Effect of NPS and Vermicompost Addition on the Physico-Chemical Properties of the Soil under (Zea mays) at the Bako Agricultural Research Center in Western Oromia, Ethiopia

Abstract The main chemical, physical, and biological limitations on soil production in western Ethiopia include low soil fertility, nutrient unavailability, and acidity. Therefore, the purpose of the study was to evaluate how specific physico-chemical properties of soil were influenced by the combined application of vermicompost and NPS fertilizer rates at Bako Agricultural Research Center. Four vermicompost levels (0, 2.32, 3.48, and 4.64 tons ha⁻ ¹) and four NPS fertilizer levels (0, 50, 75, and 100 kg ha⁻ ¹) were combined in a factorial manner were laid out in Randomized Complete Block Design (RCBD) with three replications. The study's findings demonstrated that while bulk density decreased below the control due to different levels of organic fertilizer application, all treatments applied increased soil moisture and total porosity relative to the control or NPS fertilizer alone. The results showed that the combination of vermicompost and NPS fertilizer rates significantly affected organic carbon, organic matter, total nitrogen, basic cations (Ca²⁺, Mg²⁺, K⁺), and available phosphorous. Nevertheless, the experiment indicated the integration of organic and inorganic fertilizers to enhance nutrient availability by maintaining soil fertility and health because the pH of the soil was significantly influenced by the primary effects of vermicompost levels (P ≤ 0.01).