Growing Watermelon in Nyandarua

Soil suitability analysis based on Nyandarua's nutrient profile

Nyandarua County is a challenging environment for Watermelon (soil-match score 23/100) and will need significant amendment before planting. At an average pH of 5.38 the soil is moderately acidic, below Watermelon's preferred 6–7.5 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 Watermelon's requirements, so a maintenance fertilizer programme is enough. Watermelon prefers sandy soils, while Nyandarua is largely clay, so drainage and organic-matter management matter more here. At 2300 m, the county sits above Watermelon's preferred altitude ceiling of 1500 m, where frost risk and cold nights reduce the crop's productivity. At current prices (about KES 10/kg) and a typical 5,500 kg/acre yield, a well-managed Watermelon crop here can gross roughly KES 55,000 per acre.