Growing Oilseed Rape (Canola) in Tharaka Nithi

Soil suitability analysis based on Tharaka Nithi's nutrient profile

Quick answer

Generally not ideal — Tharaka Nithi is poorly suited to Oilseed Rape (Canola). Tharaka Nithi's soil (pH 4.99, strongly acidic) gives Oilseed Rape (Canola) a suitability score of 34/100. Apply agricultural lime before planting to unlock phosphorus and lift the score.

Tharaka Nithi County is a challenging environment for Oilseed Rape (Canola) (soil-match score 34/100) and will need significant amendment before planting. At an average pH of 4.99 the soil is strongly acidic, below Oilseed Rape (Canola)'s preferred 5.8–7.5 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 Oilseed Rape (Canola), which favours loam. On ShambaIQ's soil-match model, Oilseed Rape (Canola) is the #94 soil match of the 106 crops we assess for Tharaka Nithi County. Oilseed Rape (Canola)'s full potential is about 1,000 kg/acre (~KES 60,000/acre at KES 60/kg), but at Tharaka Nithi's 34/100 suitability a realistic target here is closer to 425 kg/acre (~KES 25,500/acre) unless the constraints above are addressed.

Better matched to Tharaka Nithi's soil: Avocado, Macadamia, and Cassava — each scores higher on the same soil.

34Suitability score

Soil & climate match

FactorTharaka Nithi soilOilseed Rape (Canola) needsStatus
pH4.995.87.5Adjust
Nitrogen1.23 g/kgmin 1.2 g/kgOK
Phosphorus19.6 mg/kgmin 20 mg/kgLow
Potassium211 mg/kgmin 150 mg/kgOK
Rainfall900 mm400–900 mmOK
Altitude1,100 m1,500–2,800 mLow

Planting calendar for Tharaka Nithi

Long Rains· MarchMayMain season here

March
Land Prep & Sowing & Basal
April
Top Dressing & Weeding
May
Flowering & Pod Fill & Harvest

Short Rains· OctoberDecember

October
Land Prep & Sowing & Basal
November
Top Dressing & Weeding
December
Flowering & Pod Fill & Harvest

Top dressing guide

Product
CAN
Timing
Week 4 and at stem elongation
Instruction
Sulfur-demanding — prefer Ammonium Sulphate. Add boron at flowering for pod set.
Bags per acre in Tharaka Nithi
0.5

Tharaka Nithi's nitrogen (1.23 g/kg) already meets Oilseed Rape (Canola)'s 1.2 g/kg requirement, so this is a maintenance rate.

Economics

Market priceKES 60/kg
Expected yield in Tharaka Nithi425 kg/acre
Estimated revenueKES 25,500/acre
Adjusted for Tharaka Nithi's 34/100 suitability. Under ideal conditions Oilseed Rape (Canola) can reach 1,000 kg/acre (~KES 60,000/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