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Sample records for horticultural irrigation water

  1. Satellite Mapping of Horticultural Crop Cover in California's San Joaquin Valley - Potenial for Irrigation Water Resource Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Estimation of crop water use, and associated irrigation demand, is commonly addressed by application of so-called crop coefficients, which express water loss as a proportion of evapotranspiration from a well-characterized reference crop such as grass or alfalfa. For horticultural crops, however, pla...

  2. Use of Dehydrated Agar to Estimate Microbial Water Quality for Horticulture Irrigation.

    PubMed

    Meador, Dustin P; Fisher, Paul R; Guy, Charles L; Harmon, Philip F; Peres, Natalia A; Teplitski, Max

    2016-07-01

    Petrifilms are dehydrated agar culture plates that have been used to quantify colony forming units (CFU) mL of either aerobic bacteria (Petrifilm-AC) or fungus (Petrifilm-YM), depending on substrate composition. Microbes in irrigation systems can indicate biofilm risk and potential clogging of irrigation emitters. The research objective was to compare counts on Petrifilms versus traditional, hydrated-agar plates using samples collected from recirculated irrigation waters and cultures of isolated known species. The estimated count (in CFU mL) from a recirculated irrigation sample after 7 d of incubation on Petrifilm-YM was only 5.5% of the count quantified using sabouraud dextrose agar (SDA) with chloramphenicol after 14 d. In a separate experiment with a known species, Petrifilm-YM did not successfully culture zoospores of . Isolates of viable zoospores were cultured successfully on potato-dextrose agar (PDA), with comparable counts with a vegetable juice medium supplemented with the antibiotics pimaricin, ampicillin, rifamycin, pentochloronitrobenzene and hymexazol (PARP-H). The quantification of pv. Begoniaceae on Petrifilm-AC was not significantly different ( < 0.05) than on PDA, but was lower than on Reasoner and Goldrich agar (R2A) or with a hemocytometer. The current formulation of Petrifilm-YM is unlikely to be a useful monitoring method for plant pathogens in irrigation water because of the inability to successfully culture oomycetes. However, Petrifilm-AC was an effective method to quantify bacteria and can provide an easy-to-use on-farm tool to monitor biofilm risk and microbial density. PMID:27380096

  3. Spatial and Temporal Analysis of the Microbial Community in Slow Sand Filters Used for Treating Horticultural Irrigation Water

    PubMed Central

    Calvo-Bado, Leo A.; Pettitt, Tim R.; Parsons, Nick; Petch, Geoff M.; Morgan, J. Alun W.; Whipps, John M.

    2003-01-01

    An experimental slow sand filter (SSF) was constructed to study the spatial and temporal structure of a bacterial community suppressive to an oomycete plant pathogen, Phytophthora cryptogea. Passage of water through the mature sand column resulted in complete removal of zoospores of the plant pathogen. To monitor global changes in the microbial community, bacterial and fungal numbers were estimated on selective media, direct viable counts of fungal spores were made, and the ATP content was measured. PCR amplification of 16S rRNA genes and denaturing gradient gel electrophoresis (DGGE) were used to study the dynamics of the bacterial community in detail. The top layer (1 cm) of the SSF column was dominated by a variable and active microbial population, whereas the middle (50 cm) and bottom (80 cm) layers were dominated by less active and diverse bacterial populations. The major changes in the microbial populations occurred during the first week of filter operation, and these populations then remained to the end of the study. Spatial and temporal nonlinear mapping of the DGGE bands provided a useful visual representation of the similarities between SSF samples. According to the DGGE profile, less than 2% of the dominating bands present in the SSF column were represented in the culturable population. Sequence analysis of DGGE bands from all depths of the SSF column indicated that a range of bacteria were present, with 16S rRNA gene sequences similar to groups such as Bacillus megaterium, Cytophaga, Desulfovibrio, Legionella, Rhodococcus rhodochrous, Sphingomonas, and an uncharacterized environmental clone. This study describes the characterization of the performance, and microbial composition, of SSFs used for the treatment of water for use in the horticultural industry. Utilization of naturally suppressive population of microorganisms either directly or by manipulation of the environment in an SSF may provide a more reproducible control method for the future. PMID

  4. Wastewater treatment by a modular, domestic-scale reedbed system for safe horticultural irrigation.

    PubMed

    Derry, Chris; Maheshwari, Basant

    2015-12-15

    The aim of the study was to assess the sequential treatment performance of a commercial, domestic-scale modular reedbed system intended to provide safe horticultural irrigation water. Previously only mechanical treatment systems involving forced aeration with subsequent disinfection, usually by tablet-chlorination, had been accredited in Australia. The modular design of the hybrid, subsurface-flow reedbed system offered 5 control points where monitoring and management of the treatment train could be carried out. Ten chemical parameters (chemical and biochemical oxygen demand, total organic carbon, total Kjeldahl nitrogen, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, total nitrogen, dissolved oxygen percentage saturation and suspended solids) and 4 microbial parameters (total coliform, Escherichia coli, enterococci and Clostridium perfringens) reached satisfactory levels as a result of the treatment process. Health requirements for safe horticultural irrigation were met by the outlet of the second reedbed, providing a high level of treatment-backup capacity in terms of the remaining 2 reedbeds. This suggested that chlorination was a redundant backup precaution in treating irrigation water to the acceptable regional guideline level for all horticultural uses, including the spray irrigation of salad crops eaten raw. PMID:26282758

  5. Irrigation in a future of limited water supplies: Making every drop count. A Workshop Sponsored by the Water Utilization and Management Working Group of the American Society for Horticultural Sciences.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The production of horticultural crops, regardless of commodity, requires at the most basic level, light and water. While the sun will rise tomorrow, the prospects for rain are less certain. The occurrence of droughts and the increasing demands on water resources from municipal entities, presents ...

  6. Horticulture.

    ERIC Educational Resources Information Center

    Aitken, James

    This curriculum guide is intended to assist vocational instructors in preparing students for entry-level employment in the field of horticulture and getting them ready for advanced training in the workplace. The package contains a validated competency/skill and task list, an instructor's guide, and an annotated bibliography. The following…

  7. Treated sewage effluent (water) potential to be used for horticultural production in Botswana

    NASA Astrophysics Data System (ADS)

    Emongor, V. E.; Ramolemana, G. M.

    Botswana being semi-arid and arid country, the provision of drinking water and water for agricultural production is becoming increasingly scarce and expensive. Measures that can augment the available sources of water or measures that can reduce the demand on potable water should be given serious consideration. Horticulturists have incorporated new technology into many of their production programs, which has enabled them to grow more horticultural crops with less water; however, more effort is needed. Techniques such as drip irrigation, sensors, growing plants with low water requirements, timing and scheduling of irrigation to the growth needs of the plant, mulching, and establishing a minimum water quality standard for horticultural crops must be used to stretch agricultural water supplies. Recycling agricultural water and using treated municipal sewage effluent is a viable option for increasing horticultures’ future water supply in Botswana. Agriculture wastewater and sewage effluents often contain significant quantities of heavy metals and other substances that may be toxic to people but beneficial to horticultural crops. However, before sewage effluent can be used for commercial production of vegetables and fruits, research must be undertaken to determine whether there is accumulation of heavy metals and faecal coliforms in the edible portion of the horticultural produce which may be detrimental to human health 15-20 years later. Research must be undertaken to assess the impact of sewage effluent on soil physical, chemical properties and environment after continued use.

  8. Irrigation water quality assessments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing demands on fresh water supplies by municipal and industrial users means decreased fresh water availability for irrigated agriculture in semi arid and arid regions. There is potential for agricultural use of treated wastewaters and low quality waters for irrigation but this will require co...

  9. WATER REQUIREMENT OF IRRIGATED GARLIC

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A replicated field trial was conducted on the West side of the San Joaquin Valley to determine the crop coefficient and water requirements of irrigated garlic. Irrigation systems used included flood irrigation, subsurface drip irrigation, and surface drip irrigation. Irrigation levels were set at 5...

  10. Water Requirements Of Irrigated Garlic

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A replicated field trial was conducted on the West side of the San Joaquin Valley to determine the crop coefficient and water requirements of irrigated garlic. Irrigation systems used included flood irrigation, subsurface drip irrigation, and surface drip irrigation. Irrigation levels were set at 5...

  11. EFFICACY OF NOVEL WATER DISINFECTION TECHNIQUES IN HORTICULTURAL NUTRIENT RECYCLING.

    PubMed

    Heungens, K; Clierinck, M; Inghelbrecht, S; Vissers, M

    2015-01-01

    Hydroponic systems used for growing potted ornamentals in greenhouses are commonly ebb-and-flow irrigation systems. The drainage water is usually recycled to save water and nutrients. To avoid the spread of pathogens in these closed irrigation systems, disinfection of the recycled water is standard practice. Growers can use slow sand filtration or UV-radiation techniques, but these methods are often either not sulted for specific problems or they require an excessively large investment. The objective of this study was to test less expensive but effective alternative disinfection systems. The efficacy of five disinfection systems against fungi and oomycetes was determined: Aqua-Hort (based on Cu-ions), Reciclean (performic acid), D1-OX Forte (CIO2), ECA (electrochemically activated water = anodic oxidation: hypochlorite and free radicals) and Newtec (also anodic oxidation). These five systems and a no-sterilization control were integrated in small closed ebb-and-flow circuits with nutrient solution reservoirs of 400 L each. Activity against Fusarium was excellent with ECA, good with Newtec and DI-OX Forte, moderate with high doses of Reciclean (250 ppm H2O2 and poor with the Aqua-Hort. There was no Pythium in the ECA and Newtec systems, while still so in the Aqua-Hort system, even at high doses (up to 7 ppm Cu++). Although the Reciclean (up to 100 ppm H2O2) and Aqua-Hort systems did not perform well against the pathogens, they did very well against algae; especially Reciclean was also useful against duckweed in water and liverwort on soil substrates. Concentrations of total Cl were elevated in water, substrate and plants after treatments with ECA and Newtec; other accumulations were Cu (Aqua-Hort), Na and SO4 (DI-OX Forte). However, only on a limited number of plant species these accumulations produced phytotoxic effects. PMID:27141749

  12. Soil water monitoring equipment for irrigation scheduling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Equipment for monitoring soil water content and sometimes bulk electrical conductivity can be used for scheduling irrigations if the accuracy of the equipment is sufficient to avoid damanging plants and wasting water and fertilizer. Irrigation scheduling is the process of deciding when to irrigate a...

  13. Crop water productivity and irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Modern irrigation systems offer large increases in crop water productivity compared with rainfed or gravity irrigation, but require different management approaches to achieve this. Flood, sprinkler, low-energy precision application, LEPA, and subsurface drip irrigation methods vary widely in water a...

  14. Infiltration of unconsumed irrigation water in Utah

    USGS Publications Warehouse

    Brothers, William C.; Thiros, Susan A.

    1991-01-01

    The ground-water hydrology of Panguitch Valley and adjacent areas, south-central Utah, was studied during 1988-90. One objective of the study was to measure ground-water recharge from infiltration of unconsumed irrigation water. Water-level and soil-moisture data were used to estimate travel times for water moving down through the soil profile, and to compare quantities of water reaching the water table after application of flood and sprinkler irrigation. During this study, estimates of travel times from land surface to the water table ranged from 11 days in June 1989 to 2 days in September 1989. Estimates of irrigation water recharging the ground-water system ranged from 25 to 75 percent of the water applied to the flood-irrigated field. Virtually no recharge was apparent for the sprinkler-irrigated field.

  15. Lunar horticulture.

    NASA Technical Reports Server (NTRS)

    Walkinshaw, C. H.

    1971-01-01

    Discussion of the role that lunar horticulture may fulfill in helping establish the life support system of an earth-independent lunar colony. Such a system is expected to be a hybrid between systems which depend on lunar horticulture and those which depend upon the chemical reclamation of metabolic waste and its resynthesis into nutrients and water. The feasibility of this approach has been established at several laboratories. Plants grow well under reduced pressures and with oxygen concentrations of less than 1% of the total pressure. The carbon dioxide collected from the lunar base personnel should provide sufficient gas pressure (approx. 100 mm Hg) for growing the plants.

  16. Deficit irrigation for reducing agricultural water use.

    PubMed

    Fereres, Elias; Soriano, María Auxiliadora

    2007-01-01

    At present and more so in the future, irrigated agriculture will take place under water scarcity. Insufficient water supply for irrigation will be the norm rather than the exception, and irrigation management will shift from emphasizing production per unit area towards maximizing the production per unit of water consumed, the water productivity. To cope with scarce supplies, deficit irrigation, defined as the application of water below full crop-water requirements (evapotranspiration), is an important tool to achieve the goal of reducing irrigation water use. While deficit irrigation is widely practised over millions of hectares for a number of reasons - from inadequate network design to excessive irrigation expansion relative to catchment supplies - it has not received sufficient attention in research. Its use in reducing water consumption for biomass production, and for irrigation of annual and perennial crops is reviewed here. There is potential for improving water productivity in many field crops and there is sufficient information for defining the best deficit irrigation strategy for many situations. One conclusion is that the level of irrigation supply under deficit irrigation should be relatively high in most cases, one that permits achieving 60-100% of full evapotranspiration. Several cases on the successful use of regulated deficit irrigation (RDI) in fruit trees and vines are reviewed, showing that RDI not only increases water productivity, but also farmers' profits. Research linking the physiological basis of these responses to the design of RDI strategies is likely to have a significant impact in increasing its adoption in water-limited areas. PMID:17088360

  17. Integrated irrigation and drainage water management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Results from several research projects conducted in the 1990's are summarized in this manuscript. The first projects are irrigation studies that evaluated the impact of pre-plant irrigation water on crop water use and deep percolation losses. The results showed significant losses with pre-plant ir...

  18. Mediterranean irrigation under climate change: more efficient irrigation needed to compensate increases in irrigation water requirements

    NASA Astrophysics Data System (ADS)

    Fader, M.; Shi, S.; von Bloh, W.; Bondeau, A.; Cramer, W.

    2015-08-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. This study systematically assesses how climate change and increases in atmospheric CO2 concentrations may affect irrigation requirements in the Mediterranean region by 2080-2090. Future demographic change and technological improvements in irrigation systems are accounted for, as is the spread of climate forcing, warming levels and potential realization of the CO2-fertilization effect. Vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL after a large development that comprised the improved representation of Mediterranean crops. At present the Mediterranean region could save 35 % of water by implementing more efficient irrigation and conveyance systems. Some countries like Syria, Egypt and Turkey have higher saving potentials than others. Currently some crops, especially sugar cane and agricultural trees, consume in average more irrigation water per hectare than annual crops. Different crops show different magnitude of changes in net irrigation requirements due to climate change, being the increases most pronounced in agricultural trees. The Mediterranean area as a whole might face an increase in gross irrigation requirements between 4 and 18 % from climate change alone if irrigation systems and conveyance are not improved (2 °C global warming combined with full CO2-fertilization effect, and 5 °C global warming combined with no CO2-fertilization effect, respectively). Population growth increases these numbers to 22 and 74 %, respectively, affecting mainly the Southern and Eastern Mediterranean. However, improved irrigation technologies and conveyance systems have large water saving potentials, especially in the Eastern Mediterranean, and may be able to compensate to some degree the increases due to climate change and

  19. Does deficit irrigation of field crops increase water use efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Deficit irrigation is often proposed as a method to stretch limited irrigation water supply and increase water use efficiency. A field study of field crops in the high plains shows that water use efficiency, in terms of irrigation water applied, often increases with deficit irrigation. However, in t...

  20. Water use efficiency of irrigated cotton in Uzbekistan under drip and furrow irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cotton water use and water use efficiency as related to irrigation method and irrigation scheduling parameters are inadequately understood in the central Asian Republic of Uzbekistan. The main goal of this research was to measure cotton water use, and to determine irrigation water scheduling paramet...

  1. New soil water sensors for irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effective irrigation management is key to obtaining the most crop production per unit of water applied and increasing production in the face of competing demands on water resources. Management methods have included calculating crop water needs based on weather station measurements, calculating soil ...

  2. Automation of irrigation systems to control irrigation applications and crop water use efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural irrigation management to slow water withdrawals from non-replenishing quality water resources is a global endeavor and vital to sustaining irrigated agriculture and dependent rural economies. Research in site-specific irrigation management has shown that water use efficiency, and crop p...

  3. WESTERN WATER LAWS AND IRRIGATION RETURN FLOW

    EPA Science Inventory

    The impact of water law allocation and use of waters within the Western United States is currently recognized as one of the major constraints to adaptation by irrigated agriculture of more efficient operation practices. This project provides a background of the law and evaluation...

  4. Assessing the Suitability of Water for Irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction Water quality assessment to evaluate the suitability of an irrigation water has traditionally (Ayers and Westcot, 1985) considered only salinity and SAR (sodium adsorption ratio). The criteria have been developed from a combination of field observations by experts and short duration co...

  5. An Assessment of Global Net Irrigation Water Requirements from Various Water Supply Sources to Sustain Irrigation

    NASA Astrophysics Data System (ADS)

    Yoshikawa, Sayaka; Cho, Jail; Yamada, Hannah; Khajuria, Anupam; Hanasaki, Naota; Kanae, Shinjiro

    2014-05-01

    Water supply sources for irrigation, such as rivers, reservoirs, and groundwater, are critically important for agricultural productivity. The current rapid increase in irrigation water use threatens sustainable food production. In this study, we estimated the time-varying dependence of irrigation water requirements from water supply sources, with a particular focus on variations in irrigation area during the period 1960-2050 using the global water resources model, H08. The H08 model simulates water requirements on a daily basis at a resolution of 1.0° × 1.0° . The sources of irrigation water requirements in the past simulations were specified using four categories: rivers (RIV), large reservoirs (LR) with a storage capacity greater than 1.0 km3, medium-size reservoirs (MSR) with storage capacities ranging from 1.0 km3 to 3.0 M m3, and non-local non-renewable blue water (NNBW). We also estimated future irrigation water requirements from the above four water supply sources and an additional water supply source (ADD) in three future simulation designs; irrigation area change, climate change, and changes in both irrigation area and climate. ADD was defined as the difference between NNBW in the 1990s and NNBW in the 2040s, because it was difficult to distinguish the types of future water supply sources except for RIV. The simulated results showed that RIV, MSR, and NNBW increased significantly through the 1960s to the early 1990s globally, but LR increased at a relatively low rate. After the early 1990s, RIV approached a critical limit due to the continued expansion of the irrigation area. Furthermore, MSR and NNBW increased significantly following the expansion of the irrigation area and the increased storage capacity of the medium-size reservoirs. After the 2020s, MSR could be expected to approach the critical limit without the construction of medium-size reservoirs. ADD would account for 11-23% of the total requirements in the 2040s. We found that an expansion of

  6. Irrigation management strategies to improve Water Use Efficiency of potatoes crop in Central Tunisia

    NASA Astrophysics Data System (ADS)

    Ghazouani, Hiba; Provenzano, Giuseppe; Rallo, Giovanni; Mguidiche, Amel; Douh, Boutheina; Boujelben, Abdelhamid

    2015-04-01

    In Tunisia, the expansion of irrigated area and the semiarid climate make it compulsory to adopt strategies of water management to increase water use efficiency. Subsurface drip irrigation (SDI), providing the application of high frequency small irrigation volumes below the soil surface have been increasingly used to enhance irrigation efficiency. At the same time, deficit irrigation (DI) has shown successful results with a large number of crop in various countries. However, for some crops like potatoes, DI is difficult to manage due to the rapid effect of water stress on tuber yield. Irrigation frequency is a key factor to schedule subsurface drip irrigation because, even maintaining the total seasonal volume, soil wetting patterns can result different during the growth period, with consequence on crop yield. Despite the need to enhance water use efficiency, only a few studies related to deficit irrigation of horticultural crops have been made in Tunisia. Objective of the paper was to assess the effects of different on-farm irrigation strategies on water use efficiency of potatoes crop irrigated with subsurface drip irrigation in a semiarid area of central Tunisia. After validation, Hydrus-2D model was used to simulate soil water status in the root zone, to evaluate actual crop evapotranspiration and then to estimate indirectly water use efficiency (IWUE), defined as the ratio between crop yield and total amount of water supplied with irrigation. Field experiments, were carried out in Central Tunisia (10° 33' 47.0" E, 35° 58' 8.1° N, 19 m a.s.l) on a potatoes crop planted in a sandy loam soil, during the growing season 2014, from January 15 (plantation of tubers) to May 6 (harvesting). Soil water status was monitored in two plots (T1 and T2) maintained under the same management, but different irrigation volumes, provided by a SDI system. In particular, irrigation was scheduled according to the average water content measured in the root zone, with a total of 8

  7. Effect of biofilm in irrigation pipes on the microbial quality of irrigation water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aim: To test the hypothesis that microbial quality of irrigation water can be substantially altered by the association of E. coli with pipe lining in irrigation systems. Methods and Results: The sprinkler irrigation system was outfitted with coupons that were extracted before four 2-hour long irri...

  8. Irrigation water sources and irrigation application methods used by U.S. plant nursery producers

    NASA Astrophysics Data System (ADS)

    Paudel, Krishna P.; Pandit, Mahesh; Hinson, Roger

    2016-02-01

    We examine irrigation water sources and irrigation methods used by U.S. nursery plant producers using nested multinomial fractional regression models. We use data collected from the National Nursery Survey (2009) to identify effects of different firm and sales characteristics on the fraction of water sources and irrigation methods used. We find that regions, sales of plants types, farm income, and farm age have significant roles in what water source is used. Given the fraction of alternative water sources used, results indicated that use of computer, annual sales, region, and the number of IPM practices adopted play an important role in the choice of irrigation method. Based on the findings from this study, government can provide subsidies to nursery producers in water deficit regions to adopt drip irrigation method or use recycled water or combination of both. Additionally, encouraging farmers to adopt IPM may enhance the use of drip irrigation and recycled water in nursery plant production.

  9. Weighing Lysimeters for Developing Crop Coefficients and Efficient Irrigation Practices for Vegetable Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large weighing lysimeters are expensive but invaluable tools for measuring crop evapotranspiration and developing crop coefficients for horticultural crops. Crop coefficients are used by both growers and researchers to estimate crop water use and accurately schedule irrigations. Two lysimeters of ...

  10. Sustaining Irrigated Agriculture In The Central High Plains With Limited Irrigation Water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing demands on limited water supplies will require maximizing crop production per unit water. Field studies are being carried out to develop water production functions for crops grown in the Great Plains. Irrigation water is applied through drip irrigation systems; precipitation and reference...

  11. Water conservation in irrigation can increase water use

    PubMed Central

    Ward, Frank A.; Pulido-Velazquez, Manuel

    2008-01-01

    Climate change, water supply limits, and continued population growth have intensified the search for measures to conserve water in irrigated agriculture, the world's largest water user. Policy measures that encourage adoption of water-conserving irrigation technologies are widely believed to make more water available for cities and the environment. However, little integrated analysis has been conducted to test this hypothesis. This article presents results of an integrated basin-scale analysis linking biophysical, hydrologic, agronomic, economic, policy, and institutional dimensions of the Upper Rio Grande Basin of North America. It analyzes a series of water conservation policies for their effect on water used in irrigation and on water conserved. In contrast to widely-held beliefs, our results show that water conservation subsidies are unlikely to reduce water use under conditions that occur in many river basins. Adoption of more efficient irrigation technologies reduces valuable return flows and limits aquifer recharge. Policies aimed at reducing water applications can actually increase water depletions. Achieving real water savings requires designing institutional, technical, and accounting measures that accurately track and economically reward reduced water depletions. Conservation programs that target reduced water diversions or applications provide no guarantee of saving water. PMID:19015510

  12. Quality assessment of irrigation water under a combination of rain and irrigation

    NASA Astrophysics Data System (ADS)

    Aparicio, Virginia; Costa, Jose Luis

    2015-04-01

    Complementary irrigation is one of the proposed management practices to increase the area under grain production mainly in the Humid Pampas. The most common source of irrigation water in the Humid Pampas comes from groundwater and is characterized by its high sodium bicarbonate content. However, the effect of the combination of irrigation and rain water on the chemical and physical properties of soils, especially when irrigation water comprises water with sodium bicarbonate, is still not well documented. The objective of the present study is to establish irrigation water suitability criteria under conditions of combined rain and irrigation. The trials were carried out on six irrigated plots and another five plots were chosen for validation purposes. Hydraulic conductivity and bulk density were measured in the field. Soil chemical analysis was performed on undisturbed soil samples. Supplementary irrigation using sodium bicarbonate water raises the soil electrical conductivity, the pH, exchangeable sodium percentage, soil sodium adsorption ratio and cation exchange capacity which produce an increase in bulk density, reducing the overall porosity of the soil. The effect of the soil sodium adsorption ratio on the soil hydraulic conductivity was evident when the soil sodium adsorption ratio levels were greater than 3.5. The dilution factor proposed in this study allows the classification of water for complementary irrigation linked to the management of irrigation.

  13. Managing runoff water quality from recently manured, furrow irrigated fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient losses in furrow irrigation runoff potentially increase when soils are amended with manure. We evaluated the effect of tillage, water soluble polyacrylamide (WSPAM) and irrigation management on runoff water quality during the first furrow irrigation on a calcareous silt loam soil, which had...

  14. Evaluation of potential water conservation using site-specific irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the advent of site-specific variable-rate irrigation (VRI) systems, irrigation can be spatially managed within sub-field-sized zones. Spatial irrigation management can optimize spatial water use efficiency and may conserve water. Spatial VRI systems are currently being managed by consultants ...

  15. Alternative disinfectant water treatments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternative disinfestant water treatments are disinfestants not as commonly used by the horticultural industry. Chlorine products that produce hypochlorous acid are the main disinfestants used for treating irrigation water. Chlorine dioxide will be the primary disinfestant discussed as an alternativ...

  16. Reducing irrigation water demand with cotton production in West Texas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to declining water availability from the Ogallala Aquifer and increasing pumping costs, irrigation management options for cotton are analyzed. The study concludes that supplemental irrigation while meeting crop evapotranspiration (ET) requirements is the most profitable option. Switching from co...

  17. Basic Horticulture.

    ERIC Educational Resources Information Center

    Geer, Barbra Farabough

    This learning packet contains teaching suggestions and student learning materials for a course in basic horticulture aimed at preparing students for employment in a number of horticulture areas. The packet includes nine sections and twenty instructional units. Following the standard format established for Oklahoma vocational education materials in…

  18. Quality requirements for irrigation with sewage water

    SciTech Connect

    Bouwer, H.; Idelovitch, E. )

    1987-11-01

    Irrigation is an excellent use for sewage effluent because it is mostly water with nutrients. For small flows, the effluent can be used on special, well-supervised sewage farms, where forage, fiber, or seed crops are grown that can be irrigated with standard primary or secondary effluent. Large-scale use of the effluent requires special treatment so that it meets the public health, agronomic, and aesthetic requirements for unrestricted use. Crops in the unrestricted-use category include those that are consumed raw or brought raw into the kitchen. Most state or government standards deal only with public health aspects, and prescribe the treatment processes or the quality parameters that the effluent must meet before it can be used to irrigate a certain category of crops. However, agronomic aspects related to crops and soils must also be taken into account. Quality parameters to be considered include bacteria, viruses, and other pathogens; total salt content and sodium adsorption ratio of the water; nitrogen; phosphorus; chloride and chlorine; bicarbonate; heavy metals, boron, and other trace elements; pH; and synthetic organics. 23 refs., 9 tabs.

  19. Development of Strategies for Sustainable Irrigation Water Management in Russia

    NASA Astrophysics Data System (ADS)

    Zeyliger, Anatoly; Ermolaeva, Olga

    2013-04-01

    During 1960 - 1990 years irrigated areas in Russia have increased rapidly, helping to boost agricultural output. Although the impressive achievements of irrigation in this period its large experience indicates problems and failures of irrigation water management. In addition to large water use and low irrigation water efficiency, environmental concerns (excessive water depletion, water quality reduction, water logging, soil degradation) are usually considered like the most significant problem of the irrigation sector. Despite of considerable shrinking of irrigated areas in Russia and decreasing of water withdrawal for irrigation purposes during two last decades a degradation of environment as well as degradation of soil and water resources in irrigated areas was prolonged and will probably continue if current irrigation practices are maintained. Nowadays, in different regions of Russia there are societal demand to restore agricultural irrigation in Russia as answer to challenges from climate pattern changes and degradation of land & water resources. In the respect of these demands there is a need to develop strategies for sustainability of agricultural irrigation in Russia that should be based on three main societal objectives: costeffective use of water in irrigated agriculture at farm level, and satisfactory preserving the natural environment. Therefore sustainable irrigation water management is not only an objective at farm level but also an overall goal at the local and regional as well. A way to achieve sustainability in irrigation water management is to solve the local conflicts arising from the interactions between water use at irrigation areas and surrounding environment. Thus should be based on the development of irrigation framework program including on the irrigation water management issues, policies & decisions making at federal and regional levels should be based on the indicators of environment & irrigation water efficiency monitoring promoting the

  20. Assessment of drainage water quality in pre- and post-irrigation seasons for supplemental irrigation use.

    PubMed

    Alexakis, Dimitris; Gotsis, Dimitris; Giakoumakis, Spyros

    2012-08-01

    Knowledge on hydrochemistry is very important to assess the quality of water for effective management of water resources or drainage water reuse. On this basis, an assessment of water quality was conducted in the Agoulinitsa district in Peloponnese (western Greece). Both drainage and irrigation channel water samples have been collected, treated, and subjected to chemical analysis. A characterization has been carried out using the Piper-trilinear diagram. Assessment of the water samples from the point of view of sodium adsorption ratio, Na(+)%, and residual sodium carbonate indicated that 60.0% and 83.3% of the drainage water samples during pre- and post-irrigation season, respectively, as well as the irrigation channel water samples, are chemically suitable for irrigation use. Moreover, assessment of the water samples by comparing quality parameters with the Food and Agriculture Organization guidelines indicated that 20.0% and 44.4% of the drainage water samples collected during pre- and post-irrigation season, respectively, as well as the irrigation channel water samples could cause slight to moderate problems to the plants. On the other hand, 80.0% and 55.6% of the drainage water samples collected during pre- and post-irrigation season, respectively, could cause immediate development of severe problems to the plants growth. PMID:21915601

  1. Biofilms in irrigation pipes affect the microbial quality of irrigation water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation is an essential element in the production of many food crops. Irrigation water is often delivered to fields from surface or subsurface sources via pipe-based systems. Surface waters are known to contain pathogenic microorganisms. Disease outbreaks in crops that are eaten raw (i.e. leafy g...

