Influence of Drought and Salinity On Turfgrass Water Use and Performance.

Turf is the largest irrigated crop in the United States. Minimizing water use and using recycled water are some of the strategies to sustain the turf industry. It is anticipated that water use can be reduced for turfgrass when it is subject to drought and salinity stresses. This research is to test tall fescue turfgrass performance and quantify water use under various drought and salinity conditions in green house. The test soil was obtained from the Ap horizon of a Hanford coarse sandy loam from a site near Hemet, CA. Eighteen soil columns of 15.25 cm by 1.5 m PVC pipe were constructed and used for the study. Treatments designed to induce both water and salinity stresses on the plant include: irrigation water salinity at electrical conductivity (EC) of 0.5, 2.0, 4.0, and 6.0 dS m-1, and several different irrigation water amounts (0.7, 0.8, 0.9, 1.0, 1.1, 1.3 expressed as a fraction of potential evapotranspiration rate, ETo). Relative yield was calculated as a function of clipping dry weight; water content in the columns was measured using heat pulse thermal conductivity probes; and root zone salinity was measured using time domain reflectometry (TDR). Leacheate was collected from each column to determine the volume and EC. The greenhouse experimental data will be used to examine the ability of a computer simulation model, ENVIRO-GRO, to predict the relative yield, as well as water and salt transport in the columns. The tested model has the potential to be a very useful resource for irrigation management and water conservation.