Current estimates indicate that half of the water consumed in the urban environment is used to maintain landscapes. With this volume of water expended each year in landscape care, competition for the limited water exists. Xeriscaping reduces water demands while retaining an attractive landscape; however, the image of xeriscaping is frequently poor. In this project, workshops were conducted to measure audience perception, attitude, and knowledge of xeriscaping as a result of this type of activity. The effectiveness of the workshops was determined using pre- and postworkshop surveys. The audience's perception and attitude” toward xeriscaping improved in every area. The audience's general knowledge about the principles of xeriscaping increased significantly for almost every concept. Promotional aspects of attracting a large and diverse audience was the area needing further enhancement.
Cynthia McKenney and Robert Terry Jr.
Carlos Carpio and D. Scott NeSmith
This study evaluates the effect of irrigation on the profitability of the muscadine grape (Vitis rotundifilia) operation. Data from a 3-year experiment in which muscadine grapes were grown under four irrigation regimes were used to establish the relationship between yields and irrigation. Assuming a muscadine fruit price of $0.50/lb, harvesting costs of $0.21/lb, and irrigation costs of $16.75/acre-inch, the profit-maximizing level of irrigation was estimated to be 13.1 acre-inches for a season, or 7 gal/day per plant. Water requirements for profit maximization are 9% lower than water requirements for yield maximizing. Moreover, it is concluded that the effect of an adequate use of irrigation in the profitability of the muscadine grape operation can be substantial.
J.B. Beard, R.L. Green, and S.I. Sifers
Cultivar selection is one method used for the conservation of irrigation water. The primary objective of this research was to evaluate the evapotranspiration (ET) rates of 24 well-watered, turf-type bermudagrass (Cynodon spp.) genotypes under field conditions and established on a fritted clay root zone contained in plastic minilysimeter pots. A secondary objective was to correlate ET rate to leaf extension rate, a potential rapidly assessed predictor of the amount of leaf surface area present for ET. ET rates were determined by the water-balance method. Both the overall ET and leaf extension rate differed significantly among genotypes. ET rates were not correlated with leaf extension rates in individual years. Our data indicated a potential for water savings based on bermudagrass cultivar selection that was similar to the reported potential water savings based on warm-season turfgrass species selection.
C.A. Brown, D.A. Devitt, and R.L. Morris
Research was conducted to assess the response of tall fescue (Festuca arundinacea Schreb.) to water deficit conditions. Different leaching fractions (LF = drainage volume/irrigation volume) and irrigation frequencies (IF) were imposed over a 119-day summer period in Las Vegas, Nevada, followed by a 71-day recovery period. Plots of tall fescue contained 120 cm deep × 51 cm diameter draining lysimeters. Irrigations were based on an evapotranspiration (ET) feedback system to establish LFs of +0.15, 0.00, -0.15, -0.25, and -0.40. Plots were irrigated on a daily or twice per week schedule. N was applied to subplots at a rate of 0, 12.2, or 24.4 kg·ha-1 per month. As LF decreased, relative soil water in storage declined in a linear fashion (r 2 = 0.97, P = 0.001). Storage depletions for the four lowest LFs at the end of 119 days of imposed water deficits were about 15%, 40%, 60%, and 70% compared to the +0.15 LF treatment. Canopy temperature, soil matric potential (Ψm), leaf xylem water potential (ΨLX), leaf stomatal conductance (gs), clipping yield, color and cover ratings all statistically separated (P < 0.05) based on LF but not on IF. However, irrigation amount (I), ET, tissue moisture content and total Kjeldahl N (TKN) separated based on LF and IF with a significant LF by IF interaction for I (P < 0.05) and TKN (P < 0.001). An irrigation savings of 60.4 cm was realized during the 119-day water deficit period at the -0.40 LF. However, at the lower LFs, plant stress increased (all parameters) with color ratings declining below an acceptable value of 8.0. An Irrigation/Potential ET (I/ETo) threshold of 0.80 was determined for both color and cover. After a 71-day recovery period both color and cover returned to pre experimental values at the two higher N rates. Results of this experiment indicate that implementing a twice weekly irrigation strategy at a -0.15 LF on tall fescue during summer months in an arid environment would lead to savings of 37.5 cm of water while still maintaining acceptable color and cover ratings.
