Showing papers on "Saline water published in 1999"
TL;DR: Grain growth was less sensitive to salinity at milking stage, suggesting that the plant is able to escape stress when the duration of salinity is short, as well as suggesting that salinity affects photosynthetic pigments, soluble carbohydrates, and protein differently.
349 citations
TL;DR: In this article, the elemental and boron, strontium, and oxygen isotopic compositions of fresh and brackish groundwater (Cl up to 1500 mg/L) were determined in order to identify the origin of the salinity and formation of saline plumes in the central part of the Mediterranean coastal aquifer of Israel.
Abstract: In order to identify the origin of the salinity and formation of saline plumes in the central part of the Mediterranean coastal aquifer of Israel, we determined the elemental and boron, strontium, and oxygen isotopic compositions of fresh and brackish groundwater (Cl up to 1500 mg/L). We distinguish between two key anthropogenic sources: (1) sewage effluents used for irrigation with high Na/Cl, SO4/Cl, and B/C1 ratios and low Br/Cl ratios relative to seawater ratios, low δ11B values (0–10‰) and high δ18O values (>−4‰); and (2) imported water from the Sea of Galilee that is artificially recharged to the aquifer with high Br/Cl (3 × 10−3) and δ18O values (−1‰) and a low 87Sr/86Sr ratio of 0.70753. The brackish groundwater from the saline plumes have relatively low Na/Cl ratios (0.5–0.8) and high Ca/Mg, Mg/Cl, and Ca/(SO4 + HCO3) (>1) ratios relative to seawater ratios; marine SO4/Cl and Br/Cl ratios; δ11B values of 24.8–49.9‰; δ18O of −2.95‰ to −4.73‰ and 87Sr/86Sr ratios of 0.708275–0.708532. The composition of most of the investigated groundwater from the saline plumes differs from those of the anthropogenic sources, imported water, fresh uncontaminated groundwater (87Sr/86Sr of 0.70866, δ11B of 20–30‰), and saline water from the adjacent Eocene aquitard. Only in areas of artificial recharge does local groundwater have high Br/Cl and δ18O values that are typical to the Sea of Galilee. The linear relationships between chloride and most of the ions, including B and Sr, the relatively high δ11B (>30‰) and low δ18)O (<−4‰) values, and the chemical signature of the saline plumes (e.g., marine Br/Cl and SO4/Cl ratios), suggest that (1) mixing processes control the chemical composition of the brackish water within the aquifer, and (2) the saline postulated end-member has a chemical composition that resembles modified seawater with a marine and higher δ11B values, and a 87Sr/86Sr ratio of <0.7083. We propose that most of the salinization phenomena and the formation of saline plumes in the inner parts of the coastal aquifer are derived from upconing of underlying natural saline water bodies and enhanced by overexploitation and draw-down of the overlying fresh groundwater.
223 citations
TL;DR: The feasibility of using salt-tolerant plants (halophytes) as biofilters to remove nutrients from saline aquaculture wastewater was determined and Suaeda and Salicornia performed better than the desert saltbush, Atriplex, at the higher salinities.
151 citations
TL;DR: In this article, the capacity of mangrove soils in purifying synthetic wastewater containing pollutant concentrations four times of that found in local municipal sewage and of two salinities (fresh vs. saline water).
Abstract: Soil leaching experiments were conducted to assess the capacity of mangrove soils in purifying synthetic wastewater containing pollutant concentrations four times of that found in local municipal sewage and of two salinities (fresh vs. saline water). Results on leachate nutrient and heavy metal concentrations reveal that the mangrove soils were capable of removing certain amount of pollutants from wastewater, and the removal efficiency varied between pollutants. The soils were most effective in retaining heavy metals such as Cu but were less effective for Mn and Zn. Similarly, the wastewater-borne NH + 4 was more easily leached than P. The soil data show that most pollutants were accumulated in the top layer (0-1.5 cm) of the soil tray, with little downward migration. Differences between treated and control soil nutrient and heavy metal concentrations were not found in the soil masses below the surface 1.5 cm. In the surface layer, the mangrove soils treated with wastewater had significantly higher concentrations of NH + 4 -N, total and extractable P, total and extractable Cu, Cd, Zn and Mn. On the other hand, there was no significant elevation in total nitrogen content in mangrove soils treated with wastewater when compared with the control. Soils receiving wastewater prepared in deionized water (fresh) had slightly higher pollutant concentrations, and larger enrichment factors than that treated with saline wastewater (containing 1.5% salinity). These results suggest that mangrove soils could retain pollutants from wastewater but its efficiency would slightly be affected by salinity.
