Search Results (17)

Water scarcity in arid and semi-arid regions increasingly stresses groundwater resources, compromising their availability and quality. In this context, desalinated seawater (DSW) represents a sustainable alternative when combined with conventional water sources and efficient irrigation systems. This study assessed the effect of three irrigation treatments on greenhouse-grown tomato crops in an open hydroponic system. The treatment T1 used only DSW, while T2 and T3 were mixtures of DSW and groundwater in different proportions to achieve electrical conductivities (EC) of 2.5 (T1), 3.5 (T2), and 5.5 dS·m⁻¹ (T3), respectively. Each treatment received the same fertilization level through fertigation, adjusted to the crop’s nutritional needs. Experiments were conducted in duplicate in two greenhouse sectors (West and East). The data on yield, fruit quality, fertilizer use, and water consumption were analyzed. Results indicated that higher EC reduced marketable and total yield, decreased fertilizer use efficiency, and increased the combined cost of water and nutrients per unit of marketable fruit. Additionally, higher EC affected fruit weight and diameter, increased soluble solids, and altered dry matter content. These findings demonstrate that DSW can be an effective and environmentally sustainable irrigation strategy for greenhouse crops. Full article

Desalinated seawater (DSW) is nowadays a competitive alternative for irrigating intensive greenhouse crops in regions with scarce water resources. This research, carried out for three years, analyzed the effects of three desalinated seawater (DSW) blends with different salinity levels and two common growing media (soil and soilless) on the fruit quality of a tomato crop grown under Mediterranean greenhouse conditions. To analyze the effect of the three experimental factors on fruit quality, a randomized block design layout was employed, and a multifactorial ANOVA analysis was conducted. Four successive harvests were performed in each growing cycle at similar dates and under consistent crop conditions to analyze the effect of harvest timing on fruit quality. Fruit quality parameters, such as fresh and dry weight, fruit diameter, total dissolved solids (TDS), and firmness, were measured on a representative sample of fruits from each harvest, treatment, and growing cycle. Results showed that the experimental factors studied significantly influenced fruit quality. Increasing salinity treatments reduced fruit size but improved fruit quality. The growing media had no significant effect on fruit size, although soilless crops yielded better quality fruits than the soil-grown ones. Later harvests tended to provide lower-yield but higher-quality fruits. This study demonstrates that the conjunctive use of DSW and conventional water can help to improve both quality and yield of tomato fruit while guaranteeing the sustainability of the greenhouse horticultural system. Full article

An experimental evaluation of water productivity and footprint was carried out in a Mediterranean greenhouse tomato crop irrigated with different blends of desalinated seawater (DSW) for two different growing media: soil and soilless culture. Total and commercial water productivity values (expressed in terms of kg of fruit/m³ of water) and water footprint were calculated from empirical data on water consumption and crop yields. Regarding the growing media, the results of the experiment showed that the soilless culture had significantly lower water productivity and a higher water footprint, mainly due to the greater water consumption in these systems. These findings seem to indicate that fostering closed-loop soilless systems with water and nutrient recirculation is highly beneficial for improving the efficiency and sustainability of these soilless systems. The salinity of the irrigation water blends did not seem to have a significant influence on water productivity and water footprint. Nevertheless, treatments with higher DSW fractions and better quality showed slightly better productivity values and lower water footprints than those with higher salinity. These findings seem to support the fact that the conjunctive use of DSW and conventional water, within the range proposed in this study, is a favorable option from both economic and environmental perspectives. Full article

In water-scarce regions, policymakers resort to reclaimed water (RW) and desalinated seawater (DSW) to supply economic agents when conventional resources are not available. This paper develops a proposal for a simple methodology to apply a cost–benefit analysis (CBA) approach to RW and DSW as a support to the evaluation of water policy goals. To test the method, it applies a CBA to RW and DSW in Axarquia (southern Spain), a water-scarce region suffering a long and extreme drought that is impacting urban supply and the agricultural sector. The benefit-to-cost ratio (BCR) of 17.02 estimated for reclaimed water highlights its high return on investment, suggesting that it offers substantial economic and environmental benefits. This high BCR indicates that reclaimed water as a resource for irrigation is highly cost-effective, particularly if it is combined with nutrient management. By contrast, the estimated BCR of 4.05 for desalinated water, although positive, is considerably lower, suggesting that desalinated water is a feasible but less cost-effective solution due to its high energy requirements and associated costs. This methodology may be extended to other hydrological systems, such as aquifer basins, to promote the generation of more comprehensive insights. Full article

