Search

The present work attempts to characterize Robusta coffee producing properties located in the São Miguel do Guaporé– RO river basin and analyze water quality. Collections were carried out on 20 properties and the following parameters were evaluated: Calcium, Electrical Conductivity; Total Hardness; Total Phosphorus; Magnesium; pH; Sodium, Sodium Adsorption Ratio, salinity and sodicity. The pH ranged from 5.2 to 6.5 and 55% of the samples presented results within the limit established by CONAMA 357/2005, and around 70% of these waters presented a phosphorus content outside the recommended levels. The water classification regarding salinity and sodicity was C1S3, where C1 means that it does not present any risk of salinity and S3 indicates a severe problem when there is infiltration into the soil due to the sodicity of the water. The results obtained may add technical knowledge on the São Miguel do Guaporé river basin, assisting in sustainable management of soil and water.

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim was to evaluate the effect of salt stress on the percentage and speed of emergence of seedlings in forage cultivars of the species Megathyrsus maximus (Jacq.). The study was conducted in a completely randomized design in a 3×4 factorial scheme, with three forage cultivars (Mombaça, Tanzânia and MG12-Paredão) and four salinity levels (0, 1.5, 3.0, and 4.5 dS/m), with six replications. Stress was induced by irrigating the pots with saline solution. The percentage of seedling emergence was evaluated at seven days after sowing (DAS), and the emergence speed index (ESI) until 15 DAS was evaluated. Analysis of variance for the percentage of emergence and ESI showed significant effect (P

ABSTRACT Effluent from fish farming with saline water is a source of water, also rich in organic matter and nutrients, that can be used in irrigation of cultivated plants and even fully or partially replace mineral fertilization. The objective was to evaluate the growth, biomass production and quality of P. maximum cultivars fertigated with fish farming effluent in a greenhouse experiment, using a randomized block design with eight replicates. Treatments were arranged in a split-split-plot scheme, with three irrigation managements in the plot (irrigation with public-supply water, irrigation with public-supply water + conventional fertilization, and irrigation with fish farming effluent), three cultivars of P. maximum (Tanzania, Mombasa, and Massai) in the sub-plot, and four cutting times in the sub-sub-plot (45, 90, 135, and 180 days after sowing). Plant height, number of tillers, production of fresh biomass, neutral detergent fiber, acid detergent fiber, ether extract, crude protein, dry matter, and mineral matter contents were analyzed. The highest growth, production, and quality of P. maximum grass occurs when irrigated with public-supply water and under conventional NPK fertilization. Fertigation with fish farming effluent reduces the growth and production of P. maximum grass, but allows obtaining better quality forage. It is possible to irrigate P. maximum grass using fish farming effluent with satisfactory yields. The growth of cv. Massai was more sensitive to irrigation with fish farming effluent than those of the cultivars Tanzania and Mombasa.

ABSTRACT The use of substances that can mitigate the harmful effects of salt stress is a promising alternative for the use of saline water, especially in semi-arid regions. The aim of this study was to evaluate the effect of different concentrations of hydrogen peroxide in mitigating salt stress in the mini watermelon grown in a hydroponic system. The study was carried out in a greenhouse, in an area belonging to the Federal University of Campina Grande, Pombal, Paraíba. The experimental design was completely randomised using a split-plot factorial scheme with four levels of electrical conductivity for the nutrient solution-ECns (2.1, 3.1, 4.1, and 5.1 dS m-1) considered the plots, and four concentrations of hydrogen peroxide-H2O2 (0, 20, 40, and 60 μM) the subplots, with five replications. The foliar application of hydrogen peroxide in concentrations of between 17 and 20 µM mitigated the effects of salt stress on stomatal conductance, the rate of CO2 assimilation, carboxylation efficiency, and carotenoid content in the mini watermelon up to an ECns of 5.1 dS m-1. Foliar application of hydrogen peroxide in concentrations greater than 20 µM intensified the effects of salt stress on gas exchange and the synthesis of photosynthetic pigments in the mini watermelon. Furthermore, there was an increase in electrolyte leakage in the leaf blade.

ABSTRACT: Okra is a vegetable that stands out for its low production cost, high yield, high nutritional and value and socioeconomic importance in income generation, especially in family farming. In this context, the present study evaluated the physiology, production and water use efficiency of okra under irrigation with saline water and exogenous application of hydrogen peroxide. The treatments were distributed in a randomized block design, in a 5 × 3 factorial arrangement, with five levels of electrical conductivity of irrigation water - ECw (0.3; 1.3; 2.3; 3.3 and 4.3 dS m-1) and three concentrations of hydrogen peroxide - H2O2 (0, 25 and 50 μM), with five replicates, totaling 75 plants. Irrigation with ECw above 0.3 dS m-1 negatively affected stomatal conductance, transpiration, number of fruits, total production and water use efficiency of okra cv. Clemson Americano 80. Hydrogen peroxide at concentration of 22 μM mitigated the effects of salt stress on CO2 assimilation rate, number of fruits, average fruit weight and total production of okra cv. Clemson Americano 80. Water use efficiency is favored by H2O2 application at concentration of 12 μM, especially in plants irrigated with ECw of 0.3 dS m-1.

The salinity of soils and water for irrigation is a limitation that influences the productivity of crops that has increased worldwide and affects the morphology and physiology of plants since it causes osmotic stress and ionic toxicity and impairs the absorption of water and nutrients. The effect of salt stress on some morphological and physiological traits in Coccoloba uvifera (L.) L. (sea grape) seedlings from different origins was evaluated and the traits whose behavior under salt stress could be used as an effective criterion of tolerance to salinity were determined. A completely randomized design experiment with ten repetitions was performed. The factors under study were salinity (0, 5, 15, and 25 dS m-1), which was maintained for a period of sixteen weeks, and the second factor was the origin of the plant material. The salinity level and the seedlings’ origin significantly influenced the morphological and physiological variables controlled. However, it is necessary to carry out in situ experiments to obtain more information related to the mechanisms used by sea grape to tolerate salinity conditions, because in the consulted sources no research focused on evaluating the effect of salinity and the origin on the morphology and physiology of C. uvifera seedlings in Cuba has been found. The results of the research provide preliminary information to understand the negative effect of salt stress on this type of plant. The behavior of some controlled traits under salt stress can be used as an effective criterion of tolerance to salinity.

