Showing papers on "Saline water published in 1996"

Foliar and root absorption of Na+ and Cl− in maize and barley: Implications for salt tolerance screening and the use of saline sprinkler irrigation

Abstract: Above-canopy sprinkler irrigation with saline water favours the absorption of salts by wetted leaves and this can cause a yield reduction additional to that which occurs in salt-affected soils. Outdoor pot experiments with both sprinkler and drip irrigation systems were conducted to determine foliar ion accumulation and performance of maize and barley plants exposed to four treatments: nonsaline control (C), salt applied only to the soil (S), salt applied only to the foliage (F) and salt applied to both the soil and to the foliage (F+S). The EC of the saline solution employed for maize in 1993 was 4.2 dS m−1 (30 mM NaCl and 2.8 mM CaCl2) and for barley in 1994, 9.6 dS m−1 (47 mM NaCl and 23.5 mM CaCl2). The soil surface of all pots was covered so that in the F treatment the soil was not salinized by the saline sprinkling and drip irrigation supplied nutrients in either fresh (treatments C and F) or saline water (treatments S and F+S). Saline sprinkling increased leaf sap Na+ concentrations much more than did soil salinity, especially in maize, even though the saline sprinkling was given only two or three times per week for 30 min, whereas the roots of plants grown in saline soil were continuously exposed to salinity. By contrast, leaf sap Cl− concentrations were increased similarly by saline sprinkling and soil salinity in maize, and more by saline sprinkling than saline soil in barley. It is concluded that barley leaves, and to a greater extent maize leaves, lack the ability to selectively exclude Na+ when sprinkler irrigated with saline water. Moreover, maize leaves selectively absorbed Na+ over Cl− whereas barley leaves showed no selectivity. When foliar and root absorption processes were operating together (F+S treatment) maize and barley leaves accumulated 11–14% less Na+ and Cl− than the sum of individual absorption processes (treatment F plus treatment S) indicating a slight interaction between the absorption processes. Vegetative biomass at maturity and cumulative plant water use were significantly reduced by saline sprinkling. In maize, reductions in biomass and plant water use relative to the control were of similar magnitude for plants exposed only to saline sprinkling, or only to soil salinity; whereas in barley, saline sprinkling was more detrimental than was soil salinity. We suggest that crops that are salt tolerant because they possess root systems which efficiently restrict Na+ and Cl− transport to the shoot, may not exhibit the same tolerance in sprinkler systems which wet the foliage with saline water. ei]T J Flowers

Hydrochemical Analysis of Ground-Water Flow and Saline Incursion in the Clarendon Basin, Jamaica

Abstract: The Clarendon Basin of south-central Jamaica has been recognized for its productive sugar cane industry since the late 1800s. Much of its success is attributed to rich alluvial soils, a year-round tropical climate and copious supplies of good quality irrigation water from a karstic limestone aquifer of Tertiary age. This aquifer extends throughout the northern part of the basin, but ends abruptly at the South Coast Fault, an east west feature that forms the northern boundary of a deep graben filled with alluvial sediments. These alluvial sediments are the only source of water for the area south of the fault (the Vere Plain). However, the sediments also lap onto the limestone to the north of the fault (the Clarendon Plain) and provide a supplementary ground-water source. By the early 1970s nearly 200 wells supplied irrigation water for over 20,000 hectares of land. As development increased, the salinity of the ground water increased. Consequently, many wells were closed down and several sugar plantations were abandoned. In the study presented here, major ion (Ca, Mg, Na, K, HCO3, Cl, SO4, and NO3), minor ion (F, Br, and I), and environmental isotope (δ18O,δD) hydrochemistry is used to resolve the hydrodynamics of ground-water flow in the basin and identify the source and mode of emplacement of the saline water. Oxygen and hydrogen isotope data confirm that while the major well production areas are located in lowland coastal areas, recharge originates almost exclusively as rainfall in the cooler elevated parts of the basin above 750 m (asl). Subsurface conduit flow brings this water to the limestone well fields, and any excess water is able to cross the South Coast Fault to feed the alluvial aquifer of the Vere Plain. The thin alluvial aquifer of the Clarendon Plain also receives limestone water but this water does not enter entirely by subsurface means. Instead data suggest that while some of the water can be attributed to natural upward vertical leakage in the northwest of the Clarendon Plain, the remainder can be attributed to the seepage of irrigation water drawn, at least in part, from wells developed in the underlying limestone. Saline ground waters affect all the aquifers of the basin and several potential sources have been proposed. Major and minor ion data point to a sea-water source, and a sea-water wedge extending beneath the thick alluvial aquifer of the Vere Plain is an obvious candidate for the source of salinity observed in wells from this aquifer. Closer examination of the chemical data reveals, however, that wells in the limestone and alluvial aquifers to the north of the South Coast Fault do not derive their salinity from this source location, and instead draw sea water from the east and west along the relatively permeable South Coast Fault zone. This water can move to limestone wells directly; wells in the alluvium of the Clarendon Plain, however, receive most of the saline water indirectly via leakage of irrigation water pumped initially from the limestone. Sea water drawn along the fault may also be the primary source of salinity in the aquifer of the Vere Plain but this cannot be confirmed on the basis of hydrochemical evidence alone.

