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Màster d'Enginyeria Ambiental, Facultat de Química, Universitat de Barcelona, Curs: 2016-2017, Tutora: Carmen Sans Mazon ; Catalonia suffers from structural water deficit due to its climate and rain pattern, which is worsened by the fact that most of the population lives in the coastline, where water resources are poor. This situation has led to several difficulties in water supply during drought periods. The region of Barcelona keeps growing enhancing territorial imbalances, and climate change makes drought periods much more likely. Therefore, a good water management is vital to ensure water supply to the population. This project analyzes the regulations and organisms involved in water management in Catalonia, as well as studying the water deficit situation. The Catalan water management plans and programs have been studied, besides, the measures proposed in them to fight water deficit and the achievement of the objectives so far. Water deficit is fought with the pursuit of new water resources, which can be technologically generated or by the improvement of the water quality in the environment and decontamination of aquifers. The two main techniques, which suppose a new production of water resources, are desalination and reclamation or water reuse. The technology used in water reclamation plants and in desalination plants is very similar, consisting on a pre-treatment by coagulation-flocculation, followed by sand filters and microfiltration. Then, water is passed through reverse osmosis filters, where salts and microorganisms are eliminated from the permeate. This water is then disinfected and it can be given several uses according to its quality. Desalinized water is intended for water consumption, and thus, is distributed through water supply systems. However, the current legislation does not contemplate direct human consumption of reclaimed water. Therefore, it is reused for other purposes, such as industrial uses, urban cleaning, environmental purposes or agricultural irrigation. The Camp de Tarragona reclamation plant and the Llobregat desalination plant are two examples of how these technologies have been implemented in Catalonia to fight water deficit, the first in an industrial area and the second in the metropolitan area of the city of Barcelona. The technologies used at each plant are compared as well as the costs of the water produced. Each technology has pros and cons, but both contribute to the production of new water resources that can be given several uses, and contribute to alleviating the human pressure on those rivers and aquifers that are already overused. All in all, regeneration and desalination, not only provide a solution to water deficit, but also allow the improvement of the quality of the water ecosystems

Shortening of available volumes of a natural resource can become an engine for the development of new technologies, which could help using it more effectively. The article considers the case of Israel - the state that encounters sweet water deficit. Accessible average volume of this resource is in some sense random and hard to predict. Ordinary pricing mechanisms are difficult to implement due to political and social considerations. A range of measures has made private firms use an already existing intellectual resource to develop R&D aiming to make water use more effective. This can be viewed as a process of efficient substituting a deficit natural resource with a non-deficit intellectual one.

8 páginas.-- 6 figuras.-- 1 tabla.-- 44 referencias ; The fruit maturation stage is considered the optimal phenological stage for implementing water deficitin jujube (Zizyphus jujuba Mill.), since a low, moderate or severe water deficit at this time has no effect onyield, fruit volume or eating quality. However, no information exists at fruit water relations level on themechanisms developed by Z. jujuba to confront drought. The purpose of the present study was to increaseour understanding of the relationship between leaf and fruit water relations of jujube plants under dif-ferent irrigation conditions during fruit maturation, paying special attention to analysing whether fruitsize depends on fruit turgor. For this, adult jujube trees (cv. Grande de Albatera) were subjected to fiveirrigation treatments. Control plants (T0) were irrigated daily above their crop water requirements inorder to attain non-limiting soil water conditions in 2012 and 2013. T1 plants were subjected to deficitirrigation throughout the 2012 season, according to the criteria frequently used by the growers in thearea. T2 (2012), T3 and T4 (2013) were irrigated as T0 except during fruit maturation, in which irrigationwas withheld for 32, 17 and 24 days, respectively. The results indicated that the jujube fruit maturationperiod was clearly sensitive to water deficit. During most of this stage water could enter the fruits viathe phloem rather than via the xylem. From the beginning of water withholding to when maximumwater stress levels were achieved, fruit and leaf turgor were maintained in plants under water deficit.However, a direct relation between turgor and fruit size was not found in jujube fruits, which could bedue to an enhancement of a cell elasticity mechanism (elastic adjustment) which maintains fruit turgorby reducing fruit cells size or to the fact that jujube fruit growth depends on the fruit growth-effectiveturgor rather than just turgor pressure. ; This research was supported by Agencia Espa˜nola de Coop-eración Internacional para el Desarrollo (AECID) (A1/035430/11)and MICINN and MINECO (CICYT/FEDER AGL2010-19201-C04-01AGR and AGL2013-45922-C2-2-R) grants to the authors. AG, ZNC,JCG and HM were funded by a FPU, an AECID, a FPI an INIA grantfrom the Spanish Government, respectively. ; Peer reviewed