  2. An overview of soil water sensors for salinity & irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands while protecting the soil and water resources from degradation. Accurate irrigation management is even more important in salt affected soils ...

  3. A multisector analysis of urban irrigation and water savings potential

    NASA Astrophysics Data System (ADS)

    Bijoor, N.; Kim, H.; Famiglietti, J. S.

    2014-12-01

    Urban irrigation strains limited water supplies in semi-arid areas such as Orange County, CA, yet the quantity and controlling factors of urban irrigation are not well understood. The goals of this research are to (1) quantify and compare landscape irrigation applied by residential and commercial sectors in various retail agencies at a parcel scale (2) determine over- and under-irrigation compared to theoretical need (3) determine the climatic and socioeconomic controls on landscape irrigation. A research partnership was established between six water retail agencies in Orange County, CA representing a wide range of climatic and economic conditions. These agencies contributed between 3 and 13 years of water use data on a monthly/bimonthly basis. Irrigation depth (mm) was estimated using the "minimum month method," and landscape evapotranspiration was calculated using the Hargreaves equation for 122,345 parcels. Multiple regressions of water use were conducted with climatic and socioeconomic variables as possible explanatory variables. Single family residences accounted for the majority of urban water use. Findings from 112,192 single family residences (SFRs) show that total and indoor water use declined, though irrigation did not significantly change. Average irrigation for SFRs was 94 L/day, and a large proportion (42%) of irrigation was applied in excess to landscapes. Air temperature was found to be the primary driver of irrigation. We mapped over-irrigation relative to plant water demand to highlight areas that can be targeted for water conservation efforts. We also show the water savings that would be gained by improving the efficiency of irrigation systems. The information gained in this study would be useful for developing water use efficiency policies and/or educational programs to promote sustainable irrigation practices at the individual parcel scale.

  4. Simulating Irrigation Requirements And Water Withdrawals: The Role Of Agricultural Irrigation In Basin Hydrology And Non-Sustainable Water Use

    NASA Astrophysics Data System (ADS)

    Wisser, D.; Douglas, E. M.; Schumann, A. H.; Vörösmarty, C. J.

    2006-05-01

    The development of irrigation can cause drastic alterations of the water cycle both through changed evaporation patterns, water abstractions, and (in the case of paddy rice), increased percolation rates. The interactions of irrigation development and large-scale water cycles have traditionally not been accounted for in macroscale hydrological models. We use a modified version an existing water balance model (the WBM model) to explicitly consider the effects of irrigation on regional and continental water cycles. The irrigation module is based on the FAO-CROPWAT approach and uses a daily soil moisture balance to simulate crop consumptive water use. Time series of irrigated areas and the distribution of crops and cropping patterns are derived from a combination of remotely sensed data and national and sub-national statistics. An assessment is made of (1) how irrigation water is supplied and (2) how much of this water is abstracted in excess of the renewable water supply in the basin considering different time horizons. Using different scenarios of water availability and irrigation water demand, the response of irrigation water use to water supply and the potential threats to food security are investigated. Case studies in a few river basins that are heavily influenced by irrigated agriculture and that represent different regions of the world will be presented.

  5. Mediterranean agriculture: More efficient irrigation needed to compensate increases in future irrigation water requirements

    NASA Astrophysics Data System (ADS)

    Fader, Marianela; Shi, Sinan; von Bloh, Werner; Bondeau, Alberte; Cramer, Wolfgang

    2016-04-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. Our research shows that, at present, Mediterranean region could save 35% of water by implementing more efficient irrigation and conveyance systems. Some countries like Syria, Egypt and Turkey have higher saving potentials than others. Currently some crops, especially sugar cane and agricultural trees, consume in average more irrigation water per hectare than annual crops (1). Also under climate change, more efficient irrigation is of vital importance for counteracting increases in irrigation water requirements. The Mediterranean area as a whole might face an increase in gross irrigation requirements between 4% and 18% from climate change alone by the end of the century if irrigation systems and conveyance are not improved. Population growth increases these numbers to 22% and 74%, respectively, affecting mainly the Southern and Eastern Mediterranean. However, improved irrigation technologies and conveyance systems have large water saving potentials, especially in the Eastern Mediterranean, and may be able to compensate to some degree the increases due to climate change and population growth. Both subregions would need around 35% more water than today if they could afford some degree of modernization of irrigation and conveyance systems and benefit from the CO2-fertilization effect (1). However, in some scenarios (in this case as combinations of climate change, irrigation technology, influence of population growth and CO2-fertilization effect) water scarcity may constrain the supply of the irrigation water needed in future in Algeria, Libya, Israel, Jordan, Lebanon, Syria, Serbia, Morocco, Tunisia and Spain (1). In this study, vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL ("Lund-Potsdam-Jena managed Land") after a

  6. Mediterranean irrigation under climate change: more efficient irrigation needed to compensate for increases in irrigation water requirements

    NASA Astrophysics Data System (ADS)

    Fader, M.; Shi, S.; von Bloh, W.; Bondeau, A.; Cramer, W.

    2016-03-01

    Irrigation in the Mediterranean is of vital importance for food security, employment and economic development. This study systematically assesses how climate change and increases in atmospheric CO2 concentrations may affect irrigation requirements in the Mediterranean region by 2080-2090. Future demographic change and technological improvements in irrigation systems are taken into account, as is the spread of climate forcing, warming levels and potential realization of the CO2-fertilization effect. Vegetation growth, phenology, agricultural production and irrigation water requirements and withdrawal were simulated with the process-based ecohydrological and agro-ecosystem model LPJmL (Lund-Potsdam-Jena managed Land) after an extensive development that comprised the improved representation of Mediterranean crops. At present the Mediterranean region could save 35 % of water by implementing more efficient irrigation and conveyance systems. Some countries such as Syria, Egypt and Turkey have a higher savings potential than others. Currently some crops, especially sugar cane and agricultural trees, consume on average more irrigation water per hectare than annual crops. Different crops show different magnitudes of changes in net irrigation requirements due to climate change, the increases being most pronounced in agricultural trees. The Mediterranean area as a whole may face an increase in gross irrigation requirements between 4 and 18 % from climate change alone if irrigation systems and conveyance are not improved (4 and 18 % with 2 °C global warming combined with the full CO2-fertilization effect and 5 °C global warming combined with no CO2-fertilization effect, respectively). Population growth increases these numbers to 22 and 74 %, respectively, affecting mainly the southern and eastern Mediterranean. However, improved irrigation technologies and conveyance systems have a large water saving potential, especially in the eastern Mediterranean, and may be able to

  7. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    NASA Astrophysics Data System (ADS)

    Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y.

    2015-07-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for fresh water. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET/Y). The management practices are: four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)); four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation); and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments; wet, normal and dry years; three soil types; and three crops. The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is: 8-10 % if we change from the reference to drip or SSD; 13 % when changing to OML; 17-18 % when moving to drip or SSD in combination with OML; and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow is lower.

  8. [Ecological risks of reclaimed water irrigation: a review].

    PubMed

    Chen, Wei-Ping; Zhang, Wei-Ling; Pan, Neng; Jiao, Wen-Tao

    2012-12-01

    Wastewater reclamation and reuse have become an important approach to alleviate the water crisis in China because of its social, economic and ecological benefits. The irrigation on urban green space and farmland is the primary utilization of reclaimed water, which has been practiced world widely. To understand the risk of reclaimed water irrigation, we summarized and reviewed the publications associated with typical pollutants in reclaimed water including salts, nitrogen, heavy metals, emerging pollutants and pathogens, systematically analyzed the ecological risk posed by reclaimed water irrigation regarding plant growth, groundwater quality and public health. Studies showed that salt and salt ions were the major risk sources of reclaimed water irrigation, spreading disease was another potential risk of using reclaimed water, and emerging pollutants was the hot topic in researches of ecological risk. Based on overseas experiences, risk control measures on reclaimed water irrigation in urban green space and farmland were proposed. Five recommendations were given to promote the safe use of reclaimed water irrigation including (1) strengthen long-term in situ monitoring, (2) promote the modeling studies, (3) build up the connections of reclaimed water quality, irrigation management and ecological risk, (4) evaluate the soil bearing capacity of reclaimed water irrigation, (5) and establish risk management system of reclaimed water reuse. PMID:23379125

  9. How to save water by choice of irrigation application method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It is known that irrigation application method can impact crop water use and water use efficiency, but the mechanisms involved are incompletely understood, particularly in terms of the water and energy balances during the growing season from pre-irrigation through planting, early growth and yield de...

  10. Green and blue water footprint reduction in irrigated agriculture: effect of irrigation techniques, irrigation strategies and mulching

    NASA Astrophysics Data System (ADS)

    Chukalla, A. D.; Krol, M. S.; Hoekstra, A. Y.

    2015-12-01

    Consumptive water footprint (WF) reduction in irrigated crop production is essential given the increasing competition for freshwater. This study explores the effect of three management practices on the soil water balance and plant growth, specifically on evapotranspiration (ET) and yield (Y) and thus the consumptive WF of crops (ET / Y). The management practices are four irrigation techniques (furrow, sprinkler, drip and subsurface drip (SSD)), four irrigation strategies (full (FI), deficit (DI), supplementary (SI) and no irrigation), and three mulching practices (no mulching, organic (OML) and synthetic (SML) mulching). Various cases were considered: arid, semi-arid, sub-humid and humid environments in Israel, Spain, Italy and the UK, respectively; wet, normal and dry years; three soil types (sand, sandy loam and silty clay loam); and three crops (maize, potato and tomato). The AquaCrop model and the global WF accounting standard were used to relate the management practices to effects on ET, Y and WF. For each management practice, the associated green, blue and total consumptive WF were compared to the reference case (furrow irrigation, full irrigation, no mulching). The average reduction in the consumptive WF is 8-10 % if we change from the reference to drip or SSD, 13 % when changing to OML, 17-18 % when moving to drip or SSD in combination with OML, and 28 % for drip or SSD in combination with SML. All before-mentioned reductions increase by one or a few per cent when moving from full to deficit irrigation. Reduction in overall consumptive WF always goes together with an increasing ratio of green to blue WF. The WF of growing a crop for a particular environment is smallest under DI, followed by FI, SI and rain-fed. Growing crops with sprinkler irrigation has the largest consumptive WF, followed by furrow, drip and SSD. Furrow irrigation has a smaller consumptive WF compared with sprinkler, even though the classical measure of "irrigation efficiency" for furrow

  11. [Optimal allocation of irrigation water resources based on systematical strategy].

    PubMed

    Cheng, Shuai; Zhang, Shu-qing

    2015-01-01

    With the development of the society and economy, as well as the rapid increase of population, more and more water is needed by human, which intensified the shortage of water resources. The scarcity of water resources and growing competition of water in different water use sectors reduce water availability for irrigation, so it is significant to plan and manage irrigation water resources scientifically and reasonably for improving water use efficiency (WUE) and ensuring food security. Many investigations indicate that WUE can be increased by optimization of water use. However, present studies focused primarily on a particular aspect or scale, which lack systematic analysis on the problem of irrigation water allocation. By summarizing previous related studies, especially those based on intelligent algorithms, this article proposed a multi-level, multi-scale framework for allocating irrigation water, and illustrated the basic theory of each component of the framework. Systematical strategy of optimal irrigation water allocation can not only control the total volume of irrigation water on the time scale, but also reduce water loss on the spatial scale. It could provide scientific basis and technical support for improving the irrigation water management level and ensuring the food security. PMID:25985685

  12. Role of irrigation and irrigation automation in improving crop water use efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In arid climates, irrigation is required for significant agricultural production. In subhumid and semiarid climates, supplemental irrigation is recognized as both economically necessary (prevention of crop losses in periodic droughts) and as a means to improve overall crop water use effi...

  13. Comparison of soil water sensing methods for irrigation management and research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As irrigation water resources decrease and deficit irrigation becomes more common across the Great Plains, greater accuracy in irrigation scheduling will be required. Researchers investigating deficit irrigation practices and developing management practices must also have accurate measures of soil w...

  14. The optimal joint provision of water for irrigation and hydropower

    SciTech Connect

    Chatterjee, B.; Howitt, R.E.; Sexton, R.J.

    1998-11-01

    This study develops a dynamic optimization model to analyze the intertemporal allocation of surface water for irrigation and for hydropower production in the western United States. The issue arises because peak irrigation demands may not coincide with periods of peak demand for power. Water released for irrigation in the spring reduces the reservoir head and diminishes the capacity to generate power during summer peak demands. The optimization model is applied to irrigation districts in central California. Results show considerable deviation between the actual and the optimal allocations. Suboptimal behavior is linked to the districts` failure to articulate clear property rights to the scarce water resources.

  15. Spatial dynamics of water management in irrigated agriculture

    NASA Astrophysics Data System (ADS)

    Muralidharan, Daya; Knapp, Keith C.

    2009-05-01

    Irrigated agriculture provides 40% of worldwide food supplies but uses large amounts of scarce freshwater and contributes to environmental degradation. At the very core of this problem lie decisions made by irrigators subject to biophysical relations. This research develops a microeconomic model of irrigation management taking into account the dynamics of plant growth over the season, spatial variability in infiltration of applied irrigation water, and fundamental principles from subsurface hydrology. The analysis shows that spatial variability in water infiltration common to traditional irrigation systems increases both applied irrigation water and deep percolation flows by very substantial amounts compared to uniform infiltration. The analysis demonstrates that efficient irrigation management can significantly reduce both applied water and deep percolation at relatively low costs, at least up to a certain level. A long-run analysis of optimal irrigation systems including capital costs indicates that traditional furrow systems are economically efficient over a wide range of water prices and deep percolation costs. Overall, the results indicate that optimal irrigation management can achieve significant resource conservation and pollution control with low loss in agricultural net benefits and without land retirement, investment in capital-intensive systems, or crop switching.

  16. Using models to determine irrigation applications for water management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Simple models are used by field researchers and production agriculture to estimate crop water use for the purpose of scheduling irrigation applications. These are generally based on a simple volume balance approach based on estimates of soil water holding capacity, irrigation application amounts, pr...

  17. Consumptive Water Use and Crop Coefficients of Irrigated Sunflower

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In semi-arid environments, the use of irrigation is necessary for sunflower production to reach its maximum potential. The aim of this study was to quantify the consumptive water use and crop coefficients of irrigated sunflower (Helianthus annuus L.) without soil water limitations during two growing...

  18. Site-Specific Sprinkler Irrigation in a Water Limited Future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Available water supplies for irrigation are becoming more and more limited in the western USA and other locations around the world, and this trend is accelerating. This will force major changes to physical and managerial aspects as well as design of water delivery and on-farm irrigation systems. Th...

  19. Site-specific sprinkler irrigation in a water limited future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Available water supplies for irrigation are becoming more and more limited in the western USA and other locations around the world, and this trend is accelerating. This will force major changes to physical and managerial aspects as well as design of water delivery and on-farm irrigation systems. Th...

  20. Institutional aspects of proportional water allocation in practice: case of the Odzani River Irrigation Company, Save Catchment, Zimbabwe

    NASA Astrophysics Data System (ADS)

    Senzanje, A.; van der Zaag, P.

    Under the new Water Act [Government of Zimbabwe, 1998. Water Act, Chapter 20:24, No. 31/98. Government Printers, Harare] of Zimbabwe which abolished the priority date system for the allocation of surface water in a catchment, it is widely believed that the alternative will be the proportional water allocation system. The proportional water allocation system has been practiced by groups of water users in a number of sub-catchments in Zimbabwe including Mupfuri, Mazowe and Odzi River systems, mainly in the form of dam syndicates (groups of users jointly owning a dam) and irrigation companies (groups of irrigators sharing one source of water). This paper presents the practical experiences with, and lessons that can be learnt from proportional water allocation in the Odzani River Irrigation Company (ORIC) on the Odzi River system in Manicaland in Zimbabwe. ORIC was formed under the provisions of the old Water Act after the construction of the canal, and currently has 50 irrigating members. They are engaged in a variety of agricultural enterprises that include crop production, horticulture and dairying. All members have sub-permits (sub-rights) that enable them to draw water, but the company has a single permit to abstract water from the Odzi River into their supply canal. Farmers’ perception and understanding of proportional water allocation varied but generally defined it as getting a certain percentage of water depending on the amount available in the canal and one’s water permit. One of the major sources of problems in ORIC is inequitable access to water arising from water poaching. Overall, ORIC farmers felt that for proportional water allocation to work properly, the services of a fulltime water bailiff are required, farmers must have their own storage facilities, water should be metered, members should participate fully in decision making, politics should be kept to a minimum and conflicts must be resolved internally.

  1. Energy requirements in pressure irrigation systems

    NASA Astrophysics Data System (ADS)

    Sánchez, R.; Rodríguez-Sinobas, L.; Juana, L.; Laguna, F. V.; Castañón, G.; Gil, M.; Benítez, J.

    2012-04-01

    Modernization of irrigation schemes, generally understood as transformation of surface irrigation systems into pressure -sprinkler and trickle- irrigation systems, aims at, among others, improving irrigation efficiency and reduction of operation and maintenance efforts made by the irrigators. However, pressure irrigation systems, in contrast, carry a serious energy cost. Energy requirements depend on decisions taken on management strategies during the operation phase, which are conditioned by previous decisions taken on the design project of the different elements which compose the irrigation system. Most of the countries where irrigation activity is significant bear in mind that modernization irrigation must play a key role in the agricultural infrastructure policies. The objective of this study is to characterize and estimate the mean and variation of the energy consumed by common types of irrigation systems and their management possibilities. The work includes all processes involved from the diversion of water into irrigation specific infrastructure to water discharge by the emitters installed on the crop fields. Simulation taking into account all elements comprising the irrigation system has been used to estimate the energy requirements of typical irrigation systems of several crop production systems. It has been applied to extensive and intensive crop systems, such us extensive winter crops, summer crops and olive trees, fruit trees and vineyards and intensive horticulture in greenhouses. The simulation of various types of irrigation systems and management strategies, in the framework imposed by particular cropping systems, would help to develop criteria for improving the energy balance in relation to the irrigation water supply productivity.

  2. Pilot study of the effect of biofilms in irrigation pipes on the microbial water quality of irrigation water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation is an essential element in the production of many food crops. Irrigation water is often delivered to fields from surface or subsurface sources via pipe-based systems. Surface waters are known to contain pathogenic microorganisms. Disease outbreaks in crops that are eaten raw (i.e. leafy g...

  3. Effect of irrigation amounts applied with subsurface drip irrigation on corn evapotranspiration, yield, water use efficiency, and dry matter production in a semiarid climate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying the local crop response to irrigation is important for establishing adequate irrigation management strategies. This study evaluated the effect of irrigation applied with subsurface drip irrigation on field corn (Zea mays L.) evapotranspiration (ETc), yield, water use efficiencies (WUE = ...

  4. Heartland Horticulture

    ERIC Educational Resources Information Center

    Poquette, Bonnie L.

    2009-01-01

    Midwestern gardeners are legendary for enduring and outwitting winter, with its heavy snowpack and recurring freezes and thaws. Most of them also reckon with a relatively short growing period. All of them find their horticultural plans complicated by hot, humid summers. In fact, the Midwest deals with four seasons dictating special considerations…

  5. Ornamental Horticulture.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Bureau of Occupational and Career Curriculum Development.

    Each of the 32 curriculum modules in this packet for ornamental horticulture instruction contains a brief description of the module content, a list of the major division or units, the overall objectives, objectives by units, content outline and suggested teaching methods, student application activities, and evaluation procedures. A listing of…

  6. Chapter 24. emerging technologies for irrigation water treatment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several disinfestants that have potential for treating recycled irrigation water are less commonly used or newer developing technologies. Hydrogen peroxide can reduce spread of pathogens in water that contains nutrients or pesticide residues without generating toxic residues. Benefits potentially in...

  7. Estimating irrigation water use in the humid eastern United States

    USGS Publications Warehouse

    Levin, Sara B.; Zarriello, Phillip J.

    2013-01-01

    Accurate accounting of irrigation water use is an important part of the U.S. Geological Survey National Water-Use Information Program and the WaterSMART initiative to help maintain sustainable water resources in the Nation. Irrigation water use in the humid eastern United States is not well characterized because of inadequate reporting and wide variability associated with climate, soils, crops, and farming practices. To better understand irrigation water use in the eastern United States, two types of predictive models were developed and compared by using metered irrigation water-use data for corn, cotton, peanut, and soybean crops in Georgia and turf farms in Rhode Island. Reliable metered irrigation data were limited to these areas. The first predictive model that was developed uses logistic regression to predict the occurrence of irrigation on the basis of antecedent climate conditions. Logistic regression equations were developed for corn, cotton, peanut, and soybean crops by using weekly irrigation water-use data from 36 metered sites in Georgia in 2009 and 2010 and turf farms in Rhode Island from 2000 to 2004. For the weeks when irrigation was predicted to take place, the irrigation water-use volume was estimated by multiplying the average metered irrigation application rate by the irrigated acreage for a given crop. The second predictive model that was developed is a crop-water-demand model that uses a daily soil water balance to estimate the water needs of a crop on a given day based on climate, soil, and plant properties. Crop-water-demand models were developed independently of reported irrigation water-use practices and relied on knowledge of plant properties that are available in the literature. Both modeling approaches require accurate accounting of irrigated area and crop type to estimate total irrigation water use. Water-use estimates from both modeling methods were compared to the metered irrigation data from Rhode Island and Georgia that were used to

  8. Water use dynamics of peach trees under postharvest deficit irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Postharvest deficit irrigation is a potential strategy for conserving valuable fresh water for production of early season tree fruit crops such as peaches. However, behaviors of evapotranspiration characteristics and crop coefficient (Kc) under deficit irrigation conditions are largely unknown. A th...

  9. Scheme of water saving irrigation in autumn based on SHAW model in Inner Mongolia Hetao Irrigation District

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In accordance with the prevention of soil salination and water-saving irrigation in autumn in Inner Mongolia Hetao irrigation district, the reasonable water-saving irrigation scheme in autumn was quantified by using SHAW model for the different salinized soils. For slightly salinized soils, autumn i...

  10. Water savings and improved yield stability for irrigated and non-irrigated cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Southeast U.S. receives 130 cm of annual rainfall, however cotton production is still limited by water. Irrigation, when available, is used to supplement natural precipitation to sustain profitable crop production. Increased water capture would improve water use efficiency and reduce irrigatio...

  11. Irrigated agriculture with limited water supply:Tools for understanding and managing irrigation and crop water use efficiencies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water availability for irrigated agriculture is declining in both China and the United States due to increased use for power generation, municipalities, industries and environmental protection. Persistent droughts have exacerbated the situation, leading to increases in irrigated area as farmers atte...

  12. Using soil water sensors to improve irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation water management has to do with the appropriate application of water to soils, in terms of amounts, rates, and timing to satisfy crop water demands while protecting the soil and water resources from degradation. In this regard, sensors can be used to monitor the soil water status; and som...

  13. Analytical steady-state solutions for water-limited cropping systems using saline irrigation water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems mod...

  14. Crop water stress indices correlated with soil water storage: Implications for variable rate irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil water sensing methods are now coming to be used for irrigation scheduling of whole fields. However, newly introduced variable rate irrigation (VRI) systems require information about soil water content in many areas of a field, each called an irrigation management zone. Commonly available soil w...

  15. Elderberry: Botany, Horticulture, Potential

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Horticultural Review allows extensive reviews of the state of the knowledge on certain topics or crops. Elderberry: Botany, Horticulture, Potential, is outlined with an Introduction, Botany, Horticulture, Propagation, Uses and Conclusion sections. This review compiles literature from around the w...

  16. Irrigation with desalinated water: A step toward increasing water saving and crop yields

    NASA Astrophysics Data System (ADS)

    Silber, Avner; Israeli, Yair; Elingold, Idan; Levi, Menashe; Levkovitch, Irit; Russo, David; Assouline, Shmuel

    2015-01-01

    We examined the impact of two different approaches to managing irrigation water salinity: salt leaching from the field ("conventional" management) and water desalination before field application ("alternative" management). Freshwater commonly used for irrigation (FW) and desalinated water (DS) were applied to the high-water-demanding crop banana at four different rates. Both irrigation rate and water salinity significantly affected yield. DS application consistently produced higher yields than FW, independently of irrigation rate. The highest yield for FW-irrigation was achieved with the highest irrigation rate, whereas the same yield was obtained in the case of DS-irrigation with practically half the amount of water. Yield decreased with FW-irrigation, even when the water salinity, ECi, was lower than the limit considered safe for soil and crops. Irrigating with FW provided a massive amount of salt which accumulated in the rhizosphere, inducing increased osmotic potential of the soil solution and impairing plant water uptake. Furthermore, applying the "conventional" management, a significant amount of salt is leached from the rhizosphere, accumulating in deeper soil layers, and eventually reaching groundwater reservoirs, thus contributing to the deterioration of both soil and water quality. Removal of salt excess from the water before it reaches the field by means of DS-irrigation may save significant amounts of irrigation water by reducing the salt leaching requirements while increasing yield and improving fruit quality, and decreasing salt load in the groundwater.

  17. Effects of harvest date, irrigation level, cultivar type and fruit water content on olive mill wastewater generated by a laboratory scale 'Abencor' milling system.

    PubMed

    Aviani, I; Raviv, M; Hadar, Y; Saadi, I; Dag, A; Ben-Gal, A; Yermiyahu, U; Zipori, I; Laor, Y

    2012-03-01

    Olive mill wastewaters (OMW) were obtained at laboratory scale by milling olives from four cultivars grown at different irrigation levels and harvested at different times. Samples were compared based on wastewater quantity, pH, suspended matter, salinity, organic load, total phenols, NPK, and phytotoxicity. Principal component analysis discriminated between harvest times, regardless of olive cultivar, indicating substantial influence of fruit ripeness on OMW characteristics. OMW properties were affected both by the composition and the extraction efficiency of fruit water. As the fruit water content increased, the concentrations of solutes in the fruit water decreased, but the original fruit water composed a larger portion of the total wastewater volume. These contradicting effects resulted in lack of correlation between fruit water content and OMW properties. The significant effects shown for fruit ripeness, irrigation and cultivar on OMW characteristics indicate that olive horticultural conditions should be considered in future OMW management. PMID:22226593

  18. Salinity control on irrigated land and use of saline water for irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current irrigation practices in arid and semi-arid regions throughout the world are not sustainable. These regions are experiencing increasing population and development with increasing demands for limited fresh water for municipal and industrial use. In arid areas fresh water use is currently alrea...

  19. Comparative Assessment of Irrigation Water Quality in Sri Lanka's Tank-Cascade and Mahaweli Irrigation Schemes

    NASA Astrophysics Data System (ADS)

    Gunda, T.; Hornberger, G. M.

    2013-12-01

    Two distinct irrigation systems dominate the landscape in the dry zone of Sri Lanka. The tank-cascade system, which originates from third century BC, is a small-scale system that has been the traditional method for communities to meet their farming water needs. The Mahaweli reservoir system, in contrast, is a large-scale irrigation scheme initiated in the 1970s that diverts water across hundreds of kilometers from the headwaters of the Mahaweli River to farmers. Although approximately equal amounts of paddy land are irrigated under these two systems, very little comparative analysis has been conducted on the spatial variation of irrigation water quality in Sri Lanka. An exploratory study was conducted in June 2013 in Anuradhapura district, an area that experiences the highest level of paddy production instability and has had long-standing irrigation water quality issues. A total of 30 water samples from both cascade systems and Mahaweli system H-7 were analyzed for pH, temperature, conductivity, turbidity, and chromatic dissolved organic matter using field instruments. A subset of these samples was further analyzed for nitrate and ammonia using colorimetric methods. While the sparse data from our study revealed some interesting trends, it is difficult to extrapolate in detail. Therefore, we compare inferences drawn about the Sri Lanka data to a more detailed analysis of chromatic dissolved organic matter in a Tennessee watershed. This comparison will provide insight into possible interpretations relative to the water quality data collected in Sri Lanka. As Sri Lanka continues to develop its irrigation resources, water quality assessments such as this one are critical for identifying factors limiting paddy production in the country.

