Showing papers on "Saline water published in 1997"
TL;DR: In this article, the interactive effects of sulfate salinity and selenium on biomass production and mineral content of purslane (Portulaca oleracea) plants were evaluated.
Abstract: Drainage water reuse systems have been proposed for the west side of the San Joaquin Valley of California in order to reduce the volumes of water requiring disposal. Implementation of this system requires development of a cropping system with successively higher salt tolerance. A major limitation is the need to identify alternate species that will be suitable as the final, most salt tolerant crop in the series. These crops must be productive when irrigated with waters that are typically high in sulfate salinity and may be contaminated with potentially toxic trace elements. This study was initiated to evaluate the interactive effects of sulfate salinity and selenium on biomass production and mineral content of purslane (Portulaca oleracea). Plants were grown in greenhouse sand cultures and irrigated four times daily. Treatments consisted of three salinity levels with electrical conductivities (ECi) of 2.1, 15.2, and 28.5 dS m−1, and two selenium levels, 0 and 2.3 mg L−1. In the initial harvests, shoot dry matter was reduced by 15 to 30% at 15.2 dS m−1 and by 80 to 90% at 28.5 dS m−1. Regrowth after clipping above the first node was vigorous and biomass from plants irrigated with 15.2 dS m−1 water was nearly double that from the 2 dS m−1 treatment. Purslane appears to be an excellent candidate for inclusion in saline drainage water reuse systems. It is (i) highly tolerant of both chloride- and sulfate-dominated salinities, (ii) a moderate selenium accumulator in the sulfate-system, and (iii) a valuable, nutritive vegetable crop for human consumption and for livestock forage.
114 citations
TL;DR: In this article, two mechanisms of deep-water mixing were identified based on nearly 600 CTD profiles taken between 1993 and 1995, and they showed that cold and relatively saline water from the Selenga, the major inflow to the lake, forms a density plume that reaches the bottom of the central basin during April and early May.
Abstract: Deep-water renewal in Lake Baikal (Siberia), the world’s deepest lake and largest lake by volume, is relatively fast. Water age calculated from tritium and helium as well as from chlorofluorocarbons does not exceed 19 yr. Relative saturation of dissolved oxygen typically exceeds 80%. The equation of state of Baikal water was determined including the effect-of dissolved ions and silicic acid. Based on nearly 600 CTD profiles taken between 1993 and 1995, two mechanisms of deep-water mixing were identified. (1) In spring, cold and relatively saline water from the Selenga, the major inflow to the lake, forms a density plume that reaches the bottom of the central basin during April and early May. Due to entrainment of lake water the plume transports about 125 km? of water per year to the deepest part of the basin. Later in spring, the river water forms the thermal bar observed along the eastern shore, There are indications that parts of the Selenga are also plunging to the deep part of the southern basin. (2) At Academician Ridge, separating the cold and “saline” water of the central basin from the warmer and slightly less saline water of the northern basin, horizontal mixing results in a water mass that can sink on either side of the sill. Whereas in the central basin the water mass stays at intcrmediatc depth, in the northern basin it sinks to the decpcst part. More detailed data are needed to quantify this density flux. No indication of a wind-induced thermobaric instability was found.
106 citations
TL;DR: Findings that AM-colonized plants have optional and alternative mechanisms available to satisfy their nutritive requirements and to maintain their physiological status in stress situations and in disturbed ecosystems are confirmed.
