Growing Stevia in Kwale

Soil suitability analysis based on Kwale's nutrient profile

Kwale County is a challenging environment for Stevia (soil-match score 14/100) and will need significant amendment before planting. Local soils average pH 6.76 — neutral and inside the 6–7.5 band Stevia prefers, so no lime is usually required. The main gap is nitrogen, phosphorus, and potassium — measured at N 0.93 g/kg, P 9.8 mg/kg, K 131 mg/kg against this crop's high/medium/medium demand — so the fertilizer plan below prioritises closing those deficits. The county's predominantly sandy loam soils suit Stevia, which favours loam. At 200 m, the county sits below Stevia's preferred altitude range (500–2000 m), which limits yield potential due to heat stress. Stevia's full potential is about 3,000 kg/acre (~KES 600,000/acre at KES 200/kg), but at Kwale's 14/100 suitability a realistic target here is closer to 525 kg/acre (~KES 105,000/acre) unless the constraints above are addressed.