Growing Yams in Nyandarua

Soil suitability analysis based on Nyandarua's nutrient profile

Nyandarua County is a challenging environment for Yams (soil-match score 44/100) and will need significant amendment before planting. At an average pH of 5.38 the soil is moderately acidic, below Yams's preferred 5.5–6.5 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. The main gap is potassium — measured at N 1.28 g/kg, P 14 mg/kg, K 166 mg/kg against this crop's medium/medium/high demand — so the fertilizer plan below prioritises closing that deficit. Yams prefers sandy loam soils, while Nyandarua is largely clay, so drainage and organic-matter management matter more here. At 2300 m, the county sits above Yams's preferred altitude ceiling of 1800 m, where frost risk and cold nights reduce the crop's productivity. At current prices (about KES 80/kg) and a typical 6,000 kg/acre yield, a well-managed Yams crop here can gross roughly KES 480,000 per acre.