115 citations
TL;DR: In this article, the overall hydrogeochemical conditions at and in the near vicinity of the underground experimental Aspo Hard Rock Laboratory (HRL) in SE Sweden have been investigated.
108 citations
TL;DR: In this paper, a combination of stable isotope (H-2 and O-18) techniques and sapflow measurements were used to determine groundwater discharge by both species at three saline sites.
105 citations
TL;DR: The results indicate that brackish waters can be used for growing melon with minimum yield losses if concentration and duration of exposure are carefully monitored.
Abstract: The shortage of good quality water in semiarid zones necessitates the use of saline water for irrigation. In order to simulate the usage of brackish irrigation water in greenhouse melon (Cucumis melo L. cv. Galia) culture in perlite, plants were supplied with nutrient solutions containing 0 (control), 20, 40, and 60 mM NaCI applied at four different times. Treatments were applied during early vegetative growth [14 days after transplanting (DAT)], beginning of flowering (37 DAT), beginning of fruit set (56 DAT), and beginning of fruit ripening (71 DAT). All vegetative and fruit yield parameters were significantly reduced when salinization was started 14 DAT. This inhibitory effect of salinity was progressively lessened when salinity was imposed at later dates. This suggests that the response of melons to salinity depends on the duration of exposure to saline water. Salinity treatments increased fruit reducing sugars, acidity, and total soluble solids. Fruit yield reduction at each salinization time was correlated with salinity levels, but there was some evidence of a nutrient imbalance, since leaf concentrations of N-NO 3 , and especially K, were low at higher salinities. These results indicate that brackish waters can be used for growing melon with minimum yield losses if concentration and duration of exposure are carefully monitored.
83 citations
TL;DR: In this article, field experiments in a pear orchard verify that under subsurface drip irrigation (SDI) with saline water, reasonable yields can be obtained, in comparison with the conventional drip irrigation.
71 citations
TL;DR: In this paper, the authors measured tree growth, water use, climate, soil salinity and groundwater conditions over a 3-year period in an unirrigated 5-8-year-old plantation in northern Victoria, within an area where groundwater pumping is in use for control of shallow water tables and salinisation of irrigated farmland.
67 citations
TL;DR: In this paper, the effects of NaCl salinity and foliar application of calcium nitrate on the biomass production, water relations and mineral uptake were investigated in celery ( Apium graveolens L., cv. Istar) plants grown by the nutrient film technique (NFT) under greenhouse conditions during winter.
63 citations
01 Jan 1999
TL;DR: In this paper, saltwater intrusion in groundwater is defined as the inflow of saline water in an aquifer system, which can be in a steady state but mostly it is a transient process.
Abstract: When dealing with exploitation, restoration and management of fresh groundwater in coastal aquifers the key issue is saltwater intrusion. Saltwater intrusion in groundwater is defined as the inflow of saline water in an aquifer system. This inflow can be in a steady state but mostly it is a transient process. In the latter case the inflowing saline water replaces fresh groundwater which was originally present in the system. The freshwater disappears by outflow at a rate roughly equal to the rate of inflow of saline water. This simultaneous outflow of fresh groundwater can take place either in a natural way, by seepage, or by abstraction. The result is an increase of the volume of saline groundwater and a decrease of the volume of fresh groundwater.
TL;DR: In this paper, it was shown that P. australis will probably only survive intertidal flushing with saltwater if its roots and rhizomes are located in brackish water.
01 Jan 1999
TL;DR: In a typical scenario, when the wide cone of depression formed by extensive groundwater pumping comes into contact with underlying or surrounding seawater, saltwater intrusion in coastal aquifers is a very serious threat to subsurface water quality worldwide as discussed by the authors.