  20. Drip irrigation management in different chufa planting strategies: yield and irrigation water use efficiency

    NASA Astrophysics Data System (ADS)

    Pascual-Seva, Nuria; San Bautista, Alberto; López-Galarza, Salvador; Maroto, José Vicente; Pascual, Bernardo

    2013-04-01

    In a study presented in the EGU assembly 2012, it was analysed how yield and irrigation water use efficiency (IWUE) in chufa (Cyperus esculentus L. var. sativus), crop, were affected by planting strategy (ridges and flat raised beds, with two and three plant rows along them) and irrigation system [furrow (FI) and drip irrigation (DI)]. Each irrigation session started when the Volumetric Soil Water Content (VSWC) in ridges dropped to 80% of field capacity; beds were irrigated simultaneously with ridges and with the same irrigation duration. R produced lower yield than the two types of beds, and yields in DI were higher than those FI. Ridges led to the highest IWUE with DI, and to the lowest with FI. Then, it was decided to analyse, in DI, how yield and IWUE responded to start each irrigation session when the VSWC in the central point of different planting strategies [ridges (R), and flat raised beds with two (b) and three (B) plant rows along them] dropped to 80% of field capacity. In R and b, plants were irrigated by a single dripline per plant row, while in B two irrigation layouts were assayed: a single dripline per plant row (B3) and two driplines per bed (B2), placing each dripline between two planting rows. Irrigation session stop was also automated as a function of the VSWC. Results show that yield was affected (P˜0.01) by planting strategy; the greatest yield was obtained in b (2.4 kgm-2), differing (P˜0.05) from that obtained in R (2.1 kgm-2), with intermediate yields in B2 (2.3 kgm-2) and B3 (2.3 kgm-2). Yield was not affected (P˜0.05) by the utilisation of two or three driplines in B. Considerably less irrigation water was applied (IWA) in R (376 mm) than in B3 (465 mm), B2 (475 mm) and b (502 mm). This automatic irrigation management, as a function of the VSWC in each planting strategy, lead to adjust the IWA to the plant water requirements, which were similar in all three flat raised beds, since they correspond to the same planting density, that was

  1. Water savings potentials of irrigation systems: dynamic global simulation

    NASA Astrophysics Data System (ADS)

    Jägermeyr, J.; Gerten, D.; Heinke, J.; Schaphoff, S.; Kummu, M.; Lucht, W.

    2015-04-01

    Global agricultural production is heavily sustained by irrigation, but irrigation system efficiencies are often surprisingly low. However, our knowledge of irrigation efficiencies is mostly confined to rough indicative estimates for countries or regions that do not account for spatio-temporal heterogeneity due to climate and other biophysical dependencies. To allow for refined estimates of global agricultural water use, and of water saving and water productivity potentials constrained by biophysical processes and also non-trivial downstream effects, we incorporated a dynamic representation of the three major irrigation systems (surface, sprinkler, and drip) into a process-based bio- and agrosphere model, LPJmL. Based on this enhanced model we provide a gridded worldmap of dynamically retrieved irrigation efficiencies reflecting differences in system types, crop types, climatic and hydrologic conditions, and overall crop management. We find pronounced regional patterns in beneficial irrigation efficiency (a refined irrigation efficiency indicator accounting for crop-productive water consumption only), due to differences in these features, with lowest values (< 30%) in South Asia and Sub-Saharan Africa and highest values (> 60%) in Europe and North America. We arrive at an estimate of global irrigation water withdrawal of 2396 km3 (2004-2009 average); irrigation water consumption is calculated to be 1212 km3, of which 511 km3 are non-beneficially consumed, i.e. lost through evaporation, interception, and conveyance. Replacing surface systems by sprinkler or drip systems could, on average across the world's river basins, reduce the non-beneficial consumption at river basin level by 54 and 76%, respectively, while maintaining the current level of crop yields. Accordingly, crop water productivity would increase by 9 and 15%, respectively, and by much more in specific regions such as in the Indus basin. This study significantly advances the global quantification of

  2. Introduction to Horticulture. Teacher Edition. Horticulture Series.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This publication is designed to provide a core of instruction for the many different fields in agricultural/horticultural education. This course contains 21 instructional units that cover the following topics: introduction to horticulture; beginning a career in horticulture; hand and power tools; introduction to safety; growing facilities;…

  3. Results from a 3-year deficit irrigation experiment with drip-irrigated maize to improve water productivity

    NASA Astrophysics Data System (ADS)

    Kloss, Sebastian; Schütze, Niels; Grundmann, Jens

    2013-04-01

    Water for irrigation farming is severely limited in arid and semi-arid regions, hence reliable and robust strategies are needed that allow to use the available resources efficiently. Controlled deficit irrigation (DI) is one strategy that can help to use water in an effective way while still ensuring considerable yields from harvest. It needs precise irrigation control however where sensors are used to determine when to irrigate. Therefore, thresholds that trigger irrigation need to be chosen carefully. An irrigation experiment with drip-irrigated maize was conducted in three consecutive years (2010-2012) where different controlled DI strategies were tested. The experiments took place in a greenhouse at TU München in Freising, Germany, and comprised treatments with constant and varying irrigation thresholds throughout the growing season, which were compared to fully irrigated reference treatments. Thresholds were determined in soil tension as it is closely related to the working principle behind plant transpiration and treatments evaluated with regard to their water productivity (WP - yield over applied irrigation water). The irrigation thresholds were determined prior to the experiment by a stochastic simulation-based framework that consisted of a weather generator, the crop growth model Daisy, and an optimization algorithm for finding optimal thresholds under limiting water supply. Achieved results show similar or better WP compared to the reference and generally high WP compared to values from literature which suggests this methodology is a promising approach to improve WP.

  4. Maximizing grain sorghum water use efficiency under deficit irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Development and evaluation of sustainable and efficient irrigation strategies is a priority for producers faced with water shortages resulting from aquifer depletion, reduced base flows, and reallocation of water to non-agricultural sectors. Under a limited water supply, yield maximization may not b...

  5. Comparative study of irrigation water use and groundwater recharge under various irrigation schemes in an agricultural region, central Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

    2016-04-01

    The risk of rice production has increased notably due to climate change in Taiwan. To respond to growing agricultural water shortage without affecting normal food production in the future, the application of water-saving irrigation will be a substantial resolution. However, the adoption of water-saving irrigation may result in the reducing of groundwater recharge because continuous flooding in the paddy fields could be regarded as an important source for groundwater recharge. The aim of this study was to evaluate the irrigation water-saving benefit and groundwater recharge deficit when adopting the System of Rice Intensification, known as SRI methodology, in the Choushui River alluvial fan (the largest groundwater pumping and the most important rice-cropping region in central Taiwan). The three-dimensional finite element groundwater model, FEMWATER, was applied to simulate the infiltration process and groundwater recharge under SRI methodology and traditional irrigation schemes including continuous irrigation, and rotational irrigation in two rice-crop periods with hydro-climatic data of 2013. The irrigation water use was then calculated by water balance. The results showed that groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reduced 3.6% and 1.6% in the first crop period, and reduced 3.2% and 1.6% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. However, the SRI methodology achieved notably water-saving benefit compared to the disadvantage of reducing the groundwater recharge amount. The field irrigation requirement amount of SRI methodology was significantly lower than those of traditional irrigation schemes, saving 37% and 20% of irrigation water in the first crop period, and saving 53% and 35% in the second crop period, compared with continuous irrigation and rotational irrigation, respectively. Therefore, the amount of groundwater pumping for

  6. Forecast of irrigation water demand considering multiple factors

    NASA Astrophysics Data System (ADS)

    Wang, X.; Lei, X.; Guo, X.; You, J.; Wang, H.

    2015-05-01

    Many factors influence irrigation water requirement on the basin scale, which make it difficult to obtain comprehensive data. Despite the advantage of less needing historical data, the prediction precision of traditional trend prediction methods is hard to guarantee. For water scarce basins, the artificial influence on irrigation requirement should be thought of as important impact factors. In this paper, the PCA (principal component analysis) method is used to identify the main influencing factors, such as precipitation, irrigation area, water saving technology and so on. Based on that, an irrigation water demand prediction model considering multiple factors is developed for water shortage regions. The method is applied in the Haihe River basin as an example. The study results show that the irrigation water demand forecasting method considering multiple factors in this paper can achieve higher modelling accuracy, compared with the traditional trend prediction method and the method that does not consider the human influence. In view of the small average relative error, 1.32%, it has good values for application.

  7. Irrigation response and water productivity of deficit to fully irrigated spring camelina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Camelina [Camelina sativa L. Crantz] is an oil seed crop that could be adapted to the northern High Plains of the USA as a biofuel crop. Decreased ground water allocations in Nebraska necessitated determining the impact of limited irrigation on camelina. The objective of this research was to determi...

  8. Yield, irrigation response, and water productivity of deficit to fully irrigated spring canola

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canola (Brassica napus) is an oil-seed crop that is adapted to the northern High Plains of the USA and is considered a viable rotational and biofuel crop. However, decreased ground water allocations have necessitated determining the impact of limited irrigation on canola productivity. The objectives...

  9. Irrigation infrastructure and water appropriation rules for food security

    NASA Astrophysics Data System (ADS)

    Gohar, Abdelaziz A.; Amer, Saud A.; Ward, Frank A.

    2015-01-01

    In the developing world's irrigated areas, water management and planning is often motivated by the need for lasting food security. Two important policy measures to address this need are improving the flexibility of water appropriation rules and developing irrigation storage infrastructure. Little research to date has investigated the performance of these two policy measures in a single analysis while maintaining a basin wide water balance. This paper examines impacts of storage capacity and water appropriation rules on total economic welfare in irrigated agriculture, while maintaining a water balance. The application is to a river basin in northern Afghanistan. A constrained optimization framework is developed to examine economic consequences on food security and farm income resulting from each policy measure. Results show that significant improvements in both policy aims can be achieved through expanding existing storage capacity to capture up to 150 percent of long-term average annual water supplies when added capacity is combined with either a proportional sharing of water shortages or unrestricted water trading. An important contribution of the paper is to show how the benefits of storage and a changed water appropriation system operate under a variable climate. Results show that the hardship of droughts can be substantially lessened, with the largest rewards taking place in the most difficult periods. Findings provide a comprehensive framework for addressing future water scarcity, rural livelihoods, and food security in the developing world's irrigated regions.

  10. Characteristics of dissolved carbon change in irrigation water

    NASA Astrophysics Data System (ADS)

    Akaike, Y.; Kunishio, A.; Kawamoto, Y.; Murakami, H.; Iwata, T.

    2012-12-01

    It is necessary to estimate carbon emission from soil for understanding carbon cycle processes in cultivated fields. Since irrigation water is introduced into a typical rice paddy field, one part of emitted carbon content from soil were trapped by water and dissolved in it, and dissolved carbon content outflows from the field at the drainage moment. In this study, we continuously and regularly analyzed dissolved carbon content of irrigation water and investigated seasonal variation of efflux of carbon from a paddy field. Experimental site is located reclaimed land in the southern part of Okayama Prefecture, Japan. And rice cropping cultivation has continued in a similar method every year. Intermittent irrigation water managements, or 3 days flooded and 4 days drained condition, were carried out during almost all the period of rice cultivated term. Irrigation water was sampled every flooding and drainage days. Inorganic carbon (IC) concentration was measured with total carbon (TC) analyzer (TOC-V/CSH, SHIMAZU). Amount of dissolved carbon in irrigation water was calculated from product of the carbon concentration and water levels. The experimental paddy field was divided into two areas, and two bottle of water were sampled from each area. In order to investigate what impact is brought on the annual carbon cycle by the difference of disposal management of residual biomass after the harvest, residual biomass was burned and plowed into soil at the one area on 29th Nov., 2011, and residue was not burned and directly plowed into soil at the other area as usual. IC during cultivated term in 2011 and 2012 in both area gradually increased day by day for every flooded periods. And IC showed distinct diurnal variations with lower value in the daytime than at night, it is because of photosynthetic activities by aquatic algae in the irrigation water.

  11. Distillation irrigation: a low-energy process for coupling water purification and drip irrigation

    USGS Publications Warehouse

    Constantz, J.

    1989-01-01

    A method is proposed for combining solar distillation and drip irrigation to simultaneously desalinize water and apply this water to row crops. In this paper, the basic method is illustrated by a simple device constructed primarily of sheets of plastic, which uses solar energy to distill impaired water and apply the distillate to a widely spaced row crop. To predict the performance of the proposed device, an empirical equation for distillate production, dp, is developed from reported solar still production rates, and a modified Jensen-Haise equation is used to calculate the potential evapotranspiration, et, for a row crop. Monthly values for et and dp are calculated by using a generalized row crop at five locations in the Western United States. Calculated et values range from 1 to 22 cm month-1 and calculated dp values range from 2 to 11 cm month-1, depending on the location, the month, and the crop average. When the sum of dp plus precipitation, dp + P, is compared to et for the case of 50% distillation irrigation system coverage, the results indicate that the crop's et is matched by dp + P, at the cooler locations only. However, when the system coverage is increased to 66%, the crop's et is matched by dp + P even at the hottest location. Potential advantages of distillation irrigation include the ability: (a) to convert impaired water resources to water containing no salts or sediments; and (b) to efficiently and automatically irrigate crops at a rate that is controlled primarily by radiation intensities. The anticipated disadvantages of distillation irrigation include: (a) the high costs of a system, due to the large amounts of sheeting required, the short lifetime of the sheeting, and the physically cumbersome nature of a system; (b) the need for a widely spaced crop to reduce shading of the system by the crop; and (c) the production of a concentrated brine or precipitate, requiring proper off-site disposal. ?? 1989.

  12. Predicting Crop Water Use from Ground Cover and Remote Sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scheduling irrigations for horticultural crops with evapotranspiration calculations is difficult. Horticultural crops are grown under a wide range of cultural practices and conditions, making it difficult to select appropriate crop coefficients. A primary determinant of crop water use is light in...

  13. Site-specific variable rate irrigation a means to enhance water use efficiency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The majority of irrigated cropland in the US is watered with sprinkler irrigation systems. These systems are inherently more efficient in distributing water than furrow or flood irrigation. Appropriate system design of sprinkler irrigation equipment, application methods, and farming practices (e.g. ...

  14. Deficit irrigation of peach trees to reduce water consumption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lack of water is a major limiting factor for production tree fruits such as peaches in the San Joaquin Valley of California and many other arid- or semi-arid regions in the world. Deficit irrigation can be used in some cropping systems as a water resource management strategy to reduce non-productiv...

  15. Soil properties evolution after irrigation with reclaimed water

    NASA Astrophysics Data System (ADS)

    Leal, M.; González-Naranjo, V.; de Miguel, A.; Martínez-Hernández, V.; Lillo, J.

    2012-04-01

    Many arid and semi-arid countries are forced to look for new and alternative water sources. The availability of suitable quality water for agriculture in these regions often is threatened. In this context of water scarcity, the reuse of treated wastewater for crop irrigation could represent a feasible solution. Through rigorous planning and management, irrigation with reclaimed water presents some advantages such as saving freshwater, reducing wastewater discharges into freshwater bodies and decreasing the amount of added fertilizers due to the extra supply of nutrients by reclaimed water. The current study, which involves wastewater reuse in agriculture, has been carried out in the Experimental Plant of Carrión de los Céspedes (Sevile, Spain). Here, two survey parcels equally designed have been cultivated with Jatropha curcas L, a bioenergetic plant and a non-interfering food security crop. The only difference between the two parcels lies on the irrigation water quality: one is irrigated with groundwater and another one with reclaimed water. The main aim of this study focuses on analysing the outstanding differences in soil properties derived from irrigation with two water qualities, due to their implications for plant growth. To control and monitor the soil variables, soil samples were collected before and after irrigation in the two parcels. pH, electrical conductivity, cation exchange capacity, exchangeable cations (Ca2+, Mg2+, Na+ and K+), kjeldahl nitrogen, organic matter content and nutrients (boron, phosphorus, nitrogen, potassium) were measured. Data were statistically analyzed using the R package. To evaluate the variance ANOVA test was used and to obtain the relations between water quality and soil parameters, Pearson correlation coefficient was computed. According to other authors, a decrease in the organic matter content and an increase of parameters such as pH, electrical conductivity and some exchangeable cations were expected. To date and after

  16. Water quality criteria for use of saline/degraded water for irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current fresh water use in arid and semiarid lands is not sustainable, as use exceeds replenishment and demand for water continues to increase. Agriculture will either need to reduce acreage under irrigation, which is undesirable since it will reduce food supply, or irrigate with alternative water s...

  17. Water temperature in irrigation return flow from the Upper Snake Rock watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water returning to a river from an irrigated watershed could increase the water temperature in the river. The objective of this study was to compare the temperature of irrigation return flow water with the temperature of the diverted irrigation water. Water temperature was measured weekly in the mai...

  18. The impacts of climate change on global irrigation water requirements

    NASA Astrophysics Data System (ADS)

    Zhang, X.; Cai, X.

    2011-12-01

    Climate change tends to affect the irrigation water requirement of current irrigated agricultural land, and also changes the water availability for current rain-fed land by the end of this century. We use the most up-to-date climatic and crop datasets (e.g., global irrigated/rain-fed crop areas and grid level crop growing calendar (Portmann, Siebert and Döll, 2010, Global Biogeochemical Cycles 24)) to evaluate the requirements of currently irrigated land and the water deficit for rain-fed land for all major crops under current and projected climate. Six general circulation models (GCMs) under two emission scenarios, A1B & B1, are assembled using two methods, the Simple Average Method (SAM) and Root Mean Square Error Ensemble Method (RMSEMM), to deal with the GCM regional variability. It is found that the global irrigation requirement and the water deficit are both going to increase significantly under all scenarios, particularly under the A1B emission scenario. For example, the projected irrigation requirement is expected to increase by about 2500 million m3 for wheat, 3200 million m3 for maize and another 3300 million m3 for rice. At the same time, the water deficit for current rain-fed cropland will be widened by around 3000, 4000, 2100 million m3 for wheat, maize and rice respectively. Regional analysis is conducted for Africa, China, Europe, India, South America and the United States. It is found that the U.S. may expect the greatest rise in irrigation requirements for wheat and maize, while the South America may suffer the greatest increase for rice. In addition, Africa and the U.S. may face a larger water deficit for both wheat and maize on rain-fed land, and South America just for rice. In summary, climate change is likely to bring severe challenges for irrigation systems and make global water shortage even worse by the end of this century. These pressures will call for extensive adaptation measures. The change in crop water requirements and availability

  19. Conjunctive use of water resources for sustainable irrigated agriculture

    NASA Astrophysics Data System (ADS)

    Singh, Ajay

    2014-11-01

    The continuous increase in global population and simultaneous decrease in good quality water resources emphasizes the need of using surface water and groundwater resources conjunctively for irrigation. The conjunctive use allows the utilization of poor quality water, which cannot be used as such for the crop production due to its harmful effect on soil and crop health. This paper presents an overview on issues and methods of the conjunctive use of surface water and groundwater resources for sustainable irrigated agriculture. The background of the conjunctive water use and its applications for the management of poor quality water and management of rising watertable are presented. The management of conjunctive water use through the computer-based models is also covered in this review. The advantages and disadvantages of the approach have been described. Conclusions are provided based on this review which could be useful for all the stakeholders.

  20. Potential perchlorate exposure from Citrus sp. irrigated with contaminated water.

    PubMed

    Sanchez, C A; Krieger, R I; Khandaker, N R; Valentin-Blasini, L; Blount, B C

    2006-05-10

    Citrus produced in the southwestern United States is often irrigated with perchlorate-contaminated water. This irrigation water includes Colorado River water which is contaminated with perchlorate from a manufacturing plant previously located near the Las Vegas Wash, and ground water from wells in Riverside and San Bernardino counties of California which are affected by a perchlorate plume associated with an aerospace facility once located near Redlands, California. Studies were conducted to evaluate the uptake and distribution of perchlorate in citrus irrigated with contaminated water, and estimate potential human exposure to perchlorate from the various citrus types including lemon (Citrus limon), grapefruit (Citrus paradise), and orange (Citrus sinensis) produced in the region. Perchlorate concentrations ranged from less than 2-9 microg/L for Colorado River water and from below detection to approximately 18 microg/L for water samples from wells used to irrigate citrus. Destructive sampling of lemon trees produced with Colorado River water show perchlorate concentrations larger in the leaves (1835 microg/kg dry weight (dw)) followed by the fruit (128 microg/kg dw). Mean perchlorate concentrations in roots, trunk, and branches were all less than 30 microg/kg dw. Fruit pulp analyzed in the survey show perchlorate concentrations ranged from below detection limit to 38 microg/kg fresh weight (fw), and were related to the perchlorate concentration of irrigation water. Mean hypothetical exposures (mug/person/day) of children and adults from lemons (0.005 and 0.009), grapefruit (0.03 and 0.24), and oranges (0.51 and 1.20) were estimated. These data show that potential perchlorate exposures from citrus in the southwestern United States are negligible relative to the reference dose recommended by the National Academy of Sciences. PMID:17723376

  1. Estimated Colorado Golf Course Irrigation Water Use, 2005

    USGS Publications Warehouse

    Ivahnenko, Tamara

    2009-01-01

    Golf course irrigation water-use data were collected as part of the U.S. Geological Survey National Water Use Program's 2005 compilation to provide baseline information, as no golf course irrigation water-use data (separate from crop irrigation) have been reported in previous compilations. A Web-based survey, designed by the U.S. Geological Survey, in cooperation with the Rocky Mountain Golf Course Superintendents Association (RMGCSA), was electronically distributed by the association to the 237 members in Colorado. Forty-three percent of the members returned the survey, and additional source water information was collected by telephone for all but 20 of the 245 association member and non-member Colorado golf courses. For golf courses where no data were collected at all, an average 'per hole' coefficient, based on returned surveys from that same county, were applied. In counties where no data were collected at all, a State average 'per hole' value of 13.2 acre-feet was used as the coefficient. In 2005, Colorado had 243 turf golf courses (there are 2 sand courses in the State) that had an estimated 2.27 acre-feet per irrigated course acre, and 65 percent of the source water for these courses was surface water. Ground water, potable water (public supply), and reclaimed wastewater, either partially or wholly, were source waters for the remaining courses. Fifty-three of the 64 counties in Colorado have at least one golf course, with the greatest number of courses in Jefferson (23 courses), Arapahoe (22 courses), and El Paso Counties (20 courses). In 2005, an estimated 5,647.8 acre-feet in Jefferson County, 5,402 acre-feet in Arapahoe County, and 4,473.3 acre-feet in El Paso County were used to irrigate the turf grass.

  2. Agricultural practices and irrigation water demand in Uttar Pradesh

    NASA Astrophysics Data System (ADS)

    O'Keeffe, J.; Buytaert, W.; Brozovic, N.; Mijic, A.

    2013-12-01

    Changes in farming practices within Uttar Pradesh, particularly advances in irrigation technology, have led to a significant drop in water tables across the region. While the acquisition of monitoring data in India is a challenge, current water use practices point towards water overdraught. This is exacerbated by government and state policies and practices, including the subsidising of electricity, seeds and fertilizer, and an agreement to buy all crops grown, promoting the over use of water resources. Taking India's predicted population growth, increases in industrialisation and climate change into account, both farmland and the water resources it depends upon will be subject to increased pressures in the future. This research is centred around irrigation demands on water resources within Uttar Pradesh, and in particular, quantifying those demands both spatially and temporally. Two aspects of this will be presented; the quantification of irrigation water applied and the characterisation of the spatial heterogeneity of water use practices. Calculating the volumes of applied irrigation water in the absence of observed data presents a major challenge and is achieved here through the use of crop models. Regional crop yields provided by statistical yearbooks are replicated by the crop models AquaCrop and InfoCrop, and by doing so the amount of irrigation water needed to produce the published yields is quantified. In addition, proxy information, for example electrical consumption for agricultural use, is used to verify the likely volumes of water abstracted from tubewells. Statistical analyses of borehole distribution and the characterisation of the spatial heterogeneity of water use practices, particularly farmer decision making, collected during a field trip are also presented. The evolution of agricultural practices, technological advancement and water use for irrigation is reconstructed through the use of multiple regression and principle component analysis

  3. Behavioural modelling of irrigation decision making under water scarcity

    NASA Astrophysics Data System (ADS)

    Foster, T.; Brozovic, N.; Butler, A. P.

    2013-12-01

    Providing effective policy solutions to aquifer depletion caused by abstraction for irrigation is a key challenge for socio-hydrology. However, most crop production functions used in hydrological models do not capture the intraseasonal nature of irrigation planning, or the importance of well yield in land and water use decisions. Here we develop a method for determining stochastic intraseasonal water use that is based on observed farmer behaviour but is also theoretically consistent with dynamically optimal decision making. We use the model to (i) analyse the joint land and water use decision by farmers; (ii) to assess changes in behaviour and production risk in response to water scarcity; and (iii) to understand the limits of applicability of current methods in policy design. We develop a biophysical model of water-limited crop yield building on the AquaCrop model. The model is calibrated and applied to case studies of irrigated corn production in Nebraska and Texas. We run the model iteratively, using long-term climate records, to define two formulations of the crop-water production function: (i) the aggregate relationship between total seasonal irrigation and yield (typical of current approaches); and (ii) the stochastic response of yield and total seasonal irrigation to the choice of an intraseasonal soil moisture target and irrigated area. Irrigated area (the extensive margin decision) and per-area irrigation intensity (the intensive margin decision) are then calculated for different seasonal water restrictions (corresponding to regulatory policies) and well yield constraints on intraseasonal abstraction rates (corresponding to aquifer system limits). Profit- and utility-maximising decisions are determined assuming risk neutrality and varying degrees of risk aversion, respectively. Our results demonstrate that the formulation of the production function has a significant impact on the response to water scarcity. For low well yields, which are the major concern

  4. Ground-water resources of Riverton irrigation project area, Wyoming

    USGS Publications Warehouse

    Morris, Donald Arthur; Hackett, O.M.; Vanlier, K.E.; Moulder, E.A.; Durum, W.H.

    1959-01-01

    The Riverton irrigation project area is in the northwestern part of the Wind River basin in west-central Wyoming. Because the annual precipitation is only about 9 inches, agriculture, which is the principal occupation in the area, is dependent upon irrigation. Irrigation by surface-water diversion was begum is 1906; water is now supplied to 77,716 acres and irrigation has been proposed for an additional 31,344 acres. This study of the geology and ground-water resources of the Riverton irrigation project, of adjacent irrigated land, and of nearby land proposed for irrigation was begun during the summer of 1948 and was completed in 1951. The purpose of the investigation was to evaluate the ground-water resources of the area and to study the factors that should be considered in the solution of drainage and erosional problems within the area. The Riverton irrigation project area is characterized by flat to gently sloping stream terraces, which are flanked by a combination of badlands, pediment slopes, and broad valleys. These features were formed by long-continued erosion in an arid climate of the essentially horizontal, poorly consolidated beds of the Wind River formation. The principal streams of the area flow south-eastward. Wind River and Fivemile Creek are perennial streams and the others are intermittent. Ground-water discharge and irrigation return flow have created a major problem in erosion control along Fivemile Creek. Similar conditions might develop along Muddy and lower Cottonwood Creeks when land in their drainage basins is irrigated. The bedrock exposed in the area ranges in age from Late Cretaceous to early Tertiary (middle Eocene). The Wind River formation of early and middle Eocene age forms the uppermost bedrock formation in the greater part of the area. Unconsolidated deposits of Quaternary age, which consist of terrace gravel, colluvium, eolian sand and silt. and alluvium, mantle the Wind River formation in much of the area. In the irrigated parts

  5. Risk assessment of vegetables irrigated with arsenic-contaminated water.

    PubMed

    Bhatti, S M; Anderson, C W N; Stewart, R B; Robinson, B H

    2013-10-01

    Arsenic (As) contaminated water is used in South Asian countries to irrigate food crops, but the subsequent uptake of As by vegetables and associated human health risk is poorly understood. We used a pot trial to determine the As uptake of four vegetable species (carrot, radish, spinach and tomato) with As irrigation levels ranging from 50 to 1000 μg L(-1) and two irrigation techniques, non-flooded (70% field capacity for all studied vegetables), and flooded (110% field capacity initially followed by aerobic till next irrigation) for carrot and spinach only. Only the 1000 μg As L(-1) treatment showed a significant increase of As concentration in the vegetables over all other treatments (P < 0.05). The distribution of As in vegetable tissues was species dependent; As was mainly found in the roots of tomato and spinach, but accumulated in the leaves and skin of root crops. There was a higher concentration of As in the vegetables grown under flood irrigation relative to non-flood irrigation. The trend of As bioaccumulation was spinach > tomato > radish > carrot. The As concentration in spinach leaves exceeded the Chinese maximum permissible concentration for inorganic As (0.05 μg g(-1) fresh weight) by a factor of 1.6 to 6.4 times. No other vegetables recorded an As concentration that exceeded this threshold. The USEPA parameters hazard quotient and cancer risk were calculated for adults and adolescents. A hazard quotient value greater than 1 and a cancer risk value above the highest target value of 10(-4) confirms potential risk to humans from ingestion of spinach leaves. In our study, spinach presents a direct risk to human health where flood irrigated with water containing an arsenic concentration greater than 50 μg As L(-1). PMID:23934025

  6. Water Management For Drip Irrigated Corn In The Arid Southeastern Anatolia Project Area In Turkey

    NASA Astrophysics Data System (ADS)

    Yazar, A.; Gencel, B.

