The 2010 ASHS Annual Conference

Water supply has been a challenge in the arid and semi-arid Intermountain West region. Landscape irrigation represents a major portion of potable water use in the region; therefore water conservation in landscapes has received much attention in recent years. The effect of landscape irrigation on groundwater supplies in this region has not been studied. Additionally, nitrogen leaching from turf areas to groundwater has been investigated in other locations in the United States, but few research efforts have focused on the Intermountain West region. In this project, a field drainage lysimeter experiment was conducted to compare the water requirements of different types of landscapes: traditional (high water use), intermediate (moderate water use), and native/adapted plant species of the Intermountain West (low water use). Soil moisture data were collected hourly and the quantity and quality of leacheate from the lysimeters was monitored. Water consumption of each landscape type was obtained using a water balance equation. The Hydrus-1D model was applied to simulate water and nitrogen transport in turf, and to predict bottom water flux and N-leaching under the scenario of over watering and over fertilization in turf areas. A greenhouse column lysimeter experiment will also be conducted to confirm the simulation result of over watering and fertilizing conditions. Monitoring data from the field and greenhouse studies will be used in conjunction with model results to determine the effect of water use in landscapes on groundwater quantity and the potential effect of ground water being contaminated by leachate from urban landscapes.