Inula crithmoides: A candidate plant for saline agriculture

Abstract: Inula crithmoides L., a common halophyte from the coast of Lebanon was evaluated for use in saline agriculture. The plant is traditionally consumed in Lebanon and is claimed to have medicinal properties. Inula crithmoides offshoots were collected from the wild and propagated in a controlled environment. Germination and rooting tests under various salinity regimes ranging from 0.5 to 80 dS m‐1 (NaCl) demonstrated a severe restriction of germination above 20 dS m‐1 and indicated that vegetative propagation is probably the main reproduction strategy in saline environments. The growth of potted plants grown under 5 levels of salinity for a period of 87 days was only affected by salinity exceeding 20 dS m‐1. Yield of plants irrigated with 40 dS m‐1 saline water was nearly half that of the no‐salt control. Mean yield value for plants grown at 20 dS m‐1 reached 18.3 g dry weight (DW) per plant. At this salinity, crude protein content averaged 12.7% mg kg‐1, and shoot iodine contents ranged between 0.8 and 1.4 mg...

Mosquitoes (Diptera:Culicidae) breeding in brackish water: female ovipositional preferences or larval survival?

Abstract: Four species of mosquitoes were abundant in concrete reservoir tanks containing brackish water that ranged from 16 to 39% sea water. The ability of the larvae to survive in various salinities was compared for each species with the ovipositional preferences of the adult females to determine whether the 2 traits were correlated. Southern house mosquito, Culex quinquefasciatus Say, normally was not present in the tanks but survived well in salinities up to 25% sea water. However, gravid females almost always oviposited in fresh water. Culex sitiens Weidemann larvae survived best in saline water (66% sea water), but oviposition was greatest in 28% sea water; both larval survival and the frequency of oviposition were low in fresh water. Culex sinaiticus Kirkpatrick survived salinities up to 50% sea water, but the females refused to blood-feed; therefore, their ovipositional preferences were not tested. Larvae of Anopheles stephensi Liston and An. culicifacies Giles survived best in fresh water, but some An. stephensi were able to tolerate up to 50% sea water. The females had a similar ovipositional preference for fresh water. The preferred salinity for oviposition did not correspond with larval survival for Cx. quinquefasciatus and Cx. sitiens, but did compare well in An. stephensi and An. culicifacies.

Potentiality of Landsat, SPOT and IRS satellite imagery, for recognition of salt affected soils in Indian Arid Zone

Abstract: Landsat, SPOT and IRS data, black and white and false colour composite (FCC) imagery of the summer (April, May), rainfed crop season (October) and winter irrigated crop season (January, February) of Indian Arid Zone were interpreted for recognition or three types of salt affected soils, viz. (1) natural salt affected; slight, moderate and severe, (2) saline soils due to saline water irrigation, (3) sodic soils due to high residual sodium carbonate (RSC) water irrigation. These were field checked and supported by analytical data. The Landsat-MSS band 4 could only provide the overall extent of salinity. The moderate and severe natural salt affected soils were identified by Landsat-MSS band 2, Landsat-MSS and TM, IRS LISS-I and LISS-II and SPOT HRV2 data for April and January. But the differentiation between the saline and sodic soils was possible only by the use of multi-date imagery (October and January) and the clue provided by the cropping pattern. The potentiality of remote sensing data product...

