Flow Credit” program for reuse water returned to Lake Mead after tertiary treatment. The city of Henderson, the city of Las Vegas, and the Clark County Sanitation District all release a portion of their treated wastewater for irrigation reuse, whereas
Anne M. Lockett, Dale A. Devitt, and Robert L. Morris
resulted in the industry-wide common practice of reuse or recirculation of wash water. Our surveys conducted through various fresh-cut vegetable processors found that wash water quality deteriorated rapidly during produce washing as a result of the
D.A. Devitt, R.L. Morris, M. Baghzouz, M. Lockett, and L.K. Fenstermaker
2 Associate professor. 3 Graduate student. 4 Assistant research professor. We thank the Southern Nevada Water Authority and the Las Vegas Valley Water District for financial support of this research project. We also wish to thank Jeff
Carol Shennan, Stephen R. Grattan, Don May, and Carol J. Hillhouse
Reuse of saline drainage water for crop irrigation has been proposed as one strategy to reduce the drainage volume requiring disposal in California. A 6 y study to assess the feasibility of cyclic saline drainage reuse in a processing tomato/ cotton /cotton rotation was conducted. Treatments were: 1. fresh water applied throughout, 2. saline water applied after 1st flower to tomatoes, 3. saline water applied to tomato and the next cotton crop. Saline water generally improved tomato fruit quality, but did not reduce yields during the first 4 years. In year 6, yields were reduced 17% (n.s.) and 30% (p<0.05) in treatments 2 and 3 respectively, relative to the control. Monitoring of the root zone showed that boron has accumulated over time in saline treatments and may be limiting crop production more than soil salinity. Selenium was readily leached by periodic fresh water use and did not accumulate to levels of concern in tomato tissues. Other work has shown that salinity can enhance tomato susceptibility to root rot which may limit this practice in some areas. However, the data show that high value crops like tomato can be incorporated into saline reuse schemes if managed appropriately.
D.A. Devitt, R.L. Morris, L.K. Fenstermaker, M. Baghzouz, and D.S. Neuman
Nineteen flowering landscape species were sprinkle irrigated with either reuse water or fresh water, with an additional treatment of reuse water plus shade (solar radiation reduced by 24%), for 113 days during late summer and early fall in southern Nevada. The species selected were common to mixed landscape areas on golf courses in southern Nevada transitioning to reuse water. An index of visual damage (IVD) was assessed, along with an assessment of flower production, canopy temperature, tissue ion analysis and spectral reflectance. The IVD values separated based on species (p < 0.001), treatment (p < 0.001) and by a species by treatment interaction (p < 0.001). Irrigating with reuse water plus shade reduced the IVD compared to the reuse without shade in 7 of the 19 species (p < 0.05). When IVD values were included for all species, 40% of the variation in the IVD values could be accounted for if N, B, Ca, Mg, Na, and Zn were included in the regression equation. Higher r 2 values were obtained when individual species were isolated, with regression equations differing based on tissue ion combinations [e.g., ice plant (Mesembryanthemum crystallinum L.) r 2 = 0.81 IVD↑, Na↓, Mn↑]. Three vegetation indices chlorophyll index (CHL), red/far red (R/FR) and water band index/normalized difference vegetation index (WBI/NDVI)) accounted for 51% of the variation in the IVD values. As much as 72% of the variation in vegetation indices could be accounted for based on tissue ion concentrations when separated based on treatment, with Na being the only common ion in all of the highest correlations. Flower production was highest in the reuse plus shade treatment in all 13 species flowering during the experimental period, with as much as 86% of the flower production variation driven by different tissue ion concentrations [purple cup (Nierembergia hippomanica), r 2 = 0.86, flowers↑, Mn↑, Zn↓]. Nine of the nineteen species had acceptable levels of foliar damage (IVD < 2.0). We believe that if the spray irrigation can be minimized (bubblers/drip) and/or partial shade provided, through multi-story landscape designs, a more favorable response will be observed.
D.A. Devitt, R.L. Morris, D. Kopec, and M. Henry
This research was supported in part by Nevada Agricultural Experiment Station (publication 52042970). We also wish to thank the Clark County Sanitation District and Las Vegas Valley Water District for partial funding.
R. Kasten Dumroese, Robert L. James, and David L. Wenny
Inoculum of Douglas fir root diseases caused by the fungi Fusarium and Cylindrocarpon is carried from crop to crop in reused containers. Soaking containers for 90 seconds in 80 °C water removed ≈99% of Fusarium and 100% of Cylindrocarpon inoculum between growing cycles. Overall seedling growth was also improved: seedlings grown in containers soaked between growing cycles were 10% taller and had 20% more biomass than seedlings grown in nonsoaked containers. We obtained a 13% increase in the number of deliverable seedlings from containers soaked in hot water between crops, from the use of copper coated containers, or from both practices combined.
Dale A. Devitt, Lena Wright, Daniel C. Bowman, Robert L. Morris, and Michelle Lockett
Many golf courses in the southwestern United States are transitioning to reuse water for irrigation purposes. In Las Vegas, NV, 30 of 53 golf courses now irrigate with reuse water. As communities grow in size, the amount of reuse water generated
Rolston St. Hilaire, Michael A. Arnold, Don C. Wilkerson, Dale A. Devitt, Brian H. Hurd, Bruce J. Lesikar, Virginia I. Lohr, Chris A. Martin, Garry V. McDonald, Robert L. Morris, Dennis R. Pittenger, David A. Shaw, and David F. Zoldoske
; Martin and Stabler, 2004 ), reuse of water resources ( Arnold et al., 2003 ; Devitt et al., 2003 ), economic and noneconomic incentives ( Hurd et al., 2006 ), and policy and ordinances. The objective of this article is to review how those factors
Michael P. O'Neill and James P. Dobrowolski
management. Six broad areas were identified for USDA research, education, and extension programs to address agricultural water security: 1) water marketing, economics, and distribution; 2) water reuse; 3) general water conservation; 4) irrigation efficiency