The salinity of irrigation water affects several crops, drastically reducing their production, which generates great economic losses for many farmers, especially in semiarid regions, therefore, the objective of this work was to analyze the agronomic performance of cowpea cultivars in pots under protected environment and submitted to different levels of salinity. The experiment was carried out in randomized blocks with three replications in the 8 x 4 factorial scheme, with eight cowpea cultivars of different sizes (BRS Novaera, BRS Guariba, BRS Tumucumaque, BRS Itaim, BRS Xiquexique, BRS Pujante, BRS Pajeú and BRS Rouxinol) and four salinity levels of irrigation water (0.0; 1.5; 3.0; and 4.5 dS m-1). It was concluded that the cultivars BRS Pajeú, BRS Pujante, BRS Guariba and BRS Xiquexique had the highest grain yields and that irrigation water with 0.0 dS m-1 showed the best results, with an increase in salinity reduced the quality and yield of the grains. [ABSTRACT FROM AUTHOR]

The depressive effects caused by salt stress are responsible for the decrease in crop productivity in arid and semi-arid regions. However, these effects can be minimized with different management strategies, such as the use of genotypes and forms of fertilization. In this context, the objective was to evaluate the productivity of two peanut genotypes, submitted to increasing levels of salinity and two forms of fertilization. A completely randomized design (DIC) was used, making use of the factorial scheme 3 x 2 x 2, with 4 repetitions. The first factor corresponded to the salinity levels of the irrigation water (1.0; 3.0; and 5.0 dS m-1). The second factor comprised two genotypes (Access 26 and Access 8) and the third factor corresponded to two types of fertilization (mineral, with NPK; organic, with bovine biofertilizer). The following variables were evaluated: pod length, pod diameter, pod number, dry peel mass, dry pod mass and productivity. Irrigation with 1.0 dS m-1 electrical conductivity water did not inhibit the production components of the peanut genotypes regardless of the type of fertilization. Access 26 when fertilized with bovine biofertilizer and irrigated with high salinity water was more efficient than access 8, showing a higher number of pods, dry pod mass and productivity. The use of mineral fertilizer was not able to mitigate the harmful effects of high salinity water, affecting the number of pods, pod dry matter and the productivity of both genotypes. [ABSTRACT FROM AUTHOR]

ABSTRACT Melon cultivation under saline conditions is a challenge, as the plants can suffer a reduction in fruit production and quality. The aim of this study was to evaluate the production and quality of noble melon fruit fertigated with different saline solutions and K/Ca ratios. The experimental design was of randomised blocks, with treatments arranged in a 3 x 6 factorial scheme, using three melon cultivars (Bazuca, McLaren, County) fertigated with six nutrient solutions [S1 - standard nutrient solution (SNS); S2 - SNS + NaCl (5.0 dS m-1); S3 - S2 enriched with K (50%); S4 - S2 enriched with K (100%); S5 - S2 enriched with Ca (50%); S6 - S2 enriched with Ca (100%)]. At the end of each cultivar cycle, the fruit was harvested and assessed for the following parameters: fresh fruit weight, fruit diameter, internal cavity, pulp thickness, pulp firmness, soluble solids content, titratable acidity, soluble solids/titratable acidity ratio, and vitamin C. Salt stress impaired the physical characteristics of the fruit of the three noble melon cultivars. The nutrient solution enriched with 50% K (S3) did not reduce the effect of salt stress on fresh weight or fruit size in the melon, but afforded an increase in fruit quality.

The salinity of soil and water of irrigation can cause negative effects to agriculture by affecting the development and productivity of the cultivated species. These effects can be mitigated with the cultivation of salinity-tolerant varieties. The objective of this study was to evaluate the effect of salinity on the water imbibition curve during the germination process in cowpea seed and the response of different cultivars. An experiment was conducted in a factorial scheme, composed of three cultivars (BRS Marataoã, BRS Pajeu and BRS Tumucumaque) and four levels of salt stress, obtained by NaCl solutions at concentrations of 50, 100 and 150 mM and control, distilled water. The treatments were arranged in a completely randomized design, with four repetitions. The variables analyzed were the pattern of imbibition curve and final seed water content. It was found that the evaluated cultivars do not present the three-phase pattern for the seed soaking curve, in the absence or presence of salinity. There is variability for the pattern of the seed soaking curve among BRS Marataoã, BRS Pajeu and BRS Tumucumaque cowpea cultivars. Salinity acts by reducing the water content of cowpea seeds during the germination process and causes alteration in the pattern of the water soaking curve by the seeds. The cultivar BRS Tumucumaque shows higher tolerance to the reduction of seed water content under salt stress conditions when compared to the cultivars BRS Pajeu and BRS Marataoã.

ABSTRACT Brazil is one of the largest cashew producers in the world, and its Northeast region stands out. However, cashew growth and development are negatively affected by irrigation with brackish water in its production. In this context, strategies have been employed to alleviate salt stress effects on plants. Among the strategies, the exogenous application of elicitor substances, such as salicylic acid, has stood out. Given the above, the objective of the present study was to evaluate the effect of foliar application of salicylic acid as an attenuator of salt stress on the morphophysiology of early dwarf cashew. The study was carried out in a greenhouse, in a randomized block design, in a 5 × 4 factorial arrangement, with five levels of electrical conductivity of the irrigation water - ECw (0.4, 1.2, 2.0, 2.8, and 3.6 dS m-1) and four concentrations of salicylic acid - SA (0, 1, 2, and 3 mM), with three replicates and one plant per plot. Irrigation with water of electrical conductivity above 0.4 dS m-1 negatively affected the leaf relative water content, gas exchange, photosynthetic pigments, and growth of plants. Salicylic acid at a concentration of 1 mM attenuated the effects of salt stress on electrolyte leakage, relative water content, gas exchange, synthesis of photosynthetic pigments, and growth of early dwarf cashew irrigated using water with ECw of up to 3.6 dS m-1, at 210 days after transplanting.

