Growing Cowpeas in Kiambu

Soil suitability analysis based on Kiambu's nutrient profile

Cowpeas can be grown in Kiambu County, but the soil scores 53/100 and needs targeted management to reach full potential. Local soils average pH 5.28 — moderately acidic and inside the 5–8 band Cowpeas prefers, so no lime is usually required. Nitrogen (1.01 g/kg), phosphorus (13.7 mg/kg) and potassium (169 mg/kg) all meet Cowpeas's requirements, so a maintenance fertilizer programme is enough. Cowpeas prefers sandy soils, while Kiambu is largely clay, so drainage and organic-matter management matter more here. Cowpeas's full potential is about 450 kg/acre (~KES 29,250/acre at KES 65/kg), but at Kiambu's 53/100 suitability a realistic target here is closer to 298 kg/acre (~KES 19,370/acre) unless the constraints above are addressed.