Abstract: Saltwater intrusion in coastal aquifers is a very serious threat to subsurface water quality worldwide. This contamination of freshwater resources occurs, in a typical scenario, when the wide cone of depression formed by extensive groundwater pumping comes into contact with underlying or surrounding seawater. Twenty years ago Newport [1977] reported that at least twenty coastal areas in the United States were contaminated by saline water. Documented cases have since been reported for many other countries. Contamination by salt deteriorates water quality dramatically. A two to three percent mixing with seawater makes freshwater unsuitable for human consumption, and five percent mixing makes it unusable for irrigation as well [Custodio et al., 1987; Sherif and Singh, 1996].
TL;DR: In this paper, the impact of non-drained irrigated rice cropping on soil salinization in the Senegal River Delta was investigated using EM38 and conventional laboratory techniques.
TL;DR: In this article, the authors determined the fate of road deicing salt from retention and loss in snow cover adjacent to a 14-km section of highway in southern Ontario during the 1994-1995 winter.
Abstract: Environmental impacts of road deicing salt are well known, although salt pathways following application have rarely been quantified. Deicing salt (NaCl) fate was determined from retention and loss in snow cover adjacent to a 14-km section of highway in southern Ontario during the 1994-1995 winter. Total salt application was ∼530 Mg (29-74 kg m -1 length). Retention in snow cover in the highway right-of-way (ROW) decayed as a power function of distance from the highway, although melting of proximal snowbanks with high salt loads disrupted this pattern. Peak concentrations in snowbanks reached 6506 (Na + ) and 9916 (Cl - ) mg L -1 . Wind transport of salt from the ROW was minor and restricted to relatively exposed sites. Almost all applied NaCl reached the soil surface via (i) direct runoff and infiltration of saline water from the road into the shoulder and ROW, and (ii) transfer of salt to snow cover adjacent to the highway and release during snowmelt. Total salt flux along the two pathways during a 49-d period was similar. Salt transfer via road runoff occurred during or shortly after application, unlike the intermittent fluxes from snow to soil surfaces in the ROW during this period. The latter were relatively uniform along the highway (3-5 kg m -1 length of highway), accounting for 39 to 65% of applied NaCl. However, magnitude and timing of water and salt fluxes from snow to soil varied within the ROW and should be considered when modeling salt transport to groundwater.
Journal Article•
TL;DR: Temperature, dissolved oxygen, chlorophyll-a (chl-a) and productivity -increased in the day time and vice versa for inorganic nutrients and productivity was low in northeast monsoon compared with other seasons.
Abstract: Seasonal and diurnal variations in the hydrobiological characters of coastal water of southern Chennai, Bay of Bengal were studied. Parameters such as current, pH, salinity, inorganic nutrients, (NH 4 , NO 2 , NO 3 , PO 4 , SiO 3 -SiO 2 ) and heavy metals exhibited unimodal oscillation and temperature, dissolved oxygen (DO), biological oxygen demand (BOD) and suspended solids exhibited bimodal oscillation. Particulate organic carbon (POC) was positively correlated with suspended solids. Chlorophyll-a (chl-a) and phytoplankton density showed two maxima; one in summer and another in southwest monsoon season and minimum value during the northeast monsoon. Productivity was low in northeast monsoon compared with other seasons. Temperature, dissolved oxygen (DO), chlorophyll-a (chl-a) and productivity -increased in the day time and vice versa for inorganic nutrients. Low tide brought more nutrients and less saline water from the estuarine region; high tide brought more chl-a from the offshore water. All the parameters were highly influenced by monsoonal rain, littoral drift and land drainage in a season but diurnal variation was due to the combination of more than one factors.
TL;DR: Analysis of spatial and temporal characteristics of the saline springs that emerge along the western shore of the Sea of Galilee (Lake Kinneret) shows that in Tabgha, variations of these parameters are mainly controlled by recharge variations in the Galilee, and follow an exponential function, while in Fuliya and Tiberias, variations are mainly dependent on lake level, and following a sine-cosine function.