ABSTRACT Peanut cultivation in the northeast of Brazil has been badly affected by salts accumulating in the irrigation water; in this respect, the use of plant mulch is one way of mitigating salt stress. The aim of this study was to evaluate the effect of irrigation using brackish water under different mulching strategies on productivity and water use efficiency in the peanut. The experiment was carried out under field conditions in Redenção, in the state of Ceará, in a randomised block design of split-plots with five replications, in which the plots corresponded to two levels of electrical conductivity of the irrigation water (0.8 and 4.0 dS m-1), and the subplots to six mulching strategies based on the phenology of the crop (MS1: mulch throughout the cycle; MS2: flowering stage; MS3: appearance of the gynophore; MS4: pod formation; MS5: final flowering stage; MS6: no mulch). The following were determined at the end of the experimental cycle: commercial, non-commercial and total number of pods, number of grains per pod, pod length and diameter, productivity and water use efficiency. Irrigation with lower-salinity water, together with mulching during the phenological stages of the peanut, affords better productive performance and greater water use efficiency. Salt stress reduced the length and diameter of the pods and had a negative effect on productivity and water use efficiency, both with and without the use of plant mulch during the phenological stages.

ABSTRACT The long-term use of agrichemicals might add some heavy metals to soils and, there is little information about the dynamics of these elements in soils under saline conditions in semiarid regions. This study aimed to investigate the dynamics of heavy metals in the different fractions of Fluvic Entisols with saline conditions under long term of coconut cultivation in a semiarid region. Composite soil samples were collected in five agricultural areas and three areas under native vegetation. Physical, chemical, and heavy metal analyses were carried out in soil (semi total and fractionated contents). Quality of irrigation water and drainage water was also evaluated. Analytical results were normalized and subjected to analysis of variance, and means were compared by Scott-Knott test (P < 0.05). Pearson correlation analysis was also used to assure a minimum correlation of variables justifying its use in the matrix of a factorial analysis. Semi-total contents of Cr, Ni, Pb and Zn (except Cu in some areas) were lower than previous local assessment and national guiding values, indicating that they do not cause harmful alterations in soil quality. Analyses of waters showed high levels of HCO3, indicating moderate restriction to use (due to the high levels of EC, SAR, Na and Cl). Fractionation of heavy metals revealed low risk of environmental pollution since most metal contents were bound to the oxidic, organic and residual fractions. The water used in irrigation contributes to the contents of heavy metals and to the salinity condition of the evaluated soils.

ABSTRACT Among the main problems that compromise the development of forest species are water and salt stresses, especially in the early stages of development, when seedlings are more sensitive. Thus, the objective of this study was to evaluate the morphophysiological and biochemical changes in Enterolobium contortisiliquum seedlings subjected to abiotic stresses. The experimental design was randomized complete blocks (RCB), composed of five treatments, with four replicates, and the experimental plot consisted of twenty plants. From the 31st day after sowing, when the seedlings reached approximately 15 cm in height, they began to receive the treatments, which consisted of different levels of electrical conductivity of irrigation water (0.3; 2; 4; 6; 8 dS m-1) for salt stress and periods of water restriction (0; 4; 8; 12 and 16 days without irrigation) for water stress. The traits evaluated were: plant height, root length, stem diameter, number of leaves, leaf area, total dry matter, Dickson quality index, height/shoot dry matter ratio, total soluble sugars, starch, total amino acids and proline. An increase in the electrical conductivity of irrigation water and days without irrigation compromised the development of E. contortisiliquum seedlings, which was intensified from 2 dS m-1 and four days without irrigation for salt and water stresses, respectively. The mechanism of survival of E. contortisiliquum to abiotic stresses involves reduction in the growth and quality of seedlings, with activation of biochemical defense mechanisms of the species.

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The growing of Solanum lycopersicum L. "tomato" is affected by salinity, reducing its water consumption, and affecting negatively plant growth and development. Therefore, it is necessary to seek sustainable cultivation and fertilization options, such as the use of plant growth-promoting rhizobacteria. This research aimed to determine the potential of rhizospheric Actinobacteria isolated from Opuntia sp. "prickly pear" as tomato growth promoting under salinity. The genera of isolated Actinobacteria were identified, the synthesis of 1-aminocyclopropane-1-carboxylic acid deaminase (ACC) was characterized and its effect on the germination of tomato cultivar Río Grande seeds was evaluated. Two tests on non-saline and saline soils were carried out to compare the effect of Streptomyces spp. and Nocardia sp. in plant development in the greenhouse. Several Actinobacteria genera were isolated from 87.03% of samples, highlighting Streptomyces (46.67%) and Nocardia (34.0%). 9.33% of the Actinobacteria presented ACC deaminase activity, which increased seed germination, and the growth and yield of seedlings with increases of 88.98% (height); 96.30% (number of sheets); 201.35% (aerial biomass); 173.77% (root length); 100.0% (root weight); 150.0% (number of fruits) and 173.14% (weight of fruits), as well as 1.37 mg/g in the chlorophyll content in the saline soil. Also, Streptomyces sp. strain 21 decreased sodium content and increased potassium and K+/Na+ rate in the leaves and roots of the plants with the highest yield (1.068 kg/plant) in the saline soil. In conclusion, the positive effect of Actinobacteria as promoters of tomato growth and yield, increasing chlorophyll content, and decreasing salinity stress was demonstrated.

ABSTRACT Abiotic factors, such as saline stress, can happen in agricultural areas and can harm the metabolism of the plants. Studies that seek to evaluate the acting of P. peruviana L. under stress conditions are still incipient. Therefore, the objective was to evaluate the tolerance to salinity in plants of P. peruviana L. under different saline levels of irrigation water. The work was developed in the experimental farm of the Universidade Federal de Campina Grande, Campus Pombal, PB, from January to March 2017. Four saline concentrations of irrigation water were used (0.3; 1.2; 2.1; and 3.0 dS m-1) with five repetitions. At 60 days after the transplant, were evaluated the leaf area, intercellular CO2 concentration, stomatal conductance, transpiration, photosynthetic rate, intrinsic water use efficiency, instantaneous carboxylation efficiency, electrolyte extravasation, chlorophyll a, b and carotenoids. The results show that saline levels of irrigation water up to 3.0 dS m-1 did not provide physiological damages in plants of P. peruviana L. until 60 DAT, except for extravasation of electrolytes and chlorophyll a and b, characterizing the plant as tolerant to salinity until the studied level.

