Irrigation systems entail interacting processes that should be considered when analyzing the performances of irrigated areas. When analyzing the cause of performance gaps, one may consider the effect of one factor without taking into account the effect of other influential ones. This study addresses the performance of irrigated areas using a global approach. The analysis includes different factors of the production process and examines the relationship between irrigation and the economic performances of farmers’ irrigated fields. Results showed that technical efficiency (TE), considered as our economic indicator, evaluating the degree to which the inputs are used efficiently, was about 0.85 for fruit orchards, tomato, wheat and 0.66 for olive trees. The on-farm water distribution efficiency (Efarm) that evaluates water lost during its transport to plots was poor and can decrease to 36%. A great potential for improving water management exists. Efarm was not a significant factor for TE. So, Efarm causing substantial water waste has no significant impact on economic performance, the main concern of the farmer. However the easy access to water was a significant factor for TE (p-value < 0.032 in all the cases). The easy access to water is a possible lever for improvement.  We pointed out that irrigation performance in the studied area has no significant impact on economic performance. There is a divergence between the farmer’s interest (the economic efficiency) and the community’s objective to save water through better irrigation performance. Government efforts to provide incentives for farmers for better water management seem to have born no fruit. This study argues for the use of a bechmarking in building global representation adapted to the actual local context. The analysis approch suggests that more attention should be paid to the “water saving program” of Tunisia, by subsidising irrigation investments in a better way and focusing on subsidies that create the most of economic growth.

Agriculture in developing countries will have to transform and increase production by an estimated 70% in order to meet demands by 2050. Although well-managed commercial farms offer little manoeuvring space for increasing agricultural water productivity, smallholder farms usually operate at low input costs and therefore provide ample opportunities to reduce the potential yield gap through agricultural intensification. The aim of this paper is to analyse and compare yields and water productivities obtained in field and modelling experiments in Ethiopia (maize, garlic, onion), South Africa (tomato) and Tunisia (tomato, potato, wheat). Innovative agricultural practices were introduced on smallholder farms: irrigation scheduling and NPS Zn fertilization in Ethiopia; high-yielding cultivar, drip irrigation, mulching and organic amendments in South Africa; and crop water modelling in Tunisia. In general, crop yields increased up to eight times with innovative practices compared to current conventional farming practices. Crop water productivities were fairly stable within the same experiments, but increased with innovations, indicating that intensive farming can be more environmentally sustainable than conventional farming. Intensive farming systems in a resource-rich environment (high radiation levels, relatively fertile, deep and well-drained soils), combined with technology transfer and capacity building could be seen as viable strategies to secure food for smallholders and communities in African rural areas, as well as to improve water utilization in water-scarce catchments. Copyright (c) 2018 John Wiley & Sons, Ltd.

Boosting the productivity of smallholder farming systems continues to be a major need in Africa. Challenges relating to how to improve irrigation are multi‐factor and multisectoral, and they involve a broad range of actors who must interact to reach decisions collectively. We provide a systematic reflection on findings from the research project EAU4Food, which adopted a transdisciplinary approach to irrigation for food security research in five case studies in Ethiopia, Mali, Mozambique, South Africa and Tunisia. The EAU4Food experiences emphasize that actual innovation at irrigated smallholder farm level remains limited without sufficient improvement of the enabling environment and taking note of the wider political economy environment. Most project partners felt at the end of the project that the transdisciplinary approach has indeed enriched the research process by providing different and multiple insights from actors outside the academic field. Local capacity to facilitate transdisciplinary research and engagement with practitioners was developed and could support the continuation and scaling up of the approach. Future projects may benefit from a longer time frame to allow for deeper exchange of lessons learned among different stakeholders and a dedicated effort to analyse possible improvements of the enabling environment from the beginning of the research process. © 2020 The Authors. Irrigation and Drainage published by John Wiley & Sons Ltd on behalf of International Commission for Irrigation and Drainage