Abstract: Spatial and temporal characteristics of the saline springs that emerge along the western shore of the Sea of Galilee (Lake Kinneret) are analyzed. Three groups of onshore springs (Tiberias, Fuliya, and Tabgha) and two groups of offshore springs (Barbutim and Maagan), contribute saline water to the lake with concentrations in the range of 300 to 18,000 mg Cl/L, depending on location and season. It is well accepted that water emerging from these springs is a mixture of two endmembers: deep-seated saline ground water and shallow, fresh circulating ground water. Temporal trends of discharge rates and of chloride (representing the deep saline aquifer) and nitrate (representing the shallow fresh water aquifer) concentrations within each group of springs are presented. Results show the proportions of the two water bodies while mixing are time dependent. Discharge and concentration peaks in Tabgha springs precede those in Fuliya and Tiberias springs by approximately two months. An analytical solution shows that in Tabgha, variations of these parameters are mainly controlled by recharge variations in the Galilee, and follow an exponential function. In Fuliya and Tiberias, variations of these parameters are mainly dependent on lake level, and follow a sine-cosine function. The different patterns are attributed to different hydraulic properties of the discharge area.
TL;DR: The yield per plant was higher and fewer fruit were affected by BER in the treatment involving the higher level of irrigation, and the Ca concentration in the stylar portion of mature fruit was not significantly affected by the level of irrigation.
Abstract: SummaryAn experiment investigated the effects of two rates of irrigation, one of which reflected a substantial degree of water stress, on the mineral content, free amino acid levels and incidence of blossom-end rot (BER) in tomato (Lycopersicon esculentum Mill. `Durinta'). The plants were grown in the open with drip irrigation using saline water from a well (mean ECw 5.2 dS m21). The yield per plant was higher and fewer fruit were affected by BER in the treatment involving the higher level of irrigation. The fruit of the first and fifth truss, and the leaves immediately above, were analysed for their macronutrient, micronutrient and free amino acid content. The macronutrient leaf and fruit content hardly showed any difference, only the N concentration in fruit being significantly affected in the water stressed plants, in which the levels were higher. The Ca concentration in the stylar portion of mature fruit, which is related with the incidence of BER, was not significantly affected by the level of irriga...
TL;DR: In this paper, the authors compared the growth and hydrologic impact of a small 21-year old plantation growing over a shallow saline water table at Kyabram, in the Shepparton irrigation area.
TL;DR: It is concluded that this field-grown grapevines, Colombard on Ramsey rootstock, grown in a semi-arid climate can maintain high productivity despite eslugsi of saline irrigation.
Abstract: Mature field-grown grapevines, Colombard on Ramsey rootstock, grown in a semi-arid climate were irrigated with saline water during any one of 4 growth stages within the season: pre-flowering, during berry devel- opment, during berry ripening, and post-harvest. At other times, plots were irrigated with river water (EC 0.5 dS/m) as was the control throughout the season. Saline water (EC 3.5 dS/m) with a high sodium absorption ratio was pro- duced by addition of sodium chloride brine. Soil cation exchange capacity was 14 cmolc/kg, and at the end of the trial, the soil exchangeable sodium percentage in the control was 6%, in the treatment salinised pre-flowering 13%, during berry development 20%, during berry ripening 20%, and post-harvest 19%. Treatments were applied for 6 consecutive seasons. Vines were highly productive, with the average yield in the control equal to 62 t/ha of grapes. Saline irrigation caused significant, but small, declines in yield in 3 seasons, in pruning weights in 2 seasons, and in berry weights in 4 seasons. Effects on growth, once established, often persisted unchanged through one or more subsequent seasons of saline irrigation. The growth stage shown to be most sensitive to saline irrigation was berry development; saline irrigation during berry development reduced the yield by 7% and during berry ripening by 3%, and pre-flowering it reduced the berry weight by 1%, during berry development by 6%, and during berry ripening by 4%. The amounts of irrigation applied in each of the 4 growth stages were not equal, and hence, treatments did not receive equal additions of salt. Normalising data to remove this effect showed that the rate of yield decline per unit dS/m increase in the seasonal average salinity during berry development, 7%/dS.m, was 3-fold greater than the 2%/dS.m during berry ripening. We conclude that this scion/rootstock combination, grown under these condi- tions, can maintain high productivity despite eslugsi of saline irrigation.
