Growing Onion in Kiambu

Soil suitability analysis based on Kiambu's nutrient profile

Kiambu County is a solid choice for Onion, with a soil-match score of 62/100. At an average pH of 5.28 the soil is moderately acidic, below Onion's preferred 6–7 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. The main gap is nitrogen and phosphorus — measured at N 1.01 g/kg, P 13.7 mg/kg, K 169 mg/kg against this crop's high/high/medium demand — so the fertilizer plan below prioritises closing those deficits. Onion prefers sandy loam soils, while Kiambu is largely clay, so drainage and organic-matter management matter more here. At current prices (about KES 45/kg) and a typical 3,500 kg/acre yield, a well-managed Onion crop here can gross roughly KES 157,500 per acre.