Growing Coffee (Robusta) in Kiambu

Soil suitability analysis based on Kiambu's nutrient profile

Kiambu County is a challenging environment for Coffee (Robusta) (soil-match score 23/100) and will need significant amendment before planting. Local soils average pH 5.28 — moderately acidic and inside the 5–6.5 band Coffee (Robusta) prefers, so no lime is usually required. The main gap is nitrogen and potassium — measured at N 1.01 g/kg, P 13.7 mg/kg, K 169 mg/kg against this crop's high/medium/high demand — so the fertilizer plan below prioritises closing those deficits. Coffee (Robusta) prefers loam soils, while Kiambu is largely clay, so drainage and organic-matter management matter more here. Kiambu receives approximately 1100 mm/year — well below Coffee (Robusta)'s minimum of 1500 mm — so supplemental irrigation would be essential for this crop. Coffee (Robusta)'s full potential is about 950 kg/acre (~KES 76,000/acre at KES 80/kg), but at Kiambu's 23/100 suitability a realistic target here is closer to 273 kg/acre (~KES 21,840/acre) unless the constraints above are addressed.