Methodology was developed to estimate water requirements for production of 20 different potted ornamental plant species with practical application for water conservation in commercial operations. Water requirement prediction equations were generated using pan evaporation to estimate evaporative demand along with plant canopy height and width and flower height as input variables. Coefficients of determination (R2) for the prediction equations among plant species ranged from 0.51 to 0.91, with the lower values mostly associated with plant species with an open or less-uniform growth habit. Variation in water use among different cultivars of marigold also was associated with differences in cultivar growth habit. Estimation of the daily water requirements of potted Reiger begonia and Ficus benjamina using their developed prediction equations was compared to actual water use under common growing conditions to demonstrate the implementation of the method for plant species differing in growth habit.
Workshops are one of the primary tools utilized to convey information to audiences with diverse backgrounds. Frequently, the results obtained are of mixed success or unmeasurable. In this project, the Environmental Protection Agency sponsored the development of a model workshop to promote the concept of water conservation through xeriscaping. Two workshops were conducted in Spring 1994. Slide presentations, audience discussion sessions, tours of an existing xeriscape, and the administration of pre- and post-workshop surveys were included in the model. Statistical analysis comparing the surveys determined the effectiveness of the model. The results indicated both the perception and the general knowledge about water conservation were significantly improved. Promotion by newspaper was the most-effective method of reaching the audience, while TV spots were the least effective method used. The model was successful in reaching a new audience which was characterized as being 45 years old, having less than 1 year of gardening experience, and possessing some college education.
The physical characteristics of a particular soil affect its suitability for reduced tillage. Vegetable crops managed with reduced tillage generally will increase crop yields as drainage improves. Under reduced tillage, advantages over conventional tillage include better control of soil erosion, enhanced crop yields, soil water conservation, and more-efficient use of fossil fuel-based nonrenewable resources. Disadvantages with reduced tillage may include reduced soil temperature and increased soil moisture contents in udic soil moisture regimes, which can decrease crop yields.
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.
The Florida horticulture industry (vegetables, ornamentals, citrus, and deciduous fruit), valued at $4.5 billion, has widely adopted microirrigation techniques to use water and fertilizer more efficiently. A broad array of microirrigation systems is available, and benefits of microirrigation go beyond water conservation. The potential for more-efficient agricultural chemical (pesticides and fertilizer) application is especially important in today's environmentally conscious society. Microirrigation is a tool providing growers with the power to better manage costly inputs, minimize environmental impact, and still produce high-quality products at a profit.
Abstract
Several species of Leucophyllum are widely used in Texas and the southwestern United States (Arizona, California, Nevada, New Mexico) for amenity plantings. These taxa are among the most ornamental of all native Texas plants (8). Leucophyllum candidum I. M. Johnst. (2, 7) grows on arid sites in northern Mexico and in southern Brewster Co., Texas, and is usually found on caliche, gravelly hillsides (11). The low requirements for nutrients, water, pest control, and general maintenance make the use of ‘Thunder Cloud’ a pragmatic choice for water and energy conservation in the arid to semi-arid southwest (12).
Water use in the United States increased from 1950 to 1980 and decreased from 1980 to 1985, on the basis of estimates compiled at 5-year intervals by the U.S. Geological Survey. Total withdrawals of freshwater and saline water during 1985 were 1,510 million cubic meters per day, a rate more than double that estimated for 1950 and 10 percent less than that estimated for 1980. For most categories, the rate of increase in water use declined from 1970 to 1975 and from 1975 to 1980. Withdrawals for thermoelectric-power generation and irrigation, the two largest categories of use, were 13 and 6 percent, respectively, less during 1985 than during 1980. The combined total for industrial, commercial, and mining water use during 1985 was 25 percent less than during 1980--the lowest combined estimate for these categories since the compilations began in 1950. The decrease in water use during 1985 compared to 1980 can be attributed to the following important factors:
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Streamflow generally was more plentiful during 1985 than during 1980 because of more rainfall; this reduced the dependence on ground water in many areas and the need to irrigate in some areas.
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The economic slowdown, improved plant efficiencies, depressed commodity prices, and new technologies that require less water decreased the requirements for industrial and irrigation water.
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Enhanced awareness by the general public to water resources and conservation programs in many States probably reduced water demands.
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.
Water use in the United States increased from 1950 to 1980 and decreased from 1980 to 1985, on the basis of estimates compiled at 5-year intervals by the U.S. Geological Survey. Total withdrawals of freshwater and saline water during 1985 were 1,510 million cubic meters per day, a rate more than double that estimated for 1950 and 10 percent less than that estimated for 1980. For most categories, the rate of increase in water use declined from 1970 to 1975 and from 1975 to 1980. Withdrawals for thermoelectric-power generation and irrigation, the two largest categories of use, were 13 and 6 percent, respectively, less during 1985 than during 1980. The combined total for industrial, commercial, and mining water use during 1985 was 25 percent less than during 1980--the lowest combined estimate for these categories since the compilations began in 1950. The decrease in water use during 1985 compared to 1980 can be attributed to the following important factors:
-
Streamflow generally was more plentiful during 1985 than during 1980 because of more rainfall; this reduced the dependence on ground water in many areas and the need to irrigate in some areas.
-
The economic slowdown, improved plant efficiencies, depressed commodity prices, and new technologies that require less water decreased the requirements for industrial and irrigation water.
-
Enhanced awareness by the general public to water resources and conservation programs in many States probably reduced water demands.
Abstract
Drip irrigation of peach [Prunus persica (L.) Batsch cv. Hermosa] and grape [Vitis vinifera (L.) cv. Perlette] was scheduled according to soil matric potential and water applied was expressed as a coefficient of class A pan evaporation. Water consumption by grape increased progressively from planting until the 4th year. A sigmoidal pattern of water consumption from budbreak through harvest was evident in both crops. The gradual rise of water consumption after budbreak was correlated with development of the full canopy, while a 2nd rise coincided with the final fruit-swelling stage and harvest. An intermediate period of steady water consumption was evident in the late-maturing crop (peach) while absent in early maturing crop (grape). Volume of water, as well as frequency of applications, had to be increased to maintain soil water potential within predetermined limits. At the period of peak requirement, tensiometers indicated rapid withdrawal of soil water and the necessity for daily irrigation. Estimates show a 12% to 23% conservation in water use by programming irrigation according to soil water potential rather than by pan evaporation.