Growing Onion in Kirinyaga
Soil suitability analysis based on Kirinyaga's nutrient profile
Yes, with the right inputs — Kirinyaga is moderately suited to Onion. Kirinyaga's soil (pH 5.31, strongly acidic) gives Onion a suitability score of 57/100. Apply agricultural lime before planting to unlock phosphorus and lift the score.
Onion can be grown in Kirinyaga County, but the soil scores 57/100 and needs targeted management to reach full potential. At an average pH of 5.31 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 phosphorus — measured at N 1.36 g/kg, P 12.5 mg/kg, K 177 mg/kg against this crop's high/high/medium demand — so the fertilizer plan below prioritises closing that deficit. Onion prefers sandy loam soils, while Kirinyaga is largely clay, so drainage and organic-matter management matter more here. On ShambaIQ's soil-match model, Onion is the #74 soil match of the 106 crops we assess for Kirinyaga County. Onion's full potential is about 6,000 kg/acre (~KES 420,000/acre at KES 70/kg), but at Kirinyaga's 57/100 suitability a realistic target here is closer to 4,275 kg/acre (~KES 299,250/acre) unless the constraints above are addressed.
Better matched to Kirinyaga's soil: Tea, Macadamia, and Pineapple — each scores higher on the same soil.
Soil & climate match
| Factor | Kirinyaga soil | Onion needs | Status |
|---|---|---|---|
| pH | 5.31 | 6–7 | Adjust |
| Nitrogen | 1.36 g/kg | min 1.2 g/kg | OK |
| Phosphorus | 12.5 mg/kg | min 20 mg/kg | Low |
| Potassium | 177 mg/kg | min 150 mg/kg | OK |
| Rainfall | 1,300 mm | 500–1,000 mm | High |
| Altitude | 1,500 m | 0–2,000 m | OK |
Planting calendar for Kirinyaga
Long Rains· March–MayMain season here
Short Rains· October–December
Dry Season· January–March
Top dressing guide
Kirinyaga's nitrogen (1.36 g/kg) already meets Onion's 1.2 g/kg requirement, so this is a maintenance rate.
Seed varieties for Kirinyaga
Varieties suited to Kirinyaga's 1,500 m altitude and 1,300 mm annual rainfall — 2 of 2 onion varieties we list.
Economics
Fertilizer prices
Green = subsidized · (Commercial) per 50kg bag