Abstract: The rose of an isolate of the arbuscular mycorrhizal (AM) fungusGlomus mosseae in the protection ofMedicago sativa (+Rhizobium meliloti) against salt stress induced by the addition of increasing levels of soluble salts was studied. The interactions between soluble P in soil (four levels), mycorrhizal inoculum and degree of salinity in relation to plant growth, nutrition and infective parameters were evaluated. Salt stress was induced by sequential irrigation with saline water having four concentrations of three salts (NaCl, CaCl2, and MgCl2).15N-labelled ammonium sulphate was added to provide a quantitative estimate of N2 fixation under moderate to high salinity levels. N and P concentration and nodule formation increased with the amount of plant-available P or mycorrhizal inoculum in the soil and generally declined as the salinity in the solution culture increased from a moderate to a high level. The mycorrhizal inoculation protected the plants from salt stress more efficiently than any amount of plant-available P in soil, particularly at the highest salinity level applied (43.5 dS m−1). Mycorrhizal inoculation matched the effect on dry matter and nutrition of the addition in the soil of 150 mg P kg−1. Nevertheless the highest saline solution assayed (43.5 dS m−1) affected more severely plants supplemented with phosphorus than those with the addition of mycorrhizal inoculum. Such a saline-depressing effect was 1.5 (biomass), 1.4 (N) and 1.5 (P) times higher in plants supplied with soluble phosphate than with AM inoculum. Mechanisms beyond those mediated by P must be involved in the AM-protectioe effect against salinity. The15N methodology used allowed the determination of N2 fixation as influenced by different P applications compared to mycorrhizal inoculation. A lack of correlation between nodule formation and function (N2 fixation) was evidenced in mycorrhizal-inoculated plants. In spite of the reduced activity per nodule in mycorrhizal-inoculated In spite of the reduced activity per nodule in mycorrhizal-inoculated plants, the N contents determined indicated the highest acquisition of N occurred in plants with the symbiotic status. Moreover, N and P uptake increased while Ca and Mg decreased in AM-inoculated plants. Thus P/Ca ratios and cation/anion balance in general were altered in mycorrhizal treatments. This study therefore confirms previous findings that AM-colonized plants have optional and alternative mechanisms available to satisfy their nutritive requirements and to maintain their physiological status in stress situations and in disturbed ecosystems.
88 citations
TL;DR: In this paper, the impact of field water management and rice cropping intensity on salinization in the Senegal River Delta was determined using an electromagnetic conductivity meter (Geonics EM38).
Abstract: Soil salinization constitutes a major threat to irrigated agriculture (mainly rice, Oryza sativa L.) in the Senegal River Delta. It is generally hypothesized that salinization is caused by (i) capillary rise from a saline water table and (ii) concentration of salts in the field due to lack of adequate drainage facilities. The impact of field water management and rice cropping intensity on salinization in the Delta was determined using an electromagnetic conductivity meter (Geonics EM38). More than 4000 measurements were made in 40 rice fields on a typical heavy day soil (Vertic Xerofluvent). Thirty EM38 measurements per field (0.25 ha) estimated average field soil salinity with a relative error of 20%. A multiple linear regression model based on EM38 readings explained 60 to 75% of the variability in conductivity of 1:5 saturation extracts at 0- to 5-, 10- to 15-, and 30- to 35-cm depths. Higher cropping intensity limited upward salt transport from the water table. Average horizontal and vertical EM38 measurements increased in the following order: two rice crops per year with drainage: 0.73 and 0.98 dS m -1 ; one rice crop per year with drainage: 1.26 and 1.76 dS m -1 ; one rice crop per year without drainage: 2.23 and 2.98 dS m -1 ; and abandoned fields: 4.77 and 4.29 dS m -1 . Results indicate a benefidal effect of flooded rice on salinity for this type of heavy clay soil. Irrigation development in the area needs to be accompanied by monitoring of water table depth.
60 citations
TL;DR: Overall, increasing salinity reduced leaf biomass more than root biomass, which in turn was reduced more than stem biomass, and only leaf concentrations of Na+ and Cl− were correlated with an index of family-level differences in salt tolerance.
Abstract: Growth and physiological responses of 15 open-pollinated families of baldcypress (Taxodium distichum var.distichum) subjected to flooding with saline water were evaluated in this study. Ten of the families were from coastal sites in Louisiana and Alabama, USA that have elevated levels of soil-water salinity. The other five families were from inland, freshwater sites in Louisiana. Seedlings from all families tolerated flooding with water of low (2 g 1−1) salinity. Differences in biomass among families became most apparent at the highest salinity levels (6 and 8 g 1−1). Overall, increasing salinity reduced leaf biomass more than root biomass, which in turn was reduced more than stem biomass. A subset of seedlings from the main greenhouse experiment was periodically placed indoors under artificial light, and measurements were made of gas exchange and leaf water potential. Also, tissue concentrations of Cl−, Na+, K+, and Ca2+ were determined at the end of the greenhouse experiment. Significant intraspecific variation was found for nearly all the physiological parameters evaluated, but only leaf concentrations of Na+ and Cl− were correlated with an index of family-level differences in salt tolerance.
