation has shown promise for reduced applied water to turfgrass swards. However, additional information is needed for turfgrass managers to successful adopt the technology, especially during turfgrass establishment. Proper placement depth for drip lines is unknown. In addition, antidotal evidence has indicated surface wetting can be more easily achieved with pulsing irrigation cycles (or cycle/soak irrigation).The objectives of this project are to: 1) determine the drip line placement depth for sand-based turfgrass rootzones, 2) determine irrigation scheduling (pulsing versus continuous irrigation) for uniform surface wetting, 3) determine best depth and irrigation schedule for establishment of tall fescue from sod and seed, and 4) determine if turfgrass establishment from seed is appropriate with drip irrigation. Twelve, 3.6 m x 3.6 m independently irrigated plots were constructed in Las Cruces, NM using 40 cm sand rootzones. Each plot will be independently irrigated with one of three subsurface drip depths; 8, 15 or 23 cm or will be surface irrigated with rotary overhead sprinklers (Hunter Industries Inc.). The subsurface drip lines (Netafim Ltd) will be placed on 30 cm intervals with emitters on 30 cm centers along the drip lines. Timings of irrigation were 1 min on/1 min off (1 min pulse), 4 min on/4min off (4 min pulse) or 16 min continuous run times. Amount of water reaching the soil surface was measured by placing a 900 cm2 cloth towel and 11 kg weight on the soil surface. Initial results indicate that pulsing for either time period provided more water to soil surface than continuous irrigation. Additional data will be collected and results will be discussed.