Promoting innovation to improve both productivity and sustainability of irrigated farming systems is crucial for the first question addressed within the Sustainable Development Goals process led by the United Nations. This is a complex task that requires methods and processes which include a diversity of knowledge. For this reason, participatory approaches have been increasingly encouraged. A broad range of methods have been developed in the literature. However, debates on the effectiveness of the results, including questions on how different stakeholders influence results and how the context influences platform processes, remain theoretical. In this article, the authors evaluate the results of a participatory diagnosis aiming to identify the constraints and possible innovations to improve agricultural production in the Brahmi irrigation scheme in Tunisia. The process was implemented with individual interviews and focus groups operationalized through two types of platforms, ‘Community of Practice (CoP)' and ‘Learning and Practice Alliance (LPA)'. We highlighted that both CoP and LPA offer fruitful platforms for the interaction of all stakeholders. However, the results could be biased by the context and the expectations and strategies of powerful participants. Individual interviews are complementary to focus group results, especially in situations where open or latent conflicts exist. Copyright © 2020 John Wiley & Sons, Ltd.

Despite research efforts and the multiple interventions of States, the productivity of water, land, and capital resources is often low, particularly in Tunisia. This study provides a framework for analyzing the performance of irrigated farms and examines the level and the effective determinants of this performance. Technical and economic data were collected through detailed questionnaires and used to calculate technical efficiency (TE) and irrigation water use efficiency (IWUE) for each farm, with the data envelopment analysis (DEA) approach. These efficiencies were subjected to statistical analysis for a set of field variables. The results show that TE is satisfactory at 0.84 on average. However, IWUE is much lower, at 0.61 on average. There is therefore significant potential for improving it. The most important determinants of the efficiencies are access to water and access to credit, both of which are possible levers to improve TE and IWUE. Neither irrigation techniques nor the choice of crops nor the water distribution method influence the differences in the efficiencies. Livestock presence is significant for the differences in IWUE, showing that water is used more efficiently with forage crops for livestock. Current modernization projects in Tunisia to convert open canal systems to pressurized pipe systems should take these results into account. But converting the irrigation system alone is not enough to improve efficiency. Scenarios that do not require such large investment may thus be more worthwhile.

The precise estimation of water demand at large-scale irrigation perimeters is a key requirement for water management. Most methods for estimating water demand use biophysical models and cropping patterns but do not account for the wide range of actual farming practices. As a result, these methods only allow estimation of theoretical water demand. The objective of this study was to analyze different methods for evaluating irrigation water demands using several levels of knowledge about irrigation perimeters such as crop water requirements, cropping pattern, irrigation techniques, and water application depths (WAD). Most of this knowledge was related to farming practices, which can vary. Farm typology is an appropriate way to account for the variability in farming practices. These methods were applied in an irrigation scheme in northern Tunisia. The perimeter was subdivided into two sectors: the first sector was designed for surface irrigation and the second for sprinkler irrigation. The first method estimated water demand at the scheme scale based on actual cropping patterns and assuming that farmers used the planned irrigation techniques and satisfied plant water requirements (L1). However, the farmers did not use the planned irrigation techniques. Instead, they combined surface, sprinkler, and drip irrigation techniques depending on the crops they were growing. The second method examined current irrigation techniques using the results of farm typology that provided the areas under each crop irrigation system (L2). The two methods provided a theoretical water demand model at the scheme scale. However, water demand also needed to account for actual WADs (L3). Field surveys were performed to evaluate the WAD of each crop irrigation technique. Methods L1 and L2 showed similar estimations of water demand at the scale of the perimeter, and the savings in water obtained by converting to drip irrigation were balanced by a reduction in sprinkler irrigation due to conversion to surface irrigation. In contrast, the L3 method estimated 50% lower water demand than that provided by L1 or L2, since the supply of water was insufficient. The irrigation network was designed 50?years ago and no longer corresponds to the needs of current farmers. Farm typology was also shown to be a method that accounted for farm diversity; water demand estimated based on typology differed by only 5% from that obtained by summing the needs of individual farms. Copyright (C) 2011 John Wiley & Sons, Ltd.