The hydrographic basin of the Rio Branco lies within the agricultural expansion areas in Mato Grosso, Brazil. Due to hydric abundance, the implantation of irrigation system is possible even though it is relevant to evaluate the water quality for use in agriculture. No such investigation has yet been undertaken. Water quality of the hydrographic basin of the Rio Branco has been characterized and evaluated with regard to irrigation, or rather, salinity, sodicity, toxicity and infiltration reduction risk. Water collection was done monthly, between October 2017 and September 2018, at twelve sites along the basin. Physical, chemical and microbiological variables were comprised, namely, temperature, pH, total solids, turbidity, electric conductivity, sodium, potassium, calcium, magnesium, bicarbonates, chlorides, total and thermotolerant coliforms. Result showed water complied with irrigation regulations, with restrictions for turbidity, pH and thermotolerant coliforms. Following criteria by UNO for Food and Agriculture, there was no restriction to water use with regard to salinity and toxicity even though all sites showed high restriction rates with regard to infiltration reduction risk. The water of the hydrographic basin may be used for irrigation with technical follow-up. Its use is not recommended for the irrigation of food eaten raw. Current study contributes towards the management and planning of the use of hydric resources and for projects for the expansion of irrigated agriculture in the region. [ABSTRACT FROM AUTHOR]

ABSTRACT Salt-affected soils occupy extensive areas in arid and semi-arid regions around the world, and impact food production, particularly when salinization processes occur in irrigated areas. In this context, the possibility of using techniques for the reclamation of these soils needs to be considered. However, many of these techniques are inaccessible to most farmers in the Brazilian semi-arid region, given the high costs, mainly when it is necessary to install a subsurface drainage system. Thus, there is a need to evaluate other soil reclamation strategies as well as the possibility of using these areas for other purposes. This review covers topics related to the characterization and impacts of salt-affected soils, the influence of soil microorganisms, and strategies for soil reclamation, such as the use of chemical and organic conditioners, bio-drainage, phytoremediation, and revegetation with tolerant species. The topics addressed in this review indicate new possibilities for the reclamation and management of salt-affected soils in the Brazilian semi-arid region. A case study is also presented, which demonstrates that the use of salt-affected soils is defined by technical, social, and economic aspects.

ABSTRACT: The optimization of resources and time in the production of quality seedlings within a legal framework is of vital importance for greenhouse vegetable crops. This study evaluated the electrical conductivity of the nutrient solution and its effect on the survival and growth of bell pepper and tomato seedlings propagated by cuttings. The electrical conductivities evaluated were 0.92, 1.25, 1.50, and 1.75 dS m-1. The experiment was conducted using a randomized complete block design with four replicates. The number of rooted plants, stem diameter, root length, number of leaves, leaf area, dry weight of leaves, stem, root, and total were determined. In addition, the following indices were determined: stem root index, slenderness index, leaf area ratio, specific leaf area, and pre-transplant horticultural quality index. In both crops, the highest number of rooted cuttings was obtained with the lowest electrical conductivity. Meanwhile, the average electrical conductivity favored leaf number, leaf area, biomass, and seedling quality indices. These results showed that the production of bell pepper and tomato seedlings can be done by cuttings using Stenier nutrient solution at electrical conductivities of 1.25 to 1.50 dS m-1 without affecting seedling quality.

ABSTRACT The consumption of saline water in semiarid regions is a recurrent situation that can affect the ingestive behavior of small ruminants. This study evaluated the ingestive behavior of Santa Inês sheep maintained in a climatic chamber under two air temperatures -25 °C within the thermal comfort zone (TCZ) and 32 °C above the TCZ - and consuming water with three levels of salinity - 2.0, 4.0, and 8.0 dS m-1. The experimental design was completely randomized in 2 × 3 factorial schemes, comprising two air temperatures and drinking water with three levels of salinity, in six replicates (animals). Regardless of air temperature, the consumption of saline water did not affect feed and water intake by the sheep; however, there was a decrease in feed intake and an increase in water intake as air temperature increased. Feed and water intake; feeding, rumination, and idle times; defecation frequency; and fecal production were not affected (P > 0.05) by the water salinity levels, whereas reduction in feed intake, feeding time, and rumination time and an increase in water intake and idle time were observed as air temperature increased. In summary, increasing air temperature negatively affected the ingestive behavior of the animals; however, water with salinity up to 8.0 dS m-1 did not affect their ingestive behavior and hence could be used for drinking.

Jean laundering generates significant effluent flows with a high organic load, color, and other pollutants, making it difficult to adjust effluent releases within legal limits. Slow Sand Filters (SSF) with downflow were tested for seven days (bench scale), to propose an after-treatment of effluents from an Effluent Treatment Plant of a jean laundry. The research evaluated the removal of the following parameters: color, turbidity, chemical and biochemical oxygen demand, conductivity, ammonia, total phosphorus and salinity of the textile effluent. The experimental apparatus had four SSF: the first filter was fed with distilled water, while the other three filters (triplicates) were fed with effluent. The filters had, on average, the following removal efficiencies: 91% for ammonia, 61.24% color, 89.43% turbidity, and 83.54% for phosphorus. Regarding the removal of organic matter, 98.11% for BOD and 81.17% for COD, demonstrating that SSFs were efficient in removing particulate, dissolved materials and organic matter.

ABSTRACT: Mesosphaerum suaveolens (L.) Kuntze is a species widely used in folk medicine and has a high aromatic and therapeutic potential. However, its cultivation in semi-arid regions can be limited by salts in the irrigation water. The objective of this study was to evaluate the effect of salicylic acid (SA) as a mitigator of saline stress on the growth and gas exchange of M. suaveolens. The experimental design used was the randomized blocks in an incomplete factorial scheme (Central Composite Design), with five electrical conductivities water (ECw = 0.5, 1.45, 5.0, 8.55, and 10.0 dS m-1) and five SA doses (0.0, 0.29, 1.0, 1.71, and 2.0 mM). Plant height, number of leaves, stem diameter, leaf area, root length, and height/diameter ratio, and gas exchange (stomatal conductance, net CO2 assimilation rate, transpiration rate, instantaneous, and intrinsic water use efficiency, instantaneous carboxylation efficiency, and leaf temperature) were evaluated. The application of 0.9 mM SA attenuates the negative effect of saline stress on the number of leaves and leaf area of M. suaveolens. The application of SA stimulates the number of leaves, plant height, and root growth, but does not affect the gas exchange of M. suaveolens. ECw reduces the growth and gas exchange of M. suaveolens plants.