56 citations
TL;DR: The King River, Tasmania, contains elevated levels of heavy metals, in particular copper, a result of the discharge of mine tailings and acid mine water from the Mt Lyell copper mine, which operated until late 1994.
48 citations
TL;DR: In this article, the isotopic compositions of salt lake brine coexisting with halite, oil-field water and river water from the Qaidam Basin (Qinghai, China) have been examined using high-precision measurement of chlorine isotopes based on thermal ionization mass spectrometry of the Cs2Cl+ ion.
48 citations
TL;DR: Leptochloa fusca, Spartina patens and Sporobolus virginicus (Smyrna) appeared to be promising halophytic plants for feeding goats and sheep in desert areas using available saline water for irrigation.
40 citations
TL;DR: In this article, fossil remains of diatoms and midges were used to reconstruct salinity changes at Mahoney Lake from the early postglacial, through the early, mid and late Holocene.
Abstract: Salinity fluctuations in lakes of semi-arid regions have long been recognised as indicators of palaeoclimatic change, and have provided a valuable line of evidence in palaeo-climatic reconstruction. In the present study, fossil remains of diatoms and midges were used to reconstruct salinity changes at Mahoney Lake from the early postglacial, through the early, mid and late Holocene. A transition from midges typical of a freshwater community (Protanypus, Sergentia, Heterotrissocladius, Cladopelma, Dicrotendipes) during the early postglacial, to those indicative of saline environments (Cricotopus/Orthocladius, Tanypus) occurred in the early Holocene. The midge-inferred salinity values reflected the shift from freshwater (0.031 g/L) immediately after deglaciation, to saline water (2.4 to 55.2 g/L) in subsequent periods. A less saline period was found to have occurred after 1000 yr BP, suggesting a cooler or wetter period. The diatom record indicates similar trends, with freshwater taxa (e.g.,Cyclotella bodanica var. aff.lemanica) dominating near the bottom of the core. Diatom-inferred salinities indicate that saline conditions (about 30 g/L) prevailed throughout subsequent Holocene time, although relatively fresh conditions are indicated following deposition of the Mazama Ash, and from about 1500 yr BP until the present day. Midge and diatom-inferred salinity reconstructions for Mahoney Lake compare favorably with each other, and with climate trends inferred from earlier palynological evidence. The palaeosalinity record thus contributes new data relevant to past climatic conditions, in a region where little data have previously been collected.
36 citations
TL;DR: Wang et al. as discussed by the authors reviewed the research and practice on the utilization of shallow saline groundwater in the part east of South GreatCanal in Haihe River Plain and found that using saline water for irrigation plays important role for overcoming the constraints and increasing crops yields.
Abstract: Drought and fresh water shortage are the main limiting factorsfor sustainable development of agriculture in North China Plain.Using saline water for irrigation plays important role forovercoming the constraints and increasing crops yields. Theexploitation and utilization of shallow saline groundwaterenables to regulate the groundwater depth and to promote thetransform of precipitation into available water resources.Thispaper reviews the research and practice on the utilization ofshallow saline groundwater in the part east of South GreatCanal in Haihe River Plain. Findings are presented on the useof saline water, cycling and blending of saline and fresh waterfor irrigation, indexing of crops salt tolerances, regulating forsoil salt-water regime, saline-alkali land reclamation andgroundwater quality freshening. These approaches help therational regulation and utilization of the local water resourcesfor comprehensive control of drought, waterlogging and salinity.
TL;DR: In this paper, differences in the delta strontium-87 (δ87Sr) composition of ground-water samples from southeastern Utah were used to determine if oil-field brine or water from the upper Paleozoic aquifer is a plausible source of salinity to the Navajo aquifer.
TL;DR: It was concluded that significant mortality of the early life stages of Australian bass would occur if they are exposed to acid-sulphate soil leachate that results in a pH in the receiving estuarine water below 5.5, or when the pH is below 6.8.
TL;DR: In this article, the authors propose a method to solve the problem of homonymity in homonym identification, i.e., homonym-of-individuals-with-groups.
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TL;DR: In this article, the effects of saline irrigation (EC w 10·5 dS m −1, sodium adsorption ratio 20 mmol l −1 ) and various irrigation schedules were evaluated for 45 months.
