SAMI BOUARFA

Prevailing food insecurity and hunger, as well as the world’s increasing population, require a substantial further intensification of agricultural production. This is particularly important for rural areas in Africa, and more specifically in semi-arid and arid climates. Irrigation is essential to improve harvest security and to realize any production at all in arid areas. Anticipating an increasing occurrence of climate extremes with prolonged dry spells and more severe droughts and heatwaves, there is an even greater need for irrigated agriculture in Africa. Irrigated agriculture also plays a major role in the collective effort to advance food value chains and to create agribusiness opportunities for rural communities by fostering more predictable economic production. At the same time the precautious management of scarce water resources, addressing the economy of irrigated systems, adequate pricing of water resources and efficient ways of distributing water resources require sufficient capacity in planning and implementation. Irrigation in Africa is not fully exploiting its potential, especially for smallholder farming. Within the Dakar declaration, the heads of Sahelian countries declared in 2013 that irrigation’s potential contribution to agricultural and rural economies of the region only covers 2% of cultivated land and that less than 20% of its potential is exploited. While investments in the Sahel region have been weak over many decades, and infrastructure and equipment are underutilized, some areas in North Africa depict the opposite situation with a massive overexploitation of groundwater resources and an enormous dropping of aquifer levels. In many of these areas where smallholder farmers are practising irrigation, the yields obtained are still often comparatively low and farmers face a plethora of obstacles to substantially improving crop water productivity. Overall, there is therefore a need to make better use of the existing infrastructure, by exploring new schemes in a water-smart way, by improving irrigation scheduling and agricultural water management in general, and also by improving the coordination of water use and infrastructure maintenance in collective schemes. In summary, therefore, there is still a massive need to improve irrigation in Africa through innovation. Innovation can be understood as putting inventions and new approaches into practice. Past efforts have, however, demonstrated that changing irrigation practice in smallholder farming systems faces numerous challenges. It is essential to start from the actual farmers’ needs, their ideas and their individual possibilities for innovation, a transformation that is widely recommended in the scientific and development literature. It is also currently being well regarded by the World Bank in its efforts to advance farmer-led irrigation. However, innovating smallholder irrigated farming is not a straightforward task. Smallholder farmers are locked within a complex network of interdependencies that affects power relations and their access to finance, information and markets. Many obstacles that are preventing innovation in irrigation are often outside the farmers’ sphere of influence and this requires not only a thorough understanding of the enabling environment, but also transformations of that environment. This special issue aims to compile a series of insights related to innovation in irrigated agriculture. The 17 papers are selected from the research project EAU4Food (12 papers) and from the 26th ICID Euro Mediterranean conference (5 papers). The project EAU4Food has been funded by the European Commission under the European Knowledge Based Bio-Economy programme (KBBE) 2010.1.2-03: Sustainable water resources management (WRM) and Soil fertility conservation for food production in Africa—SICA (Africa) and was implemented in Ethiopia, Mozambique, South Africa, Mali and Tunisia. The project aimed at gaining further insights to support the participatory innovation of irrigated agriculture on smallholder farms in five African countries. The articles are based on a transdisciplinary approach whose methodological elements are described in an introductory article (Froebrich et al., 2019). This concept paper introduces the principal approach that has been implemented in the EAU4Food project. In Mali and Mozambique, the investigations centred on canal irrigation schemes. The irrigation areas studied in Tunisia and Ethiopia sourced the water from dams. Borehole-supplied irrigation systems were studied in South Africa and Tunisia. In order to facilitate the transdisciplinary approach, two distinct platforms were set up. At local level, the community of practice (CoP) addressed the participatory and farmer-led innovation process. In addition, learning practice alliances (LPAs) were established to exchange findings between stakeholders from different levels. At all study sites, farmers were involved from the beginning in problem identification,…

The increase of the world population challenges the institutions involved in the agricultural development and in particular those in charge of water resources management. The sustainability of the agricultural system and its ability to respond to that challenge has become a major concern. Among the reasons for this are the ever increasing competition for water as well as the land degradation due to erosion and salinization. As pointed out by many authors, this calls for integrated land and water resources management policies to improve the efficiency of their utilization.