Salinity‐heavy metal interactions as evaluated by soil extraction and plant analysis

Abstract: Both heavy metal pollution and saline water irrigation are increasing in the dry areas, especially in developing countries. The effects of soil and water salinity on the transfer of heavy metals to crops are, however, not well understood. The uptake of Zn, Cu and Cd from a polluted desert soil from the north west of Egypt was therefore evaluated in pot experiments with maize, irrigated either with NaCl or with NaCl + CaCl2 solutions. NaCl accelerated root mortality and increased both the concentration of heavy metals in soil saturation extract and their uptake by maize. In contrast to NaCl, CaCl2 affected solubility and plant uptake of heavy metals differently. While the solubility of heavy metals was enhanced by CaCl2, both root mortality and the uptake of heavy metals were depressed. It was concluded that salinity of irrigation water affects heavy metal uptake at least partly by modifying root functions.

Chemical Separation Process for Highly Saline Water. 1. Parametric Experimental Investigation

Abstract: The separation of highly saline waters under various conditions is carried out using a nonconventional partial-desalting process. The method utilizes a series of chemical reactions involving the conversion of sodium chloride, the major constituent in saline waters, into sodium bicarbonate, which precipitates under the experimental conditions, and ammonium chloride, which can be separated by crystallization. Experiments of absorption of carbon dioxide in an ammoniated brine have demonstrated the efficiency of the method. Interpretations using conversion parameters such as temperature, initial concentrations of ammonia, sodium chloride, and the ratio of NH3/NaCl are discussed.

Brief pre- and post-irrigation sprinkling with fresh water reduces foliar salt uptake in maize and barley sprinkler irrigated with saline water

Abstract: Brief pre- and post-irrigation sprinkling treatments using freshwater were tested to determine if these practices could reduce the uptake of salts through leaves when saline water is used to sprinkler irrigate crops. Maize and barley were sprinkler irrigated 2 to 3 times per week for 30 min with saline water (4.2 dS m−1, 30 mmol L−1 NaCl and 2.8 mmoles L−1 CaCl2 for maize and 9.6 dS m−1, 47 mmoles L−1 NaCl and 23.5 mmoles L−1 CaCl2 for barley) in separate experiments with plants grown in pots outdoors. The soil surface of all pots was covered to prevent salinization of the soil by the sprinkling water. One half of the sprinkled plants was grown in nonsaline soil to study the effects of pre-wetting and post-washing when ion uptake was primarily through leaves. The other half of the sprinkled plants was grown in soil salinized by drip irrigation, in order to evaluate the effects of pre-wetting and post-washing when Na+ and Cl- uptake was through both leaves and roots. Post-washing with freshwater (5 min) reduced the leaf sap concentrations of Cl- in saline-sprinkled plants from 56 to 43 mmol L−1 in maize and from 358 to 225 mmol L−1 in barley (averages for plants grown in nonsaline and saline soil). Na+ concentrations in leaf sap were reduced from 93 to 65 mmoles L−1 (maize) and from 177 to 97 mmoles L−1 (barley) by the post-washing. Pre-wetting had a small effect on ion uptake through leaves, the only significant reduction in seasonal means being in leaf Na+ concentrations for plants grown in nonsaline soil. Pre-wetting and post-washing, when combined, reduced leaf Cl- concentrations to levels similar to those of nonsprinkled plants grown in saline soil; however, Na+ concentrations in leaves remained 3.5 times (maize) and 1.5 times (barley) higher than those of nonsprinkled plants. When pre-wetting and post-washing were not applied, sprinkled barley plants grown in saline soil had grain yields which were 58% lower than nonsprinkled plants grown in saline soil, but the reduction in grain yield was only 17% when the freshwater treatments were given. We conclude that a brief period of post-washing with freshwater is essential when saline water is employed in sprinkler irrigation. By comparison, the benefits from pre-wetting were small in these experiments. ei]T J Flowers

The effects of zeolites and other alumino-silicate clays on water quality at various salinities