TL;DR: In this article, the authors propose a method to solve the problem of homonymity in homonym identification, i.e., homonymization, in the context of homology.
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TL;DR: Sixteen species of mosquitoes were collected in southern Oman, finding that Aedomyia furfurea, Anopheles sergentii and three species of Aedes were found only in fresh water, while the other species were found also in brackish water.
TL;DR: In this paper, the response of wheat (Triticum aestiuum L.) to varying depths of irrigation, quantity of water applied and to the drainage conditions was studied in 2m × 2 m × 2m size lysimeters filled in with a sandy loam soil.
TL;DR: Salinization of soil and groundwater resources is a common problem in the central and southwestern United States where infiltration of saline water into the shallow subsurface impacts wildlife habitat, restricts or eliminates agricultural uses of land, and pollutes aquifers and surface water bodies as mentioned in this paper.
Abstract: Salinization of soil and groundwater resources is a common problem in the central and southwestern United States where infiltration of saline water into the shallow subsurface impacts wildlife habitat, restricts or eliminates agricultural uses of land, and pollutes aquifers and surface water bodies Public concern about the environmental effects of saline water has increased interest in identifying salinity sources and determining whether oil‐field brine has been introduced into the subsurface, where it has migrated, and whether it is the cause of specific problems on the land surface, in water wells, and in surface water bodies
30 Dec 1997
TL;DR: The salinity of the ground water along the coastal aquifers of north Kelantan was investigated using both geophysical and hydrogeochemical methods as discussed by the authors, and the results showed that ground water of the first top aquifer is fresh with resistivities ranging from 47 Ohmm to 164 Ohm-m except in an area along the coast where the water is brackish.
Abstract: The salinity of the ground water along the coastal aquifers of north Kelantan was investigated using both geophysical and hydrogeochemical methods. In the geophysical method, a geoelectrical sounding technique was employed using ABEM SAS 300C terrameter. A total of 53 sounding stations had been established and resistivity values of the ground water in different aquifers were determined. Salinity ofthe ground water was interpreted using a classification made by Flathe (1974). Based on this classification, ground water with resistivity values of less than 45 Ohm-m is considered as saline or brackish water and those of greater than 45 Ohm-m is fresh water. The results show that the ground water of the first top aquifer is fresh with resistivities ranging from 47 Ohm-m to 164 Ohm-m except in an area along the coast where the water is brackish. The ground water of the second aquifer generally has resistivity lower than 45 Ohm-m and has been classified as brackish water. Resistivity map of the second aquifer indicates that the brackish water covers an area of up to about 6 kilometres from the coastal line. Only few resistivity data were obtained for the third aquifer and values are generally low (ranging from 56 to 72 Ohm-m) indicating that the ground water is relatively fresh. Salinity of the groundwater in all of the aquifers was also studied by analysing their chloride content. Ground water with chloride concentration of less than 250 mg/l is classified as fresh water and those having higher concentration of chloride is considered brackish or saline. Results of the water analysis show that the chloride concentration of the first aquifer is low and averages to only 15.8 mg/l. The fresh water/ saline water interface in this aquifer is generally located directly in the coastal area, or very close to it. The concentration of chloride in the second aquifer is high with values ranging from 500 to 3,600 mg/l and covers an area of up to about 6 kilometres from the coast. Beyond this area, the concentration of chloride appears to be low, with values ranging from 2 to 110 mg/l. Continuous monitoring of its chloride content (Haryono, 1997) indicates'little changes with time inferring that the high salinity is not due to seasonal sea water intrusion. The analysis also reveals low concentrations of sulphate which suggest that the groundwater of the second aquifer may represent fossilised sea water. The chloride content in the third aquifer is generally low with values ranging from 2 to 210 mg/l and thus the ground water in this aquifer is considered fresh and good for domestic use.
Journal Article•
TL;DR: In this paper, the extent of the intrusion up the river and into the groundwater was determined and the impact on the adjacent flora recorded and it was shown that saline water penetrated the groundwater for up to 20 m from the river bank and that this had caused the death of a number of swamp forest trees as well as the defoliation of others.
