Simulation of Water and Nutrient Transport in Three Turf Species.

Instances of groundwater pollution from use of nitrogenous fertilizer have increased in recent years. With this increase in fertilizer application to turf and urban landscapes, groundwater pollution is becoming a bigger concern in Intermountain West. A 2-year field lysimeters study was developed to determine appropriate water and nutrient management required to minimize groundwater pollution and maximize nutrient use efficiency in turf and urban landscapes. Three turf species were evaluated, Kentucky Blue grass, Tall fescue, Buffalograss. A one-dimensional solute transport model, Hydrus-1D, was applied to simulate water and nitrogen transport of three turf species established in natural soils with efficient management of irrigation and fertilization. Soil moisture and soil profile nitrogen data during the growing season were used to calibrate and validate the solute transport model. Once calibrated, the Hyrus code was used to predict the nitrogen leaching information under different combinations of soil, turf species and the water and fertilizer application. A green house column lysimeter experiment was also conducted with over watering and fertilization to confirm the Hydrus-1D simulation under extreme scenarios on turf. The results of the research provide water and nutrient transport guidelines for the three turf species studied in addition to optimal irrigation and fertilization strategies for turf were demonstrated.