References
- Bremner JM, Mulvaney CS. 1982. Total nitrogen. In: Page AL, Miller RH, Keeney DR (eds), Methods of soil analysis, part II: Chemical and microbiological properties. Madison: Soil Science Society of America. pp 595–642.
- Clement E, Coulombe JB, Dixon, Wilding LP. 1996. Mineralogy and chemistry of Vertisols. In: Ahmed N, Mermut A (eds), Vertisols and technologies for their management. Developments in Soil Science vol. 24. Amsterdam: Academic Press. pp 115–200.
- Elias E. 2016. Soils of the Ethiopian highlands: geomorphology and properties. Wageningen: ALTERA, Wageningen University and Research Centre.
- Elias E. 2017. Characteristics of Nitisol profiles as affected by land use type and slope class in some Ethiopian highlands. Environmental Systems Research 6: 1–15. doi: 10.1186/s40068-017-0097-2
- Fageria NK, Baligar VC, Jones CA. 2011. Growth and mineral nutrition of field crops (3rd edn). Boca Raton: CRC Press.
- FAO (Food and Agricultre Organization of the United Nations). 1984. Assistance to land-use planning. Ethiopia: geomorphology and soils. Addis Ababa: United Nations Development Programme, FAO.
- Fränzle S. 2010. Chemical elements in plants and soil: parameters controlling essentiality. Tasks for Vegetation Science vol. 45. Dordrecht: Springer.
- Gomez KA, Gomez AA. 1984. Statistical procedures for agricultural research (2nd edn). New York: John Wiley and Sons.
- Hazelton P, Murphy B. 2007. Interpreting soil test results: what do all the numbers mean? Collingwood: CSIRO Publishing.
- Juo A, Franzluebbers K. 2003. Tropical soils: properties and management for sustainable agriculture. Oxford: Oxford University Press.
- Mermut AR, Padmanabham E, Eswaran H, Dasog GS. 1996. Pedogenesis of Vertisols. In: Ahmad N, Mermut A (eds), Vertisols and technologies for their management. Developments in Soil Science vol. 24. Amsterdam: Academic Press. pp 43–62:
- Santra P, Kumar M, Panwar NR, Das. 2017. Digital soil mapping and best management of soil resources: a brief discussion with few case studies. In: Rakshit A, Abhilash PC, Singh HB, Ghosh S (eds), Adaptive soil management: from theory to practices. Singapore: Springer Nature. pp 3–39.
- Tan KH. 1996. Soil sampling, preparation, and analysis. New York: Marcel Dekker.
- Tefera M, Cherenet T, Haro W. 1996. Explanation of the geological map of Ethiopia at 1:2 mllion scale. Addis Ababa: Ethiopian Institute of Geological Survey.
- Towett EK, Shepherd KD, Tondoh JE, Winowiecki LA, Tamene L, Nyambura M, Sila A, Vågenb T-G, Cadisch G. 2015. Total elemental composition of soils in sub-Saharan Africa and relationship with soil forming factors. Geoderma Regional 5: 157–168. doi: 10.1016/j.geodrs.2015.06.002
- van Ranst L. 1993. Procedures for soil analysis (4th edn). Wageningen: International Soil Reference and Information Centre.
- van Reeuwijk L (ed.). 2006. Procedures for soil analysis (6th edn). Wageningen: International Soil Reference and Information Centre.
- White JG, Zasoki RJ. 1999. Mapping soil micronutrients. Field Crops Research 60: 11–26. doi: 10.1016/S0378-4290(98)00130-0
- Williams F. 2016. Understanding Ethiopia geology and scenery. Springer: New York
- Zewdie E. 2013. Properties of major agricultural soils of Ethiopia. Saarbrucken: Lambert Academic Publishing: