Supplemental irrigation

    Local farmer irrigates plants in one of the fields of the ICARDA Research Centre, an IFAD cooperating institution based in Aleppo    

The learning event has been a great opportunity for the whole division to meet the staff of the International Center for Agricultural Research in the Dry Areas (ICARDA) , to learn about their activities, and in relation to the theme of supplementary irrigation, to better understand the importance of water in the Near East and North African  region, reports Angela Colabelli and Nicole Hervieu.

What is supplemental irrigation?

Supplemental irrigation (SI) can be defined as the addition of small amounts of water to essentially rainfed crops during times when rainfall fails to provide sufficient moisture for normal plant growth, in order to improve and stabilize yields. SI in areas with limited water resources is based on the following three premises:

  • Water is applied to a rainfed crop which would normally produce some yield without irrigation.

  • Since precipitation is the principal source of moisture for rainfed crops, SI is only applied when precipitation fails to provide essential moisture for improved and stabilized production.

  • The amount and timing of SI are not scheduled to provide moisture-stress-free conditions throughout the growing season, but to ensure that the minimum amount of water required for optimal (not maximum) yield is available during the critical stages of crop growth.

Supplemental irrigation is the opposite of full or conventional irrigation (FI). In the latter, the principal source of moisture is fully controlled irrigation water, and highly variable limited precipitation is only supplementary. SI is dependent on the precipitation of a basic source of water for the crop.
Water for supplemental irrigation comes mainly from surface sources, but shallow groundwater aquifers increasingly are being used. Among non-conventional water resources that have potential for the future, such as treated sewage water-harvesting is also important.

It is widely known that rainfall in the arid and semi-arid areas of the Near East and North African region are very limited and highly variable. The learning event involved visits to IFAD-ICARDA project sites to water-capture and water reservoir areas to discuss and learn about the importance of finding solutions to retain water through methods such as supplemental irrigation.

Field visit to Aleppo plain – focus for supplemental irrigation

Tawfiq El-Zabri reports on the third field visit of the event to Aleppo plain. The visit included Project directors from Azerbaijan, Egypt and Yemen and staff from IFAD and the International Center for Agricultural Research in the Dry Areas (ICARDA).  There was also plenty of bonus time to chat with farmers that grew wheat, cotton, potatoes and sugar beet.

The participants visited the Surbaya Agricultural Research Station, where the Director explained the government's research priorities in this part of the country and elsewhere. Most of Syria's arable land is rainfed, and water-use efficiency is a key concern with falling levels of underground water and a growing population. The Director and his staff explained their supplementary irrigation techniques and showed us the centre's research plots for pistachios, olives, grapes and wheat, grown under drip or sprinkler irrigation. These were the models that generated extension messages and that are shown to farmers to persuade them not to overirrigate. The mission of the Surbaya station is to identify and disseminate optimal supplementary irrigation methods for the clayish soils predominant in the region, which crack with less then 80 per cent humidity. One of their important finding that helps farmers (who do not have station equipment to monitor the aridity stress of their wheat crop) approximate yields at the research centre, is to plant one row of beet, which shows stress before wheat. This enables farmers to best set the time for their supplementary irrigation flows.

The visit to the Ateriya farmers left most of us astonished. The farmers had adopted pioneering irrigation techniques. The star farmer among them, Abu Ali, explained how he managed water scarcity and how, by using drip irrigation, he reached a harvest of six tons of cotton per hectare. He also showed us the communities' evaporation plan and recited crop-growing times and irrigation quantities and dates. Other farmers were however not convinced. With ground water levels dropping two metres a year, they recognized water scarcity but emphasized that financial returns were their key consideration and aside from fuel costs, pumping ground water was free. They acknowledged that there was no need to overirrigate, yet most agreed that relying on their ability to forecast rain is also as fundamental (although they are aware that more water does not necessarily mean more crops). The extension workers' guidance – that more water provides higher returns only to a certain point – helped farmers save unnecessary fuel costs. Timing their supplementary watering "according to the book", did not necessarily maximize their returns.

Nadim Khouri, the NEN Division Director in IFAD, launched the discussion with questions on empowerment, for example ‘How do farmers organize themselves to influence government policies and decisions (e.g. their request to bring Euphrates water)'?  ‘Do they collaborate in farmers' organizations or cooperatives to improve their outcomes'? The answer provided was that policy decisions, and almost everything related to input supply and marketing, has depended for years on  Government planning and institutions.  The government determined the cropping patterns and quotas for the Ateriya farmers' most remunerative crops (for example wheat, cotton and sugar beet), provided inputs and extension services, set farm-gate prices and bought and marketed farmer produce.  

A market-driven system may have worked in the past, but the only system they had known in their productive lifetime was one controlled and run by the state. This was what they were used to and they were not comfortable switching to a new system that they would not know how to handle. The government could do better by protecting farmers if prices or productivity went too low, if the rains were too little or too late, or if the cost of fuel for pumping water went too high. The farmers welcomed the newly established Agricultural Support Fund. Most importantly, they looked forward to improving their livelihoods if the government completes its conveyance of Euphrates water and irrigates 87,000 hectares in the Aleppo plain. They would no longer have the problem of having sufficient water and they would even diversify to higher-value crops.