Efficient use of water and nutrients in irrigation system is important in arid and semi-arid regions, where water is a limiting resource. This study aims to analyze irrigation and fertigation practices for a widespread crop (pepper, Capsicum annuum) in Tunisia, in a context of highly diverse agricultural practices. The study took place in the irrigated plain of the Merguellil river in Central Tunisia, characterized by its high diversity of crops and practices. In 2019, irrigation and fertilization practices involved in pepper crop cultivation watered by drip irrigation, were compared on fourteen plots. This was carried out through an approach coupling semi-directive surveys with farmers and monitoring of irrigation, done using a temperature logger installed on the irrigation pipes and allowing the detection of irrigation duration. The study covered the three main seasons of pepper cultivation (Spring, Summer and late Summer). The results showed globally an opposition of two main logics. On the one hand, there are strategies aiming to a significant water supply during the first days after planting, followed by a non-irrigated period, forcing the plant to "tap into the soil water reserves", then irrigation at regular rates (once every three to five days or more) thereafter, sometime alternate with fertigation. On the other hand, there are strategies of regular water and nutrients supply, taking into account crop requirements: low water inputs at the beginning (on daily or once every two to four days rate), followed by a progressive increase. In this strategy, application of fertilizers through the drip irrigation occurred right after the first irrigations, the farmer alternating up to three irrigations for one fertigation. Commonly, fertilization was fractioned and application was done in the last quarter of watering time in order to avoid/reduce nutrient leaching. The number of splits varied significantly from a farmer to another and from a strategy to another. These irrigation and fertigation practices may have different effects on the system outputs, mainly on water and nitrogen efficiency and yield

L'etude sur l'" Impact des restrictions d'eau sur les filieres agro-alimentaires de la Nappe de la Beauce " fait l'objet de conventions qui lient l'AFEID (Association Francaise pour l'Irrigation et le Drainage), le Cemagref, le Cirad, le bureau d'etudes Diatae et les Chambres d'Agriculture d'Eure-et-Loir et du Loiret avec le soutien du Ministere de l'Agriculture de l'Alimentation de la Peche de la Ruralite et de l'Amenagement du Territoire. Le present document constitue un rapport d'analyse de travaux accomplis et d'enquetes realisees sur une zone ciblee de la Nappe de la Beauce, au cours de l'annee 2011. (Resume d'auteur)

The reuse of wastewater aims to mobilize and treat, for certain uses and under certain conditions, water that has already been used. Rather than discharging wastewater into the natural environment, this practice aims to recover it by replacing the mobilization of water withdrawn from the environment [van Loosdrecht and Brdjanovic, 2014]. By moving from a linear logic of the mobilization and use of water to a circular approach, the objective pursued is to reduce the pressure, qualitative then quantitative, on the resources while limiting, as far as possible, the usage conflicts. It is in fact a question of passing from a simple competitive mode which strongly mobilizes resources, to a complex mode, known as “circular”, of putting in complementarity of uses. This approach initially mainly concerned agricultural uses insofar as agricultural needs represent the majority of the water mobilized, including developed countries [UN Water 2018]. Cities integrate specific issues that are chara...

<p>The oases of the pre-Saharan basin of Wadi Ferkla in southeastern Morocco receives low and erratic rainfall (average of 141 mm/year and inter-annual standard deviation of 70 mm - Ait-Bouijane rain gauge over the period 1961-2018). From the 70's, surface and groundwater are increasingly used due to the expansion of irrigation, mainly along two wadis, namely Wadis Ferkla and Satt originating in the High-Atlas and the Anti-Atlas Mountains, respectively. Their flows reach the Ferkla’s irrigated perimeters only when the volume of the flood events exceed upstream evaporation, withdrawals and riverbed's infiltration.</p><p>Nowadays, these irrigated perimeters exert significant pressure on groundwater resources, through numerous drillings equipped with pumping systems, most of them are powered by solar energy. This unsustainable situation incentivizes individual farmers to design and implement innovative technics to increase water access for their farms. For instance, the spreading of floodwaters - an ancestral and collective irrigation practice in traditional oases - is currently being adopted and adapted by individuals at the farm level. The technique consists on partially diverting flood flows into earthen basins. The stored water either infiltrates to recharge local aquifers, or is pumped for flood irrigation of date palms.</p><p>An experimental protocol was set up to characterize groundwater recharge below one of these on-farm basins equipped with a recharge well. Barometric probes were installed in the basin, in the recharge well and in neighboring boreholes to automatically monitor water table levels (10-minute-time-step). Manual measurements were performed regularly to calibrate the monitoring probes. A topographic survey of the monitoring points and of the basin aimed at deriving piezometric levels from water levels measurements and estimating the height-surface-volume curves of the basin. After 7 months of continuous monitoring, 3 flood events were recorded. The establishment of the basin water balance at a fine time-resolution allowed estimating its different components including the infiltration rate influencing groundwater recharge. An Analytical modeling of this process was developed to explore alternative design and management options of the basin. This approach aims to contribute to a broader reflection on securing water management in this fragile oasis ecosystem.<img src="data:image/jpeg;base64,…