TL;DR: The pycnocline, lying at a depth range of 6-8 m, prevents mixing between the two water bodies, and thus generates anoxic conditions in the deeper waters.
TL;DR: The use of poor quality water for irrigation purposes in the urban landscape has the potential to save significant quantities of good quality water as discussed by the authors for higher priority uses, such as greenhouses.
Abstract: The use of poor quality water for irrigation purposes in the urban landscape has the potential to save significant quantities of good quality water for higher priority uses. Research was conducted to determine the impact leaching fractions (LF = drainage volume/irrigation volume) and irrigation-uniformity distributions have on the spatial distribution of water and salts and plant response when irrigating with saline water. Tall fescue (Festuca arundinacea Schreb. Monarch') was grown in IX plots, each with a centrally located lysimeter that enabled estimates of evapotranspiration and irrigation requirements. Imposed treatments included setting LF at 0.05, 0.15, or 0.25 and manipulating plot irrigation systems such that the Christiansen uniformity coefficient (CUC) was set at 0.65, 0.75, or 0.85, Saline irrigation water (2.5 dS m -1 ) was applied for an 18-mo period. Significant LF × CUC interactions were observed for depth-weighted soil salinity, yield, evapotranspiration (ET), tissue moisture content, and canopy temperatures. Although the coefficient of variation increased with each measured parameter as the CUC decreased, only the depth-weighted electrical conductivity (EC e ) showed a coefficient of variation >20%, A 14% savings in irrigation water was obtained when the high CUC, low LF treatment was compared with the high LF, low CUC treatment. Ninety-one percent of the variability in the average plot EC e could be accounted for if the actual LF, lysimeter ET, and average plot canopy temperatures at the end of the experiment were taken into consideration. Under the conditions of this experiment, irrigating tall fescue with 2.5 dS m 1 water would be an acceptable practice even at LFs as low as 0.05 if the CUC is optimized.
TL;DR: In this paper, 1-year-old seedlings of Quercus lyrata Walt, overcup oak, swamp chestnut oak, quercus nuttallii, and Nuttallii michauxii Nutt were exposed to increased flooding and salinity, individually and in combination.
Abstract: As global climate changes, sea level rise and increased frequency of hurricanes will expose coastal forests to increased flooding and salinity. Quercus species are frequently dominant in these forest, yet little is known about their salinity tolerance, especially in combination with flooding. In this study, 1-year-old seedlings of Quercus lyrata Walt. (overcup oak), Q. michauxii Nutt. (swamp chestnut oak), Q. nigra L. (water oak), and Q. nuttallii Palmer (Nuttall oak) were chronically (simulating sea level rise) and acutely (simulating hurricane storm surge) exposed to increased flooding and salinity, individually and in combination. The four species demonstrated two response patterns of photosynthesis (A), conductance, and leaf water potential, apparently related to their relative flood tolerance. In Q. lyrata, Q. nuttallii, and Q. nigra (moderately flood-tolerant), A was not immediately reduced after the initiation of the freshwater flooding, but was reduced as the duration of flooding increased. In the second pattern, demonstrated by the weakly flood-tolerant Q. michauxii, A was immediately reduced by freshwater flooding with an increasing impact over time. Watering with 2 parts per thousand (ppt) saline water did not consistently reduce A, but flooding with 2 ppt reduced A of all species, similar to the response with freshwater flooding. Photosynthesis of all species was reduced by 6 ppt watering or flooding, with the latter treatment killing all species within 8 weeks. When acutely exposed to 30 ppt salinity, A was quickly and severely reduced regardless of whether the seedlings were watered or flooded. Acutely flooded seedlings exposed to high salinity died within 2 weeks, but seedlings watered with 30 ppt saline water recovered and A was not reduced the following spring. As saline flooding of coastal areas increases due to sea level rise, photosynthesis of these species will be differentially affected based primarily on their flood tolerance. This suggests that increased flooding associated with sea level rise will impact these tree species to a greater extent than small increases in soil salinity. High salinity accompanying storm surges will be very harmful to all of these species.