Abstract: Intensive marine and brackishwater shrimp farms commonly use large quantities of zeolites in ponds with the aim of removing ammonia through ion exchange, providing physical cover over sediments to prevent leaching of metabolites into the water column, removing suspended solids, and improving water colour and diatom blooms. Zeolites have the capacity to remove ammonia and other nutrients/ metabolites from fresh waters by ion exchange and absorption. However, there are doubts as to their efficacy and cost-effectiveness in saline waters. This research was conducted to investigate the effect of zeolites on water quality under a range of conditions in seven laboratory-based trials and one pond trial. These investigated the effects of six types of commercially available zeolites and three other alumino-silicate clays at levels from one to 26 times the recommended dose rate (380 kg ha-1 month-1) in water at salinities of 0-30%o for periods of 3-19 days. The results indicated that none of the zeolites or natural alumino-silicate clays from Thailand had any significant effects on the removal of nutrients from water at salinities of 0-30%. Neither were these able to prevent nutrient emission from shrimp pond sediments in water at 20-2l%o salinity. Furthermore, none of the other suggested functions of reducing levels of particulate nutrients, enhancing algal biomass, or affecting oxygen and pH dynamics were evident. This study could not establish any useful, cost-effective role for zeolites in shrimp pond culture.

Plant species for revegetation of a saline flue gas desulfurization sludge pond

Abstract: Codisposing saline wastewater from electrical generating stations with flue gas desulfurization (FGD) scrubber sludge simplifies waste disposal but produces a saline waste that will later require revegetation. This waste is low in macronutrients, contains high levels of salts and B, and has a fine texture. This study identified plants, based on germination test results, that show promise for sowing at an evaporation pond in eastern Arizona where scrubber sludge and wastewater are codisposed. Forty-four grass, forb, and shrub accessions germinated on filter paper in saline water from the disposal pond. Dilutions of disposal pond water with untreated well water from the site ranged in EC from 0.17 to 3.03 S m -1 . Our criteria for evaluating plants to be used in revegetating saline FGD sludge were : (i) ability to germinate in increasing levels of disposal pond water and (ii) ease of establishment from seed. The percentage of pond water that would reduce germination to 50% that of well-water controls (P 50 ) ranged as high as >100 for the most tolerant plants. Accessions that show promise for sowing at these types of saline waste disposal sites include : Elytrigia pontica 'Jose' and 'Largo', Atriplex gardneri, Puccinellia airoides, P. distans 'Fults', Festuca aurundinacea 'Alta' and 'Fawn', Krascheninnikovia lanata, Kochia prostrata 'Immigrant', Panicum virgatum 'Nebraska 28', Sporobolus airoides 'Saltalk', Leymus angustus 'Praireland' and Elymus trachycaulus 'Pryor'.

The effect of a saline and non-saline water table on peach tree water use, growth, productivity and ion uptake

Abstract: The effect of salinity and shallow water tables (1.4 m depth) used in combination with Regulated Deficit Irrigation (RDI) on peach trees (Prunus persica, L. Batsch) was studied over 2 years. Under RDI management a non-saline water table contributed up to 30% of water use. A lack of control of vegetative growth in the first season indicated that a shallow water table may interfere with RDI management. A decline in tree health and growth under RDI and a non-saline water table in the following season may have resulted from salinity and/or waterlogging effects. Saline irrigation under RDI management caused an additional decline in tree growth compared with RDI under non-saline conditions, and resulted in a reduction in productivity (yield and fruit size) and increased uptake of sodium (Na) and chloride (Cl) ions in various plant tissues. Similarly, a saline water table caused a decline in tree growth and fruit size in the first season and increased uptake of Na and C1 ions. For all treatments, accumulation of C1 in the leaves, Na and C1 in the fruit, Na in the bark and storage of Na in the butt wood and structural roots was demonstrated. Differences in mechanisms of transport of Na and C1 and the importance of older wood as a storage organ for ions are proposed. The potential for butt wood as a precise indicator of past salinity treatment is suggested. A combination of a shallow water table and moderate salinity environment was shown to present a potential health hazard for peach trees. The need for refinement of RDI management to incorporate leaching in the presence of saline irrigation and/or water tables is proposed. The management of drainage is also essential.

