Growing Sweet Potato in Mandera

Soil suitability analysis based on Mandera's nutrient profile

Mandera County is a challenging environment for Sweet Potato (soil-match score 4/100) and will need significant amendment before planting. At an average pH of 8.38 the soil sits above Sweet Potato's preferred 4.5–7 range, which can limit uptake of phosphorus and micronutrients. Nitrogen (0.53 g/kg), phosphorus (38.3 mg/kg) and potassium (420 mg/kg) all meet Sweet Potato's requirements, so a maintenance fertilizer programme is enough. The county's predominantly sandy soils suit Sweet Potato, which favours sandy loam. Mandera receives approximately 180 mm/year — well below Sweet Potato's minimum of 600 mm — so supplemental irrigation would be essential for this crop. At current prices (about KES 18/kg) and a typical 3,500 kg/acre yield, a well-managed Sweet Potato crop here can gross roughly KES 63,000 per acre.