Growing Sisal in Tharaka Nithi

Soil suitability analysis based on Tharaka Nithi's nutrient profile

Sisal can be grown in Tharaka Nithi County, but the soil scores 53/100 and needs targeted management to reach full potential. At an average pH of 4.99 the soil is strongly acidic, below Sisal's preferred 5.5–8.5 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 Sisal's requirements, so a maintenance fertilizer programme is enough. The county's predominantly sandy loam soils suit Sisal, which favours sandy. Sisal's full potential is about 1,000 kg/acre (~KES 90,000/acre at KES 90/kg), but at Tharaka Nithi's 53/100 suitability a realistic target here is closer to 663 kg/acre (~KES 59,670/acre) unless the constraints above are addressed.