Michael D. Dukes

Residential Irrigation Uniformity and Efficiency in Florida

Residential water use is increasing in central Florida. Irrigation accounts for 50% or more nof typical residential use volume. The goal of this project is to document irrigation water use and nsystem uniformity in the Central Florida Ridge region. Three types of irrigation/landscape ncombinations are being installed: T1, typical irrigation and landscape; T2, well designed irrigation nsystem and typical landscape; T3, well designed irrigation system and a landscape designed to nminimize water use. To date, seven T1’s and three T3’s exist. Initial results indicate that 80% of nwater use is irrigation. Measured distribution uniformities (DUlq) are lower than Mobile Irrigation Lab nreports and may be classified as “good” (n=1), fair (n=3), “poor” (n=3), and “fail” (n=1) on the homes ntested. Over irrigation was common among home sites.

Uniformity Comparison of Common Residential Irrigation Sprinkler Heads

Due to droughts, irrigation has become a necessity for residential homeowners desiring nhigh quality landscapes in Florida. In an efficient system a number of components must be nconsidered; design, scheduling, and equipment. Catch-can tests of the system are an accepted nmethod of determining the uniformity of the irrigation distribution, which can be related to efficiency. nThe DUlq values of the spray and rotor zones of residential irrigation tests in Central Florida were n0.40 and 0.48 respectively. Brand and pressure effects on uniformity of spray and rotor heads were nfound to be significant. From uniformity tests performed on spray and rotor heads under ideal nconditions, the rotor heads had the most uniform distributions, 0.55, regardless of pressure variation. nThe spray heads had the better uniformity when fixed quarter circle nozzles were used as opposed nto adjustable nozzles, with average DUlq values of 0.52 and 0.44 respectively.

Temperature Increase on Synthetic Turf Grass

Artificial turfgrass is a synthetic material made to resemble real grass. A new generation of synthetic turfgrass is made of plastics with different composite materials, and is supported by a sand and/or rubber infill material and subsurface base layer. Synthetic turfgrass is being increasingly used on many athletic fields, such as soccer, football and rugby, as well as in urban landscapes. It is superior to natural grass in aspects, such as lower maintenance, no irrigation required, and surface uniformity. However, high temperatures on synthetic turfgrass surface during hot weather may be dangerous and could result in heat related health problems, such as heat stroke. The objective of this study was to evaluate the temperature increase among different synthetic turfgrass types and to predict temperature increase on the synthetic turfgrass surfaces. In this study, four types of synthetic turfgrasses (1 – 4) with four infill materials and base layers (A – D) were installed in central Florida, surrounded by large irrigated natural grass fields. Temperature measurements were taken at 23.5 cm above the ground and 5 cm below the ground. The results indicated that there were no differences in air temperatures above the ground between the synthetic turfgrass and the natural turfgrass, due to the small size of the plots and the high wind speed during the daytime. The temperature below the surface (base temperature) for the synthetic turfgrass was always higher than the natural surfaces at noon time. The base temperature differences between the two surfaces were higher in July and August and lower in November. Overall, the infill temperature difference increased with an increase of the depth of the base layer and the color of synthetic turfgrass. Base temperature increase on synthetic turfgrass (Tsyn) was linearly related to the incoming solar radiation (Rs). Relationships based on solar radiation and temperature on natural surfaces (Tnat) (both natural grass and bare soil surface) were developed for all units (Tsyn – Tnat = a Rs + b) so that the temperature increase on synthetic turfgrass could be predicted.

Smart Water Application Technology (SWAT™) Evaluation in Florida

Water used for turfgrass/landscape irrigation represents a significant portion of the total water used in Florida. This area of water use is increasing with population growth, which is projected to rise from 17 million to 20 million by 2015. If current water use trends continue, many areas will experience severe water shortages. Smart Water Application Technology (SWAT™) consists of irrigation controllers that establish or modify irrigation scheduling based on soil/weather variables. This paper summarizes the research carried out in Florida, regarding the use of ET controllers, soil moisture sensor controllers and rain sensors on turfgrass/landscape irrigation; and evaluates their effectiveness for irrigation water conservation. Testing locations range from plot scale on turfgrass and landscape material to cooperating home sites. Results have shown that controllers can cut irrigation as much as 90% during rainy periods and 41% during dry periods while maintaining turfgrass quality. Preliminary results in the residential arena show that soil moisture sensors and rain sensors could also save a significant amount of irrigation water when implemented (up to 50%). None of the SWAT™ controllers tested have shown a reduction in turfgrass/landscape quality when correctly set/implemented.