Accurate estimation of water demand at the irrigation scheme scale is a key requirement for water management, which is made difficult by the large diversity of crops and production systems. The main objective of this study was to estimate irrigation water demand at the farm scale, taking different types of knowledge into account: (i) database study, where water demand is supposed to be the supply (L0); (ii) actual cropping pattern (L1),; (iii) actual irrigation techniques and cropping pattern (L2); and (iv) actual irrigation practices, actual irrigation techniques, and cropping pattern (L3). Farm typology makes easy this estimation as it takes into account various farm characteristics. Firstly, a farm typology was established based on 115 farms surveyed in the irrigation scheme of Borj Toumi Toungar (Tunisia), selected for the study. Secondly, climatic crop water irrigation requirements were estimated using the agro-meteorological water balance model Pilote. Typology results were used to estimate water demand at the scale of family farms taking into account different levels of knowledge Six classes of farming areas were identified based on irrigation subsystems, cropping pattern (fruit tree area, cropping vegetable area and field crop area), intensification crop level and cropped surface. Results showed that supply could not entirely cover the climatic water demand. However, it could nearly meet actual water demand at the farm scale. According to the water demand estimation at different levels, results showed that there were few changes in water demand at farm scale when moving from L1 to L2. At the opposite, actual water demand (L3) represented about half the climatic water demand (L2). Calculations based on farm classes highlighted the importance of actual farm practices. Within the same class, the difference between water demand estimation at different levels of knowledge was remarkable. Network rehabilitation is thus necessary to enable farmers to increase water delivered to crops and limit water stress; the collective network was conceived to deliver a flow of 0.34 l/s/ha in this sector. Given changes in farming and varietal choices, this flow proved insufficient to face the climatic water demand.

L'exploitation agricole occupe une position centrale comme objet d'analyse pour apprehender les performances des systemes irrigues. Compte tenu de la diversite des exploitations dans un systeme de liberalisation des assolements, comme c'est le cas en Tunisie, un travail de prospection de ces exploitations s'avere necessaire pour envisager des travaux de prospective. Une etude de cas a porte sur le perimetre public irrigue de Borj Toumi-Toungar de la Basse Vallee de la Medjerda (BVM) en Tunisie. Ce perimetre, qui couvre 785 ha et dont sa mise en eau date des annees 1970, represente plusieurs situations contrastees relatives a l'exploitation des eaux agricoles. Une premiere etape a porte sur la reconnaissance du perimetre et la caracterisation des exploitations agricoles. Pour ce, une enquete a ete realisee en 2005 sur le perimetre et a touche l'ensemble des agriculteurs (au nombre de 115). Conjuguee a une documentation et a un travail de prospection de terrain, cette enquete a fourni les elements necessaires pour dresser une typologie des exploitations par le biais d'une analyse en composantes principales. Neuf variables, representatives de la diversite des exploitations, ont ete engagees dans cette analyse, en particulier le taux d'intensification cultural et les techniques d'irrigation employees. Six classes d'exploitations ont ete identifiees avec des contraintes, des conduites de cultures et des choix techniques differencies. La confrontation entre les volumes d'eau preleves et la demande climatique des cultures a ete etudiee en deuxieme etape. Elle a ete initiee par les changements des speculations par rapport a l'etude de base et les fortes fluctuations des volumes d'eau annuels preleves depuis la mise en eau du perimetre. Pour l'actualisation des besoins en eau des cultures, des simulations ont ete effectuees par le modele Pilote et il a ete possible de dresser une analyse frequentielle des besoins en eau d'irrigation relative a une serie climatique s'etalant de 1983 jusqu'a 2005. En 2005, ces besoins representent environs 5 fois les volumes d'eau factures aux agriculteurs durant la meme annee. S'agissant de l'adequation entre l'offre et la demande climatique en eau, nous nous sommes interesses au mois de pointe (juillet). Il en ressort que la capacite du reseau (fonctionnement 24/24 heures et 7/7 jours) n'est pas a meme d'assurer la moitie des besoins en eau des quartiers etudies. Il y a lieu de noter qu'actuellement le reseau fonctionne au maximum 12 /j, ce qui denote du faible taux de satisfaction des besoins en eau des cultures. Paradoxalement, l'etude typologique montre que certaines classes d'exploitations se distinguent par des taux d'intensification culturaux eleves avec des tendances a la generalisation des systemes d'irrigation localises en maraichage et en arboriculture. En contre partie, une majorite des agriculteurs, ont recours rarement a l'irrigation et adoptent une conduite culturale en pluvial