Integrated Nitrogen, Farmyard Manure, and Vermicompost Improve Barley Productivity in the Central Highlands of Ethiopia

Soil fertility depletion caused by declining organic matter and imbalanced nutrient inputs is a major constraint to barley (Hordeum vulgare L.) production in the Ethiopian highlands. A field experiment was conducted during the 2022/2023 main cropping season at Holeta Agricultural Research Center, Ethiopia, to evaluate the effects of integrating nitrogen fertilizer, vermicompost, and farmyard manure on soil properties and barley productivity under a randomized complete block design with three replications. Initial soil analysis indicated clay-textured, moderately acidic soil with low organic carbon (1.22%), total nitrogen (0.12%), and available phosphorus, confirming nutrient limitations in the study area. Integrated nutrient application significantly (P < 0.05) improved soil chemical properties, yield components, and grain yield compared with sole application of organic or inorganic fertilizers. The combined application of 75% recommended vermicompost and 75% recommended nitrogen fertilizer produced the highest grain yield (4545.59 kg ha⁻ 1 ), followed by 75% farmyard manure combined with 75% nitrogen fertilizer. Yield improvement was associated with increased spike length, grains per spike, and aboveground biomass production. Vermicompost-based treatments showed relatively greater yield advantages than farmyard manure treatments, likely due to faster nutrient mineralization and improved nutrient availability. Economic analysis also indicated higher net returns and marginal profitability under integrated nutrient management treatments. The results demonstrate that combining organic amendments with mineral nitrogen improves soil fertility and barley productivity and provides a sustainable nutrient management strategy for food barley production in the Ethiopian highlands.