    Microirrigation has the potential to minimize application losses to evaporation, runoff and deep percolation; improve irrigation control with smaller, frequent applications; supply nutrients to the crop as needed; and improve crop yields. The Southeastern Anatolia Project (GAP), when completed, 1.7 million ha of land will be irrigated. Wa- ter supplies are limited, and traditional irrigation practices result in high losses and low irrigation efficiences. This study was conducted to evaluate surface drip irrigation on crop performance. The effect of irrigation frequency and amount on crop yield, yield components, water use, and water use efficiency of corn (Zea mays L., PIO- 3267) were investigated in the Harran Plain in the arid Southeastern Turkey on a clay textured Harran Soil Series. Irrigation frequencies were once in three-day, and once in six-day; irrigation levels varied from full (I-100), medium (I-67; 2/3rd of full), and low (I-33; 1/3rd of full). The full irrigation treatment received 100% of the cumula- tive evaporation within the irrigation interval. Liquid nitrogen was injected into the irrigation water throughout the growing season. Treatments received the same amount of fertilizers. Highest average corn grain yield (11920 kg/ha) was obtained from the full irrigation treatment (I-100) with six-day irrigation interval. Irrigation intervals did not affect corn yields; however, deficit irrigation affected crop yields by reducing seed mass, and the seed number. Maximum water use efficiency (WUE) was found as 2.27 kg/m3 in the I-33 treatment plots with three-day irrigation interval. On the clay soil at Harran, irrigation frequencies are less critical than proper irrigation management for drip irrigation systems to avoid water deficits that have a greater effect on corn yields. The results revealed that about 40% water saving is possible with drip irrigation as compared to traditional surface irrigation methods in the region.

  7. Characterisation of areas under irrigated agriculture: mapping and water use

    NASA Astrophysics Data System (ADS)

    Peña Arancibia, Jorge; McVicar, Tim R.; Guerschman, Juan P.; Li, Lingtao T.

    2014-05-01

    The evolution of remote sensing and classification methods has enabled effective mapping, monitoring and management of irrigated agriculture. A random forest classification was implemented using learning samples inferred from Landsat TM/ETM data and monthly time-series of remotely-sensed observations from the MODerate resolution Imaging Spectroradiometer (MODIS). The covariates included in the method characterised: (i) the vegetation phenology via the recurrent and persistent fractions of photosynthetically active radiation (fPARrecandfPARper, respectively); (ii) vegetation water use via estimates of actual evapotranspiration (AET), rainfall (P) and the difference between AET and P . Maps of irrigated areas under different climates and cropping conditions were produced for the whole Murray-Darling Basin (Australia) for the years 2004 to 2010 with 0.96 observed agreement in terms of the Kappa Index (were a value of 1 indicates perfect agreement). An independent comparison of yearly irrigated area estimates and corresponding water use showed a linear relationship with good agreement (R2 >0.7) against available yearly metered water withdrawals and estimates of agricultural yields. A sequential covariate optimisation suggested that the most important predictors included the emergence-senescence period (as determined by the fPARrec and corresponding rates of change) and the AET surplus over P during this period. The latter can be important when determining more opportunistic irrigation practices due to unreliable water supply in areas with otherwise high annual rainfall. The procedure can be implemented to map irrigated areas at the global scale: the MODIS time-series used in the classification methodology are available globally since February 2000 and so are the Landsat archives which can be used to infer learning samples and irrigation practices elsewhere.

  8. Climate change and the water cycle in newly irrigated areas.

    PubMed

    Abrahão, Raphael; García-Garizábal, Iker; Merchán, Daniel; Causapé, Jesús

    2015-02-01

    Climate change is affecting agriculture doubly: evapotranspiration is increasing due to increments in temperature while the availability of water resources is decreasing. Furthermore, irrigated areas are expanding worldwide. In this study, the dynamics of climate change impacts on the water cycle of a newly irrigated watershed are studied through the calculation of soil water balances. The study area was a 752-ha watershed located on the left side of the Ebro river valley, in Northeast Spain. The soil water balance procedures were carried out throughout 1827 consecutive days (5 years) of hydrological and agronomical monitoring in the study area. Daily data from two agroclimatic stations were used as well. Evaluation of the impact of climate change on the water cycle considered the creation of two future climate scenarios for comparison: 2070 decade with climate change and 2070 decade without climate change. The main indicators studied were precipitation, irrigation, reference evapotranspiration, actual evapotranspiration, drainage from the watershed, and irrigation losses. The aridity index was also applied. The results represent a baseline scenario in which adaptation measures may be included and tested to reduce the impacts of climate change in the studied area and other similar areas. PMID:25626569

  9. Characterizing water flows in irrigated valleys of northern New Mexico

    NASA Astrophysics Data System (ADS)

    Ochoa, C. G.; Fernald, A.; Guldan, S.; Tidwell, V. C.

    2009-12-01

    Ditch seepage and deep percolation from irrigation in agricultural valleys of semi-arid regions can have multiple hydrological benefits including aquifer recharge, temporary storage, and delayed return flow. This study aims to advance scientific understanding of surface water and groundwater interactions in semi-arid region valleys of the western USA. The study is being conducted in three different irrigated valleys of the Rio Grande basin in northern New Mexico. The first site is a floodplain valley along the main stem of the Rio Grande; the second site is an upper valley along the Rio Hondo, a tributary to the Rio Grande; and the third site is a floodplain valley along the Rio Chama, which also is a tributary to the Rio Grande. Beginning in 2002, we instrumented the first study site to measure climate variables, surface water flows, and groundwater fluctuations due to deep percolation from irrigation and ditch seepage. Currently, we are installing field equipment at the second study site, and we will start instrumentation at the third study site in the spring of 2010. A multi-modeling approach is being used to extrapolate field-based results to larger spatial scales. One and two dimensional models like the Root Zone Water Quality Model and Hydrus, respectively, are being used to simulate physical processes in the vadose zone at the field scale, and the model GSFlow will be used to integrate surface water and groundwater components at the valley scale. Results from an ongoing study aimed to quantify water budget components at the first study site showed that up to 92% of the water diverted for irrigation in this floodplain valley returns back to the river, either as surface return flow (59%) or as shallow groundwater return flow that originated as canal seepage (12%) and deep percolation from irrigation (21%). Also, simulations with a System Dynamics Model showed that the coupled surface water irrigation system and shallow aquifer act together to store water

  10. Assessing the changes of groundwater recharge / irrigation water use between SRI and traditional irrigation schemes in Central Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, Shih-Kai; Jang, Cheng-Shin; Tsai, Cheng-Bin

    2015-04-01

    To respond to agricultural water shortage impacted by climate change without affecting rice yield in the future, the application of water-saving irrigation, such as SRI methodology, is considered to be adopted in rice-cultivation in Taiwan. However, the flooded paddy fields could be considered as an important source of groundwater recharge in Central Taiwan. The water-saving benefit of this new methodology and its impact on the reducing of groundwater recharge should be integrally assessed in this area. The objective of this study was to evaluate the changes of groundwater recharge/ irrigation water use between the SRI and traditional irrigation schemes (continuous irrigation, rotational irrigation). An experimental paddy field located in the proximal area of the Choushui River alluvial fan (the largest groundwater pumping region in Taiwan) was chosen as the study area. The 3-D finite element groundwater model (FEMWATER) with the variable boundary condition analog functions, was applied in simulating groundwater recharge process and amount under traditional irrigation schemes and SRI methodology. The use of effective rainfall was taken into account or not in different simulation scenarios for each irrigation scheme. The simulation results showed that there were no significant variations of infiltration rate in the use of effective rainfall or not, but the low soil moisture setting in deep soil layers resulted in higher infiltration rate. Taking the use of effective rainfall into account, the average infiltration rate for continuous irrigation, rotational irrigation, and SRI methodology in the first crop season of 2013 were 4.04 mm/day, 4.00 mm/day and 3.92 mm/day, respectively. The groundwater recharge amount of SRI methodology was slightly lower than those of traditional irrigation schemes, reducing 4% and 2% compared with continuous irrigation and rotational irrigation, respectively. The field irrigation requirement amount of SRI methodology was significantly

  11. Use of saline and recycled water as an alternative irrigation water supply: Chemical and agronomic considerations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predictions of increased occurrences of drought in the SW U.S. coupled with increasing urban demands for fresh water have resulted in projections of decreased irrigated acreage. However, agriculture can utilize saline, drainage and treated municipal and industrial waste waters for irrigation of many...

  12. Irrigation management using an expert system, soil water potentials, and vegetative indices for spatial applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Variable rate irrigation (VRI) systems are irrigation systems that are capable of applying different water depths both in the direction of travel and along the length of the irrigation system. However, when compared to traditional irrigation systems, VRI systems require a higher level of management...

  13. Impact of reclaimed water irrigation on soil health in urban green areas.

    PubMed

    Chen, Weiping; Lu, Sidan; Pan, Neng; Wang, Yanchun; Wu, Laosheng

    2015-01-01

    Rapid increase of reclaimed water irrigation in urban green areas requires investigating its impact on soil health conditions. In this research, field study was conducted in 7 parks in Beijing with different histories of reclaimed water irrigation. Twenty soil attributes were analyzed to evaluate the effects of reclaimed water irrigation on the soil health conditions. Results showed that soil nutrient conditions were ameliorated by reclaimed water irrigation, as indicated by the increase of soil organic matter content (SOM), total nitrogen (TN), and available phosphorus (AP). No soil salinization but a slight soil alkalization was observed under reclaimed water irrigation. Accumulation of heavy metals in soil was insignificant. It was also observed that reclaimed water irrigation could significantly improve the soil microorganism activities. Overall, the soil health conditions were improved with reclaimed water irrigation, and the improvement increased when the reclaimed water irrigation period became longer. PMID:25150469

  14. Interpretation of Thermal Infrared Imagery for Irrigation Water Resource Management.

    ERIC Educational Resources Information Center

    Nellis, M. Duane

    1985-01-01

    Water resources play a major role in the character of agricultural development in the arid western United States. This case study shows how thermal infrared imagery, which is sensitive to radiant or heat energy, can be used to interpret crop moisture content and associated stress in irrigated areas. (RM)

  15. PATHOGENIC PHYTOPHTHORA SPECIES IN SAN JOAQUIN VALLEY IRRIGATION WATER SOURCES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface sources of irrigation water including the Kings River and three canals were assayed for Phytophthora spp. at six locations in the San Joaquin Valley within 30 km of Hanford, CA. Four nylon-mesh bags, each containing three firm, green pear fruits (separated by Styrofoam blocks) as bait for Ph...

  16. Stewardship of water and fertilizer in irrigated cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agriculture is a vital part of the southeast Missouri economy and it is essential that we maintain our precious soil and water resources. While we have shallow, high quality groundwater for irrigation, it is important to realize that our aquifer, the Mississippi River Valley Alluvial Aquifer, also p...

  17. Global net irrigation water requirements from various water supply sources during past and future periods

    NASA Astrophysics Data System (ADS)

    Yoshikawa, S.; Cho, J.; Hanasaki, N.; Kanae, S.

    2014-12-01

    Water supply sources for irrigation (e.g. rivers and reservoirs) are critically important for agricultural productivity. The current rapid increase in irrigation water use is considered unsustainable and threatens food production. In this study, we estimated the time-varying dependence of irrigation water requirements from water supply sources, with a particular focus on variations in irrigation area during past (1960-2001) and future (2002-2050) periods using the global water resources model, H08. The H08 model can simulate water requirements on a daily basis at a resolution of 1.0° × 1.0° latitude and longitude. The sources of irrigation water requirements in the past simulations were specified using four categories: rivers (RIV), large reservoirs (LR), medium-size reservoirs (MSR), and non-local non-renewable blue water (NNBW). The simulated results from 1960 to 2001 showed that RIV, MSR and NNBW increased significantly from the 1960s to the early 1990s globally, but LR increased at a relatively low rate. After the early 1990s, the increase in RIV declined as it approached a critical limit, due to the continued expansion of irrigation area. MSR and NNBW increased significantly, during the same time period, following the expansion of the irrigation area and the increased storage capacity of the medium-size reservoirs. We also estimated future irrigation water requirements from the above four water supply sources and an additional water supply source (ADD) in three future simulation designs; irrigation area change, climate change, and changes in both irrigation area and climate. ADD was defined as a future increase in NNBW. After the 2020s, MSR was predicted to approach the critical limit, and ADD would account for 11-23% of the total requirements in the 2040s.

  18. Comparison of Irrigation Water Use Estimates Calculated from Remotely Sensed Irrigated Acres and State Reported Irrigated Acres in the Lake Altus Drainage Basin, Oklahoma and Texas, 2000 Growing Season

    USGS Publications Warehouse

    Masoner, J.R.; Mladinich, C.S.; Konduris, A.M.; Smith, S. Jerrod

    2003-01-01

    Increased demand for water in the Lake Altus drainage basin requires more accurate estimates of water use for irrigation. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Reclamation, is investigating new techniques to improve water-use estimates for irrigation purposes in the Lake Altus drainage basin. Empirical estimates of reference evapotranspiration, crop evapotranspiration, and crop irrigation water requirements for nine major crops were calculated from September 1999 to October 2000 using a solar radiation-based evapotranspiration model. Estimates of irrigation water use were calculated using remotely sensed irrigated crop acres derived from Landsat 7 Enhanced Thematic Mapper Plus imagery and were compared with irrigation water-use estimates calculated from irrigated crop acres reported by the Oklahoma Water Resources Board and the Texas Water Development Board for the 2000 growing season. The techniques presented will help manage water resources in the Lake Altus drainage basin and may be transferable to other areas with similar water management needs. Irrigation water use calculated from the remotely sensed irrigated acres was estimated at 154,920 acre-feet; whereas, irrigation water use calculated from state reported irrigated crop acres was 196,026 acre-feet, a 23 percent difference. The greatest difference in irrigation water use was in Carson County, Texas. Irrigation water use for Carson County, Texas, calculated from the remotely sensed irrigated acres was 58,555 acrefeet; whereas, irrigation water use calculated from state reported irrigated acres was 138,180 acre-feet, an 81 percent difference. The second greatest difference in irrigation water use occurred in Beckham County, Oklahoma. Differences between the two irrigation water use estimates are due to the differences of irrigated crop acres derived from the mapping process and those reported by the Oklahoma Water Resources Board and Texas Water Development Board.

  19. Analytical steady-state solutions for water-limited cropping systems using saline irrigation water

    NASA Astrophysics Data System (ADS)

    Skaggs, T. H.; Anderson, R. G.; Corwin, D. L.; Suarez, D. L.

    2014-12-01

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems modeling framework that accounts for reduced plant water uptake due to root zone salinity. Two explicit, closed-form analytical solutions for the root zone solute concentration profile are obtained, corresponding to two alternative functional forms of the uptake reduction function. The solutions express a general relationship between irrigation water salinity, irrigation rate, crop salt tolerance, crop transpiration, and (using standard approximations) crop yield. Example applications are illustrated, including the calculation of irrigation requirements for obtaining targeted submaximal yields, and the generation of crop-water production functions for varying irrigation waters, irrigation rates, and crops. Model predictions are shown to be mostly consistent with existing models and available experimental data. Yet the new solutions possess advantages over available alternatives, including: (i) the solutions were derived from a complete physical-mathematical description of the system, rather than based on an ad hoc formulation; (ii) the analytical solutions are explicit and can be evaluated without iterative techniques; (iii) the solutions permit consideration of two common functional forms of salinity induced reductions in crop water uptake, rather than being tied to one particular representation; and (iv) the utilized modeling framework is compatible with leading transient-state numerical models.

  20. [Theme: Horticulture Programs.

    ERIC Educational Resources Information Center

    Henderson, Jan; And Others

    1982-01-01

    A series of articles discusses requirements for optimum growth of horticulture education programs. Includes beginning a program, simulating working conditions, the need for mechanical skills, starting a business, and other areas to be considered for a successful horticultural program. (JOW)

  1. Horticulture and the FFA

    ERIC Educational Resources Information Center

    Nelson, Clifford L.

    1975-01-01

    The article offers teachers of vocational horticulture a number of specific suggestions for organizing FFA horticulture chapters that will appeal to urban and suburban students and that will improve the quality of their learning. (AJ)

  2. Where Does the Irrigation Water Go? An Estimate of the Contribution of Irrigation to Precipitation Using MERRA

    NASA Technical Reports Server (NTRS)

    Wei, Jiangfeng; Dirmeyer, Paul A.; Wisser, Dominik; Bosilovich, Michael G.; Mocko, David M.

    2013-01-01

    Irrigation is an important human activity that may impact local and regional climate, but current climate model simulations and data assimilation systems generally do not explicitly include it. The European Centre for Medium-Range Weather Forecasts (ECMWF) Interim Re-Analysis (ERA-Interim) shows more irrigation signal in surface evapotranspiration (ET) than the Modern-Era Retrospective Analysis for Research and Applications (MERRA) because ERA-Interim adjusts soil moisture according to the observed surface temperature and humidity while MERRA has no explicit consideration of irrigation at the surface. But, when compared with the results from a hydrological model with detailed considerations of agriculture, the ET from both reanalyses show large deficiencies in capturing the impact of irrigation. Here, a back-trajectory method is used to estimate the contribution of irrigation to precipitation over local and surrounding regions, using MERRA with observation-based corrections and added irrigation-caused ET increase from the hydrological model. Results show substantial contributions of irrigation to precipitation over heavily irrigated regions in Asia, but the precipitation increase is much less than the ET increase over most areas, indicating that irrigation could lead to water deficits over these regions. For the same increase in ET, precipitation increases are larger over wetter areas where convection is more easily triggered, but the percentage increase in precipitation is similar for different areas. There are substantial regional differences in the patterns of irrigation impact, but, for all the studied regions, the highest percentage contribution to precipitation is over local land.

  3. Effects of irrigation on crops and soils with Raft River geothermal water

    SciTech Connect

    Stanley, N.E.; Schmitt, R.C.

    1980-01-01

    The Raft River Irrigation Experiment investigated the suitability of using energy-expended geothermal water for irrigation of selected field-grown crops. Crop and soil behavior on plots sprinkled or surface irrigated with geothermal water was compared to crop and soil behavior on plots receiving water from shallow irrigation wells and the Raft River. In addition, selected crops were produced, using both geothermal irrigation water and special management techniques. Crops irrigated with geothermal water exhibited growth rates, yields, and nutritional values similar to comparison crops. Cereal grains and surface-irrigated forage crops did not exhibit elevated fluoride levels or accumulations of heavy metals. However, forage crops sprinkled with geothermal water did accumulate fluorides, and leaching experiments indicate that new soils receiving geothermal water may experience increased salinity, exchangeable sodium, and decreased permeability. Soil productivity may be maintained by leaching irrigations.

  4. Estimated Domestic, Irrigation, and Industrial Water Use in Washington, 2000

    USGS Publications Warehouse

    Lane, R.C.

    2004-01-01

    Since 1950, the U.S. Geological Survey has published a series of Circulars and other reports on the estimated use of water in the United States at 5-year intervals. This report presents State, regional, and county estimates of the amount of water used for domestic, irrigation, and industrial purposes in the State of Washington during the year 2000. Domestic water use was estimated to be 674 million gallons per day and the per-capita rate, 114 gallons per day. Crop-irrigation water use was estimated to be 3,005 million gallons per day and the application rate, 2.2 acre-feet per acre per year, or feet per year. Golf-course irrigation water use was estimated to be 23.6 million gallons per day and the application rate, 1.4 feet per year. Industrial water use was estimated to be 681 million gallons per day. Historically, these core categories account for about 92 percent of the estimated offstream water used in Washington.

  5. Food security, irrigation, climate change, and water scarcity in India

    NASA Astrophysics Data System (ADS)

    Hertel, T. W.; Taheripour, F.; Gopalakrishnan, B. N.; Sahin, S.; Escurra, J.

    2015-12-01

    This paper uses an advanced CGE model (Taheripour et al., 2013) coupled with hydrological projections of future water scarcity and biophysical data on likely crop yields under climate change to examine how water scarcity, climate change, and trade jointly alter land use changes across the Indian subcontinent. Climate shocks to rainfed and irrigated yields in 2030 are based on the p-DSSAT crop model, RCP 2.6, as reported under the AgMIP project (Rosenzweig et al., 2013), accessed through GEOSHARE (Villoria et al, 2014). Results show that, when water scarcity is ignored, irrigated areas grow in the wake of climate change as the returns to irrigation rise faster than for rainfed uses of land within a given agro-ecological zone. When non-agricultural competition for future water use, as well as anticipated supply side limitations are brought into play (Rosegrant et al., 2013), the opportunity cost of water rises across all river basins, with the increase ranging from 12% (Luni) to 44% (Brahmaputra). As a consequence, irrigated crop production is curtailed in most regions (Figure 1), with the largest reductions coming in the most water intensive crops, namely rice and wheat. By reducing irrigated area, which tends to have much higher yields, the combined effects of water scarcity and climate impacts require an increase in total cropped area, which rises by about 240,000 ha. The majority of this area expansion occurs in the Ganges, Indus, and Brahmari river basins. Overall crop output falls by about 2 billion, relative to the 2030 baseline, with imports rising by about 570 million. The combined effects of climate change and water scarcity for irrigation also have macro-economic consequences, resulting in a 0.28% reduction in GDP and an increase in the consumer price index by about 0.4% in 2030, compared the baseline. The national welfare impact on India amounts to roughly 3 billion (at 2007 prices) in 2030. Assuming a 3% social discount rate, the net present value of the

  6. Assessment of reclaimed water irrigation on growth, yield, and water-use efficiency of forage crops

    NASA Astrophysics Data System (ADS)

    Alkhamisi, S. A.; Abdelrahman, H. A.; Ahmed, M.; Goosen, M. F. A.

    2011-09-01

    Field experiments were conducted to determine the effect of water quality (reclaimed and fresh water), water quantity, and their interactions on the growth, yield, and water use efficiency of forage maize during two winter seasons in the Arabian Gulf. The plants irrigated with the reclaimed water had higher plant height than those irrigated with the fresh water. The leaf length and leaf area (cm2) did not show any significant differences among the interaction. Reclaimed water had shorter time for 50% male and female flowering of forage maize plants, indicating earlier maturity. Plants irrigated with reclaimed water had higher chlorophyll content for all levels of water applications. A significant difference in green forage yield was found among the interactions. Reclaimed water gave the highest green forage yield of 72.12 and 59.40 t/ha at 1.4ETo and 1.0ETo, respectively. Plants irrigated with the reclaimed water used water more efficiently [3.65 kg/m3 of DM (dry matter)] than those irrigated with the fresh water [2.91 kg/m3 of DM (dry matter)] for all water quantities. The enhanced growth in wastewater-irrigated crops, compared with fresh water-irrigated crops, was attributed primarily to higher nutrient content (e.g., nitrogen) and lower salinity of the reclaimed water. The study concluded that treated wastewater irrigation increased yields of forage crops and their water use efficiency. Cost-benefit analysis, studies on the use these forage crops as animal feed, and more in depth evaluation of possible crop and soil contamination were recommended.

  7. PERCHLORATE CROP INTERACTIONS VIA CONTAMINATED IRRIGATION WATER

    EPA Science Inventory

    Perchlorate has contaminated water and sods at several locations in the United States. Perchlorate is water soluble, exceedingly mobile in aqueous systems, and can persist for many decades under typical ground- and surface water conditions. Perchlorate is of concern because of un...

  8. Integrated water resource management under water supply and irrigation development uncertainty

    NASA Astrophysics Data System (ADS)

    Hassanzadeh, E.; Elshorbagy, A. A.; Nazemi, A.; Wheater, H. S.; Gober, P.

    2014-12-01

    The Saskatchewan River Basin (SaskRB) in Saskatchewan, Canada, supports various water demands including municipal, industrial, irrigated agriculture, hydropower and environmental sectors. Proposals for future development include significantly increased irrigation. However, proposing an appropriate level of irrigation development requires incorporation of water supply uncertainties in the water resources management analysis, including effects of climate variability and change. To evaluate potential climate change effects, a feasible range of shifts in annual volume and peak timing of headwater flows are considered to stochastically generate flows at the Alberta/Saskatchewan border. This envelope of flows, 30,800 realizations, is further combined with various irrigation expansion areas to form various future scenarios. Using an integrated water resources model developed for Saskatchewan, the impact of irrigation development on the system is assessed under the changing water supply conditions. The results of this study show that level of irrigation development as well as variation in volume and peak timing of flows can all contribute to change the water availability, vulnerability and economic productivity of the water resources system in Saskatchewan. In particular, the combined effect of large irrigation expansion, reduction in the volume of flows and earlier timing of the annual peak can exacerbate water resources system vulnerability, produce unstable net revenues, and decrease flood frequency in the Saskatchewan River Delta.

  9. Incentives and technologies for improving irrigation water use efficiency

    NASA Astrophysics Data System (ADS)

    Bruggeman, Adriana; Djuma, Hakan; Giannakis, Elias; Eliades, Marinos

    2014-05-01

    The European Water Framework Directive requires Member States to set water prices that provide adequate incentives for users to use water resources efficiently. These new water pricing policies need to consider cost recovery of water services, including financial, environmental and resource cost. Prices were supposed to have been set by 2010. So far the record has been mixed. The European Commission has sent reasoned opinions to a number of countries (Austria, Belgium, Denmark, Estonia, Finland, Germany, Hungary, Netherlands, Sweden) requesting them to adjust their national legislation to include all water services. Unbalanced water pricing may negatively affect the agricultural sector, especially in the southern EU countries, which are more dependent on irrigation water for production. The European Commission is funding several projects that aim to reduce the burden of increasing water prices on farmers by developing innovative technologies and decision support systems that will save water and increase productivity. The FP7 ENORASIS project (grant 282949) has developed a new integrated irrigation management decision support platform, which include high-resolution, ensemble weather forecasting, a GIS widget for the location of fields and sensors and a comprehensive decision support and database management software package to optimize irrigation water management. The field component includes wireless, solar-powered soil moisture sensors, small weather stations, and remotely controlled irrigation valves. A mobile App and a web-package are providing user-friendly interfaces for farmers, water companies and environmental consultants. In Cyprus, agricultural water prices have been set to achieve a cost recovery rate of 54% (2010). The pricing policy takes in consideration the social importance and financial viability of the agricultural sector, an important flexibility provided by the Water Framework Directive. The new price was set at 0.24 euro per m3 for water supply

  10. Yield and Irrigation Water Use Efficiency Response of Chufa (Cyperus esculentus L. var. sativus Boeck.) to Drip Irrigation Management

    NASA Astrophysics Data System (ADS)

    Pascual-Seva, Nuria; San Bautista, Alberto; López-Galarza, Salvador; Maroto, José Vicente; Pascual, Bernardo

    2016-04-01

    Chufa, also known as tigernut, is a typical crop in Valencia, Spain, where it is cultivated in ridges with furrow irrigation. Its cultivation uses large amounts of water, in the order of 10,000 m3 ha‑1 year‑1, so different studies have been undertaken in order to maximize the irrigation water use efficiency (IWUE). One of these studies faced the application of drip irrigation in the chufa cultivation, comparing three different irrigation strategies. These strategies differed on the volumetric soil water content (VSWC) when each irrigation event started. Starting each irrigation when the VSWC dropped to 90% of field capacity (FC) leaded to the highest yield, while the highest IWUE was obtained when irrigation started at 80% FC. It can be stated that starting each irrigation event when the VSWC is between 80 and 90% FC leads to the best results in terms of yield and IWUE. However, these results may still be improved by defining the best strategy in the irrigation stop, which is the aim of the herein presented research. This investigation comprises the productive response of the chufa crop with drip irrigation, determining yield and IWUE. The VSWC was monitored using multi-depth capacitance probes, with sensors at 0.10, 0.20 and 0.30 m below the top of the ridge. Each irrigation event started when the volumetric soil water content at 0.10 m dropped to 85% FC. Three irrigation strategies were considered, T1: each event being stopped when the average of the VSWC values at 0.10, 0.20 and 0.30 m depth reached the corresponding FC value; T2: each event being stopped when the VSWC values at 0.20 m reached the corresponding FC value; T3 each irrigation event lasted 30 min (corresponding to 7.33 mm). The largest yield (P ≤0.05) was obtained in T2 (2.31 kg m‑2), with no statistical differences (P ≤0.05) between T1 (1.94 kg m‑2) and T3 (1.92 kg m‑2). The highest yield in T2 was obtained with the largest volume of irrigation water applied (722 mm), resulting in the

  11. Subsurface drip irrigation emitter spacing effects on soil water redistribution, corn yield, and water productivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emitter spacings of 0.3 to 0.6 m are commonly used for subsurface drip irrigation (SDI) of corn on the deep, silt loam soils of the United States Great Plains. Subsurface drip irrigation emitter spacings of 0.3, 0.6, 0.9 and 1.2 m were examined for the resulting differences in soil water redistribut...

