Growing Onion in Garissa
Soil suitability analysis based on Garissa's nutrient profile
Generally not ideal — Garissa is poorly suited to Onion. Garissa's soil (pH 7.96, alkaline) gives Onion a suitability score of 14/100. Match fertilizer to Garissa's nitrogen and phosphorus levels for the best result.
Garissa County is a challenging environment for Onion (soil-match score 14/100) and will need significant amendment before planting. At an average pH of 7.96 the soil sits above Onion's preferred 6–7 range, which can limit uptake of phosphorus and micronutrients. The main gap is nitrogen — measured at N 0.61 g/kg, P 37.7 mg/kg, K 407 mg/kg against this crop's high/high/medium demand — so the fertilizer plan below prioritises closing that deficit. The county's predominantly sandy soils suit Onion, which favours sandy loam. Garissa receives approximately 250 mm/year — well below Onion's minimum of 500 mm — so supplemental irrigation would be essential for this crop. On ShambaIQ's soil-match model, Onion is the #28 soil match of the 106 crops we assess for Garissa County. Onion's full potential is about 6,000 kg/acre (~KES 420,000/acre at KES 70/kg), but at Garissa's 14/100 suitability a realistic target here is closer to 1,050 kg/acre (~KES 73,500/acre) unless the constraints above are addressed.
Better matched to Garissa's soil: Sisal, Aloe Vera, and Green Grams — each scores higher on the same soil.
Soil & climate match
| Factor | Garissa soil | Onion needs | Status |
|---|---|---|---|
| pH | 7.96 | 6–7 | Adjust |
| Nitrogen | 0.61 g/kg | min 1.2 g/kg | Low |
| Phosphorus | 37.7 mg/kg | min 20 mg/kg | OK |
| Potassium | 407 mg/kg | min 150 mg/kg | OK |
| Rainfall | 250 mm | 500–1,000 mm | Low |
| Altitude | 200 m | 0–2,000 m | OK |
Planting calendar for Garissa
Long Rains· March–May
Short Rains· October–DecemberMain season here
Dry Season· January–March
Top dressing guide
Garissa's nitrogen (0.61 g/kg) is 51% 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.
Recommended seed varieties
No variety in our list is specifically rated for Garissa's 200 m altitude and 250 mm rainfall, so all 2 are shown. Confirm with your agrovet before buying.
Economics
Fertilizer prices
Green = subsidized · (Commercial) per 50kg bag