Effect of water salinity and temperature on the hydrophobicity of ethylene propylene diene monomer insulator

Abstract: Ethylene propylene diene monomer (EPDM) is extensively used in outdoor composite polymer insulators. The effects of water salinity and temperature on the hydrophobicity of EPDM rubber were studied The hydrophobicity was determined by measuring the contact angle using a droplet of distilled water. The specimens were immersed in saline water solutions for up to 576 h. The salinity levels used were 5, 10/sup 3/, 10/sup 4/ and 10/sup 5/ /spl mu/S/cm. The aging temperatures were 0, 25, 50, 75 and 98/spl deg/C. The weight was also measured to determine the amount of water absorption in the polymer as might occur during a heavy rain. The change in the contact angle is related to the amount of water absorption, the salinity level of solution and the temperature. The absorption of saline water into the bulk is larger at higher temperatures and decreases with increasing salinity. At 25/spl deg/C and higher the absorption of saline water at all salinity levels was saturated during the aging period Generally, after long immersion the contact angle decreased. At 0/spl deg/C the decrease of contact angle was larger at higher salinity. At high temperatures (/spl ges/75/spl deg/C), the sample surface gradually changed its color from the original dark gray to white.

Long-term effect of irrigation with saline water on the development and productivity of jojoba clones

Abstract: SummaryThree commercial clones of jojoba (Simmondsia chinensis) (64, Q-106 and 879–154) were planted in June 1991 at the Ramat Negev Experimental Station (Israel) and fertigated with water at three salinity levels, 1.2, 3.4 or 6.2 dS m−1. The effects of salinity over three and a half years on key metabolic activities, on plant growth and development, on flowering characteristics, and on yield were studied. Salinity barely inhibited the rate of net photosynthesis, although it did reduce stomatal conductivity by about 50%. Salinity also affected the water status of the plants by reducing water potential. Growth of the plants was not greatly affected by salinity. It was found that jojoba plants accumulate sodium and chloride ions in their leaves and use a strategy typical of many halophytes to cope with the salinity. The effect of salinity on flower development was also studied, since the vitality of flowers is a key factor in obtaining seeds. Salinity did not affect the timing of the breaking of flower bud ...

Saline intrusions in the intermediate waters north of Oahu, Hawaii

Abstract: The Hawaii Ocean Time-series (HOT) hydrographic observations at station ALOHA (22°45′N, 158°W) reveal that the region is sometimes the site of intrusive interleaving of different water types near the salinity minimum of the North Pacific Intermediate Waters. This interleaving is associated with saline laminae, or lenses, 5–30 km long (submesoscale) and 5–100 m thick (finestructure). The temporal variability of these intermediate waters is investigated statistically, and a background water type is defined against which to measure the strength of intrusions. The salinity minimum shows a relative maximum in variability, caused mainly by the episodic appearance of the saline, finestructure intrusions, which are correlated with low oxygen and silicate concentrations. The intermediate salinity minimum has its southern boundary near the latitude of the Hawaiian Islands, where salinity increases towards the south and oxygen gradually decreases. Thus, stirring processes local to the Hawaiian Ridge may explain the observations. Possible mechanisms are suggested, including fluctuations of the subtropical gyre southern boundary and a hydrodynamically unstable flow at intermediate depths along the ridge. Either process could transport relatively saline water into the ALOHA region, and would lead to interleaving, driven by double diffusion on scales of the order of 10 m in the vertical.

Saline-water irrigation for the establishment of furrow-planted trees in northwestern India

Abstract: Appropriate tree species and planting methods can help rehabilitation of arid areas — that are characterized by low rainfall, high evapotranspiration demands, highly saline ground waters and calcareous subsoils. The growth of Acacia nilotica and Dalbergia sissoo saplings planted in irrigation furrows in such an arid zone of northwest India was not affected adversely by irrigation with saline water of EC W 10.5 dS m−1. The growth of A. nilotica, measured in terms of sapling survival, plant height and biomass yields, was better than that of D. sissoo. Increasing the period of irrigation from the recommended practice of irrigating only in the first year dry season (October–June) to second and third dry seasons (years) improved the sapling survival, growth and biomass (two-to-three-fold) and water use efficiency (two-to-four fold). Most of the salts added with saline irrigation were accumulated below the irrigation channels and were pushed laterally during the monsoon season. The results indicate that the furrow planting technique could be adopted as an afforestation practice in view of the creation of favourable water and salt regimes and their impact on the establishment of trees saplings. Irrigation water supplies for a minimum of intitially two years after transplanting seemed necessary.

