By Beamlak Tesfaye ,Yigzaw Dessalegn and Desalegne Tadesse
The Koga irrigation scheme in Mecha District in the West Gojjam Zone of Amhara is one of the largest irrigation schemes in Ethiopia. Under the scheme, 7,000 hectares are irrigated using 19.7, 42.3, 117 and 783 km of primary, secondary, tertiary and quaternary canals respectively, and 12 storage structures for delivering water to more than 10,000 smallholder farmers.
Farmers in the scheme use furrow irrigation to grow different crops which are planted at different times of the year. They access water at intervals (of eight or more days) depending on the amount of water available in the dam. But this method has resulted in under and over irrigation contributing to low productivity, lowering of the groundwater table, leaching of fertilizer, destruction of soil structure, higher labour costs and conflict over water access.
To address these challenges, the Livestock and Irrigation Value Chains for Ethiopian Smallholders (LIVES) project through the International Water Management Institute (IWMI) has this year (Jan 2015) introduced an irrigation scheduling device known as a ‘wetting front detector (WFD)’ for testing at the Koga scheme.
The wetting front detector, which costs 60 USD, was developed in Australia in 2004 and is being used in different countries such as South Africa to improve water management in irrigation schemes. The detector help farmers to judge how much water plants need throughout their growing period. LIVES provided eighteen WFDs to Ambomesk, one of blocks in the scheme and field days and trainings were used to guide farmers and irrigation agronomists on how to use them.
The LIVES/IWMI intervention has started bearing fruit as the WFD has been acknowledged and valued by piloting smallholders at the Abomesk block with the efficiency of the easy-to-use devices demonstrated on two test crops (wheat and potato). Many farmers have expressed perceived benefits of the WFD during the field day conducted in April 2015.
One of the piloting farmers, Liyew Fetene said the WFD has helped him estimate the appropriate irrigation interval at different growth stages of the potato crop as well as during fertilizer application. ‘I am no longer in conflict with other neighbouring smallholders and the water users association executive committee,’ he said.
Other farmers say the WFD helps save water, time, labour, fertilizer and reduces conflict caused by competition for water. Likewise, the Abomesk water users association members and irrigation agronomists have appreciated how the devices has helped improve the productivity of farmers. In addition, all participants in the trial have witnessed higher productivity of vegetable crops irrigated with the help of WFD compared to crops grown in the control plot (using current practice of frequently irrigating) which uses more water and is less productive.
LIVES/IWMI will continue testing the WFD for different crops, soil types in the Koga scheme and other parts of the country, prior to scaling it out to different parts of the country.