California's budget politics were temporarily sidetracked by an increasingly severe statewide drought, forcing the state to take action. Democratic lawmakers elected new leadership, who, like their predecessors, argued the state should increase social spending. The major budget clash centered on California's booming economy and what to do with a large projected tax surplus. The legislature wanted to spend the revenue, while Governor Jerry Brown downplayed the fiscal estimates and wanted to squirrel away the extra money in the state's new rainy-day fund. Brown sparred with the University of California over UC's increasing reliance on out-of-state students to fund the university, limiting the number of spots for California students.

The application of a moderate water deficit (water potential of 1.3 MPa) to pea (Pisum sativum L. cv Lincoln) leaves led to a 75% inhibition of photosynthesis and to increases in zeaxanthin, malondialdehyde, oxidized proteins, and mitochondrial, cytosolic, and chloroplastic superoxide dismutase activities. Severe water deficit (1.9 MPa) almost completely inhibited photosynthesis, decreased chlorophylls, -carotene, neoxanthin, and lutein, and caused further conversion of violaxanthin to zeaxanthin, suggesting damage to the photosynthetic apparatus. There were consistent decreases in antioxidants and pyridine nucleotides, and accumulation of catalytic Fe, malondialdehyde, and oxidized proteins. Paraquat (PQ) treatment led to similar major decreases in photosynthesis, water content, proteins, and most antioxidants, and induced the accumulation of zeaxanthin and damaged proteins. PQ decreased markedly ascorbate, NADPH, ascorbate peroxidase, and chloroplastic Fe-superoxide dismutase activity, and caused major increases in oxidized glutathione, NAD+, NADH, and catalytic Fe. It is concluded that, in cv Lincoln, the increase in catalytic Fe and the lowering of antioxidant protection may be involved in the oxidative damage caused by severe water deficit and PQ, but not necessarily in the incipient stress induced by moderate water deficit. Results also indicate that the tolerance to water deficit in terms of oxidative damage largely depends on the legume cultivar. ; This work was supported by the Dirección General de Enseñanza Superior (Spain) (grant no. PB95-0091). I.I.-O. was the recipient of a postdoctoral fellowship from the Basque Government and P.R.E. was the recipient of a predoctoral fellowship from the Ministerio de Educación y Cultura (Spain). ; Peer reviewed

To study the effects of water deficits on water use efficiency (WUE) of citrus trees, whole tree transpiration and CO2 assimilation were measured in a semi-arid environment during the summer of 2012. Young orange trees >Valencia Late>, either water stressed (DI) and well-irrigated (C), were monitored in selected days using a gas exchange chamber. Tree transpiration was also measured on a continuous basis with sap flow sensors. The water restriction reduced the transpiration of the DI treatment down to 60% of the maximum potential (treatment C) during the peak of water stress. The instantaneous WUE ranged between 1.7 and 79gCO2L-1H2O and was tightly related to the vapour pressure deficit. Differences in instantaneous WUE due to water stress were insignificant. On a daily basis, WUE ranged between 4.9 (7 August) and 8.8 (7 June) gL-1 for the daytime period; and between 4.0 and 8.2gL-1 for the 24h period. As water stress was imposed on the DI treatment, a trend of increasing WUE in DI relative to C was observed, reaching, in the maximum stress period, a difference, of 13-15% (daytime) and 20-22% (24h) although not statistically significant. Partial rewatering returned the WUE to similar values in both treatments. An analysis of the differences in the diurnal patterns of transpiration suggests that the increase in WUE due to water stress in citrus is achieved indirectly by shifting the overall carbon assimilation towards the morning hours of lower evaporative demand. © 2014 Elsevier B.V. ; This work was financially supported by the projects CONSOLIDER-RIDECO CSD2006-00067 and AGL2009-13105 of the Spanish Ministry of Science and Education, partly through European Union ERDF funds. ; Peer Reviewed

