Growing Onion in Tharaka Nithi
Soil suitability analysis based on Tharaka Nithi's nutrient profile
Yes, with the right inputs — Tharaka Nithi is moderately suited to Onion. Tharaka Nithi's soil (pH 4.99, strongly acidic) gives Onion a suitability score of 65/100. Apply agricultural lime before planting to unlock phosphorus and lift the score.
Tharaka Nithi County is a solid choice for Onion, with a soil-match score of 65/100. At an average pH of 4.99 the soil is strongly 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 1.23 g/kg, P 19.6 mg/kg, K 211 mg/kg against this crop's high/high/medium demand — so the fertilizer plan below prioritises closing that deficit. The county's predominantly sandy loam soils suit Onion, which favours sandy loam. Onion's full potential is about 6,000 kg/acre (~KES 420,000/acre at KES 70/kg), but at Tharaka Nithi's 65/100 suitability a realistic target here is closer to 4,875 kg/acre (~KES 341,250/acre) unless the constraints above are addressed.
Soil & climate match
| Factor | Tharaka Nithi soil | Onion needs | Status |
|---|---|---|---|
| pH | 4.99 | 6–7 | Adjust |
| Nitrogen | 1.23 g/kg | min 1.2 g/kg | OK |
| Phosphorus | 19.6 mg/kg | min 20 mg/kg | Low |
| Potassium | 211 mg/kg | min 150 mg/kg | OK |
| Rainfall | 900 mm | 500–1,000 mm | OK |
| Altitude | 1,100 m | 0–2,000 m | OK |
Planting calendar
Long Rains
Short Rains
Dry Season
Top dressing guide
Recommended seed varieties
Economics
Fertilizer prices
Green = subsidized · (Commercial) per 50kg bag