Growing Cowpeas in Tharaka Nithi

Soil suitability analysis based on Tharaka Nithi's nutrient profile

Cowpeas can be grown in Tharaka Nithi County, but the soil scores 59/100 and needs targeted management to reach full potential. At an average pH of 4.99 the soil is strongly acidic, below Cowpeas's preferred 5–8 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 Cowpeas's requirements, so a maintenance fertilizer programme is enough. The county's predominantly sandy loam soils suit Cowpeas, which favours sandy. Cowpeas's full potential is about 450 kg/acre (~KES 29,250/acre at KES 65/kg), but at Tharaka Nithi's 59/100 suitability a realistic target here is closer to 332 kg/acre (~KES 21,580/acre) unless the constraints above are addressed.