Irrigation is used as a management strategy in many regions around the world. However, due to the salinity characteristics of the semiarid region, this measure has become increasingly difficult due to the scarcity of good quality water with low levels of salts. One of the factors that can lead to salt stress are crops irrigated with water with high electrical conductivity, reflecting in a soil unfavorable to plant growth. Sunflower is a drought and salinity tolerant crop. In this context, the objective of this work was to evaluate the use of organic residue from marine macroalgae on the production of sunflower plants under two saline conditions (50 or 100 mM NaCl) and control group in substrates containing organic compound from algae or earthworm humus. The use of algae compost was more efficient than earthworm compost under control conditions. Under 50 mM salinity conditions, the results were similar to the use of humus. The use of this residue can be an alternative to commercial fertilizers under controlled conditions or with moderate salinity, minimizing production costs. [ABSTRACT FROM AUTHOR]

The Guanabara Bay (BG) localized in Rio de Janeiro city (Rio de Janeiro/Brazil) is on of the most important estuaries of the country showed intense port activity and from the start of century XIX a picture of intense degradation due mainly to fur eviction of domestic and industrial waste. Between all the environmental passives promoted per port activity stand out the biodiversity loss and exotic species introduction as alterations of levels of salinity, temperature, and pH. The present study has the objective to analyze possible correlations on standards of pH, temperature, and salinity in the port area of Rio de Janeiro from 2006 to 2018. 22 surface water sampling waters campaigns were carried out at five points. The salinity and pH varied significantly between the points sampled while for the temperature not showed significant difference. The variations in the parameters can be explained by the tidal regime and by the pluviometric standard shown in the time. The correlations occurred between the salinity and pH in a positive way at points P2, P3, and P5. Continuous monitoring should be carried out to detect possible fluctuations since pH, salinity and temperature influence local biodiversity. [ABSTRACT FROM AUTHOR]

Salinity is one of the main environmental factors that limit growth and productivity in agriculture. However, the use of organic matter may be an alternative to reduce damaging effects due to salt access in plants. Current assay evaluates the growth of radish cultivated in substrates and levels of salinity in irrigation water. Treatments comprised three types of substrates (layer soil 0-20 cm; filter + soil; earthworm humus + soil) mixed at 3:1 proportion and five electric conductivities of irrigation water (0.5; 1.5; 2.5; 3.5; 4.5 dS m-1). Randomized design comprised factor scheme 3 x 5, with 15 treatments with four replications and one plant per plot, totaling 60 experimental units. Radish plants were evaluated with regard to leaves, plant height, leaf area, relative index of chlorophyll, root mass and dry matter of aerial section. Increasing levels of salinity of irrigation water caused a decrease in the number of leaves, plant height, leaf area, relative rate of chlorophyll, root mass and dry mass of the aerial section of radish cultivar Crimson Gigant. However, substrates with earthworm humus diminished the damaging levels of salinity. The latter may be a viable alternative for radish plant in saline stress conditions. [ABSTRACT FROM AUTHOR]

Salinity is one of the limiting factors that negatively affect the germination, emergence, and development of pastures in the lower part of the Lauca - Oruro River sub-basin, reducing the availability of forages for livestock. With the purpose of identifying salinity tolerant forage species, the germination capacity in saline solutions of eight species was evaluated: Agropyron elongatum (Host) P. Beauv., Hordeum muticum J. Presl., Bromus catharticus Vahl., X. Triticosecale Wittmarck , Hordeum vulgare L., Atriplex cristata, Trifolium amabile (L.) Kunth., and Suaeda foliosa Moq. The research was carried out in laboratories of the Faculty of Agricultural and Natural Sciences - Technical University of Oruro; Saline solutions with four concentrations of NaCl per one liter of distilled water were applied to the seeds: 2.56, 5.12, 7.68, and 10.54 g, and control without salinity. The results indicate that X. Triticosecale Wittmarck and H. vulgare have greater tolerance to solutions of extreme salinity and little affected in their germination capacity. The seeds of A. elongatum, B. catharticus and S. foliosa significantly reduce germination, however, they manage to germinate at all salinity levels. The seeds of A. cristata and T. amabile are the most sensitive to saline affectation, germination is significantly reduced at all salinity levels, even at the highest concentration. It is concluded that these species can be used as forage for the use of salinized soils, depending on the maximum tolerance determined.

ABSTRACT Oyster culture has benefited traditional coastal communities along the Amazon macrotidal mangrove coast of Pará state in Brazil since 2006. Currently, seven oyster culture units in five municipalities are expanding production, but with no environmental monitoring, which is important for the control of the impacts of oyster culture on waters as well as for oyster management and conservation. Seasonal variation in environmental characteristics of the water was evaluated at all oyster culture units in Pará, from September to November 2013 (dry season) and February to April 2014 (wet season), to generate baseline data to evaluate future impacts and aid strategic planning, such as diversifying seed production. Salinity, dissolved oxygen, pH, oxidation-reduction potential, depth, temperature, and chlorophyll-a concentration were measured during flooding and ebbing tides, and compared between seasons and among culture units using uni- and multivariate statistics. All variables were significantly higher in the dry season, except depth, which was significantly greater in the wet season. Mean salinity, which varied from 2.4 to 46, explained most of the variation among culture units in relation to season, sampling date within each season and tidal state. However, dissolved oxygen, pH and depth were also important. Oyster culture units in Pará may be suitable for sustainable harvesting of seed/spat from the wild (lower salinity and pH), or for on-growing (higher salinity, higher pH, and greater depth). Seasonal variation is sufficient to allow both activities at most units at appropriate times of the year, which would help increase oyster production in Pará.