Desalinated seawater (DSW) has emerged as a promising solution for irrigation in regions facing water scarcity. However, adopting DSW may impact the existing cultivation model, given the presence of potentially harmful elements, among other factors. A three-year experiment was carried out to assess the short-term effects of four irrigation waters—freshwater (FW), DSW, a mix 1:1 of FW and DSW (MW), and DSW with low boron (B) concentration (DSW–B)—on a ‘Rio Red’ grapefruit orchard. These irrigation waters exhibited varying levels of phytotoxic elements, some potentially harmful to citrus trees. Sodium (Na⁺) and chloride (Cl⁻) concentrations exceeded citrus thresholds in all treatments, except in DSW−B, whilst B exceeded toxicity levels in DSW and MW treatments. Leaf concentrations of Cl⁻ and Na⁺ remained low in all treatments, whereas B approached toxic levels only in DSW and MW–irrigated trees. The rapid growth of the trees, preventing excessive accumulation through a dilution effect, protected the plants from significant impacts on nutrition and physiology, such as gas exchange and chlorophyll levels, due to phytotoxic elements accumulation. Minor reductions in photosynthesis in DSW–irrigated trees were attributed to high B in leaves, since Cl⁻ and Na⁺ remained below toxic levels. The accelerated tree growth effectively prevented the substantial accumulation of phytotoxic elements, thereby limiting adverse effects on tree development and yield. When the maturation of trees reaches maximal growth, the potential accumulation of phytotoxic elements is expected to increase, potentially influencing tree behavior differently. Further study until the trees reach maturity is imperative for comprehensive understanding of the long-term effects of desalinated seawater irrigation. Full article

Climate change is affecting water resources in south-eastern Spain, and this mainly affects irrigated agriculture. In this context, seawater desalination is an adaptive strategy that has provided increasing water allotments to agriculture for the last decade, to replace decreasing conventional resources. Farmers are concerned about the agronomic effects of this substitution and its economic consequences. This study focuses on the potential agronomic impacts of the progressive replacement of the irrigation water from the Tagus–Segura transfer (TST) with desalinated seawater (DSW) on the main crops of south-eastern Spain. To that end, five main agronomic concerns were selected and analyzed under three water supply scenarios using increasing rates of DSW (0, 50, and 100%). The results indicated that, in addition to other economic or environmental considerations, sufficiently relevant agronomic aspects exist that need to be considered when replacing the TST supply with DSW. This study evidences the risks of phytotoxicity and soil alkalinization, due to the increase in boron concentration and the imbalance between monovalent and divalent cations in the DSW, respectively, and also a slight increase in the cost of fertilizers. In addition, the irrigation water salinity effect on production and total irrigation requirements was negligible, as both water sources present sufficiently low salinity. The detrimental effects were mitigated under a partial replacement scenario, so the blended use of DSW with conventional resources seems the most recommendable option for its agricultural management, rather than irrigating with DSW alone. Full article

The use of desalinated seawater (DSW) for irrigation in semi-arid regions is taking hold. Citrus tolerance to ions that predominate in DSW and water stress depends on the rootstock. Deficit irrigation was applied to DSW-irrigated lemon trees and grafted on rootstocks with different tolerance (Citrus macrophylla (CM) and sour orange (SO)). Plants were irrigated with DSW or Control treatment (distilled water), and, 140 days later, irrigation treatments were started: full irrigation (FI) or DI (50% of the volume applied to FI). After 75 days, differences between CM and SO plants irrigated with DSW and under DI were found. The higher concentrations of Cl⁻ and Na⁺ in CM and B in SO were the main causes of shoot growth reduction. The osmotic adjustment of CM plants was made possible by the accumulation of Na⁺, Cl⁻, and proline, but SO failed to adjust osmotically. In CM and SO plants, photosynthesis reduction was due to lower chlorophyll levels, but also to stomatal factors (CM plants) or alterations of the photochemical machinery (SO plants). Finally, unlike CM, SO had a good antioxidant system. In the future, knowing the different responses of CM and SO under these stressful conditions could be useful in citrus-growing areas. Full article

