Effects of vermicompost and mineral fertilizers on soil properties, malt barley (Hordeum distichum L.) yield, and economic benefits

Soil fertility depletion has significantly reduced the yields of various crops in Ethiopia, mainly the yield of malt barley in the district. To address this issue, integrated applications of vermicompost and mineral nitrogen (N) fertilizers were tested. Therefore, this study aimed to evaluate the effects of vermicompost and mineral nitrogen fertilizers application on malt barley yield (Hordeum distichum L.), soil properties, and economic benefits. The experiment was arranged in a randomized complete block design with three replications. The treatments were nine in various combinations of vermicompost (VC) and N fertilizer (N): (69 kg N; 0.79 t VC + 58.65 kg N; 1.59 t VC + 48.30 kg N; 2.39 t VC + 37.95 kg N; 3.19 t VC + 27.60 kg N; 3.98 t VC + 17.25 kg N; 4.78 t VC + 6.90 kg N; 5.31 t VC ha⁻¹ and control). The highest soil pH was recorded by applying 5.31 t of vermicompost ha⁻¹ alone. The highest total nitrogen (0.34%), available phosphorus (15.58 mg kg⁻¹), grain yield (4950 kg ha⁻¹), and net benefit (4255.74 USD) were recorded from the application of 2.39 t VC plus 37.95 kg N, while the highest soil organic carbon (3.38%) and cation exchange capacity (26.17 cmol (+) kg⁻¹) were recorded from 3.19 t VC plus 27.60 kg N ha⁻¹ compared to the control. This study concludes that applying 2.39 t VC and 37.95 kg N ha⁻¹ in combination improves soil fertility, malt barley yield, and economic benefits for smallholder farmers in the study district and adopts this in similar soil types and agroecologies.