Prevailing food insecurity and hunger, as well as the world’s increasing population, require a substantial further intensification of agricultural production. This is particularly important for rural areas in Africa, and more specifically in semi-arid and arid climates. Irrigation is essential to improve harvest security and to realize any production at all in arid areas. Anticipating an increasing occurrence of climate extremes with prolonged dry spells and more severe droughts and heatwaves, there is an even greater need for irrigated agriculture in Africa. Irrigated agriculture also plays a major role in the collective effort to advance food value chains and to create agribusiness opportunities for rural communities by fostering more predictable economic production. At the same time the precautious management of scarce water resources, addressing the economy of irrigated systems, adequate pricing of water resources and efficient ways of distributing water resources require sufficient capacity in planning and implementation. Irrigation in Africa is not fully exploiting its potential, especially for smallholder farming. Within the Dakar declaration, the heads of Sahelian countries declared in 2013 that irrigation’s potential contribution to agricultural and rural economies of the region only covers 2% of cultivated land and that less than 20% of its potential is exploited. While investments in the Sahel region have been weak over many decades, and infrastructure and equipment are underutilized, some areas in North Africa depict the opposite situation with a massive overexploitation of groundwater resources and an enormous dropping of aquifer levels. In many of these areas where smallholder farmers are practising irrigation, the yields obtained are still often comparatively low and farmers face a plethora of obstacles to substantially improving crop water productivity. Overall, there is therefore a need to make better use of the existing infrastructure, by exploring new schemes in a water-smart way, by improving irrigation scheduling and agricultural water management in general, and also by improving the coordination of water use and infrastructure maintenance in collective schemes. In summary, therefore, there is still a massive need to improve irrigation in Africa through innovation. Innovation can be understood as putting inventions and new approaches into practice. Past efforts have, however, demonstrated that changing irrigation practice in smallholder farming systems faces numerous challenges. It is essential to start from the actual farmers’ needs, their ideas and their individual possibilities for innovation, a transformation that is widely recommended in the scientific and development literature. It is also currently being well regarded by the World Bank in its efforts to advance farmer-led irrigation. However, innovating smallholder irrigated farming is not a straightforward task. Smallholder farmers are locked within a complex network of interdependencies that affects power relations and their access to finance, information and markets. Many obstacles that are preventing innovation in irrigation are often outside the farmers’ sphere of influence and this requires not only a thorough understanding of the enabling environment, but also transformations of that environment. This special issue aims to compile a series of insights related to innovation in irrigated agriculture. The 17 papers are selected from the research project EAU4Food (12 papers) and from the 26th ICID Euro Mediterranean conference (5 papers). The project EAU4Food has been funded by the European Commission under the European Knowledge Based Bio-Economy programme (KBBE) 2010.1.2-03: Sustainable water resources management (WRM) and Soil fertility conservation for food production in Africa—SICA (Africa) and was implemented in Ethiopia, Mozambique, South Africa, Mali and Tunisia. The project aimed at gaining further insights to support the participatory innovation of irrigated agriculture on smallholder farms in five African countries. The articles are based on a transdisciplinary approach whose methodological elements are described in an introductory article (Froebrich et al., 2019). This concept paper introduces the principal approach that has been implemented in the EAU4Food project. In Mali and Mozambique, the investigations centred on canal irrigation schemes. The irrigation areas studied in Tunisia and Ethiopia sourced the water from dams. Borehole-supplied irrigation systems were studied in South Africa and Tunisia. In order to facilitate the transdisciplinary approach, two distinct platforms were set up. At local level, the community of practice (CoP) addressed the participatory and farmer-led innovation process. In addition, learning practice alliances (LPAs) were established to exchange findings between stakeholders from different levels. At all study sites, farmers were involved from the beginning in problem identification,…