  12. Balancing water scarcity and quality for sustainable irrigated agriculture

    NASA Astrophysics Data System (ADS)

    Assouline, Shmuel; Russo, David; Silber, Avner; Or, Dani

    2015-05-01

    The challenge of meeting the projected doubling of global demand for food by 2050 is monumental. It is further exacerbated by the limited prospects for land expansion and rapidly dwindling water resources. A promising strategy for increasing crop yields per unit land requires the expansion of irrigated agriculture and the harnessing of water sources previously considered "marginal" (saline, treated effluent, and desalinated water). Such an expansion, however, must carefully consider potential long-term risks on soil hydroecological functioning. The study provides critical analyses of use of marginal water and management approaches to map out potential risks. Long-term application of treated effluent (TE) for irrigation has shown adverse impacts on soil transport properties, and introduces certain health risks due to the persistent exposure of soil biota to anthropogenic compounds (e.g., promoting antibiotic resistance). The availability of desalinated water (DS) for irrigation expands management options and improves yields while reducing irrigation amounts and salt loading into the soil. Quantitative models are used to delineate trends associated with long-term use of TE and DS considering agricultural, hydrological, and environmental aspects. The primary challenges to the sustainability of agroecosystems lies with the hazards of saline and sodic conditions, and the unintended consequences on soil hydroecological functioning. Multidisciplinary approaches that combine new scientific knowhow with legislative, economic, and societal tools are required to ensure safe and sustainable use of water resources of different qualities. The new scientific knowhow should provide quantitative models for integrating key biophysical processes with ecological interactions at appropriate spatial and temporal scales.

  13. Rational use of water in trickle irrigation design.

    NASA Astrophysics Data System (ADS)

    Saad, J. C. C.; da Silva Junior, H. M.

    2012-04-01

    In trickle irrigation systems, the design is based on the pre-established emission uniformity (EU) which is the combined result of the equipment characteristics and its hydraulic configuration. However, this desired value of the EU may not be confirmed by the final project (in field conditions) and neither by the yield uniformity. However, the most important is to assure yield uniformity with rational use of water. The hypotheses of this research were: a) the EU of a trickle irrigation system at field conditions is equal to the emission uniformity pre-established in the design; b) EU has always the lowest value when compared with other indicators of uniformity; c) the discharge variation coefficient is not equal to production variation coefficient in the operational unit; d) the productivity variation coefficient is more dependent on water depth applied than the EU. This study aimed to evaluate the relationships among EU used in the irrigation system design, water depth applied and the final yield uniformity. The uniformity indicators evaluated were: EU, distribution uniformity (UD) and the index proposed by Barragan & Wu (2005). They were compared estimating the performance of a trickle irrigation system applied in a citrus orchard with dimensions of 400m x 600m. The design of the irrigation system was optimized by a Linear Programming model. The tree rows were leveled in the larger direction and the spacing adopted in the orchard was 7m x 4m. The manifold line was always operating on a slope condition. The sensitivity analysis involved different slopes, 0, 3, 6, 9 and 12%, and different values of emission uniformity, 60, 70, 75, 80, 85, 90 and 94%. The citrus yield uniformity was evaluated by the variation coefficient. The emission uniformity (EU) after design differed from the EU pre-established, more sharply in the initial values lower than 90%. Comparing the uniformity indexes, the EU always generated lower values when compared with the UD and with the index

  14. Soil quality assessment of urban green space under long-term reclaimed water irrigation.

    PubMed

    Lyu, Sidan; Chen, Weiping

    2016-03-01

    Reclaimed water is widely used for landscape irrigation with the benefits of saving fresh water and ameliorating soil quality. Field samples were collected from seven parks in Beijing irrigated reclaimed water with different irrigation history in 2011 and 2014 to evaluate the long-term impacts of reclaimed water irrigation on soil quality. Soil quality index method was used to assess the comprehensive effects of reclaimed water irrigation on soil. Results showed that the effects of reclaimed water irrigation on the soil nutrient conditions were limited. Compared with tap water irrigation, soil salinity was significantly higher in 2011, while the difference was insignificant in 2014; soil heavy metals were slightly higher by 0.5-10.6 % in 2011 and 2014, while the differences were insignificant. Under reclaimed water irrigation, soil biological activities were significantly improved in both years. Total nitrogen in reclaimed water had a largest effect on soil quality irrigated reclaimed water. Soil quality irrigated with reclaimed water increased by 2.6 and 6.8 % respectively in 2011 and 2014, while the increases were insignificant. Soil quality of almost half samples was more than or closed to soil quality of natural forest in Beijing. Soil quality was ameliorated at some extent with long-term reclaimed water irrigation. PMID:26527339

  15. Infiltration into cropped soils: Effect of rain and sodium adsorption ration - impacted irrigation water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The SAR salinity criteria for irrigation have been developed for conditions where the irrigation water is the only source of water supply. It is not clear that these criteria are applicable to conditions where there are rain and irrigation events during the growing season. The low electrical conduct...

  16. Water distribution in traditionally irrigated valleys under different scenarios of water availability in Northern New Mexico

    NASA Astrophysics Data System (ADS)

    Cruz, J. J.; Fernald, A.; Gutierrez, K. Y.; Ochoa, C. G.; Guldan, S. J.

    2014-12-01

    Population growth and water scarcity are factors that increase pressures on water resources of the semiarid southwestern United States. In these areas, groundwater recharge and delayed return flow to rivers are hydrological benefits of traditional irrigation systems. A broad spatial-temporal analysis of the dynamics of surface water and groundwater interactions is necessary to improve water planning and management. Our study at three northern New Mexico agricultural valleys with low to high water availability was carried out to characterize surface water and groundwater interactions and to quantify different water budget components. The study sites were instrumented to collect weather data, water flows from rivers and acequias, shallow groundwater level fluctuations, soil physical properties and irrigation and crop management on irrigated lands. From one crop field of our study sites, results showed up to 38 cm of water level response after the beginning of an irrigation event. Other results in our study sites, showed water level response up to 80 cm after canal flow started and ditch seepage of 12% of the total valley surface water flow. Preliminary field scale results from our three study sites showed that deep percolation from irrigation is the major component of the total water budget with 43, 46 and 52% from low, medium and high water availability sites respectively. This farm scale study revealed that, water availability drives the amount of applied water and the irrigation schedule on the farms that in turn drive deep percolation and shallow aquifer recharge. It appears that traditional irrigation is an important source of groundwater recharge in our study valleys. From the ongoing study, we expect to get detailed information about the water distribution over larger spatial scales using field measurements and geographic information systems-based land use classification.

  17. Unexpected Increases in Fecundity of Ceriodaphnia dubia Exposed to Reused Rice Irrigation Water.

    PubMed

    Grippo, Richard S; McNeely, Van M; Farris, Jerry L

    2016-06-01

    Steady increases in agricultural irrigation raise concerns about environmental impacts. Rice producing regions face declining irrigation groundwater and have started reusing irrigation water as a substitute. The goal of this project was to determine if reused irrigation water is potentially toxic compared to conventional well irrigation water. Reused and well water samples, collected from three Arkansas rice farms at field inlets and outlets on three dates corresponding to fertilizer/chemical applications or crop management, were used in acute 48-h (Pimephales promelas) and chronic (Ceriodaphnia dubia) toxicity evaluations. Acute toxicity tests indicated no effects on P. promelas. Fecundity of C. dubia was significantly increased in the reused water inlet and in both the reused and well water rice field outlets compared to well water inlets and laboratory reference water. This study suggests that, compared to well water, reused rice irrigation water has reduced potential for significant negative environmental impact on biota in receiving waters. PMID:27189359

  18. Overview of advances in water management in agricultural production:Sensor based irrigation management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technological advances in irrigated agriculture are crucial to meeting the challenge of increasing demand for agricultural products given limited quality and quantity of water resources for irrigation, impacts of climate variability, and the need to reduce environmental impacts. Multidisciplinary ap...

  19. Surface Water and Ground Water Interactions in an Irrigated Valley in Northern New Mexico

    NASA Astrophysics Data System (ADS)

    Ochoa, C.; Fernald, A.; Guldan, S.; Tidwell, V.; King, P.; Cevik, Y.; Cusack, C.

    2008-12-01

    Interactions between surface water and ground water can provide many benefits like terrestrial and aquatic species habitat, aquifer recharge, and shallow ground water return flow. In northern New Mexico, the use of traditional irrigation systems has effectively expanded riparian functions to encompass full irrigated valley width. The objective of this study was to characterize the surface water and ground water interactions occurring in an irrigated valley along the Rio Grande in northern New Mexico. We used a combination of field measurements and modeling for determining different components of the water budget. Our results show that on average ditch flow is 0.9 cms, ditch seepage is 10%, irrigated field deep percolation is 30%, and ground water level rise is 0.4 m over the entire valley after the irrigation season started. We calculated that on average, 50% of the water diverted into the main irrigation ditch returns back to the river as surface return flow and about 10% of the total ditch inflow returns as groundwater flow. Results from this study show that a significant amount of water being diverted into the valley returns back to the river after completing its task of supporting important production and ecological functions in this expanded riverine valley.

  20. Microbiological irrigation water quality of the Marchfeld canal system.

    PubMed

    Stauffer, F; Makristathis, A; Hassl, A; Nowotny, S; Neudorfer, W

    2001-07-01

    The Marchfeld basin with a size of approximately 1000 km2 represents the Austrian "granary". To prevent shortage of water as a result of increased ground water removal for irrigation, industrial purposes and drinking water supply, a canal being 18 km in length was constructed from the Danube to the center of the Marchfeld. From there, water is further distributed via two creeks (Russbach and Stempfelbach). This study was intended to evaluate whether the surface water of the Marchfeld canal system can be classified into hygienic-microbiological categories as proposed by DIN (Deutsche Industrienorm) standards for irrigation water. For this purpose, water sampled monthly from three different sampling sites from 1996 to 1999 was examined for E. coli and enterococci. In addition, water samples were examined for salmonella twice a year from 1996 to 1998 and for cryptosporidia six times during the year 1999. Though the water showed varying degrees of fecal load, the results of the examinations revealed that only one of the three sampling sites showed constant quality levels according to the DIN classification system over prolonged periods of time. However, exceeding of the limit values was occasionally observed indicating the need for regular bacteriological examinations. The high variation of the results from the other sampling sites hardly permits a definite classification in one of the quality classes. PMID:11556148

  1. Irrigation water demand: A meta-analysis of price elasticities

    NASA Astrophysics Data System (ADS)

    Scheierling, Susanne M.; Loomis, John B.; Young, Robert A.

    2006-01-01

    Metaregression models are estimated to investigate sources of variation in empirical estimates of the price elasticity of irrigation water demand. Elasticity estimates are drawn from 24 studies reported in the United States since 1963, including mathematical programming, field experiments, and econometric studies. The mean price elasticity is 0.48. Long-run elasticities, those that are most useful for policy purposes, are likely larger than the mean estimate. Empirical results suggest that estimates may be more elastic if they are derived from mathematical programming or econometric studies and calculated at a higher irrigation water price. Less elastic estimates are found to be derived from models based on field experiments and in the presence of high-valued crops.

  2. Irrigation in water restricted regions: Managing water use efficiency with limited available water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Political and social pressures to increase water-use efficiency in agriculture from plant to regional scales are reaching critical levels. A region where these pressures have been extremely acute is most semi-arid parts of Texas where reliable crop production is possible only through irrigation. Re...

  3. Quantifying crop water stress factors from soil water measurements in a limited irrigation experiment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantifying crop water stress factors from soil water measurements in a limited irrigation experiment. A correct simulation of crop responses to water stress is essential for a system model. In this study, we investigated three methods of quantifying water deficit stresses based on soil water meas...

  4. Field kites: Crop-water production functions and the timing of water application for supplementary irrigation

    NASA Astrophysics Data System (ADS)

    Smilovic, M.; Gleeson, T.; Adamowski, J. F.

    2015-12-01

    Agricultural production is directly related to water management and water supply. The temporal distribution of water use throughout the growing season can significantly influence crop yield, and the facility to manage both the timing and amount of irrigation water may result in higher yields. The crop-water production function quantitatively evaluates the relationship between seasonal water use and crop yield. Previous efforts have attempted to describe and formalize the crop-water production function as a single-variable function of seasonal water use. However, these representations do not account for the effects of temporal distribution of water use and trivialize the associated variability in yields by assuming an optimized or arbitrary temporal distribution of soil moisture. This over-simplification renders the function inappropriate for recommendations related to irrigation scheduling, water management, economically optimal irrigation, water and agricultural productivity, and assessing the role of full and supplementary irrigation. We propose field kites, a novel representation of the crop-water production function that explicitly acknowledges crop yield variability as a function of both seasonal water use and associated temporal distributions of water use. Field kites are a tool that explicitly considers the farmers' capacity to manage their water resources, to more appropriately evaluate the optimal depth of irrigation water under water-limiting conditions. The field kite for winter wheat is presented both generally and cultivar- and climate-specific for Western Canada. The field kites are constructed using AquaCrop and previously validated cultivar-specific variables. Field kites provide the tools for water authorities and policy makers to evaluate agricultural production as it relates to farm water management, and to determine appropriate policies related to developing and supporting the necessary irrigation infrastructure to increase water productivity.

  5. New steady-state models for water-limited cropping systems using saline irrigation waters: Analytical solutions and applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems mode...

  6. New steady-state models for water-limited cropping systems using saline irrigation waters: Analytical solutions and applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems mod...

  7. Water-saving techniques in Chinese agriculture: water-saving irrigation and straw mulching for winter wheat

    NASA Astrophysics Data System (ADS)

    Zhao, Guoqiang; Zhu, Zixi; Zheng, Youfei; Fang, Wensong

    2004-01-01

    Based on the relationship between water balance and crop-water, water-saving irrigation model was integrated with monitoring and prediction of soil moisture, forming a system of decision-making of irrigation. It is demonstrated that straw mulching for winter wheat is an effective way to reduce soil evaporation at early stages and increase yield and improve water utilization efficiency. Combination of water-saving irrigation and straw mulching plays an important role in China water-saving agriculture.

  8. Water balance and irrigation water pumping of Lake Merdada for potato farming in Dieng Highland, Indonesia.

    PubMed

    Fadlillah, Lintang N; Widyastuti, M

    2016-08-01

    Lakes provide water resources for domestic use, livestock, irrigational use, etc. Water availability of lakes can be estimated using lake water balance. Lake water balance is calculated from the water input and output of a lake. Dieng Highland has several volcanic lakes in its surroundings. Lake Merdada in Dieng Highland has been experiencing extensive water pumping for several years more than other lakes in the surrounding area. It provides irrigation water for potato farming in Dieng Highland. The hydrological model of this lake has not been studied. The modeled water balance in this research uses primary data, i.e., bathymetric data, soil texture, and outflow discharge, as well as secondary data, i.e., rainfall, temperature, Landsat 7 ETM+ band 8 image, and land use. Water balance input components consist of precipitation on the surface area, surface (direct) runoff from the catchment area, and groundwater inflow and outflow (G net), while the output components consist of evaporation, river outflow, and irrigation. It shows that groundwater is the dominant input and output of the lake. On the other hand, the actual irrigation water pumping plays the leading role as human-induced alteration of outflow discharge. The maximum irrigation pumping modeling shows that it will decrease lake storage up to 37.14 % per month and may affect the ecosystem inside the lake. PMID:27384226

  9. SEBAL Model Using to Estimate Irrigation Water Efficiency & Water Requirement of Alfalfa Crop

    NASA Astrophysics Data System (ADS)

    Zeyliger, Anatoly; Ermolaeva, Olga

    2013-04-01

    The sustainability of irrigation is a complex and comprehensive undertaking, requiring an attention to much more than hydraulics, chemistry, and agronomy. A special combination of human, environmental, and economic factors exists in each irrigated region and must be recognized and evaluated. A way to evaluate the efficiency of irrigation water use for crop production is to consider the so-called crop-water production functions, which express the relation between the yield of a crop and the quantity of water applied to it or consumed by it. The term has been used in a somewhat ambiguous way. Some authors have defined the Crop-Water Production Functions between yield and the total amount of water applied, whereas others have defined it as a relation between yield and seasonal evapotranspiration (ET). In case of high efficiency of irrigation water use the volume of water applied is less than the potential evapotranspiration (PET), then - assuming no significant change of soil moisture storage from beginning of the growing season to its end-the volume of water may be roughly equal to ET. In other case of low efficiency of irrigation water use the volume of water applied exceeds PET, then the excess of volume of water applied over PET must go to either augmenting soil moisture storage (end-of-season moisture being greater than start-of-season soil moisture) or to runoff or/and deep percolation beyond the root zone. In presented contribution some results of a case study of estimation of biomass and leaf area index (LAI) for irrigated alfalfa by SEBAL algorithm will be discussed. The field study was conducted with aim to compare ground biomass of alfalfa at some irrigated fields (provided by agricultural farm) at Saratov and Volgograd Regions of Russia. The study was conducted during vegetation period of 2012 from April till September. All the operations from importing the data to calculation of the output data were carried by eLEAF company and uploaded in Fieldlook web

  10. Soil water measurement and thermal indices for center pivot irrigation scheduling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this two-year study, the relationship between irrigation scheduling using soil water measurements, and two thermal indices was investigated. One-half of a three-span center pivot irrigated field was planted to cotton in circular rows and irrigated with LEPA (low energy, precision application) dra...

  11. Sprinkler and surface irrigation effects on return flow water quality and quantity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major conservation practice in the Upper Snake-Rock (USR) watershed is the conversion from furrow irrigation to sprinkler irrigation. We compared the effect of irrigation system type on water quality and quantity at the watershed scale. Six small watersheds (150-700 ha) were identified with 5 to 7...

  12. Using Computer Models to Explore Alternative Scenarios for Managing Limited Irrigation Water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop water stress due to low precipitation and high temperatures are the main limiting factors for agricultural production in the Great Plains. Corn is grown under either rainfed or irrigated regimes. Irrigation can improve corn profitability in this region, but over-irrigation accelerates depletio...

  13. Remote sensing based water-use efficiency evaluation in sub-surface irrigated wine grape vines

    NASA Astrophysics Data System (ADS)

    Zúñiga, Carlos Espinoza; Khot, Lav R.; Jacoby, Pete; Sankaran, Sindhuja

    2016-05-01

    Increased water demands have forced agriculture industry to investigate better irrigation management strategies in crop production. Efficient irrigation systems, improved irrigation scheduling, and selection of crop varieties with better water-use efficiencies can aid towards conserving water. In an ongoing experiment carried on in Red Mountain American Viticulture area near Benton City, Washington, subsurface drip irrigation treatments at 30, 60 and 90 cm depth, and 15, 30 and 60% irrigation were applied to satisfy evapotranspiration demand using pulse and continuous irrigation. These treatments were compared to continuous surface irrigation applied at 100% evapotranspiration demand. Thermal infrared and multispectral images were acquired using unmanned aerial vehicle during the growing season. Obtained results indicated no difference in yield among treatments (p<0.05), however there was statistical difference in leaf temperature comparing surface and subsurface irrigation (p<0.05). Normalized vegetation index obtained from the analysis of multispectral images showed statistical difference among treatments when surface and subsurface irrigation methods were compared. Similar differences in vegetation index values were observed, when irrigation rates were compared. Obtained results show the applicability of aerial thermal infrared and multispectral images to characterize plant responses to different irrigation treatments and use of such information in irrigation scheduling or high-throughput selection of water-use efficient crop varieties in plant breeding.

  14. Tap water nasal irrigation in adults with seasonal allergic rhinitis: a randomized double-blind study.

    PubMed

    Xiong, Min; Fu, Xiaoyan; Deng, Wenting; Lai, Huangwen; Yang, Chuanhong

    2014-06-01

    Saline nasal irrigation is effective in the treatment of seasonal allergic rhinitis, and sodium chloride itself has no antiallergic effects. The mechanism of saline nasal irrigation depends mainly on washing away allergens and inflammatory mediators induced by allergic reactions. Tap water has the same washing effects as saline. In this study, it was investigated if tap water nasal irrigation was effective in the treatment of seasonal allergic rhinitis. Sixty-four patients diagnosed with seasonal allergic rhinitis were enrolled. Patients were randomized to tap water nasal irrigation group and non-tap water nasal irrigation group for treatment. Patients of both groups were treated with desloratadine. Treatment outcomes were measured using allergic rhinitis Quality of Life (QoL) survey was completed at baseline and after 3 weeks of therapy. There were statistically significant differences in QoL scores between tap water nasal irrigation group and non-tap water nasal irrigation group. The tap water nasal irrigation group had better QoL scores than the non-tap water nasal irrigation group. Tap water nasal irrigation can be a valuable adjuvant therapy for patients with seasonal allergic rhinitis. PMID:24091560

  15. Seasonal simulation of water, salinity and nitrate dynamics under drip irrigated mandarin (Citrus reticulata) and assessing management options for drainage and nitrate leaching

    NASA Astrophysics Data System (ADS)

    Phogat, V.; Skewes, M. A.; Cox, J. W.; Sanderson, G.; Alam, J.; Šimůnek, J.

    2014-05-01

    and to reduce their leaching out of the crop root zone. Slightly higher nitrogen uptake (1.73 kg ha-1) was recorded when fertigation was applied second to last hour in an irrigation event, as compared to applying it earlier during an irrigation event. Similarly, a 20% reduction in irrigation and N application produced a pronounced reduction in drainage (28%) and N leaching (46.4%), but it also decreased plant N uptake by 15.8% and water uptake by 4.8%, and increased salinity by 25.8%, as compared to the normal practice. This management would adversely impact the sustainability of this expensive irrigation system. However, reducing only irrigation by 30% during the 2nd half of the crop season (January to August) reduced drainage and N leaching by 37.2% and 50.5%, respectively, and increased N uptake by 6.9%. Such management of irrigation would be quite promising for the sustainability of the entire system. It is concluded that judicious manipulations of irrigation and fertilizer applications can be helpful in designing drip irrigation schedules for perennial horticultural crops to achieve improved efficiency of irrigation and fertigation applications and reduced contamination of receiving water bodies.

  16. 25 CFR 171.215 - What if the elevation of my farm unit is too high to receive irrigation water?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... receive irrigation water? 171.215 Section 171.215 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Irrigation Service § 171.215 What if the elevation of my farm unit is too high to receive irrigation water? (a) We will not change our service...

  17. 25 CFR 171.215 - What if the elevation of my farm unit is too high to receive irrigation water?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... receive irrigation water? 171.215 Section 171.215 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Irrigation Service § 171.215 What if the elevation of my farm unit is too high to receive irrigation water? (a) We will not change our service...

  18. 25 CFR 171.215 - What if the elevation of my farm unit is too high to receive irrigation water?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... receive irrigation water? 171.215 Section 171.215 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Irrigation Service § 171.215 What if the elevation of my farm unit is too high to receive irrigation water? (a) We will not change our service...

  19. 25 CFR 171.215 - What if the elevation of my farm unit is too high to receive irrigation water?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... receive irrigation water? 171.215 Section 171.215 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER IRRIGATION OPERATION AND MAINTENANCE Irrigation Service § 171.215 What if the elevation of my farm unit is too high to receive irrigation water? (a) We will not change our service...

  20. Quantifying and mapping China's crop yield gains from sustainable and unsustainable irrigation water use

    NASA Astrophysics Data System (ADS)

    Grogan, D. S.; Zhang, F.; Glidden, S.; Wisser, D.; Proussevitch, A. A.; Li, C.; Lammers, R. B.; Frolking, S.

    2012-12-01

    About 40 - 50% of China's cropland is irrigated. We used the DNDC model to predict crop yield for ~17 crop types involved in ~28 cropping systems across China, under zero and full irrigation for each county for 1981-2000. We estimate that yield increases due to irrigation range from 0 - 100%, depending on water deficits arising from local climate and weather conditions and crop types. We used gridded water balance simulations with the UNH WBM driven by MERRA weather reconstructions for 1981-2000 to compute demand for irrigation water, and the capacity of various sources to supply that demand in each grid cell. We estimate that approximately 15% - 20% of the water needed to fulfill the country's irrigation water demand must come from unsustainable sources such as fossil groundwater. Yields using only the sustainable irrigation water capacity are calculated by weighing the DNDC zero and full irrigation yields based on the water availability results of WBM for each grid cell. Restricting irrigation water use to only sustainable sources results in a national crop yield decrease of ~20%. Irrigation water demand, unsustainable water use, and crop yield gains due to irrigation all have significant spatial variation across China. These spatial variations show that irrigation water use - sustainable and unsustainable - results in significant crop yield gains in some regions, and little to no crop yield gains in other regions. Unsustainable water use for irrigation is concentrated in the highly populated and agriculturally valuable North China Plain region, particularly Hebei, Shandong and Henan Provinces. While current plans for the South-North Water Transfer could mitigate some of the water deficit we do not expect the projected transfers to adequately supply this region with sufficient water resources to supply both the people and crops sustainably.

  1. [Effect of climate change on rice irrigation water requirement in Songnen Plain, Northeast China].

    PubMed

    Huang, Zhi-gang; Wang, Xiao-li; Xiao, Ye; Yang, Fei; Wang, Chen-xi

    2015-01-01

    Based on meteorological data from China national weather stations and climate scenario grid data through regional climate model provided by National Climate Center, rice water requirement was calculated by using McCloud model and Penman-Monteith model combined with crop coefficient approach. Then the rice irrigation water requirement was estimated by water balance model, and the changes of rice water requirement were analyzed. The results indicated that either in historical period or in climate scenario, rice irrigation water requirement contour lines during the whole growth period and Lmid period decreased along southwest to northeast, and the same irrigation water requirement contour line moved north with decade alternation. Rice irrigation water requirement during the whole growth period increased fluctuantly with decade alternation at 44.2 mm . 10 a-1 in historical period and 19.9 mm . 10 a-1 in climate scenario. The increase in rice irrigation water requirement during the Lmid period with decade alternation was significant in historical period, but not significant in climate scenario. Contribution rate of climate change to rice irrigation water requirement would be fluctuantly increased with decade alternation in climate scenario. Compared with 1970s, contribution rates of climate change to rice irrigation water requirement were 23.6% in 2000s and 34.4% in 2040s, which increased 14.8 x 10(8) m3 irrigation water in 2000s and would increase 21.2 x 10(8) m3 irrigation water in 2040s. PMID:25985678

  2. Alternating irrigation water quality as a method to control solute concentrations and mass fluxes below irrigated fields: A numerical study

    NASA Astrophysics Data System (ADS)

    Russo, David

    2016-05-01

    The aim of the present numerical study was to extend the data-driven protocol for the control of soil salinity, to control chloride and nitrate concentrations and mass fluxes below agricultural fields irrigated with treated waste water (TWW). The protocol is based on alternating irrigation water quality between TWW and desalinized water (DSW), guided by solute concentrations at soil depth, zs. Two different schemes, the first requires measurements of soil solution concentrations of chloride and nitrate at zs, while, the second scheme requires only measurements of soil solution EC at zs, were investigated. For this purpose, 3-D numerical simulations of flow and transport were performed for variably saturated, spatially heterogeneous, flow domains located at two different field sites. The sites differ in crop type, irrigation method, and in their lithology; these differences, in turn, considerably affect the performance of the proposed schemes, expressed in terms of their ability to reduce solute concentrations that drained below the root zone. Results of the analyses suggest that the proposed data-driven schemes allow the use of low-quality water for irrigation, while minimizing the consumption of high-quality water to a level, which, for given climate, soil, crop, irrigation method, and water quality, may be determined by the allowable nitrate and chloride concentrations in the groundwater. The results of the present study indicate that with respect to the diminution of groundwater contamination by chloride and nitrate, the more data demanding, first scheme is superior the second scheme.

  3. Optimal crop selection and water allocation under limited water supply in irrigation

    NASA Astrophysics Data System (ADS)

    Stange, Peter; Grießbach, Ulrike; Schütze, Niels

    2015-04-01

    Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with limited water resources in irrigation systems, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand at the same time. For modeling the regional water demand, local (and site-specific) water demand functions are used which are derived from optimized agronomic response on farms scale. To account for climate variability the agronomic response is represented by stochastic crop water production functions (SCWPF). These functions take into account different soil types, crops and stochastically generated climate scenarios. The SCWPF's are used to compute the water demand considering different conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed which helps to evaluate combined water supply and demand management policies.

  4. Sorghum response to foliar application of phosphorus and potassium with saline water irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing demand for fresh water resources for urban and industrial uses is leading to limited availability of better quality water for crop irrigation. Therefore, crop response to poor quality irrigation water (ex: saline water), and strategies to mitigate the negative effects of poor quality irri...

  5. Soil Water in Relation to Irrigation, Uptake, and Potato Yield in a Humid Climate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Efficiently controlling soil water content with irrigation is essential for water conservation and often improves potato yield. Volumetric soil water content ('v) in relation to irrigation, plant uptake, and yield in potato hills and replicated plots was studied to evaluate four water management opt...

  6. Daily irrigation attenuates xylem abscisic acid concentration and increases leaf water potential of Pelargonium × hortorum compared with infrequent irrigation.