Studies determining physiological characteristics of field-grown pineapples irrigated with low-quality water are lacking. This work evaluated the photochemical efficiency of ‘Pérola’ pineapple irrigated with saline water in the semiarid region of Bahia, Brazil. The experiment was carried out in randomized blocks with five treatments consisting of the following irrigation depths: 100% of ETc using water with electrical conductivity (ECw) of 0.75 dS m-1; and 50, 75, 100 and 125% of ETc using water with ECw of 3.6 dS m-1. Chlorophyll a fluorescence measurements were made over the course of 13 months using a pulse-modulated fluorometer, in all treatments. Quantum efficiency (Fv/Fm) fluctuated throughout the cycle of the pineapple with values below the ideal, especially at the end of the crop cycle. Quantum yield of photosystem II (Yield), photochemical quenching (qP), non-photochemical quenching (NPQ) and chlorophyll fluorescence decrease ratio (RFd) were not influenced by irrigation depths. Therefore, energy used for photosynthetic processes in pineapple plants is not affected by irrigation using saline water with electrical conductivity of 3.6 dS m-1.

ABSTRACT Topograph ic data extracted from a digital terrain model (DTM) make it possible to analyze factors associated with various phenomena arising on the earth’s surface. The aim of this study was to evaluate environmental susceptibility to soil salinization using the modeling of topographic data in the semiarid region of Brazil. The municipality of Jeremoabo, Bahia, was defined as the spatial scale for the analysis due to the climate characteristics and signs of environmental deterioration. The fuzzy gamma operator was applied to integrate the slope, plan and profile curvature, and topographic wetness index, and to configure scenarios of susceptibility to salinization. Together, the classes of high and severe susceptibility to soil salinization occur in around 22.29% of the total area. They are associated with low slopes, high topographic wetness indices, a concave curvature profile, and the planar class of plan curvature of the terrain. The data show the need to carry out effective land use planning for agriculture, such as the use of irrigation, to minimize the process of soil salinization, which is associated with the phenomenon of desertification.

ABSTRACT Salinization occurring through irrigation on arable land has been a growing concern worldwide. This study aimed to evaluate the germination and initial development of common rue subjected to different saline concentrations. Two salts (sodium chloride and calcium chloride) and five saline concentrations (zero,-0.1,-0.2,-0.3, and-0.4 MPa) were utilized. Germination tests, first germination count, seedling length and dry weight were employed to assess seed responses to the studied variations. Based on the results, the excess of salt reduces the germination percentage and the initial development of common rue seedlings, regardless of the substance used for stress induction.

Micaschists that host the Acari batholith (Ediacaran age, 572 to 577 My) are characterized by a large number of quartz veins. The veins are more abundant in higher-temperature metamorphic zones and, together with lower metamorphic zones, form an aureole centered in the batholith. Most of the fluid inclusions are two-phase (H2O-CO2 and liquid/vapor), but three-phase varieties (liquid/vapor/salt cubes; liquid/liquid/vapor) occur locally. The analyzed veins come from the biotite + chlorite + muscovite, biotite + garnet, cordierite + andalusite, and cordierite + sillimanite metamorphic zones. CO2 melting temperatures (TmCO2) vary from -62.6 to -56.7°C, suggesting CH4 and/or N2. Eutectic temperatures (Te) in quartz veins show average values of -30.8°C in the biotite + chlorite + muscovite and biotite + garnet zones, and -38.6°C in the cordierite + andalusite and cordierite + sillimanite zones. Ice-melting temperatures (Tmice) are lower in the higher-temperature metamorphic zones. The mode values are -3.8, -5.5, -5.6, and -7.3°C, corresponding respectively to the biotite + chlorite + muscovite, biotite + garnet, cordierite + andalusite, and cordierite + sillimanite zones. A fluid characterized by the H2O-Na-Cl (KCl)-MgCl2-FeCl2-CaCl2 system is defined by: Tmice from near -1.9 to -32°C, the presence of salt cubes mainly in the cordierite + andalusite and cordierite + sillimanite zones, and recorded eutectic temperatures (Te) from -16.5 to -59.1°C. In addition, total homogenization temperatures (Tht) ranging from 117 to 388°C were obtained for primary aqueous fluid inclusions. This indicates a long period of fluid circulation under conditions of falling temperatures. Our results are consistent with an increase in the salinity of the aqueous fluid across the thermal aureole toward the granitic batholith.

ABSTRACT Proper management of brackish water can increase plant production in the Brazilian semi-arid region. The objective of this study was to evaluate the production performance and water use efficiency of two peanut genotypes irrigated with brackish water during the reproductive stage, in soil with and without soil cover. The study was conducted in a greenhouse. The experimental design used was randomized blocks, with four replicates, in a 2 x 2 x 2 factorial scheme (two electrical conductivities of irrigation water - ECw 0.9 and 5.0 dS m-1, two peanut genotypes - AC 130 and cv. BR1, and the presence or absence of soil cover). At 72 days after sowing, harvest was performed and the following variables were evaluated: number of marketable pods, number of non-marketable pods, pod mass, diameter and length, production and water use efficiency. Salinity impacted production more than the water use efficiency in the two peanut genotypes, with the relative reduction in production being higher in cv. BR-1. Soil cover with dead plant material mitigated the effects of salinity on production and increased water use efficiency, only in genotype AC 130.

ABSTRACT Salinity is one of the problems that limit plant development, with the germination, growth, and initial establishment stages being the most sensitive to saline stress. Erythrina velutina, popularly known as “mulungu” in Brazil, is a species native to the Caatinga biome, which grows in conditions of soil rich in salts. The damage caused by salinity to the quality of its seeds and the use of techniques that mitigate such effects are little known. Thus, this work aimed to evaluate salicylic acid as a mitigator of saline stress in the physiological quality of mulungu seeds. The quality of two seed lots from two Brazilian states (L1: Mossoró, Rio Grande do Norte, and L2: Pentencostes, Ceará) was evaluated. A completely randomized design in a 2 (seed soaking with salicylic acid (SA) - distilled water and 1.0 mM SA) × 4 (electrical conductivity of irrigation water - ECw - 0.0, 3.0, 6.0 and 9.0 dS m-1) factorial scheme with four replications of 50 seeds each was used. Saline stress reduces the quality of mulungu seeds and seedlings. SA increases the vigor of the seeds, promoting improvements in germination under saline conditions.

