Fig. 3From: Status of soil organic carbon and nitrogen stocks in Koga Watershed Area, Northwest EthiopiaRelation between soil bulk density (BD) and organic carbon concentration. a Top soil layer (0–15 cm) of irrigation, b sub soil layer (15–30 cm) of irrigation, c top soil layer (0–15 cm) of rainfed, d subsoil layer (15–30 cm) of rainfedBack to article page