Growing Quinoa in Tharaka Nithi

Soil suitability analysis based on Tharaka Nithi's nutrient profile

Tharaka Nithi County is a challenging environment for Quinoa (soil-match score 30/100) and will need significant amendment before planting. At an average pH of 4.99 the soil is strongly acidic, below Quinoa's preferred 6–8.5 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. Nitrogen (1.23 g/kg), phosphorus (19.6 mg/kg) and potassium (211 mg/kg) all meet Quinoa's requirements, so a maintenance fertilizer programme is enough. The county's predominantly sandy loam soils suit Quinoa, which favours loam. Quinoa's full potential is about 700 kg/acre (~KES 105,000/acre at KES 150/kg), but at Tharaka Nithi's 30/100 suitability a realistic target here is closer to 263 kg/acre (~KES 39,450/acre) unless the constraints above are addressed.