ABSTRACT The cultivation of soursop has increased in recent years due to the advance of agribusiness and due to its use by the pharmaceutical industry. As a source of vitamin C, calcium, carbohydrates and antioxidant substances, soursop helps to protect the human body against oxidative stress, acting in the prevention of a series of chronic degenerative disorders. In this context, the objective of present study was to evaluate the effects of foliar sprays with salicylic acid to mitigate the effects of salt stress on the morphophysiology of soursop. The study was conducted in a greenhouse, in a randomized block design and a 5 × 4 factorial arrangement, with five levels of electrical conductivity of irrigation water - ECw (0.8-control; 1.6; 2.4; 3.2 and 4.0 dS m-1) and four concentrations of salicylic acid - SA (0; 1.2; 2.4 and 3.6 mM), with three replicates. Foliar application of SA at concentrations between 1.2 and 1.6 mM mitigated the effects of salt stress on stomatal conductance, CO2 assimilation rate, transpiration and instantaneous carboxylation efficiency of soursop at 480 days after transplanting. Spraying with SA at concentrations between 1.3 and 1.6 mM induced acclimatization to salt stress in soursop plants, since the percentage of intercellular electrolyte leakage was reduced and the growth was favored by the application of SA, even when exposed to salinity. Irrigation with ECw above 0.8 dS m-1 reduced the relative water content in the leaves of soursop cv. Morada Nova.

The seeds are subject to multiple stresses, such as water and salt stress, which limit imbibition and its chances of germination. Therefore, the aim of this study was to evaluate the germination behavior of seeds of Melocactus zehntneri (Britton & Rose) Luetzelb. (Cactaceae) when subjected to water and saline stress. From a completely randomized block experimental design, the water deficit was simulated with PEG6000 solutions at potentials: 0.0 (distilled water); -0.1; -0.3; -0.6 and -0.9 MPa, the same was done with NaCl for salt stress. Non-germinated seeds were washed and replaced to germinate in distilled water to assess recovery, and germinability (%) and t50 (days) were evaluated. Seeds subjected to water stress germinated up to the potential of -0.3MPa (82.0 ± 16.2%), without germination at -0.6 and -0.9 MPa. Under salt stress, the seeds germinated up to the potential of -0.6 MPa, with a reduction in germination as the NaCl concentration increased. When placed back in distilled water, the seeds that had been subjected to water stress germinated at -0.6 MPa and -0.9 MPa, but with a delay in germination (0.0 MPa: 5.96 ± 0.32 days; -0.3 MPa: 11.10 ± 0.76 days). Under salt stress, seeds submitted to -0.9 MPa germinated, demonstrating that NaCl did not cause damage (0% stress versus 39.0 ± 14.7% in recovery). Therefore, the seeds of the studied population of M. zehntneri are tolerant to water and salt stress. [ABSTRACT FROM AUTHOR]

ABSTRACT Nile tilapia (Oreochromis niloticus) is a euryhaline species which, in marine systems, can provide animal protein where fresh water is scarce. As a result, adequate water management to maintain sustainability is essential, and the use of a salt water recirculating system would be an advantage at the present time. In addition, Arthrospira platensis is used in the diet of aquatic organisms, as it is rich in protein. The aim of this study, therefore, was to evaluate the use of A. platensis as a food supplement in the performance of Nile tilapia in a salt water recirculating system. The experimental model included two groups, with four replications. Each crop had a duration of 45 days (control and test), giving a total of 90 days, with the control being offered commercial feed, and the test crop commercial feed supplemented with 20% A. platensis meal. Water quality results showed that total ammonia (NH3) and phosphate (PO4 3-) levels remained high during cultivation. In zootechnical performance, specific growth rate and survival were higher in the control; on the other hand, for the percent composition of the filleted fish, the treatment supplemented with A. platensis had a higher level of protein. It is therefore possible to cultivate Nile tilapia in salt water at a salinity of 35 ppt.

ABSTRACT The need to use strategies for using brackish water in agriculture, especially in semi-arid conditions, is evident. Based on this information, this study was developed with the aim of evaluating the consumption, efficiency and water content, as well as the dry mass of the arugula plants (cv. Broad Leaf) exposed to brackish nutrient solutions as a function of replacement strategies and circulation frequencies. The treatments consisted of six salinity levels of the nutrient solution (1.5, 3.0, 4.5, 6.0, 7.5 and 9.0 dS m-1) and two circulation frequencies (twice a day 8 a.m. and 4 p.m., and three times a day at 8 a.m., 12 p.m. and 5 p.m.). In Experiment I, the evapotranspiration line was replaced with the respective brackish water used in the preparation of the solution, and in Experiment II, the water supply was used. In both treatments, the experimental design was completely randomized, in a 6 x 2 factorial scheme, with five replications. The conclusion is that it is technically feasible to circulate the nutrient solution twice a day and there were lower losses in the water relations, in the biomass production of the shoot and in the partition of photoassimilates when the replacement with water supply was adopted.

ABSTRACT: Supplemental irrigation during dry spells could reduce maize yield losses in tropical semi-arid regions, notably in small farms. However, good quality water reserves are not sufficient to meet the demands of farming communities. Consequently, our objective was to evaluate the productivity and profitability of maize under different simulated rainfall scenarios, with and without supplemental irrigation (SI) with brackish water. The field experiments were carried out during the cropping seasons of 2018 and 2019 on Ultisol. The experiment followed a randomized block design in the split-plot scheme with four replicates. The plots were formed by simulating the water supply in the soil corresponding to four water scenarios (rainy, normal, drought and severe drought), and the sub-plots with or without SI with brackish water (Electrical conductivity of 4.5 dS m−1). Mean yields of green maize ears were 13,083, 11,532, 10,358 and 9,609 kg ha−1 for rainy, normal, drought and severe drought scenarios, as supplemented with brackish water. For the same treatments without SI the values were 11,394, 7,896, 3,913 and 1,374 kg ha−1, respectively. Data on farmer's income showed that under normal, drought and severe drought supplementation with brackish water becomes economically advantageous from 0.9, 1.0 and 2.4 ha, respectively, while maize cultivation without SI is not advantageous under the last two scenarios. For severe drought conditions, however, SI using brackish water reduced commercial yield by 27 % with negative effects on the farmers’ profitability. In this case, it is necessary to use water with either lower salinity or select salt tolerant crops.

