On Farm Evaluation and Demonstration of Onion Yield and Water Productivity Under Irrigation in Melka Irrigation Scheme, Western Hararghe Zone, Oromia Regional State, Ethiopia

Onion is one of the most important in the daily Ethiopian diet and the most economically vital horticultural crops in the country including west Hararghe zones. The lack of knowledge on efficient water utilization is the major constraint on onion production under irrigation which has to be addressed through efficient utilization of available water resources. This activity was initiated to evaluate and demonstrate the effect of crop water requirement based irrigation on onion yield and water productivity. The study was conducted at Melka irrigation scheme in Gemechis district of west Hararghe zone. Two FREGs (Farmer Research and extension Groups) which consist of 20 members per FREG was established, and a total of 40 farmers were grouped per schemes. Four trial farmers were selected on which to establish the experiment, whereas the remaining farmers were participated during training, field works like; land preparation, furrow layout and construction on selected trial farmers’ field. Two treatments namely; cropwat based irrigation and farmers practice were used on total areas of 21 m x 10 m with 1 m spacing between plot areas of 10 m x 10 m per farmers on which experimental farmers were used as replication. The intra and inter space of 15 x 40 cm was used. The agronomic data such as single bulb weight (g), plant height (cm), marketable and un marketable yield were collected and analyzed using R software as well as farmer perception analyzed using direct matrix ranking method. The cropwat based irrigation treatment used about 387.3 mm total seasonal water use (Etc) throughout growing period of onion while the estimated traditional irrigation was about 490.7 mm. The cropwat based irrigation saved about 103 kg/ha/mm water throughout growing period and 28.53% yield advantage compared to farmers practice (traditional irrigation). Furthermore, improving farmers’ awareness and knowledge through field demonstrations and giving training for farmers on improved water management practices is needed in the future.