This study assesses the impact of irrigating with desalinated seawater (DSW) on the profitability of greenhouse tomato in south-eastern Spain, comparing different water-quality sources in both traditional sanding cultivation and soilless hydroponic production. The assessment is based on the combination of partial crop budgeting techniques with field data from the LIFE DESEACROP Project experimental activities. Our results show that the exclusive use of DSW for tomato production increases fertilization costs by 20% in soilless systems and by 34% in traditional sanding cultivation, and water costs by 30% in soilless systems and by 48% in traditional soil cultivation. As a result, production costs increase by 5% in soilless cultivation and 3% in soil cultivation, increases that are reduced when DSW is blended with brackish water. However, the lower salinity of DSW, compared with conventional water resources in the area, increases both crop yield and profitability. Soilless cultivation would also increase tomato profitability but only if good quality water is available. The materialization of the potential benefits of soilless production requires improving water quality through the increased use of DSW. Otherwise, the traditional sanding production system, better adapted to the area’s poor soils and bad quality water, would be more profitable. Full article

Desalinated seawater (DSW) can provide water resources for irrigation in coastal regions where freshwater is scarce. Reverse osmosis (RO) is the most common technique to obtain DSW worldwide. Nevertheless, using DSW for irrigation could pose an agronomic risk as RO permeates may have a boron concentration above the phytotoxicity thresholds of certain crops, such as woody crops (0.5 to 1.0 mg/L). In this study, an on-farm ion exchange resin system with an average flow of 1 m³/h, designed to reduce the boron concentration of DSW, was evaluated from a technical and economic perspective. The impact of variations in the feed water and operating temperatures on the boron reduction process was assessed. The results show that the system can provide an outflow with a boron concentration below the threshold of 0.5 mg/L over 92 h of operation, with boron rejections of up to 99% during the first 41 h. The estimated cost of boron removal with the on-farm system of the trial was EUR 0.992/m³. However, this cost is expected to decrease to EUR 0.226/m³ for a commercial ion exchange resin (IX) plant (20 m³/h), highlighting the importance of the scale factor. Our results provide novel guidance on the viability of using boron removal IX systems for farms irrigated with DSW, when it is provided by coastal plants with boron concentrations above the crop tolerance. Full article

Seawater desalination can provide water for irrigation in coastal regions where freshwater resources are scarce. Reverse osmosis (RO) is the most common technique to obtain desalinated seawater (DSW) worldwide. However, using DSW for irrigation may pose an agronomic risk as RO permeates have a boron concentration above the phytotoxicity thresholds of some sensitive crops, such as woody crops (0.5 to 1.0 mg/L). In this study, an on-farm RO system designed to reduce the boron concentration of DSW was evaluated from a technical and economic perspective. The impact of variations in the operating parameters feed water temperature, pressure, and pH, on the boron reduction process was assessed. The results showed that boron rejections close to 99% can be obtained by increasing the feed water pH to 11 with an operating pressure of 10 bar. Looking at the affordability of the system, a total production cost of 1.076 EUR/m³ was estimated for the 1.1 m³/h on-farm system used in the trial. However, this cost is expected to decrease to 0.307 EUR/m³ for a commercial RO plant (42 m³/h), highlighting the importance of the scale factor. Our results provide novel guidance on the feasibility of implementing on-farm boron removal RO systems, when DSW is provided by coastal plants with boron concentrations above the crop tolerance. Full article

Curbing greenhouse gas (GHG) emissions to combat climate change is a major global challenge. Although irrigated agriculture consumes considerable energy that generates GHG emissions, the biomass produced also represents an important CO₂ sink, which can counterbalance the emissions. The source of the water supply considerably influences the irrigation energy consumption and, consequently, the resulting carbon footprint. This study evaluates the potential impact on the carbon footprint of partially and fully replacing the conventional supply from Tagus–Segura water transfer (TSWT) with desalinated seawater (DSW) in the irrigation districts of the Segura River basin (south-eastern Spain). The results provide evidence that the crop GHG emissions depend largely on the water source and, consequently, its carbon footprint. In this sense, in the hypothetical scenario of the TSWT being completely replaced with DSW, GHG emissions may increase by up to 50% and the carbon balance could be reduced by 41%. However, even in this unfavourable situation, irrigated agriculture in the study area could still act as a CO₂ sink with a negative total and specific carbon balance of −707,276 t CO₂/year and −8.10 t CO₂/ha-year, respectively. This study provides significant policy implications for understanding the water–energy–food nexus in water-scarce regions. Full article

