Growing Sunflower in Nyandarua

Soil suitability analysis based on Nyandarua's nutrient profile

Nyandarua County is a challenging environment for Sunflower (soil-match score 43/100) and will need significant amendment before planting. At an average pH of 5.38 the soil is moderately acidic, below Sunflower'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 Sunflower's requirements, so a maintenance fertilizer programme is enough. Sunflower prefers sandy soils, while Nyandarua is largely clay, so drainage and organic-matter management matter more here. Sunflower's full potential is about 750 kg/acre (~KES 36,000/acre at KES 48/kg), but at Nyandarua's 43/100 suitability a realistic target here is closer to 403 kg/acre (~KES 19,344/acre) unless the constraints above are addressed.