Abbreviations: DAFB, days after full bloom; DC, drying cycle; E pan , potential water use measured from a Class A pan; ET, evapotranspiration; k c , crop coefficient; WU, water use; Ψ 1 , leaf water potential. 2 Senior Lecturer. 3 Professor. Current
Although water conservation programs in the arid southwestern United States have prompted prudent landscaping practices such as planting low water use trees, there is little data on the actual water use of most species. The purpose of this study was to determine the actual water use of two common landscape tree species in Tucson, Ariz., and water use coefficients for two tree species based on the crop coefficient concept. Water use of oak (Quercus virginiana `Heritage') and mesquite (Prosopis alba `Colorado') trees in containers was measured from July to October 1991 using a precision balance. Water-use coefficients for each tree species were calculated as the ratio of measured water use per total leaf area or per projected canopy area to reference evapotranspiration obtained from a modified FAO Penman equation. After accounting for tree growth, water-use coefficients on a total leaf area basis were 0.5 and 1.0 for oak and mesquite, respectively, and on a projected canopy area basis were 1.4 and 1.6 for oaks and mesquites, respectively. These coefficients indicate that mesquites (normally considered xeric trees) use more water than oaks (normally considered mesic trees) under nonlimiting conditions.
-related differences in water use. In the United States, the yearly average residential water use ranged from a low of 208.4 L·d −1 per person in the temperate mesic state of Wisconsin to a high of 784.5 L·d −1 in the arid state of Nevada ( Emrath, 2000 ). This
). Consequently, much attention has been focused on developing turfgrass germplasm and management practices that contribute to reduced water use and increased efficiency of water use by turfgrass systems. However, in many cases, we still lack a basic understanding
, 2006 ). Leaf Cl − concentration and, thus, relative salt tolerance has been linked to plant growth, water use ( Castle and Krezdorn, 1975 ; Syvertsen et al., 1989 ), and transpiration ( Moya et al., 1999 , 2003 ). Because rapidly growing trees always
). Citrus water requirements vary with environmental conditions and cultivar ( Fares and Alva, 1999 ). Various studies indicated that citrus water use averaged between 1.1 and 6.5 mm·d −1 ( Morgan et al., 2006 ; Rogers et al., 1983 ). Thus, estimates of
based on the amount of water lost since the last irrigation ( Michigan Department of Agriculture, 2009 ; Southern Nursery Association, 2007 ). Applying irrigation based on plant demand or daily water use (DWU) is a key concept in water
Crop production systems must become more water use efficient. About 70% of global and 80% of the U.S. fresh water consumption is for agricultural practices ( Evans and Sadler, 2008 ; Schaible and Aillery, 2012 ). With continual growth in global
Defense Council (2010) included Florida in the list of states with the greatest risk of water shortages in the coming years. One of the reasons is that while the daily per capita domestic water use in Florida (96 gal/ person/day) is close to the national
.L. Schulbach, K. Jackson, L.E. 1996 Crop growth and water use model for lettuce J. Irrig. Drain. Eng. 122 354 359 10.1061/(ASCE)0733-9437(1996)122:6(354) Harter, T. Lund, J. 2012 Addressing nitrate in California’s drinking water with a focus on Tulare Lake