ABSTRACT: This study evaluated the effect of low, medium, and high-water salinity (5, 35, and 50 ppt) on the apparent dry matter, protein, and energy digestibility of two formulated and six commercial diets for juvenile whiteleg shrimp, Litopenaeus vannamei, in a 120-day trial. Digestibility was determined in vivo using chromic oxide as an inert diet marker. Hydrostability in pellets varied from 86.8% to 99.9%; dry matter digestibility varied from 49.1% to 64.1%; protein digestibility showed greater variations at all salinities (56.9%-85.8%); and energy digestibility ranged from 70.1 to 86.4%. Salinity had a significant effect on dry matter, protein, and energy digestibility. Using a principal component analysis (PCA) with a covariance matrix, our findings suggested that the E2 (fishmeal-based formulation) diet and 35 ppt salinity provided optimum hydrostability and digestibility to Pacific white leg shrimp juveniles.

The biofertilizer can mitigate the effect of salt stress on the initial growth and on the physiology of cowpea (Vigna unguiculata). The objective of this work was to evaluate the effect of bovine biofertilizer on initial growth and gas exchange of cowpea plants irrigated with saline water. The experiment was conducted in a field condition in the Didactic garden on the Liberdade campus of the University of International Integration of Afro-Brazilian Lusophony (UNILAB), Redenção, Ceará. In the experiment, the cultivar "BRS Tumucumaque" was used, sown in 8-liter plastic pots, in a randomized block design in a 5x2 factorial scheme, with four replications, the first consisting of five concentrations of biofertilizers (5, 10, 15, 20 and 25% of the pot volume and the second factor composed by the electrical conductivity of the irrigation water (CEa: 0.5 and 5.0 dS m-1) .The leaf area, number of leaves, stem diameter, height of the plant, stomata, conductance, photosynthesis rate and transpiration were evaluated. Saline stress reduced plant height, transpiration and photosynthesis. The 15% concentration of bovine biofertilizer was the most efficient to mitigate the use of high water salinity for the number of leaves, stem diameter, leaf area and stomatal conductance. [ABSTRACT FROM AUTHOR]

Copyright of Anuario do Instituto de Geociencias is the property of Universidade Federal do Rio de Janeiro, Instituto de Geociencias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT Rugosa rugosa has high tolerance to various stresses; however, the molecular mechanisms of this behavior under adverse conditions are unclear. The objective of this study is to investigate expression patterns of stress-related genes in response to salinity stress. Changes in transcript levels of R. rugose, grown under different salt stress conditions (0, 25, 50, and 100 mM NaCl) over a long exposure period (30 days), have been investigated. In addition, the effects of salt shock stress on seedlings exposed to a high level (200 mM) of NaCl for a relatively short duration (3 h) have also been investigated. Expression levels of selected differentially expressed genes have been determined using relative reverse transcription polymerase chain reaction (RT-PCR). It has been observed that seedlings exposed to salt stress for a long duration exhibited no signs of stress in both leaves and roots. In addition, expression of NHX1 in R. rugosa increased in the presence of NaCl. Furthermore, transcripts of EXP4, GPP, NHX1, NAC, and DREB genes also increased under high levels of NaCl. In contrast, expression levels of MYB and TIR decreased during this salt shock treatment. Of particular interest is the increase in levels of transcripts of NHX1 in leaves of seedlings grown under both salt stress and salt shock conditions, thus suggesting that this gene plays an important role in salt stress tolerance in R. rugosa. These findings will support efforts in enhancing salt tolerance in roses, and perhaps in other members of the Rosaceae family.

In freshwater fish with external fertilization, sperm sampling can be contaminated with urine, which triggers motility and gives rise to decreased fertilization success. The maintenance of freshwater fish in hyperosmotic conditions may reduce urine production and improve sperm quality. Thus, the aim of this work was to verify if acute exposure to various NaCl concentrations improves sperm quality in the yellowtail tetra Astyanax altiparanae. Spermiation was induced using a single dose of carp pituitary gland (5 mg kg-1) and the males were maintained at various NaCl concentrations: NaCl 0.00% (control), NaCl 0.45% (hypoosmotic), NaCl 0.9% (isosmotic) and NaCl 1.0% (hyperosmotic) for 6 h at 26 °C. Sperm was collected and verified for activation by urine and motility traits. At 0.00%, 0.45%, and 0.90%, the sperm was motile just after sampling, indicating activation by urine. Surprisingly, at hyperosmotic conditions, no activation was observed. Other sperm and motility parameters did not show any statistical differences, including sperm viability (P = 0.7083), concentration (P = 0.9030), total motility (P = 0.6149), VCL (curvilinear velocity; P = 0.1216), VAP (average path velocity; P = 0.1231) and VSL (straight-line velocity; P = 0.1340). Our results indicate that acute maintenance at hyperosmotic conditions eliminates sperm activation by urine and maintains sperm quality. Such a new procedure is interesting for both basic and applied sciences, including reproductive practice in fish.

ABSTRACT Cultivation using brackish waters can result in nutritional and metabolic imbalances in several plant species, consequently reducing the production of dry matter (DM) and accumulation of toxic ions (Na+ and/or Cl-) in plants. We evaluated the DM production, and nutrient and inorganic solute (Na+ and Cl-) content in green onion plants (cv. Todo Ano Evergreen - Nebuka) under different levels of nutrient solution salinity in combination with circulation frequencies of this solution. Two experiments were conducted in a hydroponic system, using a completely randomized design, in a 6 × 2 factorial scheme, with five replicates: six levels of nutrient solution salinity (1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 dS m-1) and two solution circulation frequencies (twice and thrice a day). In Experiment I, the evapotranspired depth was replaced using brackish water that was used to prepare each of the salinity levels (used exclusively), whereas in Experiment II, brackish water was used only to prepare each of the salinity levels and public water was used (electrical conductivity [ECw] = 0.12 dS m-1) for replacement in all treatments. The increase in the nutrient solution salinity reduced the production of DM and accumulation of nutrients; the reductions were more pronounced when brackish waters were used exclusively (Experiment I). However, the circulation of solutions thrice a day resulted in the harmful effects of the salinity effect. Replacing the evapotranspirated blade with water supply (Experiment II) mitigated the deleterious effects of salinity. Moreover, three circulations of the nutrient solution daily resulted in lower accumulation of inorganic Na+ and Cl- solutes and increased accumulation of nutrients N, P, K+, Ca2+, Mg2+, and S in the culture.