Abstract: Acid soils are a major constraint to agricultural productivity in the West Shewa Zone of Oromia Regional State. Restoring soil pH to optimal ranges for agriculture can have a significant impact on yields. The application of agricultural lime is the standard corrective. Lack of farmer awareness, and weak or non-existent lime supply chains, insufficient training, limited participatory on-farm demonstration of technologies given to the farmer and development workers make this a complex problem to address at a large-scale technology that has not reached the intended target efficiently and effectively. To this work of large-scale acid soil reclamation through lime technology, no large-scale farmer trials of lime application have been undertaken in Ethiopia. To overcome these constraints, an Acid soil management research team of Ambo Agricultural Research Center, in collaboration with an integrated wheat project demonstrated proven liming technologies for acid soil management in the west Shewa Zone of the Oromia region using full package technology a large-scale-clustered farm approach. Lime (Calcium carbonate) and improved wheat varieties (wane) were demonstrated. The experimental Sites were selected based on the acid saturation of the soil, farmers’ willingness and accessibility for supervision, and input transportation. A total of 182 farmers were targeted in both districts and these farmers were involved in six clusters on 55 hectares of land. The training was given before the implementation of the activity for a total of 24 development Agents (18 male and 6 women) and 16 agricultural experts (12 male and 4 female). Advisory services were continuously given to farmers from land preparation up to harvesting. Inputs including 110-ton lime, and 10-ton wheat seed (Wane variety) were distributed to these beneficiaries. The lime requirement (LR) of the soil was determined based on the EA or acid saturation of the study soil. Improved bread wheat varieties of “Wane” for both districts were planted at the seedling rate of 150 kg/ha. Field days were organized with participants of 50 agricultural experts, 35 Development agents, 48 AmARC workers, and 338 farmers. The maximum grain yield (44.3 qt/ha) was recorded from the limed acid soil of the Bodda Cluster in the Dandi district. However, the overall average grain yields obtained from a hectare of land under limed and unlimed acid soil accounted for 35.73 and 22.73 quintals respectively, which is 57.37% of yield variation due to lime amendment. Based on this productivity per hectare across districts; using lime amendment technology for acid soil had been by far better than unlimed/without any amendments under acidic soil of the study area. Therefore, it is better to strengthen liming technology awareness and should be continued for improving acid soil and productivity of the crop in acid soil areas.
Keywords: Lime; cluster and Amendment