22 páginas.- 2 figuras.- 5 tablas.- 62 referencias.- Supplementary Materials: The following are available online at http://www.mdpi.com/2073-4395/10/10/1470/s1, Table S1: Mean values of morphological and chemical parameters of irrigation treatments (T1, T2, T3, and T4) for 3 years (2017, 2018, and 2019) and Table S2: Mean values of functional and sensorial parameters of irrigation treatments (T1, T2, T3, and T4) for 3 years (2017, 2018, and 2019). ; Global warming enhances the rainfall and temperature irregularity, producing a collapse in water resources and generating an urgent need for hydro-sustainable thinking in agriculture. The aim of this study was to evaluate the correlation between the water stress of almond trees and quality parameters of fruits, after 3 years of experiments, with the objective of establishing quality markers necessary in the certification process of hydroSOStainable almonds. The results showed positive correlations among the stress integral (SI) and dry weight, color coordinates (L*, a* and b*), minerals (K, Fe, and Zn), organic acids (citric acid), sugars (sucrose, fructose, and total sugars), antioxidant activity, and fatty acids [linoleic acid, polyunsaturated (PUFA)/monounsaturated (MUFA) ratio, PUFA and SFA, among others]. As well as negative correlations of SI with water activity, weight (almond, kernel, and shell), kernel size, minerals (Ca and Mg), fatty acids (oleic acid, oleic/linoleic ratio, MUFA, and PUFA/SFA ratio), and sensory attributes (size, bitterness, astringency, benzaldehyde, and woody). Finally, this research helped to prove key quality parameters that can be used as makers of hydroSOStainable almonds. In addition, it was demonstrated that controlling water stress in almond trees by using deficit irrigation strategies can lead to appropriate yields, improve the product quality, and consequently, lead to a final added value. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. ; This research was funded by the Spanish Government (Ministerio de Ciencia e Innovacion (MCI), Agencia Estatal de Investigacion (AEI), through a coordinated research project (hydroSOS) including the Universidad Miguel Hernández de Elche (AGL2016-75794-C4-1-R, Productos hidroSOStenibles: identificación de debilidades y fortalezas, optimización del procesado, creación de marca propia, y estudio de su aceptación en el mercado europeo, hydroSOS foods) and the Universidad de Sevilla (AGL2016-75794-C4-4-R); these projects have been also funded by Fondo Europeo de Desarrollo Regional (FEDER) "Una manera de hacer Europa", (MCI/AEI/FEDER, UE). ; Peer reviewed