The Gharb plain in Morocco suffers from water excess in winter and from water deficit during the spring and summer. This explains the low profitability of the investments in irrigation agreed by the Moroccan state and low yields of winter crops. Furrow irrigation systems may be a way to increase water productivity by improving the surface drainage in winter, and by irrigating the crops efficiently in spring and summer. The aim of this study was to assess the hydraulic performance of furrow systems and its agronomic impacts based on an experimental and a modelling approach. Yields were simulated for a series of 11 climatic years (1995–2006). Results clearly showed the advantage of the furrow system whatever the sowing dates. These results confirmed that to improve the water productivity of winter crops in the context of the Gharb scheme, attention has to be paid to surface drainage. Copyright © 2009 John Wiley & Sons, Ltd.

Page 1. vingt ans après Réalités agricoles aux portes d'Alger La Mitidja A. Imache, T. Hartani, S. Bouarfa, M. Kuper, coord. Page 2. LA MITIDIA 20 ANS APRÈS Réalités agricoles aux portes d'Alger Page 3. Page 4. Editions Alpha ...

En perimetre irrigue, les flux de remontee capillaires a partir de nappes peu profondes sont responsables de phenomenes de salinisation. Le drainage y est concu pour evacuer une fraction de la dose d'irrigation (fraction de lessivage) pour maintenir un equilibre des sels dans le sol. L'objectif de la these est d'apporter des elements de comprehension sur les interactions de ces flux de remontee capillaire avec le fonctionnement hydraulique du drainage, afin d'en ameliorer les regles de conception. Le fonctionnement de la zone saturee est modelise par l'equation de boussinesq integree a l'echelle du systeme drainant. L'influence de l'imposition d'une condition a la limite (pluie ou prelevement par evaporation) au toit de la nappe sur les debits et les hauteurs de nappe a l'interdrain simules par le modele est etudiee. L'importante variabilite de la forme de la nappe et ses consequences sur les debits draines est mise en evidence. Le modele de boussinesq est couple a une fonction de prelevement par evaporation dans la nappe. Cette fonction est fondee sur la resolution de la loi de darcy generalisee ; les hypotheses sur lesquelles elle repose sont discutees par une etude experimentale et theorique. Cette etude fait apparaitre les consequences des variations journalieres de la demande evaporative sur les gradients thermiques dans le sol, responsables de variations significatives des intensites de prelevement dans la nappe. Elle met egalement en evidence la difficulte d'utiliser le concept de porosite de drainage en phase de prelevement par evaporation dans la nappe. Le modele permet d'entrevoir une nouvelle methode de conception basee sur le calcul de la restitution des reseaux et sur la verification du critere de fraction de lessivage

La plaine du Gharb s'étend sur une superficie totale d'environ 616 000 ha avec un potentiel irrigable de 250 000 ha. La superficie équipée actuellement en grande hydraulique est d'environ 114 000 ha et 86 000 ha irrigués par pompage privé. La mise en valeur de la plaine est entravée par l’excès d’eau hivernal compte tenu de la nature subhumide de son climat et de la nature argileuse de ses sols conjuguée à une pente très faible. Il est à souligner que sur un potentiel irrigable au Maroc de 1 600 000 ha, 350 000 ha seraient soumis aux risques d’excès d’eau ou de salinisation dont 200 000 ha concerne le Gharb. Pour pallier ces problèmes, l’assainissement et le drainage agricole sont considérés comme l’un des piliers de l’aménagement et du développement de la plaine du Gharb. Malgré les efforts consentis, l’analyse des performances des systèmes de drainage révèle des déficiences de fonctionnement des réseaux. Les acquis au niveau de la station expérimentale de Souk Tlet, ré...

... Pour une prise en compte de ceux qui travaillent la terre dans la construction de l'avenir dela Mitidja. Bouarfa S., Imache A., Kuper M., Hartani T.. 2010. In : Imache Amar, Hartani Tarik, Bouarfa Sami, Kuper Marcel. La Mitidja 20 ans après. Réalités agricoles aux portes d'Alger. ...

