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. On ShambaIQ's soil-match model, Sesame (Simsim) is the #90 soil match of the 106 crops we assess for Nyandarua County. Sesame (Simsim)'s full potential is about 250 kg/acre (~KES 87,500/acre at KES 350/kg), but at Nyandarua's 32/100 suitability a realistic target here is closer to 100 kg/acre (~KES 35,000/acre) unless the constraints above are addressed.

Better matched to Nyandarua's soil: Tea, Pyrethrum, and Potato — each scores higher on the same soil.