Effects of Combined Application of Compost and Mineral Fertilizer on Soil Carbon and Nutrient Content, Yield, and Agronomic Nitrogen Use Efficiency in Maize-Potato Cropping Systems in Southern Ethiopia

Low nutrient input and low soil fertility are limiting agricultural productivity in Ethiopia. The main objectives were therefore to evaluate the effects of combined compost mineral fertilizer (MF) application on properties, yield, agronomic nitrogen use efficiency, adoption maize (Zey mays L.)—potato (Solanum tuberosum L.) cropping systems. Yield data collected from 20 smallholders applying (i) MF at a total rate 110 kg N ha?1, with 6 Mg ha?1 + (6CF), 12 (12CF), 16 (16CF; fresh weight basis), (ii) 108 (F), (iii) zero fertilization. Soil 0–20 20–40 cm depths was farms using MF. Compost treatments showed significantly lower bulk density iron contents, while pH, electrical conductivity, cation exchange capacity higher compared F treatments. 6CF, 12CF, 16CF 22, 43, 54% grain yield 8, 16, 18% potato tuber F, respectively. scarcity organic material major socioeconomic constraint for producing compost.