Linking landscape types to water use of residential urban landscapes

Residential landscapes benefit the homeowner and neighborhood. In the southwestern, United States, various residential landscape types are used to conserve water. Although there are some reports that describe residential landscapes, I am unaware of any report that provided a robust classification of residential landscape types or the water budget for each landscape type. For those landscapes, the homeowners require a professional technology to help them irrigate their landscapes with the proper amount of water. Therefore, I conducted two studies to help homeowners and landscape designers choose the landscape types that fit their water budget and identify the best technology to irrigate those landscapes with the proper amount of water.;In the first study, I classified residential landscapes in Las Cruces, New Mexico into distinct types and matched each type with its water budget. Purposive sampling was used to study landscapes in 54 homes. Each landscape was divided into zones based on the design unity. Each zone was treated as a separate segment and considered as a separate landscape. Water budget, landscape indices, and percentages of irrigated elements were calculated. In the selected properties, 158 landscapes (zones) were found. Nine common landscape types were classified and formed 93% of studied landscapes. Mulch landscape formed 39% of common landscape types and dominated front yards. Mulch, Hard-Surface Shade-structure, and Tree Mulch landscapes were the dominant type in the back yards.;In the second study, I evaluated the performance of residential weather-based irrigation controllers in a desert environment. Two experiments were conducted on tall fescue (Festuca arundinacea Schreber) in Las Cruces, New Mexico. In Experiment 1, five weather-based and one manually-controlled irrigation controller were tested. The manually-controlled irrigation controller was set at 80% of historical ETO. Compared to the manually-controlled irrigation controller, Irritrol Smart Dial and RainBird ET Manager saved 53% and 34% of irrigated water, respectively. Weathermatic applied irrigation similar to the manually-controlled irrigation controller, and Hunter ET system and Aqua Conserve over-irrigated the turfgrass plots by 189% and 259%, respectively. In Experiment 2, Irritrol Smart Dial and RainBird ET Manager were tested further and for a year. Monthly average water savings of the Irritrol treatment was 41% higher than RainBird treatment. The relative water content in both treatments was above 85% which is an adequate level for photosynthesis. Although Irritrol had higher significant Normalized Difference Vegetation Index in May 2010, both treatments remained above the adequate threshold value of six. There were no significant differences in shallow root length density (RLD), deep RLD, and root to shoot ratio between both treatments, except for October 2010 when the deep RLD was significant lower in Irritrol treatments. The ratio of variable to maximal fluorescence, a measure of photosystem II efficiency, was 0.78 for both treatments, indicating that tissues were stress-free. Therefore, while both the Irritrol Smart Dial and RainBird ET Manager maintained adequate turfgrass quality, I recommend Irritrol Smart Dial because of its potential water savings.