Assessing Selected Nutrient Content and Quality of Conventional Composts for Crop Production in Western Oromia, Ethiopia

One of the main reasons for poor soil fertility status of acidic soils is low content of soil available plant nutrients like N, P, S, exchangeable Ca and Mg and toxicity of Al and Fe resulted from low soil pH value. Amendment of acidic soil using organic sources like compost is very crucial for improving the livelihood of the society through increasing crop productivity. Therefore, this study was conducted to assess the nutrient content and quality of compost prepared at farmers‘ level and guiding the integrated use of both chemical and organic fertilizers approach sustainably. The compost samples were collected from seven districts, namely Guto-Gida, Sassiga, Guduru, Horo, Jima-Genet, Hawa-Gelan and Nedjo, in western Oromia Regional State. The composts were prepared at farmers’ level from the locally available composting materials. The composting materials used were more or less similar in all districts except it might vary in one or two sources which were used at very low ratio compared to the main sources. The result of the compost nutrient content revealed that the mean values of EC, pH, TN and C:N ratio ranged from 1.22 to 1.99 mmhos/cm, 7.25 to 8.20, 0.45 to 0.74% and 11.51 to 12.65, respectively which fell within the acceptable range for good quality compost. On the other hand, the mean values of OC, available P, exchangeable Ca and Mg were ranged from 5.19 to 7.83%, 0.006 to 0.013%, 44.79 to 83.72 mg kg soil<sup>–</sup><sup>1</sup> and 1.40 to 8.61 mg kg compost<sup>–</sup><sup>1</sup>, respectively which fell below the acceptable range for good quality compost. Based on the crucial parameters indicating good quality compost like pH and C:N ratio the compost prepared from the locally available composting materials by the farmers were for improving the overall quality of the soil. Hence, productivity of crops would increased by using compost as source of organic fertilizers from which farmers in the study area benefited sustainably.