TL;DR: In this paper, the authors defined the hydrochemical typology and applied mass balance considerations, and found that the saline water is derived from two endmembers designated as the "Lahish" and "Hazerim" water types.
Abstract: The Judea Group Aquifer of late Albian-Turonian age is mainly composed of karstic limestone and dolomite In the western part of Israel it is known as the Yarkon-Taninim ground water basin The study area is located in the southern part of the basin Fresh ground water (46 to 200 mg/L Cl) flows northward from the south and southeast Saline ground water (1200 to 8350 mg/L Cl), which occurs irregularly in the midst of this flowpath, severely jeopardizes the development and exploitation of this aquifer By defining the hydrochemical typology and applying mass balance considerations, it was found that the saline water is derived from two endmembers designated as the "Lahish" and "Hazerim" water types The Lahish water type is generally responsible for salinization of the lower portion of the Judea Group Aquifer It apparently evolved from transgressing Messinian sea water which penetrated inland through prior incised Neogene erosional channels Upon inundation, it dissolved halite and gypsum from the Mavqi'im Formation This was followed by massive bacterial reduction of sulfates in the presence of oil The Hazerim water type infiltrated into the Judea Group Aquifer through the overlying Avedat and Mt Scopus rock successions It appears that the Hazerim water developed from the transgressing Pliocene sea which percolated through these low-permeability rock units Subsequent rain percolated through these formations, dissolved evaporites that are mainly concentrated in the shallow layers and mixed with residual sea water of Pliocene age, which became more diluted over time Geological studies revealed that during the Neogene age, the back-cut incision of channels into the Coastal Plain facilitated inland ingression of the sea and dissolution of evaporites The Pliocene marine transgression deposited a thick sequence of clay that sealed the underlying beds This process resulted in trapping and pressurizing the saline water landward along pre-existing fault lines These findings contribute to the formulation of an updated ground water exploitation scheme that avoids subsurface fault systems, which act as conduits of brines The geological processes occurred during the Neogene and Pliocene This case study could help solve similar problems in the eastern Mediterranean region which experienced similar geological events
TL;DR: CO2 enrichment of plants grown with 7 dS m–1 salt increased total fresh fruit yields and maintained fruit quality in terms of total soluble salts, glucose and acidity and suggested that fruit ripening was about 10.d earlier under CO2 enrichment, regardless of salinity treatment.
Abstract: SummaryTomato plants (Lycopersicon esculentum (L.) Mill. cv. F144) were irrigated with low concentrations of mixed salts; the highest level (E.C. 7 dS m–1) simulated conditions used to produce quality tomatoes in the Negev highlands. CO2 enrichment (to 1200.mmol mol–1, given during the daytime) increased plant growth at the early stage of development. However, later growth enhancement was maintained only when combined with salt stress. In the absence of CO2 supplementation, overall growth decreased with salt (7 dS m–1) to 58% and fresh biomass yields to 53% of the controls. However, under elevated CO2 concentrations total plant dry biomass was not reduced by salt stress. CO2 enrichment of plants grown with 7 dS m–1 salt increased total fresh fruit yields by 48% and maintained fruit quality in terms of total soluble salts, glucose and acidity. Fruit ripening was about 10.d earlier under CO2 enrichment, regardless of salinity treatment. It is suggested that a combined utilization of brackish water and CO2 s...
TL;DR: Results show that irrigation with saline water and ethephon sprayings improve earliness and fruit quality without dramatic yield depressions, especially in the hybrid clones.