Drought tolerance is a complex phenomenon comprising many physiological, biochemical and morphological changes at both aerial and below ground levels. We aim to reveal changes on root morphology that promote drought tolerance in oat in both seedling and adult plants. To this aim, we employed two oat genotypes, previously characterized as susceptible and tolerant to drought. Root phenotyping was carried out on young plants grown either in pots or in rhizotrons under controlled environments, and on adult plants grown in big containers under field conditions. Overall, the tolerant genotype showed an increased root length, branching rate, root surface, and length of fine roots, while coarse to fine ratio decreased as compared with the susceptible genotype. We also observed a high and significant correlation between various morphological root traits within and between experiments, identifying several of them as appropriate markers to identify drought tolerant oat genotypes. Stimulation of fine root growth was one of the most prominent responses to cope with gradual soil water depletion, in both seedlings and adult plants. Although seedling experiments did not exactly match the response of adult plants, they were similarly informative for discriminating between tolerant and susceptible genotypes. This might contribute to easier and faster phenotyping of large amount of plants. ; This work was supported by the Spanish Ministry of Economy and Competitiveness [AGL2016-78965AGR], (AEI/FEDER, UE) and regional government through the AGR-253 group, the European Regional and Social Development Funds and the COST action FA1306. FC is holder of a FPI fellowship from the Spanish Ministry of Economy and Competitiveness. ; Peer reviewed

16 páginas.- 6 figuras.- 1 tablas.- referencias. The following supplementary data are available at JXB online.- We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). ; Chloride (Cl−), traditionally considered harmful for agriculture, has recently been defined as a beneficial macronutrient with specific roles that result in more efficient use of water (WUE), nitrogen (NUE), and CO2 in well-watered plants. When supplied in a beneficial range of 1–5 mM, Cl− increases leaf cell size, improves leaf osmoregulation, and reduces water consumption without impairing photosynthetic efficiency, resulting in overall higher WUE. Thus, adequate management of Cl− nutrition arises as a potential strategy to increase the ability of plants to withstand water deficit. To study the relationship between Cl− nutrition and drought resistance, tobacco plants treated with 0.5–5 mM Cl− salts were subjected to sustained water deficit (WD; 60% field capacity) and water deprivation/rehydration treatments, in comparison with plants treated with equivalent concentrations of nitrate, sulfate, and phosphate salts. The results showed that Cl− application reduced stress symptoms and improved plant growth during water deficit. Drought resistance promoted by Cl− nutrition resulted from the simultaneous occurrence of water deficit avoidance and tolerance mechanisms, which improved leaf turgor, water balance, photosynthesis performance, and WUE. Thus, it is proposed that beneficial Cl− levels increase the ability of crops to withstand drought, promoting a more sustainable and resilient agriculture. ; This work was supported by Spanish Ministry of Science Innovation and Universities-FEDER grants AGL2015-71386-R and RTI2018-094460-B-I00, Spanish National Research Council grants CSIC-201840E132, CSIC-201940E039, and CSIC-201940E077, and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 895613. ; We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). ; Peer reviewed

Abstract
Sowing in dry soil aims to alleviate the effects of water restriction, allowing for an earlier start of sowing and maximizing operational productivity in the use of agricultural machinery and implements. Thus, the objective of the present work was to evaluate the physiological quality of soybean seed lots submitted to different periods of water deficit after sowing in dry soil under vegetal cover. The experimental design was completely randomized, in a 2x5x2 factorial scheme (seed lots: high and low vigor; periods of water deficit after sowing in dry soil: 0; 4; 8; 12 and 16 days after sowing (DAS) and soil cover crops: without and with), with four replications. The evaluations were carried out from emergence to the beginning of the crop's reproductive phase. It was verified that there was no triple interaction of the factorial, where each factor individually interfered on the physiological quality of soybean seeds, regardless of their initial vigor. It was concluded that the use of plots with different vigor affects negatively the emergence of soybean seedlings, as well as the different periods of water deficit after sowing in dry soil. However, the presence of vegetation cover on the soil mitigates this effect, allowing greater emergence due to this promoting more favorable environmental conditions.
Keywords: Glycine max. Vegetation Ground Cover. Seed Vigor.
ResumoA semeadura em solo seco visa amenizar os efeitos de restrição hídrica, permitindo o início da semeadura mais precoce e a maximização da produtividade operacional no uso de máquinas e implementos agrícolas. Deste modo, o objetivo do presente trabalho foi avaliar a qualidade fisiológica de lotes de sementes de soja submetidas aos diferentes períodos de déficit hídrico após a semeadura no solo seco sob cobertura vegetal do solo. O delineamento experimental foi conduzido inteiramente casualizado, no esquema fatorial de 2x5x2 (lotes de sementes: alto e baixo vigor; períodos de déficit hídrico após a semeadura no solo seco: 0; 4; 8; 12 e 16 dias após a semeadura (DAS) e coberturas vegetais do solo: sem e com), com quatro repetições. As avaliações foram realizadas a partir da emergência até o início da fase reprodutiva da cultura. Verificou-se que não houve interação tripla do fatorial, onde cada fator individualmente teve interferência sobre a qualidade fisiológica das sementes de soja, independente do seu vigor inicial. Conclui-se que a utilização de lotes com diferença de vigor afeta negativamente a emergência das plântulas de soja, bem como os diferentes períodos de déficit hídrico após a semeadura no solo seco. Todavia, a presença de cobertura vegetal sobre o solo ameniza esse efeito, possibilitando maior emergência em virtude dessa promover condições ambientais mais favoráveis.
Palavras-chaves: Glycine max. Cobertura Vegetal do Solo. Vigor de Sementes.

