7 - Land suitability evaluation for cereals and coffee in Cheleleka Bobe (Wolonkomi area), Ethiopia

Abstract

Land suitability evaluation, which is expected to serve as basis for sustainable land use planning, is estimated in Cheleleka-Bobe (Wolonkomi area of Ethiopia) based on soil survey data collected in October 2006. In the evaluation study, suitability ratings were made for four land use types (LUTs) [teff (Eragrostis teff); wheat (Triticum aestivum); maize (Zea mays); and coffee (Coffea arabica)]. The “Matching Table” method was used to compare the measured land qualities (LQs) with land requirements (LRs). Among the assessed LUTs, coffee was found nonsuitable on four soil mapping units (SMUs) due to climatic, wetness, and root depth limitations and was found marginally suitable on one SMU. SMU “C” (the koticha soil zone) was found temporarily nonsuitable for the three cereal crops due to fertility limitations owing to marginal total nitrogen (TN) levels. Wetness stands to be the only factor that limits cereal cultivation in SMU “B2,” SMU “B1” also appears to be marginal to the cereals because of wetness and fertility limitations. The proxy of steep slope gradient and shallow soil depths indicate less moisture availability and emerge as limiting factors for the LUTs in SMU “A.” Thus, generally, wetness and fertility limitations emerge as major limitations for all the LUTs in all the SMUs. Shallow rooting depth is also a principal factor that makes land use to be marginal in SMU “A.” Based on the preceding results, SMU “A” is better to stay under vegetation cover with the support of terracing. Addition of animal manure, legume rotation fallowing, and use of chemical fertilizers are recommended for SMU “C.” The seasonally renewed soils at “B1,” “B2,” and “B3” could be cultivated sometime after the rainy season with no addition of fertilizer by removing of the excess water in “B1” and “B2” using drainage channels.