Growing Onion in Kiambu
Soil suitability analysis based on Kiambu's nutrient profile
Yes, with the right inputs — Kiambu is moderately suited to Onion. Kiambu's soil (pH 5.28, strongly acidic) gives Onion a suitability score of 62/100. Apply agricultural lime before planting to unlock phosphorus and lift the score.
Kiambu County is a solid choice for Onion, with a soil-match score of 62/100. At an average pH of 5.28 the soil is moderately acidic, below Onion's preferred 6–7 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. The main gap is nitrogen and phosphorus — measured at N 1.01 g/kg, P 13.7 mg/kg, K 169 mg/kg against this crop's high/high/medium demand — so the fertilizer plan below prioritises closing those deficits. Onion prefers sandy loam soils, while Kiambu is largely clay, so drainage and organic-matter management matter more here. On ShambaIQ's soil-match model, Onion is the #62 soil match of the 106 crops we assess for Kiambu County. Onion's full potential is about 6,000 kg/acre (~KES 420,000/acre at KES 70/kg), but at Kiambu's 62/100 suitability a realistic target here is closer to 4,650 kg/acre (~KES 325,500/acre) unless the constraints above are addressed.
Soil & climate match
| Factor | Kiambu soil | Onion needs | Status |
|---|---|---|---|
| pH | 5.28 | 6–7 | Adjust |
| Nitrogen | 1.01 g/kg | min 1.2 g/kg | Low |
| Phosphorus | 13.7 mg/kg | min 20 mg/kg | Low |
| Potassium | 169 mg/kg | min 150 mg/kg | OK |
| Rainfall | 1,100 mm | 500–1,000 mm | High |
| Altitude | 1,700 m | 0–2,000 m | OK |
Planting calendar for Kiambu
Long Rains· March–MayMain season here
Short Rains· October–December
Dry Season· January–March
Top dressing guide
Kiambu's nitrogen (1.01 g/kg) is 84% of the 1.2 g/kg Onion needs, so the standard 0.5 bags/acre is raised to 0.75. Split it across two applications to limit leaching.
Seed varieties for Kiambu
Varieties suited to Kiambu's 1,700 m altitude and 1,100 mm annual rainfall — 2 of 2 onion varieties we list.
Economics
Fertilizer prices
Green = subsidized · (Commercial) per 50kg bag