The black oat (Avena strigosa Schreb.) stands out as a forage of great importance in Brazilian agriculture. However, the productivity and quality of this forage can be affected by abiotic factors, such as temperature and water availability, which affect the physiological processes and facilitate the accumulation of free radicals (reactive oxygen species - ROS). Thus, the objective of this study was to understand the biochemical changes in black oat plants subjected to water deficit at different temperatures. Experiments were conducted in a greenhouse in two experimental periods, which presented an average temperature of 20 °C and 24 °C, respectively. Black oat seeds, of the variety IAPAR 61, were sown in pots and the plants were irrigated for 60 days. After which, the pots were covered with plastic bags and the irrigation was suspended. The analyses were carried out in five periods of evaluation - M1: plants before the suspension of irrigation, M2: plants at the first wilting point, M3: three days after plastic removal and irrigation return, M4: four days after M3 and before the second suspension of irrigation, and M5: the second wilting point. The levels of total protein and malondialdehyde (MDA), and the activity of the enzymes catalase (CAT) and ascorbate peroxidase (APX), were analyzed. The experimental design was completely randomized, with six replications, in a factorial scheme of average temperature × water management × periods of evaluation, and the means were compared by Tukey's test at 5%. In response to water deficiency and temperature increase, black oat plants increased their levels of total soluble proteins, and there was greater lipid peroxidation due to the increase in malondialdehyde content. There was no change in the activity of the enzymes catalase and ascorbate peroxidase under water deficit, and these activities decreased with increasing temperature.

The hydration pattern associated with the physiological quality of seeds can be an early indicator for the evaluation of seed quality. The present study aimed to evaluate the hydration pattern of seeds subjected, or not, to water restriction, and to relate these patterns to their physiological quality. The physiological quality of seeds from five maize strains (L1, L2, L3, L4, and L5) and four hybrids (HT1, HT2, HS1, and HS2) was initially determined using seed germination and vigor tests (accelerated ageing and electric conductivity). A completely randomized experimental design was used with four repeats for the physiological analyses and a regression analysis was performed in order to assess the behavior of the seeds over time. The hydration curve was determined by imbibing the seeds in distilled water (0.0 control) and in a -0.9-MPa osmotic solution of polyethylene glycol 6000. Water uptake by the seeds was found to follow a triphasic pattern in the absence of water stress (0.0 MPa); however, when exposed to a -0.9- MPa osmotic potential, an extended phase II was observed. Diversity was observed between the strains in terms of the hydration pattern of the seeds, which can influence the physiological quality of the hybrid seeds. Regarding the hybrids, a positive relationship was observed between the shortest time to root protrusion and the quality of the seeds, both with or without water restriction, which allows us to conclude that hydration pattern can be used as a parameter for the early evaluation of physiological quality in hybrid maize seeds.