Wastewater reuse in the Mediterranean region: Case of Morocco

10 p.International audienceThe southern Mediterranean region being one of the most dry and water scarce regions in the world. It is also expected that by 2025, due to population increase, the regional average water availability is projected to be just less than 500 cubic meters per person per year. Many countries in the region are mining groundwater, a temporary and risky expedient. The extended reuse of reclaimed (treated) wastewater could contribute considerably to the reduction of 'water stress' and 'water scarcity' in the Mediterranean countries as part of an Integrated Water Resources Management (IWRM) approach, focusing on the component wastewater reuse for irrigation and other purposes. The present article deals with the experiences carried out in Morocco in this domain. In spite of the progress that has been achieved in the last decade on technical, institutional, financial and legislative levels as regards the development of the process "sewage network-treatment-re-use", obstacles still hinder the deployment of the re-use of treated wastewater. In the current state of affairs, no project integrating the three components has been realized. This paradoxical situation is due to several constraints

Using deficit irrigation with treated wastewater in the production of quinoa (Chenopodium quinoa Willd.) in Morocco | El uso de riego deficitario con aguas residuales tratadas en la producción de quinua (Chenopodium quinoa Willd.) en Marruecos

Scarcity of water resources and growing competition for water, reduce water availability for irrigation. In this experiment which was carried out in the south of Morocco, treated wastewater was used as an alternative resource for irrigation of quinoa (Chenopodium quinoa Willd.). During the first season (2010), six deficit irrigation treatments were applied during all crop stages on DO708 cultivar alternating water stress level at either 100 or 50% of ETm (maximal evatranspiration), while during the second season (2011), three deficit irrigation treatments 100, 50 and 25% were applied only during vegetative growth stage on two quinoa cultivars DO708 and QM1113. The highest water productivity was obtained when deficit irrigation was applied during the vegetative growth stage. Applying 50% of ETm during first season and second season resulted in highest yield. The most sensitive growth stage of quinoa to drought stress was the seed filling stage, and during this stage it is recommended to supply water to avoid yield and water productivity decrease. Combining deficit irrigation strategy, engineering solution (modernization of the irrigation systems, soil moisture monitoring), and the reuse of treated wastewater for irrigation, could improve water productivity of this drought tolerant crop under conditions of limited water resources. Key words: Drought stress, water productivity, leaf area index, salinity, yield RESUMEN La escasez de recursos hídricos y la creciente competencia por el agua reduce la disponibilidad de agua para el riego. En este experimento que se llevó a cabo en el sur de Marruecos, el agua residual tratada se utilizó como un recurso alternativo para el riego de quinua (Chenopodium quinoa Willd.). Durante la primera temporada (2010), se aplicaron seis tratamientos de riego deficitario alternando 100 y 50% de la ETm (evapotranspiración máxima) durante todas las etapas del cultivo en el cultivar DO708, mientras que en la segunda temporada (2011) se aplicaron tres tratamientos de riego deficitario 100, 50 y 25% sólo durante la etapa de crecimiento vegetativo en dos cultivares de quinua DO708 y QM1113. La mayor productividad del agua se obtuvo cuando se aplicó el riego deficitario durante la etapa de crecimiento vegetativo. Un tratamiento de riego deficitario con 50% de la ETm durante la primera y la segunda temporada registró la mayor productividad del agua. La etapa de crecimiento más sensible de la quinua al estrés hídrico fue la etapa de llenado de la semilla y durante esta etapa se recomienda el suministro de agua para evitar la disminución del rendimiento y reducir la productividad del agua. La combinación de la estrategia de riego deficitario, solución de ingeniería (modernización del sistema de riego, sensores de humedad del suelo) y la reutilización de aguas residuales tratadas para el riego, podría mejorar la productividad del agua de este cultivo tolerante a la sequía bajo condiciones de los recursos hídricos limitados. Palabras clave: Estrés hídrico, productividad del agua, índice de área foliar, salinidad, rendimient

Utilisation de l'irrigation déficitaire avec des eaux usées traitées pour améliorer la productivité des cultures du maïs sucré, pois chiche, féverole et quinoa

