Growing Onion in Makueni

Soil suitability analysis based on Makueni's nutrient profile

Quick answer

Yes, with the right inputs — Makueni is moderately suited to Onion. Makueni's soil (pH 7.5, alkaline) gives Onion a suitability score of 71/100. Match fertilizer to Makueni's nitrogen and phosphorus levels for the best result.

Makueni County is a solid choice for Onion, with a soil-match score of 71/100. At an average pH of 7.5 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 0.86 g/kg, P 29.6 mg/kg, K 351 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 Makueni's 71/100 suitability a realistic target here is closer to 5,325 kg/acre (~KES 372,750/acre) unless the constraints above are addressed.

71Suitability score

Soil & climate match

FactorMakueni soilOnion needsStatus
pH7.567Adjust
Nitrogen0.86 g/kgmin 1.2 g/kgLow
Phosphorus29.6 mg/kgmin 20 mg/kgOK
Potassium351 mg/kgmin 150 mg/kgOK
Rainfall600 mm500–1,000 mmOK
Altitude1,000 m0–2,000 mOK

Planting calendar

Long Rains

Month 1
Nursery Preparation & Transplanting
Month 2
Top Dressing (CAN) & Weed Control
Month 3
Bulbing Stage & NPK 17:17:17 Application

Short Rains

Month 1
Nursery & Transplanting & Basal Fertilizer
Month 2
Top Dressing & Bulb Formation
Month 3
Harvesting & Curing

Dry Season

Month 1
Harvesting & Curing & Storage
Month 2
Land Preparation
Month 3
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
0.5

Recommended seed varieties

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 Makueni5,325 kg/acre
Estimated revenueKES 372,750/acre
Adjusted for Makueni's 71/100 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(4,500)
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