Growing Yams in Kiambu

Soil suitability analysis based on Kiambu's nutrient profile

Kiambu County is a solid choice for Yams, with a soil-match score of 70/100. At an average pH of 5.28 the soil is moderately acidic, below Yams's preferred 5.5–6.5 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. The main gap is potassium — measured at N 1.01 g/kg, P 13.7 mg/kg, K 169 mg/kg against this crop's medium/medium/high demand — so the fertilizer plan below prioritises closing that deficit. Yams prefers sandy loam soils, while Kiambu is largely clay, so drainage and organic-matter management matter more here. At current prices (about KES 80/kg) and a typical 6,000 kg/acre yield, a well-managed Yams crop here can gross roughly KES 480,000 per acre.

70Suitability score

Soil match analysis

NutrientKiambu soilYams needsStatus
pH5.285.56.5Adjust
Nitrogen1.01 g/kgmin 0.8 g/kgOK
Phosphorus13.7 mg/kgmin 12 mg/kgOK
Potassium169 mg/kgmin 200 mg/kgLow

Recommended seed varieties

Local White (Nyandarua/Meru)Medium/Highland 1000-1800m
Local · 240-300 days · 2.5–3.5 tons/acre
Traditional tuber crop; highly valued for food security; propagated via tuber sets.
Local PurpleMedium/Highland 1000-1800m
Local · 270-330 days · 2–3 tons/acre
Vigorous climbing vine; highly nutritious tuber.

Economics

Market priceKES 80/kg
Expected yield6,000 kg/acre
Estimated revenueKES 480,000/acre

Preferred textureSandy Loam

Fertilizer prices

DAP
KES 2,500(6,500)
CAN
KES 2,500(4,500)
NPK 17:17:17
KES 2,500(5,600)
Urea
KES 2,500(5,500)
Lime
KES 1,500(1,800)

Green = subsidized · (Commercial) per 50kg bag