Selected chemical properties of agricultural soils in the Ethiopian highlands: A rapid assessment

Abstract

Lack of information on the characteristics of soils occurring in different locations has constrained the development of soil- and site-specific fertiliser recommendations in Ethiopia. A rapid assessment of the fertility status of some dominant agricultural soils was conducted. A total of 72 composite soil samples were analysed to determine soil pH and the contents of organic carbon (OC), total nitrogen (TN), available phosphorus (AP), cation exchange capacity (CEC), base saturation and selected micronutrients (iron, manganese, zinc and copper). The soils showed high CEC (25–49 cmol(+) kg⁻¹) and base status (72%–83%), were strongly acidic to neutral in pH (5.2–6.9), and had low to medium contents of OC, TN, AP, and copper (mean values of 1.75%, 0.28%, 12 mg kg⁻¹ and 2 mg kg⁻¹, respectively). Soil properties varied significantly among soil types and across locations reflecting differences in parent materials, climate and land use. Blend fertilisers containing NPKZn are recommended for Vertisols and Leptosols, but inclusion of copper in the fertiliser blends is required for Nitisols and Luvisols.

Keywords:

• blend fertiliser
• kaolinitic clays
• smectitic clays
• soil fertility assessment