Abstract: The success of the pepino (Solanum muricatum Aiton) as a new crop for intensive horticultural areas relies on shortening the growing cycle and on securing a high standard of fruit quality. Irrigation with saline water and ethephon sprayings could be useful in achieving these goals. Two consecutive pepino crops consisting of two hybrids and their four parents were grown in the autumn–winter cycle. Plants were irrigated with water having electrical conductivities of 3 or 8 dS m−1 and full sized fruits were sprayed with ethephon at 0 or 500 mg l−1 . Salinity reduced yield and fruit size, although this effect was less important in the hybrids, which showed heterosis for yield characters. Overall, yields and fruit size of hybrids irrigated with saline water were greater than in the parents irrigated with non-saline water. Ethephon had no effect on yield characters. Salinity and ethephon improved earliness. In most clones combination of salinity and ethephon shortened the growing cycle by 1 month. Salinity improved fruit quality as it increased the soluble solids content (SSC) and dry matter (DM) in all clones, and titratable acidity (TA) in some cases. Ethephon sprayings had no marked effects on quality characters, except for parental clone 9-1 in which ethephon treated fruits had a lower SSC and TA. Organoleptic tests conducted on the best flavoured clones (0-8 and 6-10) showed that salinity improved fruit aroma and flavour although not texture, while ethephon had no effects. Results show that irrigation with saline water and ethephon sprayings improve earliness and fruit quality without dramatic yield depressions, especially in the hybrid clones.
© 1999 Society of Chemical Industry
TL;DR: The mechanisms underlying the effects of salinity on the acclimation of tomato plants to CO2 supplementation and salinity were elucidated to elucidate the mechanisms behind the decline in quantum yield efficiency and photosynthetic capacity under elevated CO2.
Abstract: SummaryPhotosynthesis of tomato plants (Lycopersicon esculentum (L.) Mill. cv. F144) was studied under conditions of CO2 supplementation and salinity. The purpose of the study was to elucidate the mechanisms underlying the effects of salinity on the acclimation of tomato plants to CO2 supplementation. Plants were grown under either low (355.mmol mol–1) or elevated (1200.6.50 mmol mol–1) CO2 and were irrigated with low concentrations of mixed salts. The highest salinity level (E.C. 7 dS m–1) was that used to produce quality tomatoes in the Negev highlands, in Israel. During early development (three weeks after planting), the net photosynthetic rate of the leaves was much higher under elevated CO2, and other than a slight decrease in quantum yield efficiency as measured by fluorescence (DF/F 9 m ), no signs of acclimation to high levels of CO2 were apparent. Clear acclimation to high CO2 concentration was evide t ten weeks after planting when the net photosynthetic rate, photosynthetic capacity, and carboxy...
TL;DR: In this article, the authors used 14C-analyses of dissolved organic Carbon and HCO−3 in order to trace different sources contributing to the HCO −3 in the groundwater.
TL;DR: Although sugarbeet grown with saline water produced adequate yields on test plots, sugar percentages declined because nitrogen also was present in the irrigation water source, so irrigating sugarbeets with alternative water sources is more complex, requiring accounting of nitrogen in reused water together with soil nitrogen to assure adequate crop quality.
Abstract: Salt is currently being transported into the San Joaquin Valley via rivers and irrigation water at about three times the rate that it is being removed, endangering the productivity of agricultural land. As a possible salt-management solution, the San Joaquin Valley Drainage Implementation Program seeks to reuse saline water, such as tile drainage water or shallow well water, in crop production. Sugarbeet is a deep-rooted, salt-tolerant crop that can be used as part of a cyclic reuse program to reduce drainage-water volume and conserve high-quality water. Although sugarbeets grown with saline water produced adequate yields on test plots, sugar percentages declined because nitrogen also was present in the irrigation water source. For this reason, irrigating sugarbeets with alternative water sources is more complex, requiring accounting of nitrogen in reused water together with soil nitrogen to assure adequate crop quality.
Patent•
02 Nov 1999
TL;DR: In this article, a solar cell floats over a body of saline water and a submerged fresh water collection system underlies the cell, and a partial vacuum is created in the solar cell for drawing water vapor from the cell to the collection system.
Abstract: A solar cell floats over a body of saline water. A submerged fresh water collection system underlies the cell. A partial vacuum is created in the solar cell for drawing water vapor from the cell to the collection system. Water vapor is condensed in a condenser disposed between the cell and the collection system. Heat generated by the condensation of water vapor is utilized to heat the salt water, which rises upwardly to replace the salt water vaporized in the cell.