Innovative Solution

dripping irrigation acf diversification diet seasonality

technical

This work has been developed in collaboration with the NGO Action Against Hunger– Spain (Acción Contra el Hambre – España ACF–E). Since 2007, ACF-E is fighting food insecurity in Mauritania with the development of vegetables gardens run by women’s cooperatives. The vegetables produced are used to complement the diet of the population, mostly based on crops cultivated during the raining period (from June to September). This complement is particularly important when the grain stocks are being depleted, from February to the new harvest. Moreover, vegetables are a source of vitamins which can not been found otherwise in the daily diet of the population.

Nowadays, the production of vegetables is compromised due to the difficult conditions of irrigation (hand pumps used many hours a day) and its low efficiency (traditional irrigation involves many losses by evaporation). Therefore, this work was focused on three main parts:

(1) First, it was necessary to design a more suitable and efficient irrigation system. As a start, a system of crop rotation was proposed so as to make better use of soil nutrients and prevent transmission of plant pathogens. With this simple method, the vegetables production could be improved without adding any technology. The next step was to calculate the water needs to develop vegetable gardens. Two different methods were used, one with the help of a specialized tool of the FAO, the program CROPWAT, and another with analytical methods. This calculation was the basis for the design of the irrigation structure. The traditional irrigation had proven not to be suitable, and a drip irrigation was proposed as an alternative. However, instead of using industrial droppers, the system proposed uses dropwise microtubes. The microtubes are pipes with a very small inner diameter which generate enough internal friction to release water drop by drop and not as a jet. As such, they can replace industrial droppers, with the advantages that they are much cheaper and need less pressure to work properly. In addition, the flow released can be regulated as a function of the length of the microtube. Some experimental tests were used to characterize the relation between the pressure at the entrance of the microtube, its length and the flow released. As a result, it was determined that this was a viable irrigation method for cooperation projects. Finally was the problem of pumping.  After studying the pros and cons of rope pumps (cheap and simple technology widely used inSouth America), it was shown that rope pumps were inaccurate for community garden and photovoltaic pumping was chosen instead. This part concludes with a guide to sizing all system components: photovoltaic panels, pumps, tanks etc.

(2) The second part objective was to provide a calculation tool and decision support on the above design. This tool was developed in Excel to be easily accessible. It is organized as a sequential tool: the first sheet is used to calculate the water requirements, based on the vegetable cultivated, the type of soil and some meteorological data. The next sheets are a guide to determine the pipes dimensions for all the irrigation system in accordance with designing criteria such as the minimum pressure needed or the amount of water released. A choice of pump is proposed, with the possibility of checking if the characteristics of another pump are enough to allow the proper operation of the system. Once the system has been validated, the last sheet allows the user to export the irrigation net to a free program called EPANET where the dynamic behavior of the net can be simulated more accurately. The whole tool has been design to be used by people with little knowledge of irrigation theoretical calculations but with a good idea of what can be found on the field, so that the program could be used easily by cooperating people with little need of specific formation.

(3)  Finally, the last part consisted in applying the whole methodology to a specific case: the vegetable garden supported by ACH-E in the town ofN’Diokouti,Mauritania. Before starting any culture, the parcel was divided in an equitable way between the 58 beneficiaries. Then, after choosing which plants were going to be cultivated, the repartition of the parcel was decided and every element of the irrigation system was dimensioned and chosen: pipes, tanks, photovoltaic panels, pump etc. paying special attention to the selection of material. The main criteria for the selection of material were robustness, low maintenance, availability in the country of deployment and energy self-sufficient. Regarding the economical aspect, part of the agricultural production can be sold to finance some of the initial costs of the project. The conclusion of a cost assessment was that the long-term benefits, both human and financial, justify the necessary investment.

Rural areas in the Sahel desert, extrem arid context. N’Diokouti, Mauritania.

The project has been initiated by the demand of farmers to be independent from the seasonality and to be able to diversify the diet with higly porductive crops and vegetables. The research has been conducted by ACF in collaboration with the University Jaume I in Spain.

ACF is present in the for many years working with diferent farmers counterparts on the field, the will test and ensure the sustainabilty and replicabilty of the project, as it has a direct impact in the socioeconomic development of the region.

The reserach is ready to be piloted. Actually irrigation system are in place using sola panels pumping, but the solution present is pending on financial opportunities.

The solution reduces drastically the food insecurity in the area (making people independent from seasonality) and nutritional insecurity (it allowas to diversify their diet with richer vegetable and crops)

It has and hige advantage as is working with very low pressure (o,5 m H20) anda can be used with the traditional punping mechanisms.

It is based in affordable comercial products by the target population, the added value is the low pressure working and the design tool developed taht ensures the yield in all the points of the network

Inclusion in the vegetable production high demand water vegetable as tomato.

Harvesting  3/4 times per year (depending on the vegetables)

The solution is based the demand of the farmers, if the pilot project is succesful the replication will come by itself as it has a direct imapct on the production and is a low cost solution.

It is designed for small garden areas, wtih a restriction of water access. The cost will depend on the surface to be irrigated,and the depth of the water and the pumping technology. In the specific context of study with solar power (already used in the area) it will cost 6680€ (1 hectar)  and recovery time of 4 years.

Yes, farmers has been involved in the research, and ACF is present in the area to start piloting.

 Acción Contra el Hambre ACF-E

Pablo Alcalde Head of WASH Department

Calle Caracas 6

28010 Madrid SPAIN