Beaucoup d'agriculteurs, comme les opérateurs des filières aval qui transforment leur production, dépendent aujourd'hui des ressources en eau souterraine. Or, dans de nombreuses régions du monde, en climat aride comme tempéré, les nappes souterraines sont surexploitées et les ressources disponibles déclinent. Les agriculteurs sont alors confrontés à une pression croissante pour préserver cette ressource. Cette situation les amène d'une part, à économiser l'eau en mettant l'accent sur des productions moins consommatrices, d'autre part, à mieux valoriser les quantités utilisées. Plusieurs stratégies sont envisageables comme modifier les choix d'assolement ou adapter les modes de conduite des cultures. Ces stratégies peuvent avoir des conséquences importantes sur l'organisation des filières aval. Cette communication propose les bases d'une démarche visant à analyser les conséquences de fortes restrictions d'eau sur l'organisation de filières ...

Rapidly increasing population growth and food requirements call for increases in agricultural production, especially in irrigated areas. Environmental impacts arising from farming intensification in groundwater irrigated areas worldwide are manifold and the Life Cycle Assessment (LCA) is very relevant for assessing these impacts. But a regional LCA can not be done by transferring the “standard” product-oriented methodology to this meso-scale, especially in a context of data scarcity. Our objective is to propose a methodology to build a regional-scale Life Cycle Inventory (LCI) that would account for farming system diversity, avoid double counting and make clear allocation rules within this multi product system. We propose to base this methodology on the Agrarian System Diagnosis (ASD). This approach leads to a typology of farming systems which reflects the different agricultural exploitation modes existing on a regional scale. Enquiries are then carried out in farms representative o...

Les vingt dernieres annees ont ete marquees en Algerie par l'emergence de nouvelles dynamiques agricoles notamment sur les terres publiques qui concentrent l'essentiel du potentiel productif du pays. A l'origine de leur emergence, l'adoption d'une loi fonciere en 1987 de tendance liberale qui proposait un nouveau modele d'exploitation agricole collective "EAC". De nouvelles formes d'organisation de la production agricole ont alors emerge, basees sur des acces informels aux facteurs de production, souvent apportes par une multiplicite d'acteurs. Nous mettons en evidence a travers l'etude de cas de la commune d'Ouarizane dans le Bas-Cheliff different types d'arrangements informels qui regulent l'acces aux ressources productives. Nous montrons le role determinant de ces arrangements dans les allocations des facteurs de production (terre, eau, travail, savoir-faire etc.) dans un contexte ou les dotations individuelles et les capa...

La Tunisie cherche à réorienter ses politiques d’Aménagement et de conservation des eaux et des sols (ACES) afin qu’elles gagnent en efficacité, en s’appuyant sur des démarches participatives innovantes. Cette orientation s’inscrit dans des contextes ruraux souvent peu documentés où la dimension environnementale nécessite d’être objectivée. De plus, il existe peu d’espaces de dialogue et de concertation entre les principales catégories d’acteurs des espaces ruraux concernés. Cet article analyse une démarche participative originale conçue pour produire de l’information de qualité en valorisant les savoirs locaux, partager et prendre en compte les perceptions des différents acteurs, et enfin construire des consensus pour contribuer à l’élaboration de politiques d’ACES plus efficaces. L’évaluation mobilise un double dispositif comprenant des observateurs extérieurs et une enquête de satisfaction auprès des participants. Elle s’appuie sur une grille d’évaluation de cette démarche, de se...

La situation de l'irrigation en Poitou-Charentes est emblématique des tensions entre le monde agricole et la société. Pour dépasser ces conflits, un observatoire alliant système d'information et action collective a été mis en place en Charente à l'initiative d'un collectif ...

Beaucoup d'agriculteurs, comme les opérateurs des filières aval qui collectent ou transforment leur production, dépendent de l'irrigation. Or, dans de nombreuses régions du monde, structu-rellement ou conjoncturellement, les ressources en eau disponibles déclinent et sont soumises à des contingentements de plus en plus sévères. Cette étude vise à analyser les conséquences de scénarios de fortes baisses de la disponibilité en eau sur les stratégies des agriculteurs en termes de choix d'assolement et de mode de conduite et d'irrigation des cultures ainsi que l'effet de ces stratégies sur l'organisation de filières locales. Elle a été mise en oeuvre en France, dans la plaine de la Beauce, où une forte proportion de l'agriculture est irriguée à partir d'une ressource souterraine soumise à un dispositif de gestion volumétrique. L'évaluation des impacts de restrictions d'eau s'appuie sur une analyse économique des filières locales ainsi que sur ...