Growing Onion in Marsabit

Soil suitability analysis based on Marsabit's nutrient profile

Quick answer

Generally not ideal — Marsabit is poorly suited to Onion. Marsabit's soil (pH 8.22, alkaline) gives Onion a suitability score of 18/100. Match fertilizer to Marsabit's nitrogen and phosphorus levels for the best result.

Marsabit County is a challenging environment for Onion (soil-match score 18/100) and will need significant amendment before planting. At an average pH of 8.22 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 0.52 g/kg, P 37.3 mg/kg, K 420 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. Marsabit receives approximately 300 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 #38 soil match of the 106 crops we assess for Marsabit County. Onion's full potential is about 6,000 kg/acre (~KES 420,000/acre at KES 70/kg), but at Marsabit's 18/100 suitability a realistic target here is closer to 1,350 kg/acre (~KES 94,500/acre) unless the constraints above are addressed.

Better matched to Marsabit's soil: Sisal, Chia, and Aloe Vera — each scores higher on the same soil.

18Suitability score

Soil & climate match

FactorMarsabit soilOnion needsStatus
pH8.2267Adjust
Nitrogen0.52 g/kgmin 1.2 g/kgLow
Phosphorus37.3 mg/kgmin 20 mg/kgOK
Potassium420 mg/kgmin 150 mg/kgOK
Rainfall300 mm500–1,000 mmLow
Altitude1,100 m0–2,000 mOK

Planting calendar for Marsabit

Long Rains· MarchMay

March
Nursery Preparation & Transplanting
April
Top Dressing (CAN) & Weed Control
May
Bulbing Stage & NPK 17:17:17 Application

Short Rains· OctoberDecemberMain season here

October
Nursery & Transplanting & Basal Fertilizer
November
Top Dressing & Bulb Formation
December
Harvesting & Curing

Dry Season· JanuaryMarch

January
Harvesting & Curing & Storage
February
Land Preparation
March
Nursery for next season

Top dressing guide

Product
CAN then NPK 17:17:17
Timing
Week 3–4 and at bulbing
Instruction
Apply at week 3–4 before bulbing then switch to NPK 17:17:17 at bulbing stage for bulb size and quality.
Bags per acre in Marsabit
0.750.5

Marsabit's nitrogen (0.52 g/kg) is 43% 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 Marsabit's 1,100 m altitude and 300 mm rainfall, so all 2 are shown. Confirm with your agrovet before buying.

Red CreoleMedium/Highland
Simlaw Seeds · 90-120 days · 6–8 tons/acre
Popular red onion; good storage quality.
Bombay RedMedium
East Africa Seeds · 100-130 days · 5–7 tons/acre
Large bulb size; pungent flavor; high market value.

Economics

Market priceKES 70/kg
Expected yield in Marsabit1,350 kg/acre
Estimated revenueKES 94,500/acre
Adjusted for Marsabit's 18/100 suitability. Under ideal conditions Onion can reach 6,000 kg/acre (~KES 420,000/acre) — attainable here only after the climate and soil constraints below are addressed.

Preferred textureSandy Loam

Fertilizer prices

DAP
KES 3,500(6,500)
CAN
KES 2,875(5,700)
NPK 17:17:17
KES 3,275(5,600)
Urea
KES 3,500(5,500)
Lime
KES 1,500(1,800)

Green = subsidized · (Commercial) per 50kg bag