Growing Arrow Root in Machakos

Soil suitability analysis based on Machakos's nutrient profile

Machakos County is a challenging environment for Arrow Root (soil-match score 37/100) and will need significant amendment before planting. At an average pH of 7.03 the soil sits above Arrow Root's preferred 5–7 range, which can limit uptake of phosphorus and micronutrients. Nitrogen (0.82 g/kg), phosphorus (31.4 mg/kg) and potassium (338 mg/kg) all meet Arrow Root's requirements, so a maintenance fertilizer programme is enough. The county's predominantly sandy loam soils suit Arrow Root, which favours clay loam. Machakos receives approximately 700 mm/year — well below Arrow Root's minimum of 1000 mm — so supplemental irrigation would be essential for this crop. At current prices (about KES 55/kg) and a typical 4,500 kg/acre yield, a well-managed Arrow Root crop here can gross roughly KES 247,500 per acre.