Growing Sesame (Simsim) in Nyandarua

Soil suitability analysis based on Nyandarua's nutrient profile

Nyandarua County is a challenging environment for Sesame (Simsim) (soil-match score 32/100) and will need significant amendment before planting. At an average pH of 5.38 the soil is moderately acidic, below Sesame (Simsim)'s preferred 5.5–7 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. Nitrogen (1.28 g/kg), phosphorus (14 mg/kg) and potassium (166 mg/kg) all meet Sesame (Simsim)'s requirements, so a maintenance fertilizer programme is enough. Sesame (Simsim) prefers sandy soils, while Nyandarua is largely clay, so drainage and organic-matter management matter more here. At 2300 m, the county sits above Sesame (Simsim)'s preferred altitude ceiling of 1600 m, where frost risk and cold nights reduce the crop's productivity. At current prices (about KES 350/kg) and a typical 180 kg/acre yield, a well-managed Sesame (Simsim) crop here can gross roughly KES 63,000 per acre.