    PubMed

    Boyle, Richard K A; McAinsh, Martin; Dodd, Ian C

    2016-09-01

    The physiological response of plants to different irrigation frequencies may affect plant growth and water use efficiency (WUE; defined as shoot biomass/cumulative irrigation). Glasshouse-grown, containerized Pelargonium × hortorum BullsEye plants were irrigated either daily at 100% of plant evapotranspiration (ET) (well-watered; WW), or at 50% ET applied either daily [frequent deficit irrigation (FDI)] or cumulatively every 4 days [infrequent deficit irrigation (IDI)], for 24 days. Both FDI and IDI applied the same irrigation volume. Xylem sap was collected from the leaves, and stomatal conductance (gs ) and leaf water potential (Ψleaf ) measured every 2 days. As soil moisture decreased, gs decreased similarly under both FDI and IDI throughout the experiment. Ψleaf was maintained under IDI and increased under FDI. Leaf xylem abscisic acid (ABA) concentrations ([X-ABA]leaf ) increased as soil moisture decreased under both IDI and FDI, and was strongly correlated with decreased gs , but [X-ABA]leaf was attenuated under FDI throughout the experiment (at the same level of soil moisture as IDI plants). These physiological changes corresponded with differences in plant production. Both FDI and IDI decreased growth compared with WW plants, and by the end of the experiment, FDI plants also had a greater shoot fresh weight (18%) than IDI plants. Although both IDI and FDI had higher WUE than WW plants during the first 10 days of the experiment (when biomass did not differ between treatments), the deficit irrigation treatments had lower WUE than WW plants in the latter stages when growth was limited. Thus, ABA-induced stomatal closure may not always translate to increased WUE (at the whole plant level) if vegetative growth shows a similar sensitivity to soil drying, and growers must adapt their irrigation scheduling according to crop requirements. PMID:26910008

  7. Effects of shallow water table, salinity and frequency of irrigation water on the date palm water use

    NASA Astrophysics Data System (ADS)

    Askri, Brahim; Ahmed, Abdelkader T.; Abichou, Tarek; Bouhlila, Rachida

    2014-05-01

    In southern Tunisia oases, waterlogging, salinity, and water shortage represent serious threats to the sustainability of irrigated agriculture. Understanding the interaction between these problems and their effects on root water uptake is fundamental for suggesting possible options of improving land and water productivity. In this study, HYDRUS-1D model was used in a plot of farmland located in the Fatnassa oasis to investigate the effects of waterlogging, salinity, and water shortage on the date palm water use. The model was calibrated and validated using experimental data of sap flow density of a date palm, soil hydraulic properties, water table depth, and amount of irrigation water. The comparison between predicted and observed data for date palm transpiration rates was acceptable indicating that the model could well estimate water consumption of this tree crop. Scenario simulations were performed with different water table depths, and salinities and frequencies of irrigation water. The results show that the impacts of water table depth and irrigation frequency vary according to the season. In summer, high irrigation frequency and shallow groundwater are needed to maintain high water content and low salinity of the root-zone and therefore to increase the date palm transpiration rates. However, these factors have no significant effect in winter. The results also reveal that irrigation water salinity has no significant effect under shallow saline groundwater.

  8. Modeling as a tool for management of saline soils and irrigation waters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optimal management of saline soils and irrigation waters requires consideration of many interrelated factors including, climate, water applications and timing, water flow, plant water uptake, soil chemical reactions, plant response to salinity and solution composition, soil hydraulic properties and ...

  9. Agricultural-to-hydropower water transfers: sharing water and benefits in hydropower-irrigation systems

    NASA Astrophysics Data System (ADS)

    Tilmant, A.; Goor, Q.; Pinte, D.

    2009-03-01

    This paper presents a methodology to assess agricultural-to-hydropower water transfers in water resources systems where irrigation crop production and hydropower generation are the main economic activities. In many countries, water for crop irrigation is often considered as a static asset: irrigation water is usually allocated by a system of limited annual rights to use a prescribed volume of water. The opportunity cost (forgone benefits) of this static management approach may be important in river basins where large irrigation areas are present in the upstream reaches. Temporary reallocation of some (or all) of the irrigation water downstream to consumptive and/or non-consumptive users can increase the social benefits if the sum of the downstream productivities exceeds those of the upstream farmers whose entitlements are curtailed. However, such a dynamic allocation process will be socially acceptable if upstream farmers are compensated for increasing the availability of water downstream. This paper also presents a methodology to derive the individual contribution of downstream non-consumptive users, i.e. hydropower plants, to the financial compensation of upstream farmers. This dynamic management approach is illustrated with a cascade of multipurpose reservoirs in the Euphrates river basin. The analysis of simulation results reveals that, on average, the annual benefits obtained with the dynamic allocation process are 6% higher that those derived from a static allocation.

  10. Deep subsurface drip irrigation using coal-bed sodic water: Part I. Water and solute movement

    SciTech Connect

    Bern, Carleton R; Breit, George N; Healy, Richard W; Zupancic, John W; Hammack, Richard

    2013-02-01

    Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300–480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

  11. Deep subsurface drip irrigation using coal-bed sodic water: part I. water and solute movement

    USGS Publications Warehouse

    Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.; Hammack, Richard

    2013-01-01

    Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300-480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

  12. Irrigation Management with Remote Sensing Techniques. Crop Water Requirements and Biophysical Indicators

    NASA Astrophysics Data System (ADS)

    Toureiro, Célia; Serralheiro, Ricardo

    2013-04-01

    Saving water in irrigated agriculture is increasingly relevant, as the irrigation sector is in many regions the biggest water consumer, but must be a sustainable activity. Therefore, the need urges for water use control methods and water resources planning. In irrigated agriculture, the right way for saving water is constituted by the increase of efficiency in water management. This work validates procedures and methodologies with remote sensing to determine the water availability in the soil at each moment and therefore the opportunity for the application of the water volume strictly necessary to optimize crop growth (irrigation opportunity and irrigation amount). The analysis applied to the Irrigation District of Divor, Évora, having used 7 experiment plots, which are areas watered by center-pivot systems, cultivated to corn. Data were determined from multispectral and infrared images of the cultivated surface obtained by satellite or by flying unmanned platform and integrated with parameters of the atmosphere and of the crops for calculating biophysical indicators and indices of water stress in the vegetation (NDVI, Kc, Kcb, CWSI). Therefore, evapotranspiration (ETc) was estimated, with which crop water requirement was calculated, with the opportunity and the amount of irrigation water to allocate. As this information is geographic referenced, maps can be prepared with GIS technology, describing water situation and the opportunity for watering crops. If the remote images are available with enough high spatial and temporal resolution, the frequent availability of maps can serve as a basis for a farmers irrigation advice system and for the regional irrigation authority to make decisions on the irrigation management at the regional scale. This can be a significant contribute to an efficient water management technology and a sustainable irrigated agriculture. Key-Words: Remote Sensing, Vegetation Index, Crop Coefficients, Water Balance

  13. Agriculture Education. Horticulture.

    ERIC Educational Resources Information Center

    Stuttgart Public Schools, AR.

    This curriculum guide is designed for group instruction of secondary agricultural education students enrolled in one or two semester-long courses in ornamental horticulture. The guide presents units of study in the following areas: (1) horticulture and job opportunities, (2) preparing soil mixtures, (3) control, (4) plant propagation, (5) plant…

  14. Environmental Horticulture Program Guide.

    ERIC Educational Resources Information Center

    Georgia Univ., Athens. Dept. of Vocational Education.

    This program guide contains the standard environmental horticulture curriculum for technical institutes in Georgia. The curriculum encompasses the minimum competencies required for entry-level workers in the environmental horticulture field. The general information section contains the following: purpose and objectives; program description,…

  15. Competencies in Ornamental Horticulture

    ERIC Educational Resources Information Center

    Loewen, Curtis E.

    1974-01-01

    Based on the author's dissertation, this article pertains to the identification of competencies for ornamental horticulture workers in Oregon. Findings were based on interviews with 56 ornamental horticulture business employers regarding 100 competencies. The method used can serve as a model for obtaining occupational information to develop and…

  16. Horticultural Mechanics Competencies

    ERIC Educational Resources Information Center

    Shipley, W. Edward

    1974-01-01

    Ornamental horticulture teachers and managers of ornamental horticulture businesses were surveyed to determine which agricultural mechanics knowledges and skills are needed for entry-level employment in nursery, greenhouse, turf, and landscape management, which are common to the four areas, and the appropriate grade level at which they should be…

  17. Surface and subsurface water quality appraisal for irrigation.

    PubMed

    Isaac, R K; Khura, T K; Wurmbrand, J R

    2009-12-01

    Use of irrigation water available from various sources in agriculture is justified on agronomic and economic grounds but care must be taken to minimize its adverse environmental and health impacts. During the study 44 water samples, available from the various resources viz., canal, sewage pipe line, tube wells in confined aquifers, tube wells in unconfined aquifers, and wells in the Chaka block district Allahabad, were chemically analyzed to check its suitability for irrigation and to classify it according to amount of salts present. The analysis reveals that most of the samples were within the lower alkalinity limit (pH 7.17-8.42), except sewage water (pH 7.34-9.04). The electrical conductivity of the samples ranged from 0.26 to 1.37 millimhos/cm. Potassium, sodium, calcium, and phosphorus are all found to be in permissible range except one sample in the village Kuria in which Na percentage was found in doubtful category. The other parameters like sodium adsorption ratio, SAR (1.17-2.74), residual sodium carbonate, RSC (-4.46 to -1.07), and soluble sodium percentage, SSP (63.97-28.15) were also found below the permissible limit. PMID:19101814

  18. Water losses from irrigation canals evaluation: comparison among different methodologies

    NASA Astrophysics Data System (ADS)

    Clemente, Paolo; De Luca, Domenico Antonio; Antonella Dino, Giovanna; Lasagna, Manuela

    2013-04-01

    The research investigates the field methodologies to evaluate water losses from canals, in order to find a reliable method to identify and quantify them. This study was conducted in five canal lines in Piedmont, north-western Italy, different for hydraulic, morphological, geological and hydrogeological contexts (De Luca et alii, 2012). At a regional scale, Piedmont network consists of several tens of thousands km of irrigation canals. The loss of water due to seepage from irrigation canals constitutes a substantial part of the usable water. Irrigation canals placed in natural soil or fine and coarse sediments are characterized by water losses ranging from 20 % to more than 50 %. These losses cause economic, hydrogeological and environmental consequences: water losses evaluation from irrigation canals in the basis for the sustainable water resource use and management. First, hydrogeological and hydrological characterisation of the study area and of the bottom of the irrigation canals was carried out for every investigated canal, in order to evaluate the relationships between groundwater and stream water (eg. piezometric and hydrogeochemical survey campaigns, infiltrometry tests, penetrometric tests and electrical tomographies, soil characterizations from the bottom of investigated canals). The canals seepage rates were subsequently estimated using different methodologies: empirical formulas, inflow-outflow tests and double tracer tests. The empirical formulas applied for the study underestimated the real amount of the losses probably due to the scarce number of the considered variables. Then the canals seepage rates were evaluated employing inflow-outflow tests, considered the best tool by several authors. This method allows the determination of seepage quantities measuring inflow and outflow of a canal test reach either by instruments. The canal discharge was evaluated using a current meter. This method, even if easy to apply and practical, is not efficient

  19. Quantifying the Impacts of Irrigation Technology Adoption on Water Resources in the High Plains Aquifer, USA

    NASA Astrophysics Data System (ADS)

    Kendall, Anthony; Cotterman, Kayla; Hyndman, David

    2016-04-01

    Producers in key agricultural regions worldwide are contending with increasing demand while simultaneously managing declining water resources. The High Plains Aquifer (HPA) is the largest aquifer system in the United States, and supplied most of the water to irrigate 6 million hectares in 2012. Water levels in the central and southern sections of the aquifer have steadily declined, as groundwater recharge in this semi-arid region is insufficient to meet water demands. Individual irrigators have responded to these declines by moving from less efficient irrigation technologies to those that apply water more precisely. Yet, these newer technologies have also allowed for water to be pumped from lower-yielding wells, thus extending the life of any given well and allowing drawdown to continue. Here we use a dataset of the annual irrigation technology choices from every irrigator in the state of Kansas, located in the Central High Plains. This irrigation data, along with remotely-sensed Leaf Area Index, crop choice, and irrigated area, drives a coupled surface/groundwater simulation created using the Landscape Hydrology Model (LHM) to examine the impacts of changing irrigation technology on the regional water cycle, and water levels in the HPA. The model is applied to simulate cases in which no irrigation technology change had occurred, and complete adoption of newer technologies to better understand impacts of management choices on regional water resources.

  20. Water quality, pesticide occurrence, and effects of irrigation with reclaimed water at golf courses in Florida

    USGS Publications Warehouse

    Swancar, Amy

    1996-01-01

    Reuse of treated wastewater for golf course irrigation is an increasingly popular water management option in Florida, where growth has put stress on potable water supplies. Surface water, ground water, and irrigation water were sampled at three pairs of golf courses quarterly for one year to determine if pesticides were present, and the effect of irrigation with treated effluent on ground-water quality, with an emphasis on interactions of effluent with pesticides. In addition to the six paired golf courses, which were in central Florida, ground water was sampled for pesticides and other constituents at three more golf courses in other parts of the State. This study was the first to analyze water samples from Florida golf courses for a broad range of pesticides. Statistical methods based on the percentage of data above detection limits were used to determine the effects of irrigation with reclaimed water on ground-water quality. Shallow ground water at golf courses irrigated with treated effluent has higher concentrations of chloride, lower concentrations of bicarbonate, and lower pH than ground water at golf courses irrigated with water from carbonate aquifers. There were no statistically significant differences in nutrient concentrations in ground water between paired golf courses grouped by irrigation water type at a 95 percent confidence level. The number of wells where pesticides occurred was significantly higher at the paired golf courses using ground water for irrigation than at ones using reclaimed water. However, the limited occurrences of individual pesticides in ground water make it difficult to correlate differences in irrigation- water quality with pesticide migration to the water table. At some of the golf courses, increased pesticide occurrences may be associated with higher irrigation rates, the presence of well-drained soils, and shallow depths to the surficial aquifer. Pesticides used by golf courses for turf grass maintenance were detected in

  1. Field measurements of water and nitrogen losses under irrigated maize

    NASA Astrophysics Data System (ADS)

    Kengni, L.; Vachaud, G.; Thony, J. L.; Laty, R.; Garino, B.; Casabianca, H.; Jame, P.; Viscogliosi, R.

    1994-10-01

    An intensive multidisciplinary experiment has been conducted over several years at La Côte Saint-André, near Grenoble, France. The major objective is to determine an optimal fertilizer application scheme for an irrigated agricultural system. Such a scheme would not degrade the quality of the environment, and yet would maintain a profitable level of crop production. This study is explicitly related to the cultivation of irrigated maize, a major crop in the area. The various terms of the water balance (consumption, drainage, soil storage) and of the nitrogen cycle (mineralization, plant uptake, leaching) were obtained from intensive monitoring in the upper layer of the 0.8 m of soil which corresponds to the root zone of the crop. This entailed the combined use of a neutron moisture meter, tensiometers and soil suction cups. To determine the specific effects of fertilization and crop growth, there were different treatments. These corresponded to a traditional fertilizer application of 260 kg N ha -1, no fertilization, and bare soil, carried out within an area of approximately 2 ha. Several sites were instrumented on each treatment, one of them being specifically for the application and the monitoring of 15N-tagged fertilizer. The results have shown that, in terms of the water balance, irrigation water management is extremely efficient, as drainage losses under the maize culture are negligible during the crop cycle. The situation is totally different, however, during the intercrop period (October-April), owing to rainfall. Then the soil is left bare and evaporation is very small, and now the drainage corresponds to about 90% of total inputs from precipitation. In terms of the nitrogen cycle, the results showed clearly that up to 150 kg N ha -1 was produced by mineralization in the soil. Nitrogen leaching beyond the root zone during the crop cycle is negligible, regardless of the rate of fertilizer application, as a result of the very small amount of drainage, despite

  2. Evaluating regional water scarcity: Irrigated crop water budgets for groundwater management in the Wisconsin Central Sands

    NASA Astrophysics Data System (ADS)

    Nocco, M. A.; Kucharik, C. J.; Kraft, G.

    2013-12-01

    Regional water scarcity dilemmas between agricultural and aquatic land users pervade the humid northern lake states of Wisconsin, Minnesota, and Michigan, where agricultural irrigation relies on groundwater drawn from shallow aquifers. As these aquifers have strong connectivity to surface waters, irrigation lowers water levels in lakes and wetlands and reduces stream discharges. Irrigation expansion has cultivated a 60-year water scarcity dilemma in The Wisconsin Central Sands, the largest irrigated region in the humid northern lake states, dedicated to potato, maize, and processing vegetable production. Irrigation has depleted Wisconsin Central Sands surface waters, lowering levels in some lakes by over 2 m and drying some coldwater trout streams. Aquatic ecosystems, property values, and recreational uses in some surface waters have been devastated. While the causal link between pumping and surface water stress is established, understanding crop-mediated processes, such as the timing and magnitude of groundwater consumption by evapotranspiration (ET) and groundwater recharge, will be useful in management of groundwater, irrigated cropping systems, and surface water health. Previous modeling and field efforts have compared irrigated crop water use to a natural reference condition on a net annual basis. As a result, we presently understand that for irrigated potatoes and maize, the average annual ET is greater and therefore, the average annual recharge is less than rainfed row crops, grasslands, and both coniferous and deciduous forests. However, we have a limited understanding of the magnitude and timing of ET and recharge from irrigated cropping systems on shorter time scales that proceed with the annual cropping cycle (i.e. planting, full canopy, harvest, residue cover). We seek to understand the spatiotemporal variability of crop water budgets and associated water scarcity in the Wisconsin Central Sands through detailed measurements of drainage (potential

  3. Holistic irrigation water management approach based on stochastic soil water dynamics

    NASA Astrophysics Data System (ADS)

    Alizadeh, H.; Mousavi, S. J.

    2012-04-01

    Appreciating the essential gap between fundamental unsaturated zone transport processes and soil and water management due to low effectiveness of some of monitoring and modeling approaches, this study presents a mathematical programming model for irrigation management optimization based on stochastic soil water dynamics. The model is a nonlinear non-convex program with an economic objective function to address water productivity and profitability aspects in irrigation management through optimizing irrigation policy. Utilizing an optimization-simulation method, the model includes an eco-hydrological integrated simulation model consisting of an explicit stochastic module of soil moisture dynamics in the crop-root zone with shallow water table effects, a conceptual root-zone salt balance module, and the FAO crop yield module. Interdependent hydrology of soil unsaturated and saturated zones is treated in a semi-analytical approach in two steps. At first step analytical expressions are derived for the expected values of crop yield, total water requirement and soil water balance components assuming fixed level for shallow water table, while numerical Newton-Raphson procedure is employed at the second step to modify value of shallow water table level. Particle Swarm Optimization (PSO) algorithm, combined with the eco-hydrological simulation model, has been used to solve the non-convex program. Benefiting from semi-analytical framework of the simulation model, the optimization-simulation method with significantly better computational performance compared to a numerical Mote-Carlo simulation-based technique has led to an effective irrigation management tool that can contribute to bridging the gap between vadose zone theory and water management practice. In addition to precisely assessing the most influential processes at a growing season time scale, one can use the developed model in large scale systems such as irrigation districts and agricultural catchments. Accordingly

  4. Economic impacts on irrigated agriculture of water conservation programs in drought

    NASA Astrophysics Data System (ADS)

    Ward, Frank A.

    2014-01-01

    This study analyzes vulnerability, impacts, and adaptability by irrigation to drought.It accounts for economic incentives affecting choices on irrigation technology, crop mix, and water sources.When surface water supplies fall, farmers increase pumping, even when pumping raises production costs.Conservation program subsidies raise the value of food production but can increase crop water depletions.

  5. Soil water sensors for irrigation scheduling:Can they deliver a management allowed depletion?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil water sensors are widely marketed in the farming sector as aids for irrigation scheduling. Sensors report either volumetric water content (theta-v, m**3 m**-3) or soil water potential, with theta-v sensors being by far the most common. To obtain yield and quality goals, irrigations are schedule...

  6. Characterizing irrigation water requirements for rice production from the Arkansas Rice Research Verification Program

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated rice irrigation water use in the University of Arkansas Rice Research Verification Program between the years of 2003 and 2011. Irrigation water use averaged 747 mm (29.4 inches) over the nine years. A significant 40% water savings was reported for rice grown under a zero gr...

  7. Intelligent irrigation performance: evaluation and quantifying its ability for conserving water in arid region

    NASA Astrophysics Data System (ADS)

    Al-Ghobari, Hussein M.; Mohammad, Fawzi S.

    2011-12-01

    Intelligent irrigation technologies have been developed in recent years to apply irrigation to turf and landscape plants. These technologies are an evapotranspiration (ET)-based irrigation controller, which calculates ET for local microclimate. Then, the controller creates a program for loading and communicating automatically with drip or sprinkler system controllers. The main objective of this study was to evaluate the effectiveness of the new ET sensors in ability to irrigate agricultural crops and to conserve water use for crop in arid climatic conditions. This paper presents the case for water conservation using intelligent irrigation system (IIS) application technology. The IIS for automating irrigation scheduling was implemented and tested with sprinkle and drip irrigation systems to irrigate wheat and tomato crops. Another irrigation scheduling system was also installed and operated as another treatment, which is based on weather data that retrieved from an automatic weather station. This irrigation control system was running in parallel to the former system (IIS) to be control experiments for comparison purposes. However, this article discusses the implementation of IIS, its installation, testing and calibration of various components. The experiments conducted for one growing season 2009-2010 and the results were represented and discussed herein. Data from all plots were analyzed, which were including soil water status, water consumption, and crop yield. The initial results indicate that up to 25% water saving by intelligent irrigation compared to control method, while maintaining competing yield. Results show that the crop evapotranspiration values for control experiments were higher than that of ET-System in consistent trend during whole growth season. The analysis points out that the values of the two treatments were somewhat close to each other's only in the initial development stages. Generally, the ET-System, with some modification was precise in

  8. Catchment scale analysis on river-return ratio of irrigation water from densely developed paddy areas

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Masumoto, T.; Horikawa, N.; Kudo, R.; Minakawa, H.; Nawa, N.

    2013-12-01

    Irrigation in Japan is predominantly used for rice cultivation, and it accounts for 70% of total water withdrawal. Water loss, which is attributable to nature of open channel irrigation system and percolation from fields, leads to relatively low irrigation efficiencies compared with ones for upland crops. However, because part of water gradually returns to rivers (river-return flow), it contributes to stable water use in downstream. This study investigated how irrigation water circulates and returns to rivers, and quantified a ratio of river-return flow to irrigation intake for an irrigation area (river-return ratio). One difficulty in river-return flow analysis lies in the fact that two types of flow pathways exist in an irrigation area; natural rivers that drain water from the areas, and channel networks whose directions do not necessarily coincide with river directions. In addition, outflux from irrigation area is consisted of water from different sources, such as water loss during water allocation, rainfall, irrigation, and influx from adjacent upstream areas. To cope with such difficulties, we used a grid-based distributed water circulation model that represents both catchment scale hydrological cycles and water flows related to irrigation channel network. The model calculates water flow for irrigation networks based on a GIS database of water use facilities. The model also incorporates operation rules for facilities and field level water management. Using the modeled river network, we first identify grid-cells where influx and outflux occurs across boundaries of irrigation areas. Then, to eliminate the effect of influx from adjacent upstream areas, we subtract influx from outflux. This makes us to capture outflux that purely originates in rainfall and irrigation within an irrigated area. Next, we separate the amount of outflux that originates in irrigation from the total amount of outflux. As residence time of each flow pathway had not been clarified yet, we

  9. Uptake of antibiotics from irrigation water by plants.

    PubMed

    Azanu, David; Mortey, Christiana; Darko, Godfred; Weisser, Johan Juhl; Styrishave, Bjarne; Abaidoo, Robert Clement

    2016-08-01

    The capacity of carrot (Daucus corota L.) and lettuce (Lactuca sativa L.), two plants that are usually eaten raw, to uptake tetracycline and amoxicillin (two commonly used antibiotics) from irrigated water was investigated in order to assess the indirect human exposure to antibiotics through consumption of uncooked vegetables. Antibiotics in potted plants that had been irrigated with known concentrations of the antibiotics were extracted using accelerated solvent extraction and analyzed on a liquid chromatograph-tandem mass spectrometer. The plants absorbed the antibiotics from water in all tested concentrations of 0.1-15 mg L(-1). Tetracycline was detected in all plant samples, at concentrations ranging from 4.4 to 28.3 ng/g in lettuce and 12.0-36.8 ng g(-1) fresh weight in carrots. Amoxicillin showed absorption with concentrations ranging from 13.7 ng g(-1) to 45.2 ng g(-1) for the plant samples. The mean concentration of amoxicillin (27.1 ng g(-1)) in all the samples was significantly higher (p = 0.04) than that of tetracycline (20.2 ng g(-1)) indicating higher uptake of amoxicillin than tetracycline. This suggests that the low antibiotic concentrations found in plants could be important for causing antibiotics resistance when these levels are consumed. PMID:27213239

  10. Theme: Staying Current--Horticulture.

    ERIC Educational Resources Information Center

    Shry, Carroll L., Jr.; And Others

    1986-01-01

    This theme issue on staying current in horticulture includes articles on sex equity in horticulture, Future Farmers of America, career opportunities in horticulture, staying current with your school district's needs, staying current in horticulture instruction, staying current with landscape trade associations, emphasizing the basics in vocational…

  11. LOWER PAYETTE RIVER, IDAHO AGRICULTURE IRRIGATION WATER RETURN STUDY AND GROUND WATER EVALUATION, 1992-1993

    EPA Science Inventory

    This report covers the final 17 miles of the Payette River (17050112) and 32,000 acres of irrigated cropland referred to as the Lower Payette State Agricultural Water Quality Project. An in-depth surface and ground water monitoring effort was initiated in June 1992 and completed...

  12. Water use and water productivity of sugarbeet, malt barley and potato as affected by irrigation frequency

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Successful irrigation management is one of the most important agronomic practices for achieving profitable yield and maximizing crop water productivity (CWP) while maintaining environmental quality by minimizing water losses to runoff and deep drainage. This study was conducted to compare the influe...

  13. Greenhouse gas emissions, irrigation water use, and arsenic concentrations; a common thread in rice water management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice has historically been grown as a flooded crop in the United States. As competition for water resources has grown, there is interest in reducing water use in rice production so as to maintain a viable and sustainable rice industry into the future. An irrigation study was established in 2011 at ...

  14. Water Stress & Biomass Monitoring and SWAP Modeling of Irrigated Crops in Saratov Region of Russia

    NASA Astrophysics Data System (ADS)

    Zeyliger, Anatoly; Ermolaeva, Olga

    2016-04-01

    Development of modern irrigation technologies are balanced between the need to maximize production and the need to minimize water use which provides harmonious interaction of irrigated systems with closely-spaced environment. Thus requires an understanding of complex interrelationships between landscape and underground of irrigated and adjacent areas in present and future conditions aiming to minimize development of negative scenarios. In this way in each irrigated areas a combination of specific factors and drivers must be recognized and evaluated. Much can be obtained by improving the efficiency use of water applied for irrigation. Modern RS monitoring technologies offers the opportunity to develop and implement an effective irrigation control program permitting today to increase efficiency of irrigation water use. These technologies provide parameters with both high temporal and adequate spatial needed to monitor agrohydrological parameters of irrigated agricultural crops. Combination of these parameters with meteorological and biophysical parameters can be used to estimate crop water stress defined as ratio between actual (ETa) and potential (ETc) evapotranspiration. Aggregation of actual values of crop water stress with biomass (yield) data predicted by agrohydrological model based on weather forecasting and scenarios of irrigation water application may be used for indication of both rational timing and amount of irrigation water allocation. This type of analysis facilitating an efficient water management can be easily extended to irrigated areas by developing maps of water efficiency application serving as an irrigation advice system for farmers at his fields and as a decision support tool for the authorities on the large perimeter irrigation management. This contribution aims to communicate an illustrative explanation about the practical application of a data combination of agrohydrological modeling and ground & space based monitoring. For this aim some

  15. Drainage water quality and end-member identification in La Violada irrigation district (Spain)

    NASA Astrophysics Data System (ADS)

    Isidoro, D.; Quílez, D.; Aragüés, R.

    2010-03-01

    SummaryThe identification of the different components in a water course is required to individualize and assess the actual contribution of irrigated agriculture to the pollution of the water course. This paper aimed at identifying and assessing the composition of the end-members in La Violada irrigation district (VID) and establishing a statistical procedure to reduce the sampling effort needed to establish drainage water quality. The quality of irrigation water, groundwater, and irrigated-land drainage water in VID was monitored during three hydrologic years to identify the components of flow in La Violada Gully, the natural exit course of VID. A network of sampling points in the secondary ditches and main drains of VID allowed identifying and separating those collecting irrigated-land drainage waters from those conveying high proportions of irrigation waters. Three end-member flows were identified in La Violada Gully during the irrigation season: (a) irrigation water arising from tail-waters, leakages and spills from the irrigation canals, very low in salts; (b) groundwater originating from the non-irrigated upper reaches of La Violada Gully watershed, high in Cl - and Na +; and (c) VID drainage water, high in SO42- and Ca 2+. The overall VID drainage water quality was accurately assessed through a simplified sampling scheme of only four sampling points that produced low errors of 0.1 dS/m for EC and 0.1 mmol c/L for Cl -. The separation of La Violada Gully flow in these three components is essential for estimating the actual contribution of irrigation in VID to the salt and nitrogen loads in La Violada Gully.

  16. Economics of Irrigation Water Mixing Within a Farm Framework

    NASA Astrophysics Data System (ADS)

    Feinerman, E.; Yaron, D.

    1983-04-01

    Linear programing models, deterministic in the short run and stochastic (random rainfall) in the long run, aimed at guiding annual decision making with regard to crop mix and saline irrigation water mixing from various sources within a farm framework, are presented. The short-run model incorporates the physical, biological, and economic relationships involved in one endogenous system and enables an in depth analysis of them but is limited to a single year. The long-run model considers the effects of the short-run decisions on the future but several relationships are incorporated exogenously. The short run model's results are utilized for the determination of some of these predetermined relationships. The models are applied to a potential farm situation in southern Israel. The results provide priorities in the allocation of water and soil plots of varying salinity levels and empirical estimates of the shadow prices and the rates of substitution between the limited resources.