The Korean bottled water market has continuously expanded during the last 25 years. However, in-depth studies of its geochemistry have not been conducted. Four types of bottled water manufactured in South Korea (i.e., natural mineral water, NMW; functional water, FW; carbonated water, CW; and desalinated seawater, DSW) were investigated to classify the water type, verify the accuracy of the ion contents detailed on the bottle labels, and decipher the origin of the water sources using major and trace elements and their isotopes. The waters was classified into three types: Ca-HCO₃, Ca(Mg)-Cl, and Na-HCO₃. NMW and FW are mainly of the Ca-HCO₃ type. Our findings indicate that Korean bottled water chemistry is associated with lithological features and manufacturing processes; NMW is closely related to lithology while FW and DSW are strongly affected by manufacturing processes. Unlike major ions, trace elements cannot be used to decipher Korean bottled water chemistry because they show little apparent relationship with lithology. Regardless of the water chemistry, typical isotopic signals corresponding to intrinsic water were observed in all of the samples, indicating that groundwater and seawater were the sources of Korean bottled water. Full article

Food security concerns, climate change impacts, and increased pressure on conventional water resources have encouraged the agricultural use of nonconventional water resources in the last decade. As a result, desalinated seawater (DSW) has already consolidated its position as an alternative source to increase the supply for crop irrigation in Spain and Israel, where farmers’ acceptance is progressively on the rise. The first experiences in these regions highlighted that DSW agricultural use involves new agronomic, economic, and environmental challenges which require innovative research approaches and imply novel water management strategies. In this Special Issue, eight high-quality papers which present current research trials and study cases, covering a wide range of topics that are relevant when irrigating with DSW, have been selected. The papers came from the three regions of the world that currently have a massive agricultural DSW supply: Southeastern Spain, Israel, and the Canary Islands. Full article

The use of desalinated seawater (DSW) as an alternative to conventional water resources is gradually gaining more interest due to the strong water deficit and increasing pressure on water resources in semi-arid regions. Furthermore, the combination of this alternative irrigation with the hydroponic cultivation system would allow continuous production almost through the whole year and hydroponic-related high crop yield. Nevertheless, the effects of DSW irrigation in hydroponic systems on the product quality need to be firstly studied to avoid product quality losses. In this study, we evaluated the effects on the quality of two tomato cvs. (Ramyle and Racymo) of three different irrigation treatments (T1, DSW; T2, DSW/well water mix; and T3, well water) under hydroponic or traditional cultivation systems. The soluble solid content of samples (highly correlated to dry matter content) grown under hydroponic conditions and T3 irrigation showed the highest values (5.8 °Brix) although such differences (<0.6 °Brix) with T1 might not be sensorially appreciated. Similarly, although T3 samples showed higher acidity than T1 samples, such differences (0.06%) would be not appreciated by the consumer. Tomatoes grown in hydroponic conditions had 1.1–1.2-fold higher firmness than conventional soil conditions showing hydroponic T3 samples had the highest value (21–23 N). Tomato cv. Racymo displayed higher color index (chroma) than cv. Ramyle, registering hydroponic T1 samples the most intense red color correlated with the highest lycopene content of 41.1 mg/kg. T1 irrigation of tomatoes cv. Ramyle did not induce significant changes while differences lower than 10% were observed in the tomato cv. Racymo. The highest total antioxidant capacity, which was highly correlated to the total phenolic content (R² = 0.80), was found for hydroponic T1 samples with 1637/1243 µmol/kg for the tomato cvs. Ramyle/Racymo. Conclusively, the use of DSW would not compromise the consumer acceptance of tomatoes due to the low (not appreciable) quality differences, with even the total antioxidant capacity of these samples being increased. Furthermore, the mix of DSW with conventional water resources (lower cost) would not compromise the tomato quality. Full article

The growing need for alternative water resources for irrigation has led to advanced technological developments, which are addressing some of the challenges that our planet is facing regarding the water supply. The Canary Islands Archipelago (Spain) is a singular territory with several years of desalination experience while using desalinated seawater (DSW) for agricultural purposes. The current paper will address the conducted research of one of the case studies done into the Horizon 2020 project MAGIC, with the aim of analyzing the use of DSW for crop production in the Southeast of Gran Canaria Island. A methodology of surveying farmers in the area has been put in practice, as well as an assessment of potential soil degradation risks that are related to DSW irrigation (with fifteen years of DSW data). Additionally, local good practices to improve the DSW quality for irrigation are discussed. This study demonstrates an excellent endorsement of the surveyed farmers in the studied area regarding the use of DSW for irrigation: the strategy of combining this type of water with other water resources, such as groundwater and/or reclaimed water is very frequent and it can guarantee water and food security in the island’s territory. Full article