Fruit quality and partitioning of mineral elements in processing tomato in response to saline nutrients

Abstract: A sand culture experiment was conducted to study the effect of saline water on the growth and fruit quality of processing tomato (Lycopersicon esculentum Mill) Seedlings of five tomato cultivars were transplanted in quartz‐sand pots in a greenhouse at the Agricultural Experiment Station of Sultan Qaboos University There were four saline nutrient solutions and a control consisting of half‐strength Hoagland solution Salinity treatments were: 50 raM NaCl + 3 mM K2SO4 (EC 675), 50 mM NaCl + 15 mM orthophosphoric acid (EC = 718), 50 mM NaCl + 15 mM orthophosphoric acid + 3 mM R2SO4 (EC 729), and 50 mM NaCL (EC = 56) Treatments were applied daily commencing two weeks after transplanting Data were collected on growth, and fruit yield and quality Partitioning of mineral elements was determined in the vegetative tissue The results obtained clearly show that concentrations of total soluble solids were increased in fruits treated with saline nutrients Dry matter content of fruits exposed to sa

Use and Management of Saline Water for Irrigation Towards Sustainable Development

Abstract: The goal of sustainable development should be to make sure that natural resource will be available for future generations. This applies to the use of water resources in such a way that renewable water does not diminish over the long term.

Double-Emitter Source (DES) for Irrigation Experiments in Salinity and Fertilization

Abstract: A double-emitter source (DES) irrigation system was designed, using trickle instead of sprinkler irrigation. Two trickle laterals and their emitters connected to two tanks of stock solutions are coupled together to form a double-joint lateral. Tbe emitters of the two lines have different and varying discharges to obtain various mixings between the two stock solutions while maintaining constant application rates. The layout produces a sequence of intermediates between maximal and minimal concentrations. The method was tested for a salinity experiment on globe artichoke (Cynara scolymus L.) and a fertilization experiment for amaryllis (Hippeastrum hybrid). Average electrical conductivity (EC) of the fresh and saline laterals was 1.5 and 6.2 dS m -1 , respectively. The N and K concentrations in the stock solution were 13.12 g L -1 and 9.38 g L -1 , respectively, for a mixed and diluted maximum of 777 and 556 mg L -1 N and K at the irrigation solution. Artichoke yield declined by 60% due to salinity when EC increased from 1.5 to 6.2 dS m -1 . Hippeastrum bulb diameter and weight increased 35% with high N and low K application. We condude that the double-emitter source can be used for precise application of varying salts or nutrients in multivariable experiments. Advantages include prevention of canopy wetting by saline water, precise distribution of the factor to be evaluated, and small experimental plots (reducing time, area, and labor requirements).

The behavior of stratified pools in the Wimmera River, Australia

Abstract: Numerous inland Australian streams contain density-stratified or saline pools, which are usually located on channel bends Saline pools consist of a layer of saline water underlying a layer of fresh water Saline pools generally form as a result of saline groundwater seeping into the stream and collecting in scour depressions during periods of low flow Inflows of saline river water can also collect in scour depressions Field and laboratory investigations of saline pool mixing by overflowing fresh water reveal that mixing depends on a balance between interfacial shear and buoyancy forces acting on a thin dense layer flowing up the downstream slope of the scour depression, and on the bend sharpness Convection associated with surface cooling also causes mixing A model for saline pools formed by groundwater inflows and mixed by fresh overflows is proposed and applied to several saline pools in the Wimmera River

Sustainable irrigation scheduling: effects of saline water on soil physical properties

Abstract: In the Mediterranean environment, characterized by hot and dry summers, a soil salinity research has been carried out on clay loam soil classified as Haplustolls. Spring-summer vegetables were irrigated with NaCl solutions of 0%, 0.125%, 0.25%, 0.5% and 1% with intervals of 2, 5 and 10 d. During the extreme treatments (0% and 1%, 2 and 10 d), soil samples were taken in duplicate at depths of 0-10 and 20-30 cm. Water retention and unsaturated hydraulic conductivity characteristics were measured for each sample and Van Genuchten parameters were determined. Significant differences were observed between the mean values of most of these parameters, particularly for the treatments with 0% and 1% at intervals of 2 d.

Geochemical properties and saline-water intrusion in the Valle de Yabucoa alluvial aquifer, southeastern Puerto Rico

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