Growing Broccoli in Kirinyaga

Soil suitability analysis based on Kirinyaga's nutrient profile

Quick answer

Possible but challenging — Kirinyaga is only marginally suited to Broccoli. Kirinyaga's soil (pH 5.31, strongly acidic) gives Broccoli a suitability score of 43/100. Apply agricultural lime before planting to unlock phosphorus and lift the score.

Kirinyaga County is a challenging environment for Broccoli (soil-match score 43/100) and will need significant amendment before planting. At an average pH of 5.31 the soil is moderately acidic, below Broccoli's preferred 6–7.5 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. The main gap is phosphorus and potassium — measured at N 1.36 g/kg, P 12.5 mg/kg, K 177 mg/kg against this crop's high/high/high demand — so the fertilizer plan below prioritises closing those deficits. Broccoli prefers loam soils, while Kirinyaga is largely clay, so drainage and organic-matter management matter more here. On ShambaIQ's soil-match model, Broccoli is the #92 soil match of the 106 crops we assess for Kirinyaga County. Broccoli's full potential is about 6,000 kg/acre (~KES 540,000/acre at KES 90/kg), but at Kirinyaga's 43/100 suitability a realistic target here is closer to 3,225 kg/acre (~KES 290,250/acre) unless the constraints above are addressed.

Better matched to Kirinyaga's soil: Tea, Macadamia, and Pineapple — each scores higher on the same soil.

43Suitability score

Soil & climate match

FactorKirinyaga soilBroccoli needsStatus
pH5.3167.5Adjust
Nitrogen1.36 g/kgmin 1.2 g/kgOK
Phosphorus12.5 mg/kgmin 20 mg/kgLow
Potassium177 mg/kgmin 200 mg/kgLow
Rainfall1,300 mm800–1,500 mmOK
Altitude1,500 m1,800–2,800 mLow

Planting calendar

Long Rains

Month 1
Nursery Preparation & Transplanting & DAP Basal
Month 2
CAN Top Dressing (week 3) & Caterpillar Control
Month 3
Head Initiation Top Dress & Harvesting

Short Rains

Month 1
Nursery & Transplanting
Month 2
Top Dressing & DBM Scouting
Month 3
Harvesting

Dry Season

Month 1
Irrigation-based Transplanting
Month 2
CAN Top Dressing & Pest Management
Month 3
Harvesting & Land Preparation

Top dressing guide

Product
CAN
Timing
Week 3 then head initiation (week 6)
Instruction
Apply 3 weeks after transplanting and again at head initiation (~week 6); broccoli needs steady N for tight heads
Bags per Acre
1.5

Recommended seed varieties

CalabreseHighland
Simlaw Seeds · 70-90 days · 2–3.5 tons/acre
Open-pollinated broccoli; central head plus side shoots; suited to cool highlands.
Green Magic F1Highland
East Africa Seeds · 60-75 days · 3–4.5 tons/acre
Hybrid; uniform dome heads; heat tolerant; export and supermarket quality.
Marathon F1Highland
Royal Seeds · 75-95 days · 2.8–4.3 tons/acre
Large dense heads; downy mildew tolerant; excellent for high-altitude production.

Economics

Market priceKES 90/kg
Expected yield in Kirinyaga3,225 kg/acre
Estimated revenueKES 290,250/acre
Adjusted for Kirinyaga's 43/100 suitability. Under ideal conditions Broccoli can reach 6,000 kg/acre (~KES 540,000/acre) — attainable here only after the climate and soil constraints below are addressed.

Preferred textureLoam

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