  17. Effects of climate and irrigation changes on the water balance of a Mediterranean catchment

    NASA Astrophysics Data System (ADS)

    von Gunten, Diane; Wöhling, Thomas; Haslauer, Claus; Cirpka, Olaf

    2015-04-01

    Climate change will strongly impact the water cycle of Mediterranean catchments as a result of the changes in precipitation patterns and increased temperature. However, effects of climate change are difficult to predict with precision and are often influenced by land-use or water management choices. In agricultural catchments, irrigation is of particular interest because of its importance for cultivation in semi-arid climate and because of its strong impacts on hydrological processes. Interactions between irrigation and climate change impacts are likely to be important and should be considered when studying the future of a catchment. However, they are still difficult to quantify. A better understanding of the differences in climate-change sensitivity between irrigated and non-irrigated catchments would allow a finer description of local climate change effects. In this study, we compared the impacts of climate change in various irrigation scenarios, including a scenario without irrigation. Our case study was a relatively small catchment (about 7.5km2) in north-east Spain, called the Lerma catchment. This catchment was not irrigated prior to 2006, but 54% of its surface is now used for irrigated agriculture. This transition to irrigated agriculture was closely monitored and data on hydraulic heads, discharge and daily irrigation volume are available. Based on these measurements, a coupled surface-subsurface model of the catchment was developed using the pde-based model HydroGeoSphere. The model performs well for both irrigated and non-irrigated periods. Future climate was predicted using four regional climate models from the ENSEMBLE project (P.van der Linden and J.Mitchell, ENSEMBLES: Climate Change and its Impacts [...], Met Office Hadley Center, 2009) and two downscaling methods, including one based on a weather generator. Four irrigation scenarios, based on projected potential evapotranspiration changes, were compared. Our results show a shift in the climate

  18. Irrigation: Erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation is essential for global food production. However, irrigation erosion can limit the ability of irrigation systems to reliably produce food and fiber in the future. The factors affecting soil erosion from irrigation are the same as rainfall—water detaches and transports sediment. However, t...

  19. Emergy Evaluation of a Production and Utilization Process of Irrigation Water in China

    PubMed Central

    Chen, Dan; Luo, Zhao-Hui; Chen, Jing; Kong, Jun; She, Dong-Li

    2013-01-01

    Sustainability evaluation of the process of water abstraction, distribution, and use for irrigation can contribute to the policy of decision making in irrigation development. Emergy theory and method are used to evaluate a pumping irrigation district in China. A corresponding framework for its emergy evaluation is proposed. Its emergy evaluation shows that water is the major component of inputs into the irrigation water production and utilization systems (24.7% and 47.9% of the total inputs, resp.) and that the transformities of irrigation water and rice as the systems' products (1.72E + 05 sej/J and 1.42E + 05 sej/J, resp.; sej/J = solar emjoules per joule) represent their different emergy efficiencies. The irrigated agriculture production subsystem has a higher sustainability than the irrigation water production subsystem and the integrated production system, according to several emergy indices: renewability ratio (%R), emergy yield ratio (EYR), emergy investment ratio (EIR), environmental load ratio (ELR), and environmental sustainability index (ESI). The results show that the performance of this irrigation district could be further improved by increasing the utilization efficiencies of the main inputs in both the production and utilization process of irrigation water. PMID:24082852

  20. Irrigation scheduling by ET and soil water sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation scheduling is the process of deciding when, where and how much to irrigate, usually with the goal of optimizing economic return on investment in land, equipment, inputs and personnel. This hour-long seminar presents methods of irrigation scheduling based, on the one hand on estimates of t...

  1. Emergy evaluation of a pumping irrigation water production system in China

    NASA Astrophysics Data System (ADS)

    Chen, Dan; Luo, Zhaohui; Webber, Michael; Chen, Jing; Wang, Weiguang

    2014-03-01

    The emergy concept was used to evaluate a pumping irrigation water production system in China. A framework for emergy evaluation of the significance of irrigation water and its production process was developed. The results show that the irrigation water saved has the highest emergy value (8.73E + 05 sej·J-1), followed by the irrigation water supplied to farmlands (1.72E + 05 sej·J-1), the pumped water (4.81E + 04 sej·J-1), with the lowest value shown from water taken from the local river (3.72E + 04 sej·J-1). The major contributions to the emergy needed for production are the inputs of soil and water. This production system could contribute to the irrigated agriculture and economy, according to several calculated emergy indices: emergy yield ratio ( EYR), emergy investment ratio ( EIR), environmental load ratio ( ELR), and environmental sustainability index ( ESI). The comparative analysis shows that the emergy theory and method, different from the conventional monetary-based analysis, could be used to evaluate irrigation water and its production process in terms of the biophysical account. Additional emergy evaluations should be completed on different types of water production and irrigated agricultural systems to provide adequate guidelines for the sustainability of irrigation development.

  2. Ground water for irrigation in the Viking Basin, west-central Minnesota

    USGS Publications Warehouse

    McBride, M.S.

    1975-01-01

    The Viking Basin consists of six glacial outwash areas in Douglas, Ottertail, and Todd Counties, west-central Minnesota. Total area is 340 square miles (880 square kilometres). Soils are sandy and excessively well-drained. Crops grown on the outwash would benefit from supplemental irrigation. Irrigation supplies can be obtained from wells in the surface outwash aquifer in significant parts of the large outwash areas near Carlos and Parkers Prairie and the small outwash area near Clotho. Irrigation supplies are unlikely in the outwash areas near Alexandria, Urbank, and Rose City. Major use of ground water for irrigation may lower ground-water levels sufficiently to affect lake and marsh levels and streamflow out of the irrigation areas. Water from the outwash is of excellent chemical quality for irrigation.

  3. Identification of Extended-Spectrum β-Lactamases Escherichia coli Strains Isolated from Market Garden Products and Irrigation Water in Benin

    PubMed Central

    Moussé, Wassiyath; Sina, Haziz; Baba-Moussa, Farid; Noumavo, Pacôme A.; Agbodjato, Nadège A.; Adjanohoun, Adolphe; Baba-Moussa, Lamine

    2015-01-01

    The present study aimed at biochemical and molecular characterization of Escherichia coli strains isolated from horticultural products and irrigation water of Cotonou. The samples were collected from 12 market gardeners of 4 different sites. Rapid' E. coli medium was used for identification of E. coli strains and the antimicrobial susceptibility was performed by the agar disk diffusion method. The β-lactamases production was sought by the liquid acidimetric method. The genes coding for β-lactamases and toxins were identified by PCR method. The results revealed that about 34.95% of the analyzed samples were contaminated by E. coli. Cabbages were the most contaminated by E. coli (28.26%) in dry season. All isolated strains were resistant to amoxicillin. The penicillinase producing E. coli carried blaTEM (67.50%), blaSHV (10%), and blaCTX-M (22.50%) genes. The study revealed that the resistance genes such as SLTI (35.71%), SLTII (35.71%), ETEC (7.15%), and VTEC (21.43%) were carried. Openly to the found results and considering the importance of horticultural products in Beninese food habits, it is important to put several strategies aiming at a sanitary security by surveillance and sensitization of all the actors on the risks of some practices. PMID:26770972

  4. Identification of Extended-Spectrum β-Lactamases Escherichia coli Strains Isolated from Market Garden Products and Irrigation Water in Benin.

    PubMed

    Moussé, Wassiyath; Sina, Haziz; Baba-Moussa, Farid; Noumavo, Pacôme A; Agbodjato, Nadège A; Adjanohoun, Adolphe; Baba-Moussa, Lamine

    2015-01-01

    The present study aimed at biochemical and molecular characterization of Escherichia coli strains isolated from horticultural products and irrigation water of Cotonou. The samples were collected from 12 market gardeners of 4 different sites. Rapid' E. coli medium was used for identification of E. coli strains and the antimicrobial susceptibility was performed by the agar disk diffusion method. The β-lactamases production was sought by the liquid acidimetric method. The genes coding for β-lactamases and toxins were identified by PCR method. The results revealed that about 34.95% of the analyzed samples were contaminated by E. coli. Cabbages were the most contaminated by E. coli (28.26%) in dry season. All isolated strains were resistant to amoxicillin. The penicillinase producing E. coli carried blaTEM (67.50%), blaSHV (10%), and blaCTX-M (22.50%) genes. The study revealed that the resistance genes such as SLTI (35.71%), SLTII (35.71%), ETEC (7.15%), and VTEC (21.43%) were carried. Openly to the found results and considering the importance of horticultural products in Beninese food habits, it is important to put several strategies aiming at a sanitary security by surveillance and sensitization of all the actors on the risks of some practices. PMID:26770972

  5. Forest Irrigation of Tritiated Water: A Proven Tritiated Water Management Tool - 13357

    SciTech Connect

    Prater, Phil; Blount, Gerald; Kmetz, Thomas; Vangelas, Karen

    2013-07-01

    Tritium releases from the Old Radioactive Waste Burial Ground (ORWBG) at the SRS in South Carolina has impacted groundwater and surface water. Tritiated groundwater plumes discharge into Fourmile Branch which is a small tributary of the Savannah River, a regional water resource. Taking advantage of the groundwater flow paths and the local topography a water collection and irrigation system was constructed and has been used at the SRS for over a decade to reduce these tritiated water releases to Fourmile Branch. The tritiated water is transferred to the atmosphere by evaporation from the pond surface, and after irrigation, wetted surface evaporation and evapotranspiration through the forest vegetation. Over the last decade SRS has irrigated over 120,000,000 gallons of tritiated water, which diverted over 6000 curies away from Fourmile Branch and the Savannah River. The system has been effective in reducing the flux of tritiated groundwater by approximately 70%. Mass balance studies of tritium in the forest soils before operations and over the last decade indicate that approximately 90% of the tritiated water that is irrigated is transferred to the atmosphere. Dose studies indicate that exposure to site workers and offsite maximally exposed individual is very low, approximately 6 mrem/year and 0.004 mrem/year, respectively. To consistently meet the flux reduction goal of tritium into Fourmile Branch optimization activities are proposed. These efforts will increase irrigation capacity and area. An additional 17 acres are proposed for an expansion of the area to be irrigated and a planting of approximately 40 acres of pine forest plantations is underway to expand irrigation capacity. Co-mingled with the tritiated groundwater are low concentrations of chlorinated volatile organic compounds (cVOCs), and 1,4-dioxane. Research studies and SRS field data indicate the forest irrigation system may have an added benefit of reducing the mass of these co-contaminants via

  6. Forest Irrigation Of Tritiated Water: A Proven Tritiated Water Management Tool

    SciTech Connect

    Vangelas, Karen; Blount, Gerald; Kmetz, Thomas; Prater, Phil

    2012-11-08

    Tritium releases from the Old Radioactive Waste Burial Ground (ORWBG) at the SRS in South Carolina has impacted groundwater and surface water. Tritiated groundwater plumes discharge into Fourmile Branch which is a small tributary of the Savannah River, a regional water resource. Taking advantage of the groundwater flow paths and the local topography a water collection and irrigation system was constructed and has been used at the SRS for over a decade to reduce these tritiated water releases to Fourmile Branch. The tritiated water is transferred to the atmosphere by evaporation from the pond surface, and after irrigation, wetted surface evaporation and evapotranspiration through the forest vegetation. Over the last decade SRS has irrigated over 120,000,000 gallons of tritiated water, which diverted over 6000 curies away from Fourmile Branch and the Savannah River. The system has been effective in reducing the flux of tritiated groundwater by approximately 70%. Mass balance studies of tritium in the forest soils before operations and over the last decade indicate that approximately 90% of the tritiated water that is irrigated is transferred to the atmosphere. Dose studies indicate that exposure to site workers and offsite maximally exposed individual is very low, approximately 6 mrem/year and 0.004 mrem/year, respectively. To consistently meet the flux reduction goal of tritium into Fourmile Branch optimization activities are proposed. These efforts will increase irrigation capacity and area. An additional 17 acres are proposed for an expansion of the area to be irrigated and a planting of approximately 40 acres of pine forest plantations is underway to expand irrigation capacity. Co-mingled with the tritiated groundwater are low concentrations of chlorinated volatile organic compounds (cVOCs), and 1,4-dioxane. Research studies and SRS field data indicate the forest irrigation system may have an added benefit of reducing the mass of these co-contaminants via

  7. Reuse potential of laundry greywater for irrigation based on growth, water and nutrient use of tomato

    NASA Astrophysics Data System (ADS)

    Misra, R. K.; Patel, J. H.; Baxi, V. R.

    2010-05-01

    SummaryGreywater is considered as a valuable resource with a high reuse potential for irrigation of household lawns and gardens. However, there are possibilities of surfactant and sodium accumulation in soil from reuse of greywater which may affect agricultural productivity and environmental sustainability adversely. We conducted a glasshouse experiment to examine variation in growth, water and nutrient use of tomato ( Lycopersicon esculentum Mill. cv. Grosse Lisse) using tap water (TW), laundry greywater (GW) and solutions of low and high concentration of a detergent surfactant (LC and HC, respectively) as irrigation treatments. Each treatment was replicated five times using a randomised block design. Measurements throughout the experiment showed greywater to be significantly more alkaline and saline than the other types of irrigation water. Although all plants received 16 irrigations over a period of 9 weeks until flowering, there were little or no significant effects of irrigation treatments on plant growth. Soil water retention following irrigation reduced significantly when plants were irrigated with GW or surfactant solutions on only three of 12 occasions. On one occasion, water use measured as evapotranspiration (ET) with GW irrigation was similar to TW, but it was significantly higher than the plants receiving HC irrigation. At harvest, various components of plant biomass and leaf area for GW irrigated plants were found to be similar or significantly higher than the TW irrigated plants with a common trend of GW ⩾ TW > LC ⩾ HC. Whole-plant concentration was measured for 12 essential plant nutrients (N, P, K, Ca, Mg, S, Fe, Cu, Mn, Zn, Mo and B) and Na (often considered as a beneficial nutrient). Irrigation treatments affected the concentration of four nutrients (P, Fe, Zn and Na) and uptake of seven nutrients (P, K, Ca, Mg, Na, Fe and B) significantly. Uptake of these seven nutrients by tomato was generally in the order GW ⩾ TW > HC ⩾ LC. GW

  8. Quantifying corn yield and water use efficiency in response to growth-stage based irrigation scheduling and seasonal water availability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A calibrated agricultural system model can help optimize limited irrigation water for higher crop yield and water use efficiency (WUE) across a wide range of climate conditions. In this study, the Root Zone Water Quality Model (RZWQM2) was calibrated for corn growth under a range of irrigation treat...

  9. Models for root water uptake under deficit irrigation

    NASA Astrophysics Data System (ADS)

    Lazarovitch, Naftali; Krounbi, Leilah; Simunek, Jirka

    2010-05-01

    Modern agriculture, with its dependence on irrigation, fertilizers, and pesticide application, contributes significantly to the water and solute influx through the soil into the groundwater, specifically in arid areas. The quality and quantity of this water as it passes through the vadose zone is influenced primarily by plant roots. Root water uptake is a function of both a physical root parameter, commonly referred to as the root length density, and the soil water status. The location of maximum water uptake in a homogenous soil profile of uniform water content and hydraulic conductivity occurs in the soil layer containing the largest root length density. Under field conditions, in a drying soil, plants are both subject to, and the source of, great spatial variability in the soil water content. The upper soil layers containing the bulk of the root zone are usually the most water depleted, while the deeper regions of the soil profile containing fewer roots are wetter. Changes in the physiological functioning of plants have been shown to result from extended periods of water stress, but the short term effects of water stress on root water uptake are less well understood. While plants can minimize transpiration and the resulting growth rates under limiting conditions to conserve water, many plants maintain a constant potential transpiration rate long after the commencement of the drying process. Compensatory uptake, whereby plants respond to non-uniform, limiting conditions by increasing water uptake from areas in the root zone characterized by more favorable conditions, is one such mechanism by which plants sustain potential transpiration rates in drying soils. The development of models which accurately characterize temporal and spatial root water uptake patterns is important for agricultural resource optimization, upon which subsequent management decisions affecting resource conservation and environmental pollution are based. Numerical simulations of root water

  10. Assessing irrigated agriculture's surface water and groundwater consumption by combining satellite remote sensing and hydrologic modelling.

    PubMed

    Peña-Arancibia, Jorge L; Mainuddin, Mohammed; Kirby, John M; Chiew, Francis H S; McVicar, Tim R; Vaze, Jai

    2016-01-15

    Globally, irrigation accounts for more than two thirds of freshwater demand. Recent regional and global assessments indicate that groundwater extraction (GWE) for irrigation has increased more rapidly than surface water extraction (SWE), potentially resulting in groundwater depletion. Irrigated agriculture in semi-arid and arid regions is usually from a combination of stored surface water and groundwater. This paper assesses the usefulness of remotely-sensed (RS) derived information on both irrigation dynamics and rates of actual evapotranspiration which are both input to a river-reach water balance model in order to quantify irrigation water use and water provenance (either surface water or groundwater). The assessment is implemented for the water-years 2004/05-2010/11 in five reaches of the Murray-Darling Basin (Australia); a heavily regulated basin with large irrigated areas and periodic droughts and floods. Irrigated area and water use are identified each water-year (from July to June) through a Random Forest model which uses RS vegetation phenology and actual evapotranspiration as predicting variables. Both irrigated areas and actual evapotranspiration from irrigated areas were compared against published estimates of irrigated areas and total water extraction (SWE+GWE).The river-reach model determines the irrigated area that can be serviced with stored surface water (SWE), and the remainder area (as determined by the Random Forest Model) is assumed to be supplemented by groundwater (GWE). Model results were evaluated against observed SWE and GWE. The modelled SWE generally captures the observed interannual patterns and to some extent the magnitudes, with Pearson's correlation coefficients >0.8 and normalised root-mean-square-error<30%. In terms of magnitude, the results were as accurate as or better than those of more traditional (i.e., using areas that fluctuate based on water resource availability and prescribed crop factors) irrigation modelling. The RS

  11. Evaluation of Monensin Transport to Shallow Groundwater after Irrigation with Dairy Lagoon Water.

    PubMed

    Hafner, Sarah C; Harter, Thomas; Parikh, Sanjai J

    2016-03-01

    Animal waste products from concentrated animal feeding operations are a significant source of antibiotics to the environment. Monensin, an ionophore antibiotic commonly used to increase feed efficiency in livestock, is known to have varied toxicological effects on nontarget species. The current study builds on prior studies evaluating the impact of dairy management on groundwater quality by examining the transport of monensin in an agricultural field with coarse-textured soils during irrigation with lagoon wastewater. The dairy is located in California's San Joaquin Valley, where groundwater can be encountered <5 m below the surface. Groundwater samples were collected from a network of monitoring wells installed throughout the dairy and adjacent to irrigated fields before and after an irrigation event, which allowed for measurement of monensin potentially reaching the shallow groundwater as a direct result of irrigation with lagoon water. Monensin was extracted from water samples via hydrophilic-lipophilic balance solid-phase extraction and quantified with liquid chromatography-mass spectrometry. Irrigation water was found to contain up to 1.6 μg L monensin, but monensin was only detected in monitoring wells surrounding the waste storage lagoon. Water chemistry changes in the wells bordering the irrigated field suggest that up to 7% of irrigation water reached groundwater within days of irrigation. The study suggests that contamination of groundwater with monensin can occur primarily by compromised waste storage systems and that rapid transport of monensin to groundwater is not likely to occur from a single irrigation event. PMID:27065394

  12. Irrigation water is an unlikely source of inoculum of Pseudomonas cannabina pv. alisalensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pseudomonas cannabina pv. alisalensis causes severe bacterial blight on crucifers across the United States. These experiments examined the potential of irrigation water as a source of inoculum for P. cannabina pv. alisalensis. Water samples were collected from multiple irrigation reservoirs and spri...

  13. Compensating inherent linear move water application errors using a variable rate irrigation system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Continuous move irrigation systems such as linear move and center pivot irrigate unevenly when applying conventional uniform water rates due to the towers/motors stop/advance pattern. The effect of the cart movement pattern on linear move water application is larger on the first two spans which intr...

  14. Improving estimates of N and P loads in irrigation water from swine manure lagoons

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The implementation of nutrient management plans (NMPs) for confined animal feeding operations (CAFOs) requires recording N and P loads from land-applied manure, including nutrients applied in irrigation water from manure treatment lagoons. By regulation, lagoon irrigation water nutrient records in ...

  15. Improving N and P estimates for swine manure lagoon irrigation water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nutrient management plans (NMPs) for confined animal feeding operations (CAFOs) require a record of N and P loads from manure land-applications, including irrigation with lagoon water. Mississippi regulations require nutrient records for lagoon irrigation water be based on at least one annual analy...

  16. Adapting irrigation management to water scarcity: constraints of plant growth, hydraulics and carbon assimilation.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water shortages are responsible for the greatest crop losses around the world and are expected to worsen. In arid areas where agriculture is dependent on irrigation, various forms of deficit irrigation management have been suggested to optimize crop yields for available soil water. The relationshi...

  17. Perchlorate uptake in spinach as related to perchlorate, nitrate and chloride concentrations in irrigation water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several studies have reported on the detection of perchlorate in edible leafy vegetables irrigated with Colorado River water. However, there is no information on spinach as related to perchlorate in irrigation water nor on the effect of other anions on perchlorate uptake. A greenhouse perchlorate up...

  18. Soil water sensors for irrigation management-What works, what doesn't, and why

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Irrigation scheduling can be greatly improved if accurate soil water content data are available. There are a plethora of available soil water sensing systems, but those that are practical for irrigation scheduling are divided into two major types: the frequency domain (capacitance) sensors and the t...

  19. Simulated Corn Yield Responses to Limited-Water Irrigation Under Varying Soil and Climate Conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water holding capacity of soils is a key factor in successful dryland and irrigated agriculture as it influences the fraction of precipitation and irrigation that is stored in the soil profile that can be subsequently used for crop production. There is a well-known dependence of water holding capaci...

  20. Optimal demand reponse to water pricing policies under limited water supply in irrigation: a case study

    NASA Astrophysics Data System (ADS)

    Grießbach, Ulkrike; Stange, Peter; Schuetze, Niels

    2015-04-01

    Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with the higher demand of water, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand. For modeling the regional water demand, local stochastic water demand functions are used which are derived from optimized agronomic response on farms scale. These functions take into account different soil types, crops, stochastically generated climate scenarios considering different economic conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed and applied for a case study in Saxony which helps to evaluate combined water supply and demand management policies on a regional level.

  1. Assessment of water use in the Spanish irrigation district "Río Adaja"

    NASA Astrophysics Data System (ADS)

    Naroua, Illiassou; Rodriguez-Sinobas, Leonor; Sánchez Calvo, Raúl

    2013-04-01

    Intensive agricultural practices combined with the increasing pressure of urbanization and the changing lifestyles, have strengthened the problems of competing users over limited water resources in a fragile and already stressed environment. Sustainable irrigated agriculture is prescribed as a policy approach that maximizes economic benefits while maintaining environmental quality. Within this framework a proper management of irrigation systems saving water is required. On the other hand, crops with high tolerance to water stress and deficit irrigation are recommended. However, crop yield, among other factors, is very sensitive to water Thus, studies addressing the relations among crop water requirements, irrigation depth and crop yield are necessary. This type of study has been carried out in the Spanish irrigation District "Río Adaja" in the year 2010-2011 with the crops: wheat, barley, sugarbeet, corn, onion, potato, sunflower, clover and carrot. A soil hydrology balance model was applied taking into account climatic data for the nearby weather station and soil characteristics. Effective precipitation was calculated by the index curve number. Crop water requirements were calculated by the FAO Penman-Monteith with the application of the dual crop coefficient. Likewise, productivity was measured by the following indexes: annual relative irrigation supply (ARIS), relative water supply (RWS), relative rainfall supply (RS) and water productivity (WP). Results show that water applied with the irrigation of clover, sugarbeet, corn and onion was less than their water requirements There was a 35 % difference between the amount of water simulated with the model and the gross amount applied during the irrigation period by the irrigation district. WP values differed among crops depending, mainly, on the crop`s market price and the amount of irrigation water. The highest values corresponded to potato and onion crops.

  2. A coupled agronomic-economic model to consider allocation of brackish irrigation water

    NASA Astrophysics Data System (ADS)

    Ben-Gal, Alon; Weikard, Hans-Peter; Shah, Syed Hamid Hussain; Zee, Sjoerd E. A. T. M.

    2013-05-01

    In arid and semiarid regions, irrigation water is scarce and often contains high concentrations of salts. To reduce negative effects on crop yields, the irrigated amounts must include water for leaching and therefore exceed evapotranspiration. The leachate (drainage) water returns to water sources such as rivers or groundwater aquifers and increases their level of salinity and the leaching requirement for irrigation water of any sequential user. We develop a conceptual sequential (upstream-downstream) model of irrigation that predicts crop yields and water consumption and tracks the water flow and level of salinity along a river dependent on irrigation management decisions. The model incorporates an agro-physical model of plant response to environmental conditions including feedbacks. For a system with limited water resources, the model examines the impacts of water scarcity, salinity and technically inefficient application on yields for specific crop, soil, and climate conditions. Moving beyond the formulation of a conceptual frame, we apply the model to the irrigation of Capsicum annum on Arava Sandy Loam soil. We show for this case how water application could be distributed between upstream and downstream plots or farms. We identify those situations where it is beneficial to trade water from upstream to downstream farms (assuming that the upstream farm holds the water rights). We find that water trade will improve efficiency except when loss levels are low. We compute the marginal value of water, i.e., the price water would command on a market, for different levels of water scarcity, salinity and levels of water loss.

  3. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Can I receive irrigation water if I am granted an Annual... AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an Annual Assessment Waiver? No. Water will not be delivered in any...

  4. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Can I receive irrigation water if I am granted an Annual... AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an Annual Assessment Waiver? No. Water will not be delivered in any...

  5. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Can I receive irrigation water if I am granted an Annual... AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an Annual Assessment Waiver? No. Water will not be delivered in any...

  6. 25 CFR 171.710 - Can I receive irrigation water if I am granted an Annual Assessment Waiver?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Can I receive irrigation water if I am granted an Annual... AND WATER IRRIGATION OPERATION AND MAINTENANCE Non-Assessment Status § 171.710 Can I receive irrigation water if I am granted an Annual Assessment Waiver? No. Water will not be delivered in any...

  7. GlobWat - a global water balance model to assess water use in irrigated agriculture

    NASA Astrophysics Data System (ADS)

    Hoogeveen, J.; Faurès, J.-M.; Peiser, L.; Burke, J.; van de Giesen, N.

    2015-01-01

    GlobWat is a freely distributed, global soil water balance model that is used by FAO to assess water use in irrigated agriculture; the main factor behind scarcity of freshwater in an increasing number of regions. The model is based on spatially distributed high resolution datasets that are consistent at global level and calibrated against values for Internal Renewable Water Resources, as published in AQUASTAT, FAO's global information system on water and agriculture. Validation of the model is done against mean annual river basin outflows. The water balance is calculated in two steps: first a "vertical" water balance is calculated that includes evaporation from in situ rainfall ("green" water) and incremental evaporation from irrigated crops. In a second stage, a "horizontal" water balance is calculated to determine discharges from river (sub-)basins, taking into account incremental evaporation from irrigation, open water and wetlands ("blue" water). The paper describes methodology, input and output data, calibration and validation of the model. The model results are finally compared with other global water balance models.

  8. GlobWat - a global water balance model to assess water use in irrigated agriculture

    NASA Astrophysics Data System (ADS)

    Hoogeveen, J.; Faurès, J.-M.; Peiser, L.; Burke, J.; van de Giesen, N.

    2015-09-01

    GlobWat is a freely distributed, global soil water balance model that is used by the Food and Agriculture Organization (FAO) to assess water use in irrigated agriculture, the main factor behind scarcity of freshwater in an increasing number of regions. The model is based on spatially distributed high-resolution data sets that are consistent at global level and calibrated against values for internal renewable water resources, as published in AQUASTAT, the FAO's global information system on water and agriculture. Validation of the model is done against mean annual river basin outflows. The water balance is calculated in two steps: first a "vertical" water balance is calculated that includes evaporation from in situ rainfall ("green" water) and incremental evaporation from irrigated crops. In a second stage, a "horizontal" water balance is calculated to determine discharges from river (sub-)basins, taking into account incremental evaporation from irrigation, open water and wetlands ("blue" water). The paper describes the methodology, input and output data, calibration and validation of the model. The model results are finally compared with other global water balance models to assess levels of accuracy and validity.

  9. Market Simulations for Irrigation Water Rights: A Hypothetical Case Study

    NASA Astrophysics Data System (ADS)

    Wong, Benedict D. C.; Eheart, J. Wayland

    1983-10-01

    The efficiency of two marketable water rights systems in a lentic (lakelike) structure is assessed quantitatively for a case study based on hypothetical irrigation water use. Water rights are simulated on the bases of (1) the expected values of water rights to the users and (2) perfect foresight on the parts of users, and the economic outcomes of these markets are evaluated from both ex ante and ex post perspectives. The market outcomes are compared to the optimal (efficient) scheme and to two alternative nonmarket policies. Distributional aspects of the markets are examined on the basis of individual payoff. Simulation results show that higher efficiency is obtained for the two market systems than for the nonmarket policies and that the market systems recoup about 95% of the economic value of the optimal distribution. The results suggest that most of the 5% efficiency loss should be attributed to the design of the market system itself (i.e., the restrictions imposed by the definition of the rights and/or the water rights allocation policy), rather than the users' inability to predict future events.