Several experiments were conducted in the south of Morocco (IAV-CHA, Agadir) during two seasons 2010 and 2011 in order to evaluate the effect of deficit irrigation with treated wastewater on several crops (quinoa, sweet corn, faba bean and chickpeas).  During the first season (2010) three crops were tested, quinoa, chickpeas and sweet corn applying 6 deficit irrigation treatments during all crop stages alternating 100% of full irrigation as non-stress condition and 50% of full irrigation as water deficit condition applied during vegetative growth, flowering and grain filling stage. For all crops, the highest water productivity and yield were obtained when deficit irrigation was applied during the vegetative growth stage. During the second season (2011) two cultivars of quinoa, faba bean and sweet corn have been cultivated applying 6 deficit irrigation treatments (rainfed, 0, 25, 50, 75 and 100% of full irrigation) only during the vegetative growth stage, while in the rest of crop cycle full irrigation was provided except for rainfed treatment. For quinoa and faba bean, treatment receiving 50% of full irrigation during vegetative growth stage recorded the highest yield and water productivity, while for sweet corn applying 75% of full irrigation was the optimal treatment in terms of yield and water productivity.Plusieurs essais ont été conduits dans le sud du Maroc (IAV-CHA, Agadir) durant deux saisons 2010 et 2011 dont le but d’évaluer l’effet de l’irrigation déficitaire par les eaux usées traitées sur plusieurs cultures (quinoa, maïs doux, fève et pois chiche). Durant la première saison (2010) trois cultures ont été testées, quinoa, maïs doux et pois chiche en appliquant 6 traitements d’irrigation déficitaire durant tout les stades culturaux en alternant 100% d’ETm comme condition de confort hydrique et 50% d’ETm comme conditions de stress durant le stade de croissance végétative, floraison et remplissage des grains. Pour toutes les cultures, le rendement et la productivité d’eau les plus élevés ont été obtenus lorsque l’irrigation déficitaire a été appliquée durant le stade de croissance végétative. Pendant la deuxième saison (2011) deux lignés du quinoa, la fève et le maïs doux ont été cultivées en adoptant 6 traitements d’irrigation déficitaire (bour, 0, 25, 50, 75 et 100 d’ETm) appliqués juste pendant le stade de croissance végétative, tandis que durant le reste du cycle cultural les cultures ont reçues une irrigation complète sauf pour le traitement bour. Pour le quinoa et la fève, appliquant 50% d’ETm durant le stade végétatif a permis d’obtenir le rendement et la productivité d’eau les plus élevés, tandis que pour le maïs doux le traitement optimal qui a enregistré le rendement et la productivité d’eau les plus élevés est celui qui a reçu 75% d’ETm.&nbsp

Influence of cutting time interval and season on productivity, nutrient partitioning, and forage quality of blue panicgrass (Panicum antidotale Retz.) under saline irrigation in Southern region of Morocco

Salinity has become a major issue in various parts of the world negatively impacting agricultural activities and leading to diminished crop potential and lower yields. Such situation calls for urgent interventions such as adopting salt-tolerant crops to fill the gap in food and feed availability. Blue panicgrass (Panicum antidotale Retz.) is a promising salt-tolerant forage crop that has shown an appropriate adaptation and performance in the saline, arid, and desertic environments of southern Morocco. However, for obtaining a highest forage productivity with nutritional quality, optimization of the cutting interval is required. Thus, the objective of this study was to determine the optimal cutting time interval allowing high forage production and quality under high salinity conditions. This experiment was conducted over one entire year covering the summer and winter seasons. The effect of five cutting time intervals on selected agro-morphological traits, crop productivity, mineral nutrient accumulation, and forage quality of blue panicgrass in the region of Laayoune, southern Morocco. The finding of this study recommend that cutting blue panicgrass every 40 days maximized the annual fresh and dry forage yield as well as the protein yield, which reached 74, 22, and 2.9 t/ha, respectively. This study also revealed a significant effect of the season on both productivity and quality. However, forage yield declined during the winter and increased during the summer, while protein content increased during winter compared to summer. The mineral nutrient partitioning between shoots and roots, especially the K+/Na+ ratio, indicated that blue panicgrass has salt tolerance mechanism as it excluded sodium from the roots and compartmentalized it in the leaves. In conclusion, there is a potential of blue panicgrass on sustaining forage production under salt-affected drylands, as demonstrated by the response to two key questions: (a) a technical question to farmers for its adoption such as at which interval should blue panicgrass be harvested maximizing both forage yield and quality? And (b) a scientific question on how does blue panicgrass maintain high K+/Na+ ratio to cope with salinity stress