Virginia I. Lohr and Lenore H. Bummer
Implementing water-conserving landscapes is one action that many individuals can take to help ease the nation's water crisis, but few people seem to be exercising this option. Some horticulturists attribute this to a negative attitude toward such landscapes. Our research was designed to assess these attitudes and to see if they could be improved with information. Questionnaires were administered to people in treatment or control groups. Those in the treatment group viewed a short videotape about water issues and water-conserving landscapes. Initial attitudes in both groups were neutral or positive, not negative as predicted. Viewing the videotape was associated with significantly improved attitudes. People in the treatment group described water-conserving landscapes as less hot, more colorful, and more attractive three weeks after viewing the videotape than they had initially.
Jianjun Chen, Richard C. Beeson Jr., Thomas H. Yeager, Robert H. Stamps, and Liz A. Felter
Irrigation runoff water from a containerized landscape plant production bed was blended with rainwater from green house roofs in a constructed collection basin. Water from both the collection basin and an on-site potable well were characterized and used to grow foliage and bedding plants with overhead and ebb-and-flow irrigation systems. Over a 2-year period, a total of 18 foliage and 8 bedding plant cultivars were produced with plant growth and quality quantified. Alkalinity, electrical conductivity, hardness, and concentrations of nutrients of water from both sources were well within desired levels for greenhouse crop production. Turbidity and pH were relatively high from algal growth in the collection basin. However, substrate pH, irrigated by either water source, remained between 6 and 7 throughout the production periods. All plants at the time of finishing were of marketable sizes and salable quality independent of water source. No disease incidences or growth disorders related to water sources were observed. Results suggest that captured irrigation runoff blended with rainwater can be an alternative water source for green house crop production.
Katharine B. Perry, J. David Martsolf, and C. Terry Morrow
Adjustment of the sprinkling application rate to existing atmospheric conditions to conserve water may be accomplished by turning systems on and off. The maximum off period that is tolerable is calculated. It is the sum of time required to freeze the applied water plus time during which the ice coated plant parts cool to the critical temperature. Values of the off period for typical frost conditions are proportional to wind speed and wet bulb temperature. Field test results indicate intermittent sprinkling provides a method to reduce water consumption in sprinkling for frost protection.
Dwayne H. Fink and William L. Ehrler
Runoff farming was used to produce Eldarica pine (Pinus eldarica Medw.) and Arizona cypress (Cupressus arizonica Green) as Christmas trees in a semiarid, 300-mm precipitation zone in Arizona. Natural precipitation was supplemented with runoff from treated, noncropped catchment-terraces adjoining the cropping area. Catchement treatments were wax (0.5 kg·m−2) on a sandy soil and sodium chloride salt (1.1 kg·m−2) on a clay soil. Terrace widths were varied to provide the crop an estimated 2, 3, and 4 times the precipitation. Trees were hand-watered from March to August the first year to ensure establishment. Regardless of terrace width, 90% of the cypress on the wax site were marketable in 3 years, and 90% of the pines on the salt site were marketable in 4 years. The other 2 tree-treatment combinations were less successful because of soil-species interrelated problems.
Tatiana Borisova and Pilar Useche
implemented by regional and local agencies, Cooperative Extension Services, and other organizations to encourage more efficient irrigation water use and residential water conservation; however, limited information exists about the effectiveness of such
We investigated mixtures of buffalograss [Buchloë dactyloides (Nutt.) Engelm. `Texoka' and `Cody'] and fine fescue species (Festuca rubra ssp. rubra L. `Vista', F. ovina var. glauca Lam. `Minotaur', F. rubra ssp. commutata Gaud. `Jamestown II') or stream-bank wheatgrass [Agropyron riparium Scribn. & Smith `Sodar'; syn. Elymus lanceolatus (Scribn. & Smith) Gould subsp. lanceolatus] as a low-maintenance turf with low irrigation requirements and season-long green color and growth. Buffalograss plots in Logan, Utah, were overseeded with fine fescue and streambank wheatgrass at two seeding rates. Plots of fine fescue, wheatgrass, or buffalograss alone were also established. At 50% evapotranspiration (ETo) replacement, fine fescues dominated the mixtures with no differences due to seeding rates. Wheatgrass mixture plots were unacceptable in quality. Buffalograss control plots and mixtures were similar for turfgrass quality in August, and fine fescue controls and mixtures were similar in spring and fall. The mixtures performed well in the low-maintenance turf situation, but dominance of fine fescue over the buffalograss limits the potential of these specific mixtures.