Growing Yams in Machakos

Soil suitability analysis based on Machakos's nutrient profile

Machakos County is a challenging environment for Yams (soil-match score 26/100) and will need significant amendment before planting. At an average pH of 7.03 the soil sits above Yams's preferred 5.5–6.5 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 Yams's requirements, so a maintenance fertilizer programme is enough. The county's predominantly sandy loam soils suit Yams, which favours sandy loam. Machakos receives approximately 700 mm/year — well below Yams's minimum of 1200 mm — so supplemental irrigation would be essential for this crop. On ShambaIQ's soil-match model, Yams is the #96 soil match of the 106 crops we assess for Machakos County. Yams's full potential is about 7,000 kg/acre (~KES 560,000/acre at KES 80/kg), but at Machakos's 26/100 suitability a realistic target here is closer to 2,275 kg/acre (~KES 182,000/acre) unless the constraints above are addressed.

Better matched to Machakos's soil: Mango, Sisal, and Moringa — each scores higher on the same soil.