1. Alemayehu K (2007) Effects of different land use systems and topography on selected soil properties at Delbo Watershed, Wolayita Zone, southern Ethiopia. Msc thesis. Hawassa University, Hawssa, Ethiopia
2. Allison LE (1965) Organic carbon. In: Black CA (ed) Methods of soil analysis. Part 2: Chemical and microbiological properties, vol. 9. Am. Soc. Agro. Inc., Madison, WI
3. Bewket W, Stroosnijder L (2003) Effects of agroecological land use succession on soil properties in Chemoga watershed, Blue Nile basin, Ethiopia. Geoderma 111:85–98
4. Blake GR, Hartge KH (1965) Bulk density. In: Black CA (ed) Methods of soil analysis. Part 1: Physical and mineralogical methods, vol. 9. Am. Soc. Agro. Inc., Madison, WI, pp 374–390
5. Brady N, Weil R (1996) The nature and properties of soils, 11th edn. Prentice-Hall, Upper Saddle River, NJ