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. Arrow Root prefers clay loam soils, while Machakos is largely sandy loam, so drainage and organic-matter management matter more here. Machakos receives approximately 700 mm/year — well below Arrow Root's minimum of 1000 mm — so supplemental irrigation would be essential for this crop. Arrow Root's full potential is about 5,000 kg/acre (~KES 275,000/acre at KES 55/kg), but at Machakos's 37/100 suitability a realistic target here is closer to 2,313 kg/acre (~KES 127,215/acre) unless the constraints above are addressed.