Abstract: Drought conditions in the Richards Bay area coupled with abstraction for domestic and industrial use caused freshwater outflow from Lake Mzingazi to cease in February 1992. This led to the tidal intrusion of saline water from Richards Bay into the Mzingazi River. The extent of the intrusion up the river and into the groundwater was determined and the impact on the adjacent flora recorded. Results showed that saline water penetrated the groundwater for up to 20 m from the river bank and that this had caused the death of a number of swamp forest trees as well as the defoliation of others. Spring tides and particularly a very high equinox tide had further aggravated the situation causing damage to, and the death of, numerous plants in herbaceous swamp areas.
TL;DR: P Phelps and Spechler as mentioned in this paper evaluated the hydrogeology of the Upper Zone of the Lower Floridan aquifer and its relation to water quality during a 3-year (1993-96) study and found that the pathways for movement of saline water are interconnecting vertical and horizontal fracture or solution zones probably developed along paleokarst features that are not mappable from the land surface.
Abstract: 1 The Relation Between Hydrogeology and Water Quality of the Lower Floridan Aquifer in Duval County, Florida, and Implications for Monitoring Movement of Saline Water by G. G. Phelps and Rick M. Spechler Abstract The hydrogeology of the Upper zone of the Lower Floridan aquifer and its relation to water quality were evaluated during a 3-year (1993-96) study. The Floridan aquifer system, a carbonate aquifer system composed of the Upper Floridan aquifer, a middle semi-confining unit, and the Lower Floridan aquifer, is the major source of water supply in northeastern Florida. The Lower Floridan aquifer is further subdivided into the Upper zone, a semi-confining unit, and the Fernandina permeable zone. As a result of increased withdrawals, heads in the aquifer system have declined and at the same time chloride concentrations have increased in the water from many wells in Duval County. A better understanding of the sources of and pathways for movement of brackish water is needed so that water managers can monitor the movement of brackish water and plan future water development. Most of the wells in Duval County deeper than 900 feet penetrate the Upper Floridan aquifer and the Upper zone of the Lower Floridan aquifer. Transmissivity estimates for these zones range from 2,000 to 194,000 feet squared per day. Permeability in the Upper zone of the Lower Floridan aquifer is primarily related to secondary porosity developed along bedding planes, joints, and fractures as a result of paleokarst processes. The Upper zone is about 300 to 500 feet thick in Duval County, based on the geophysical logs of about 40 wells ranging in depth from about 1,000 to 2,200 feet. In some areas the Upper zone has a single flow zone, but in other areas, two distinct flow zones are apparent. Water samples collected during this study confirm the continued increase in chloride concentrations in both the Upper Floridan aquifer and the Upper zone of the Lower Floridan aquifer. Most of the observed increases are in the eastern part of the county, but a pattern in the locations of wells yielding water with chloride increases is not discernible. In some areas, zones bearing brackish water are underlain by zones of fresher water, but in other areas, fresher water was not found beneath the brackish water. A single fracture or solution feature was the source of brackish water in several wells. The most likely source of brackish water to the Upper zone of the Lower Floridan aquifer is the underlying Fernandina permeable zone, which contains freshwater in the western part of the county but saline water in the eastern part. The pathways for movement of saline water are interconnecting vertical and horizontal fracture or solution zones probably developed along paleokarst features that are not mappable from the land surface; therefore, a conventional monitor-well network probably would not provide early warning of saline-water intrusion. Continued monitoring of water-quality trends in water-supply wells, combined with collection of additional surface
TL;DR: Medium quality waters (wastewater and saline water) can be used for the irrigation of loquat trees grafted on Anger stock, without causing damages on plant nutrition.
Abstract: An investigation was conducted to study the possible use of municipal wastewater for watering loquat plants, and to determine the effects of this water on nutrient status of two‐year‐old loquat plants (Eriobotriae japonica L.) during two complete vegetative cycles. The plants, grafted on franco and Anger stocks, were planted on major soils of the area of La Marina Babea. Plants (grafted on franco stock), irrigated with this wastewater, suffered from foliar necrosis, and all of them died at the end of the experiment, whereas only 12.5% of the plants watered with municipal drinking water died at the same period of time. The Anger stock proved to be much more resistant to salinity than the franco stock. Therefore, medium quality waters (wastewater and saline water) can be used for the irrigation of loquat trees grafted on Anger stock, without causing damages on plant nutrition.