  10. On farm evaluation of the effect of low cost drip irrigation on water and crop productivity compared to conventional surface irrigation system

    NASA Astrophysics Data System (ADS)

    Maisiri, N.; Senzanje, A.; Rockstrom, J.; Twomlow, S. J.

    This on-farm research study was carried out at Zholube irrigation scheme in a semi-arid agro tropical climate of Zimbabwe to determine how low cost drip irrigation technologies compare with conventional surface irrigation systems in terms of water and crop productivity. A total of nine farmers who were practicing surface irrigation were chosen to participate in the study. The vegetable English giant rape ( Brassica napus) was grown under the two irrigation systems with three fertilizer treatments in each system: ordinary granular fertilizer, liquid fertilizer (fertigation) and the last treatment with no fertilizer. These trials were replicated three times in a randomized block design. Biometric parameters of leaf area index (LAI) and fresh weight of the produce, water use efficiency (WUE) were used to compare the performance of the two irrigation systems. A water balance of the inflows and outflows was kept for analysis of WUE. The economic profitability and the operation, maintenance and management requirements of the different systems were also evaluated. There was no significant difference in vegetable yield between the irrigation systems at 8.5 ton/ha for drip compared to 7.8 ton/ha in surface irrigation. There were significant increases in yields due to use of fertilizers. Drip irrigation used about 35% of the water used by the surface irrigation systems thus giving much higher water use efficiencies. The leaf area indices were comparable in both systems with the same fertilizer treatment ranging between 0.05 for surface without fertilizer to 6.8 for low cost drip with fertigation. Low cost drip systems did not reflect any labour saving especially when manually lifting the water into the drum compared to the use of siphons in surface irrigation systems. The gross margin level for surface irrigation was lower than for low cost drip irrigation but the gross margin to total variable cost ratio was higher in surface irrigation systems, which meant that surface

  11. Breeding Horticultural Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant breeding involves selection of plants with combinations of improved traits that are inherited in a predictable manner. Collecting, understanding, and incorporating genetic variation into a horticultural breeding program are critical to success. Clearly defined goals help plant breeders choose ...

  12. Agricultural-to-hydropower water transfers: sharing water and benefits in hydropower-irrigation systems

    NASA Astrophysics Data System (ADS)

    Tilmant, A.; Goor, Q.; Pinte, D.

    2009-07-01

    This paper presents a methodology to assess agricultural-to-hydropower water transfers in water resources systems where irrigation crop production and hydropower generation are the main economic activities. In many countries, water for crop irrigation is often considered as a static asset: irrigation water is usually allocated by a system of limited annual rights to use a prescribed volume of water, which remains to a large extent independent of the availability of water in the basin. The opportunity cost (forgone benefits) of this static management approach may be important in river basins where large irrigation areas are present in the upstream reaches. Continuously adjusting allocation decisions based on the hydrologic status of the system will lead to the temporary reallocation of some (or all) of the irrigation water downstream to consumptive and/or non-consumptive users. Such a dynamic allocation process will increase the social benefits if the sum of the downstream productivities exceeds those of the upstream farmers whose entitlements are curtailed. However, this process will be socially acceptable if upstream farmers are compensated for increasing the availability of water downstream. This paper also presents a methodology to derive the individual contribution of downstream non-consumptive users, i.e. hydropower plants, to the financial compensation of upstream farmers. This dynamic management approach is illustrated with a cascade of multipurpose reservoirs in the Euphrates river basin. The analysis of simulation results reveals that, on average, the annual benefits obtained with the dynamic allocation process are 6% higher that those derived from a static allocation.

  13. Potentials and problems of sustainable irrigation with water high in salts

    NASA Astrophysics Data System (ADS)

    Ben-Gal, Alon

    2015-04-01

    Water scarcity and need to expand agricultural productivity have led to ever growing utilization of poor quality water for irrigation of crops. Almost in all cases, marginal or alternative water sources for irrigation contain relatively high concentrations of dissolved salts. When salts are present, irrigation water management, especially in the dry regions where water requirements are highest, must consider leaching in addition to crop evapotranspiration requirements. Leaching requirements for agronomic success are calculable and functions of climate, soil, and very critically, of crop sensitivity and the actual salinity of the irrigation water. The more sensitive the crop and more saline the water, the higher the agronomic cost and the greater the quantitative need for leaching. Israel is a forerunner in large-scale utilization of poor quality water for irrigation and can be used as a case study looking at long term repercussions of policy alternatively encouraging irrigation with recycled water or brackish groundwater. In cases studied in desert conditions of Israel, as much of half of the water applied to crops including bell peppers in greenhouses and date palms is actually used to leach salts from the root zone. The excess water used to leach salts and maintain agronomic and economic success when irrigating with water containing salts can become an environmental hazard, especially in dry areas where natural drainage is non-existent. The leachate often contains not only salts but also agrochemicals including nutrients, and natural contaminants can be picked up and transported as well. This leachate passes beyond the root zone and eventually reaches ground or surface water resources. This, together with evidence of ongoing increases in sodium content of fresh produce and increased SAR levels of soils, suggest that the current policy and practice in Israel of utilization of high amounts of low quality irrigation water is inherently non- sustainable. Current

  14. Assessing soil water storage distribution under sprinkler irrigation by coupling 3D simulations and field observations

    NASA Astrophysics Data System (ADS)

    Taha, Uday; Shabeeb, Ahmed; dragonetti, giovanna; Lamaddalena, Nicola; Coppola, Antonio

    2016-04-01

    This work analyzed the variability of sprinkler irrigation application over a bare soil, both in terms of water application efficiency and uniformity, by integrating and comparing the information on the irrigation depth data (ID), as measured by catch cans, soil water storage in the upper root zone, as measured by TDR probes, and a 3D simulations of water flow in soils. Three irrigation tests were performed at three different pressures (2, 3 and 4 bar). A lateral water redistribution was observed and simulated after each irrigation event by comparing spatial distributions of site-specific water application efficiency (AEs), as well as ratios of site-specific actual water storage increase (SWEs) and irrigation depth (IDs) to the water content before irrigation. Because of soil water redistribution processes, distribution uniformity based on soil storages was systematically higher than the catch can uniformity. The obvious consequence of lateral water redistribution processes was that the soil smoothing action on non-uniformity observed at the surface increased both with depth and over time. At a given depth the uniformity of soil water storages always attained the same value, whatever the pressure considered and the catch can-based uniformity coefficient. It was concluded that, for the case of random distribution of ID, the uniformity of water storages is driven by the soil behavior rather than by the irrigation system.

  15. Assessment of water use and its productivity in the Spanish irrigation district "Río Adaja"

    NASA Astrophysics Data System (ADS)

    Rodriguez-Sinobas, Leonor; Naroua, Iliassou; Sánchez-Calvo, Raúl

    2015-04-01

    A study of the assessment of the irrigation water use has been carried out in the Spanish irrigation District "Río Adaja" that has analyzed the water use efficiency and the water productivity indicators for the main crops during the first three years of operation (2010/2011, 2011/2012 and 2012/2013). A soil water balance model was applied taking into account climatic data for the nearby weather station and soil properties. Crop water requirements were calculated by the FAO Penman-Monteith with the application of the dual crop coefficient and by considering the readily available soil water content (RAW) concept. Likewise, productivity was measured by the indexes: annual relative irrigation supply (ARIS), annual relative water supply (ARWS), relative rainfall supply (RRS), the water productivity (WP), the evapotranspiration water productivity (ETWP), and the irrigation water productivity (IWP). The results show that the irrigation district applied deficit irrigation in most crops (ARIS<1), and also improved water productivity. This was higher in 2010/2011 which showed the highest effective precipitation Pe. The IWP (€/m3) index varied among crops with the highest values for onion (4.14), potato (2.79), carrot (1.37) and barley (1.21) for the first year and, onion (1.98), potato (1.69), carrot (1.70) and barley (1.16) in the second year. Thus, these crops would be a proper cropping pattern to maximize the gross income in the irrigation district.

  16. Farm water budgets for semiarid irrigated floodplains of northern New Mexico: characterizing the surface water-groundwater interactions

    NASA Astrophysics Data System (ADS)

    Gutierrez, K. Y.; Fernald, A.; Ochoa, C. G.; Guldan, S. J.

    2013-12-01

    KEY WORDS - Hydrology, Water budget, Deep percolation, Surface water-Groundwater interactions. With the recent projections for water scarcity, water balances have become an indispensable water management tool. In irrigated floodplains, deep percolation from irrigation can represent one of the main aquifer recharge sources. A better understanding of surface water and groundwater interactions in irrigated valleys is needed for properly assessing the water balances in these systems and estimating potential aquifer recharge. We conducted a study to quantify the parameters and calculate the water budgets in three flood irrigated hay fields with relatively low, intermediate and, high water availability in northern New Mexico. We monitored different hydrologic parameters including total amount of water applied, change in soil moisture, drainage below the effective root zone, and shallow water level fluctuations in response to irrigation. Evapotranspiration was calculated from weather station data collected in-situ using the Samani-Hargreaves. Previous studies in the region have estimated deep percolation as a residual parameter of the water balance equation. In this study, we used both, the water balance method and actual measurements of deep percolation using passive lysimeters. Preliminary analyses for the three fields show a relatively rapid movement of water through the upper 50 cm of the vadose zone and a quick response of the shallow aquifer under flood irrigation. Further results from this study will provide a better understanding of surface water-groundwater interactions in flood irrigated valleys in northern New Mexico.

  17. [Simulation of soil water dynamics in triploid Populus tomentosa root zone under subsurface drip irrigation].

    PubMed

    Xi, Ben-Ye; Jia, Li-Ming; Wang, Ye; Li, Guang-De

    2011-01-01

    Based on the observed data of triploid Populus tomentosa root distribution, a one-dimensional root water uptake model was proposed. Taking the root water uptake into account, the soil water dynamics in triploid P. tomentosa root zone under subsurface drip irrigation was simulated by using HYDRUS model, and the results were validated with field experiment. Besides, the HYDRUS model was used to study the effects of various irrigation technique parameters on soil wetting patterns. The RMAE for the simulated soil water content by the end of irrigation and approximately 24 h later was 7.8% and 6.0%, and the RMSE was 0.036 and 0.026 cm3 x cm(-3), respectively, illustrating that the HYDRUS model performed well in simulating the short-term soil water dynamics in triploid P. tomentosa root zone under drip irrigation, and the root water uptake model was reasonable. Comparing with 2 and 4 L x h(-1) of drip discharge and continuous irrigation, both the 1 L x h(-1) of drip discharge and the pulsed irrigation with water applied intermittently in 30 min periods could increase the volume of wetted soil and reduce deep percolation. It was concluded that the combination of 1 L x h(-1) of drip discharge and pulsed irrigation should be the first choice when applying drip irrigation to triploid P. tomentosa root zone at the experiment site. PMID:21548283

  18. Evaluating the accuracy of soil water sensors for irrigation scheduling to conserve freshwater

    NASA Astrophysics Data System (ADS)

    Ganjegunte, Girisha K.; Sheng, Zhuping; Clark, John A.

    2012-06-01

    In the Trans-Pecos area, pecan [ Carya illinoinensis (Wangenh) C. Koch] is a major irrigated cash crop. Pecan trees require large amounts of water for their growth and flood (border) irrigation is the most common method of irrigation. Pecan crop is often over irrigated using traditional method of irrigation scheduling by counting number of calendar days since the previous irrigation. Studies in other pecan growing areas have shown that the water use efficiency can be improved significantly and precious freshwater can be saved by scheduling irrigation based on soil moisture conditions. This study evaluated the accuracy of three recent low cost soil water sensors (ECH2O-5TE, Watermark 200SS and Tensiometer model R) to monitor volumetric soil water content (θv) to develop improved irrigation scheduling in a mature pecan orchard in El Paso, Texas. Results indicated that while all three sensors were successful in following the general trends of soil moisture conditions during the growing season, actual measurements differed significantly. Statistical analyses of results indicated that Tensiometer provided relatively accurate soil moisture data than ECH2O-5TE and Watermark without site-specific calibration. While ECH2O-5TE overestimated the soil water content, Watermark and Tensiometer underestimated. Results of this study suggested poor accuracy of all three sensors if factory calibration and reported soil water retention curve for study site soil texture were used. This indicated that sensors needed site-specific calibration to improve their accuracy in estimating soil water content data.

  19. Irrigation depth far exceeds water uptake depth in an oasis cropland in the middle reaches of Heihe River Basin

    PubMed Central

    Yang, Bin; Wen, Xuefa; Sun, Xiaomin

    2015-01-01

    Agricultural irrigation in the middle reaches of the Heihe River Basin consumes approximately 80% of the total river water. Whether the irrigation depth matches the water uptake depth of crops is one of the most important factors affecting the efficiency of irrigation water use. Our results indicated that the influence of plastic film on soil water δ18O was restricted to 0–30 cm soil depth. Based on a Bayesian model (MixSIR), we found that irrigated maize acquired water preferentially from 0–10 cm soil layer, with a median uptake proportion of 87 ± 15%. Additionally, maize utilised a mixture of irrigation and shallow soil water instead of absorbing the irrigation water directly. However, only 24.7 ± 5.5% of irrigation water remained in 0–10 cm soil layer, whereas 29.5 ± 2.8% and 38.4 ± 3.3% of the irrigation water infiltrated into 10–40 cm and 40–80 cm layers. During the 4 irrigation events, approximately 39% of the irrigation and rainwater infiltrated into soil layers below 80 cm. Reducing irrigation amount and developing water-saving irrigation methods will be important strategies for improving the efficiency of irrigation water use in this area. PMID:26463010

  20. Irrigation depth far exceeds water uptake depth in an oasis cropland in the middle reaches of Heihe River Basin.

    PubMed

    Yang, Bin; Wen, Xuefa; Sun, Xiaomin

    2015-01-01

    Agricultural irrigation in the middle reaches of the Heihe River Basin consumes approximately 80% of the total river water. Whether the irrigation depth matches the water uptake depth of crops is one of the most important factors affecting the efficiency of irrigation water use. Our results indicated that the influence of plastic film on soil water δ(18)O was restricted to 0-30 cm soil depth. Based on a Bayesian model (MixSIR), we found that irrigated maize acquired water preferentially from 0-10 cm soil layer, with a median uptake proportion of 87 ± 15%. Additionally, maize utilised a mixture of irrigation and shallow soil water instead of absorbing the irrigation water directly. However, only 24.7 ± 5.5% of irrigation water remained in 0-10 cm soil layer, whereas 29.5 ± 2.8% and 38.4 ± 3.3% of the irrigation water infiltrated into 10-40 cm and 40-80 cm layers. During the 4 irrigation events, approximately 39% of the irrigation and rainwater infiltrated into soil layers below 80 cm. Reducing irrigation amount and developing water-saving irrigation methods will be important strategies for improving the efficiency of irrigation water use in this area. PMID:26463010

  1. Irrigation depth far exceeds water uptake depth in an oasis cropland in the middle reaches of Heihe River Basin

    NASA Astrophysics Data System (ADS)

    Yang, Bin; Wen, Xuefa; Sun, Xiaomin

    2015-10-01

    Agricultural irrigation in the middle reaches of the Heihe River Basin consumes approximately 80% of the total river water. Whether the irrigation depth matches the water uptake depth of crops is one of the most important factors affecting the efficiency of irrigation water use. Our results indicated that the influence of plastic film on soil water δ18O was restricted to 0-30 cm soil depth. Based on a Bayesian model (MixSIR), we found that irrigated maize acquired water preferentially from 0-10 cm soil layer, with a median uptake proportion of 87 ± 15%. Additionally, maize utilised a mixture of irrigation and shallow soil water instead of absorbing the irrigation water directly. However, only 24.7 ± 5.5% of irrigation water remained in 0-10 cm soil layer, whereas 29.5 ± 2.8% and 38.4 ± 3.3% of the irrigation water infiltrated into 10-40 cm and 40-80 cm layers. During the 4 irrigation events, approximately 39% of the irrigation and rainwater infiltrated into soil layers below 80 cm. Reducing irrigation amount and developing water-saving irrigation methods will be important strategies for improving the efficiency of irrigation water use in this area.

  2. An assessment of global net irrigation water requirements from various water supply sources to sustain irrigation: rivers and reservoirs (1960-2050)

    NASA Astrophysics Data System (ADS)

    Yoshikawa, S.; Cho, J.; Yamada, H. G.; Hanasaki, N.; Kanae, S.

    2014-10-01

    Water supply sources for irrigation (e.g. rivers and reservoirs) are critically important for agricultural productivity. The current rapid increase in irrigation water use is considered unsustainable and threatens food production. In this study, we estimated the time-varying dependence of irrigation water requirements from water supply sources, with a particular focus on variations in irrigation area during past (1960-2001) and future (2002-2050) periods using the global water resources model, H08. The H08 model can simulate water requirements on a daily basis at a resolution of 1.0° × 1.0° latitude and longitude. The sources of irrigation water requirements in the past simulations were specified using four categories: rivers (RIV), large reservoirs (LR) with a storage capacity greater than 1.0 × 109 m3, medium-size reservoirs (MSR) with storage capacities ranging from 1.0 × 109 m3 to 3.0 × 106 m3, and non-local non-renewable blue water (NNBW). The simulated results from 1960 to 2001 showed that RIV, MSR and NNBW increased significantly from the 1960s to the early 1990s globally, but LR increased at a relatively low rate. After the early 1990s, the increase in RIV declined as it approached a critical limit, due to the continued expansion of irrigation area. MSR and NNBW increased significantly, during the same time period, following the expansion of the irrigation area and the increased storage capacity of the medium-size reservoirs. We also estimated future irrigation water requirements from the above four water supply sources and an additional water supply source (ADD) in three future simulation designs; irrigation area change, climate change, and changes in both irrigation area and climate. ADD was defined as a future increase in NNBW. After the 2020s, MSR was predicted to approach the critical limit, and ADD would account for 11-23% of the total requirements in the 2040s.

  3. Irrigation efficiency and water-policy implications for river basin resilience

    NASA Astrophysics Data System (ADS)

    Scott, C. A.; Vicuña, S.; Blanco-Gutiérrez, I.; Meza, F.; Varela-Ortega, C.

    2014-04-01

    Rising demand for food, fiber, and biofuels drives expanding irrigation withdrawals from surface water and groundwater. Irrigation efficiency and water savings have become watchwords in response to climate-induced hydrological variability, increasing freshwater demand for other uses including ecosystem water needs, and low economic productivity of irrigation compared to most other uses. We identify three classes of unintended consequences, presented here as paradoxes. Ever-tighter cycling of water has been shown to increase resource use, an example of the efficiency paradox. In the absence of effective policy to constrain irrigated-area expansion using "saved water", efficiency can aggravate scarcity, deteriorate resource quality, and impair river basin resilience through loss of flexibility and redundancy. Water scarcity and salinity effects in the lower reaches of basins (symptomatic of the scale paradox) may partly be offset over the short-term through groundwater pumping or increasing surface water storage capacity. However, declining ecological flows and increasing salinity have important implications for riparian and estuarine ecosystems and for non-irrigation human uses of water including urban supply and energy generation, examples of the sectoral paradox. This paper briefly considers three regional contexts with broadly similar climatic and water-resource conditions - central Chile, southwestern US, and south-central Spain - where irrigation efficiency directly influences basin resilience. The comparison leads to more generic insights on water policy in relation to irrigation efficiency and emerging or overdue needs for environmental protection.

  4. Water and solute balances as a basis for sustainable irrigation agriculture

    NASA Astrophysics Data System (ADS)

    Pla-Sentís, Ildefonso

    2015-04-01

    The growing development of irrigated agriculture is necessary for the sustainable production of the food required by the increasing World's population. Such development is limited by the increasing scarcity and low quality of the available water resources and by the competitive use of the water for other purposes. There are also increasing problems of contamination of surface and ground waters to be used for other purposes by the drainage effluents of irrigated lands. Irrigation and drainage may cause drastic changes in the regime and balance of water and solutes (salts, sodium, contaminants) in the soil profile, resulting in problems of water supply to crops and problems of salinization, sodification and contamination of soils and ground waters. This is affected by climate, crops, soils, ground water depth, irrigation and groundwater composition, and by irrigation and drainage management. In order to predict and prevent such problems for a sustainable irrigated agriculture and increased efficiency in water use, under each particular set of conditions, there have to be considered both the hydrological, physical and chemical processes determining such water and solute balances in the soil profile. In this contribution there are proposed the new versions of two modeling approaches (SOMORE and SALSODIMAR) to predict those balances and to guide irrigation water use and management, integrating the different factors involved in such processes. Examples of their application under Mediterranean and tropical climate conditions are also presented.

  5. Probabilistic description of crop development and irrigation water requirements with stochastic rainfall

    NASA Astrophysics Data System (ADS)

    Vico, Giulia; Porporato, Amilcare

    2013-03-01

    Supplemental irrigation represents one of the main strategies to mitigate the effects of climatic variability on agroecosystems, stabilizing yields and profits. Because of the significant investments and water requirements associated with irrigation, strategic choices are needed to preserve productivity and profitability while ensuring a sustainable water management, a nontrivial task given rainfall unpredictability. Decision-making under uncertainty requires the knowledge of the probability density function (pdf) of the outcome variable (yield and economic return) for the different management alternatives to be considered (here, irrigation strategies). A stochastic framework is proposed, linking probabilistically the occurrence of rainfall events and irrigation applications to crop development during the growing season. Based on these linkages, the pdf of yields and the corresponding irrigation requirements are obtained analytically as a function of climate, soil, and crop parameters, for different irrigation strategies and both unlimited and limited water availability. Approximate expressions are also presented to facilitate their application. Our results employ relatively few parameters and are thus broadly applicable to different crops and sites, under current- and future-climate scenarios, offering a quantitative tool to quantify the impact of irrigation strategies and water allocation on yields. As a tool for decision-making under uncertainty (e.g., via expected utility theory), our framework will be useful for the assessment of the feasibility of different irrigation strategies and water allocations, toward a sustainable management of water resources for human and environmental needs.

  6. Reclamation of used urban waters for irrigation purposes--a review of treatment technologies.

    PubMed

    Norton-Brandão, Diana; Scherrenberg, Sigrid M; van Lier, Jules B

    2013-06-15

    The worldwide fresh water scarcity is increasing the demand for non-conventional water resources. Despite the technology being available for application of treated wastewater in irrigation, the use of effluent in agriculture is not being properly managed in the majority of cases. Industrial countries, where financial resources are available but restricted, face difficulties in some cases related to the lack of a complete definition of irrigation water quality standards, as well as to the lack of monitoring components that determine if the effluent is suitable for such use. The present paper presents a critical review on urban reclamation technologies for irrigation. The technologies are presented by the four most important parameters for irrigation water quality: salinity, pathogens, nutrients and heavy metals. An overview is given of the current, on-going evaluation of different reclamation technologies for irrigation. PMID:23562951

  7. Irrigation efficiency and water-policy implications for river-basin resilience

    NASA Astrophysics Data System (ADS)

    Scott, C. A.; Vicuña, S.; Blanco-Gutiérrez, I.; Meza, F.; Varela-Ortega, C.

    2013-07-01

    Rising demand for food, fiber, and biofuels drives expanding irrigation withdrawals from surface- and groundwater. Irrigation efficiency and water savings have become watchwords in response to climate-induced hydrological variability, increasing freshwater demand for other uses including ecosystem water needs, and low economic productivity of irrigation compared to most other uses. We identify three classes of unintended consequences, presented here as paradoxes. Ever-tighter cycling of water has been shown to increase resource use, an example of the efficiency paradox. In the absence of effective policy to constrain irrigated-area expansion using "saved water", efficiency can aggravate scarcity, deteriorate resource quality, and impair river-basin resilience through loss of flexibility and redundancy. Water scarcity and salinity effects in the lower reaches of basins (symptomatic of the scale paradox) may partly be offset over the short-term through groundwater pumping or increasing surface water storage capacity. However, declining ecological flows and increasing salinity have important implications for riparian and estuarine ecosystems and for non-irrigation human uses of water including urban supply and energy generation, examples of the sectoral paradox. This paper briefly examines policy frameworks in three regional contexts with broadly similar climatic and water-resource conditions - central Chile, southwestern US, and south-central Spain - where irrigation efficiency directly influences basin resilience. The comparison leads to more generic insights on water policy in relation to irrigation efficiency and emerging or overdue needs for environmental protection.

  8. Soil chemical changes resulting from irrigation with water co-produced with coalbed natural gas

    SciTech Connect

    Ganjegunte, G.K.; Vance, G.F.; King, L.A.

    2005-12-01

    Land application of coalbed natural gas (CBNG) co-produced water is a popular management option within northwestern Powder River Basin (PRB) of Wyoming. This study evaluated the impacts of land application of CBNG waters on soil chemical properties at five sites. Soil samples were collected from different depths (0-5, 5-15, 15-30, 30-60, 60-90, and 90-120 cm) from sites that were irrigated with CBNG water for 2 to 3 yr and control sites. Chemical properties of CBNG water used for irrigation on the study sites indicate that electrical conductivity of CBNG water (EC{sub w}) and sodium adsorption ratio of CBNG water (SAR{sub w}) values were greater than those recommended for irrigation use on the soils at the study sites. Soil chemical analyses indicated that electrical conductivity of soil saturated paste extracts (ECe) and sodium adsorption ratio of soil saturated paste extracts (SAR(e)) values for irrigated sites were significantly greater (P < 0.05) than control plots in the upper 30-cm soil depths. Mass balance calculations suggested that there has been significant buildup of Na in irrigated soils due to CBNG irrigation water as well as Na mobilization within the soil profiles. Results indicate that irrigation with CBNG water significantly impacts certain soil properties, particularly if amendments are not properly utilized. This study provides information for better understanding changes in soil properties due to land application of CBNG water.

  9. Productivity of irrigated bean submitted to water deficit in different phenological stages

    NASA Astrophysics Data System (ADS)

    Miorini, T. J. J.; Saad, J. C. C.

    2012-04-01

    Water scarcity is the most important factor limiting crop yields worldwide. An increased sustainable use of irrigation water will be necessary to feed our growing population. Bean (Phaseolus vulgaris L.) is widespread in the social and economic scene in Brazil, as well it is Brazilian population main dish, and it also helps small and medium farmers' income. The damage caused by water deficit depends on the duration, severity and stage of plant development. The bean plant is classified as sensitive to both water deficit and excess water in the soil. The hypothesis is that if the water supply is suppressed in just one of the five development stages of irrigated beans, it can result in productivity reduction lower than 20%, allowing water economy. The objective of this study was to compare the performance of bean Carioca group IAC Alvorada yield components, with irrigation suppression in each of the five phenological phases (emergence, vegetative, flowering, grain filling and maturation) and no irrigation and irrigated in all stages. The study was conducted at Agronomical Sciences College, UNESP, Botucatu, SP, Brazil. The statistical design was the randomized block with seven treatments and four replications. Data were subjected to analysis of variance and "t" test at 5% probability. The irrigation suppression only during emergence, filling, and maturation phases did not show any statistical difference in productivity when compared with the irrigated at all stages. The irrigation suppression at vegetative and flowering phase, reduced the production at 75.1 and 76.2%, respectively, when compared with irrigation at all stages, despite the reduction of the water depth being around 20% for flowering and 33.8% for the vegetative phase when compared to the irrigated at all stages. Irrigation suppression in all phases generated a reduction of approximately 87.3% when compared with irrigation at all stages. During the experiment there was a total recorded rainfall of 156mm

  10. Water relations of differentially irrigated cotton exposed to ozone

    SciTech Connect

    Temple, P.J.

    1990-01-01

    The field study was conducted to test the hypothesis that plants chronically exposed to O{sub 3} may be more susceptible to drought because O{sub 3} typically inhibits root growth and increases shoot-root ratios in plants. Cotton was grown in open-top chambers on Hanford coarse sandy loam in Riverside, CA. Plants were grown under three irrigation regimes: Optimum water for lint production (OW), suboptimum or moderate drought stress (SO), and severely drought stressed (SS) and were exposed to seasonal 12 h (0800-2000) O{sub 3} centrations of 0.015, 0.074, 0.094, or 0.111/microLL. Leaf xylem pressure potentials Psi(sub 1) and soil water content Theta(sub v) were measured weekly from June to October. Mean seasonal Psi(sub 1) increased from -1.89 MPa to -1.72 MPa in low to high O{sub 3} treatments, averaged across soil water regimes. Ozone had no effect on seasonal water use of cotton, but water use efficiency was significantly reduced by O{sub 3} in OW and SO, but not in SS treatments. Drought-stressed plants extracted proportionally greater amounts of water from deeper in the soil profile than OW cotton, and O{sub 3} had no apparent effect on this redistribution of roots in the soil. Since O{sub 3} had no apparent effect on the ability of drought-stressed cotton to maintain Psi(sub 1) and to increase root growth relative to shoot growth, this suggests that O{sub 3} may have little or no effect on the potential of cotton to adapt to or tolerate drought.