Deep eutectic solvent-ultrasound assisted extraction as a green approach for enhanced extraction of naringenin from Searsia tripartita and retained their bioactivities

BackgroundNaringenin (NA) is a natural flavonoid used in the formulation of a wide range of pharmaceutical, fragrance, and cosmetic products. In this research, NA was extracted from Searsia tripartita using an environmentally friendly, high efficiency extraction method: an ultrasound-assisted extraction with deep eutectic solvents (UAE-DES).MethodsSix natural deep eutectic solvent systems were tested. Choline chloride was used as the hydrogen bond acceptor (HBA), and formic acid, ethylene glycol, lactic acid, urea, glycerol, and citric acid were used as hydrogen bond donors (HBD).ResultsBased on the results of single-factor experiments, response surface methodology using a Box-Behnken design was applied to determine the optimal conditions for UAE-DES. According to the results, the optimal NA extraction parameters were as follows: DES-1 consisted of choline chloride (HBA) and formic acid (HBD) in a mole ratio of 2:1, an extraction time of 10 min, an extraction temperature of 50°C, an ultrasonic amplitude of 75 W, and a solid-liquid ratio of 1/60 g/mL. Extracted NA was shown to inhibit the activity of different enzymes in vitro, including α-amylase, acetylcholinesterase, butyrylcholinesterase, tyrosinase, elastase, collagenase, and hyaluronidase.ConclusionThus, the UAE-DES technique produced high-efficiency NA extraction while retaining bioactivity, implying broad application potential, and making it worthy of consideration as a high-throughput green extraction method

Prediction of climate change impact on corn grown in the south of Morocco using the Saltmed model

Climate change is currently considered a major concern for humanity. Future climate projections carried out for the Souss region in the south of Morocco show that temperature will increase by 3 °C and precipitation will dramatically decrease by 63% towards the end of the twenty-first century. This will have negative impacts on water resource availability in the Souss region which is already suffering from water scarcity. In this study, 'baseline data' based on field experiments, as well as climate change scenarios, were implemented in the SALTMED model to simulate climate change impact. After successful calibration and validation of the SALTMED model for three growing seasons with supplied ‘baseline data’ for Sweet corn, the SALTMED model was run in forecasting mode to obtain future projections of crop evapotranspiration and crop productivity under a changing climate. The obtained results suggested that with increasing temperature, crop evapotranspiration is expected to increase by 15% while crop water requirements are expected to decrease by 13% as a result of the shortening growth season of corn, expected to be 20 days earlier. Crop productivity could exhibit a reduction of 2.5% towards the end of the twenty-first century

Irrigated barley–grass pea crop mixtures can revive soil microbial activities and alleviate salinity in desertic conditions of southern Morocco

Abstract Soil salinity adversely limits crop and soil health, and this can be reversed by cropping systems where species exclude salts and activate microbial nutrient cycling. A randomized complete block design experiment was established in Laayoune–Morocco to evaluate the influence of irrigated grass pea and barley monocrops or combined together in 50–50% and 70–30% mixtures against soil salinity and CO2-C flux in sites with varying salinity. Site by treatment interaction significantly influenced (p < 0.05) soil salinity and CO2-C flux. Salinity reduced by 37 to 68 dS m−1 in highly saline soils across season regardless of treatment and barley monocrop retained the least salinity (15 dS m−1). Same applied to sites with low (1 to 2 dS m−1) and medium (2 to 5 dS m−1) salinity although less pronounced. The 70–30% grass pea, barley mixture maintained the greatest CO2-C flux in soils with low salinity and marginally enhancing soil active carbon (130 to 229 mg kg−1 soil) in different sites. Increasingly saline water filled pore space devastated CO2-C flux, although this process recovered under barley at extreme salinity. Overall, barley in mixture with grass pea can alleviate salinity and accelerate microbial carbon sequestration if irrigation is modulated in shallow desertic soils