23 Mar 1997
TL;DR: In this article, an interpreted resistivity map for a depth of 30m showed low resistivities associated with clays, shales, and saline waters near some of the abandoned brine disposal pits.
Abstract: Hydrologic and geophysical studies of saline waters at the Brookhaven oil field (Mississippi) began in 1985. Past and present practices to dispose of brines produced with oil and gas poise an environmental risk to ground water resources, agriculture, and other land uses. At Brookhaven, there is an elevated total chloride content in shallow ( (mg/L), which is exceptionally fresh water in comparison to other oil producing areas, particularly in the western United States. Contamination in the oil field at some sites is several hundred mg5 chloride as determined from water well samples taken in the mid-1980s. The EPA funded a feasibility study that included a dc resistivity survey which showed low resistivities in one area of known saline water contamination. Detailed electrical geophysical surveys are not possible due to numerous metallic features associated with oil production. In 1988 a helicopter electromagnetic (HEM) survey of the oil field was flown under contract to the USGS as part of an EPA funded research project. An interpreted resistivity map for a depth of 30m showed low resistivities associated with clays, shales, and saline waters near some of the abandoned brine disposal pits. In 1995 water wells were re-sampled and two areas of high changes in chloride content were found. Also in 1995, a new HEM survey was flown and new dc resistivity soundings were made. Comparison of the ground and airborne survey along a profile where there has been a high change in chloride content shows good agreement for interpreted subsurface resistivities. The HEM survey shows greater detail than the ground measurements and suggests there may be local vertical migration of saline waters in areas where there has been a large increase in ground water chloride content.
01 Jan 1997
TL;DR: The root elongation rate and root length have also been shown to be inversely proportional to the soil impedance (Misra et al., 1986; Bennnie, 1991) as discussed by the authors, which indicates that salinity levels and a low rate of oxygen diffusion may become mostly inhibitory to root growth in deep soil layers.
Abstract: Intensive irrigation in heavy clay soils, especially with brackish water, may induce a saline water table to rise. Since the salts are mostly Na salts, the high sodium content may lead to deterioration of soil structure and reduction of its hydraulic conductance. Problems of soil salinity and lack of aeration in the root zone may be intensified if artificial drainage systems are ineffective or absent. Salinity levels and a low rate of oxygen diffusion may become mostly inhibitory to root growth in deep soil layers. Salinity has been shown to reduce root growth, in studies of different crops (Shalhevet and Bernstein, 1968; Poljakoff-Mayber and Lerner, 1994). The root elongation rate and root length have also been shown to be inversely proportional to the soil impedance (Misra et al., 1986; Bennnie, 1991).
01 Jan 1997
TL;DR: A field experiment was conducted to determine if grain yields of sorghum [Sorghum bicolor (L.) Moench] irrigated with undiluted saline wastewater from cooling towers of an electrical power generation plant can be significantly increased by applying nonsaline water at a critical growth stage as mentioned in this paper.
Abstract: Saline wastewater from industrial or agricultural sources may be an alternative irrigation supply in arid regions if effective crop and water management strategies for their use are developed. A field experiment was conducted to determine if grain yields of sorghum [Sorghum bicolor (L.) Moench] irrigated with undiluted saline wastewater from cooling towers of an electrical power generation plant can be significantly increased by applying nonsaline water at a critical growth stage. The wastewater had an average electrical conductivity (EC) of 0.67 S m -1 and was high in CaSO 4 . Plot studies were conducted for 4 yr using conventional cultural practices and sprinkler irrigation on Tujunga loamy sand-Hanford fine sandy loam soil (mixed, thermic Typic Xeropsamment-coarse-loamy, mixed, nonacid, thermic Typic Xerorthent). Highest grain yields were obtained from the nonsaline control plots and from treatments that received nonsaline water during either the vegetative or reproductive growth stages. Plant height decreased in response to salinity, and differences between treatments were apparent by 27 d after planting. Plant height and grain yield were both negatively correlated with soil salinity by the 3rd yr of the experiment. Over an extended length of time, the best treatment for maximizing yield and utilizing saline wastewater is the application of nonsaline water early in the season to germinate and establish seedlings, followed by saline water during the grain-filling stage.
Journal Article•
TL;DR: It is indicated that camels are more tolerant than sheep both to drinking saline water and to dietary protein shortage both to salt load and protein deficiency.