Growing Cashew Nuts in Tharaka Nithi

Soil suitability analysis based on Tharaka Nithi's nutrient profile

Tharaka Nithi County is a challenging environment for Cashew Nuts (soil-match score 15/100) and will need significant amendment before planting. At an average pH of 4.99 the soil is strongly acidic, below Cashew Nuts's preferred 5–7.5 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. Nitrogen (1.23 g/kg), phosphorus (19.6 mg/kg) and potassium (211 mg/kg) all meet Cashew Nuts's requirements, so a maintenance fertilizer programme is enough. The county's predominantly sandy loam soils suit Cashew Nuts, which favours sandy. At 1100 m, the county sits above Cashew Nuts's preferred altitude ceiling of 500 m, where frost risk and cold nights reduce the crop's productivity. Cashew Nuts's full potential is about 900 kg/acre (~KES 247,500/acre at KES 275/kg), but at Tharaka Nithi's 15/100 suitability a realistic target here is closer to 169 kg/acre (~KES 46,475/acre) unless the constraints above are addressed.