Growing Arrow Root in Tharaka Nithi

Soil suitability analysis based on Tharaka Nithi's nutrient profile

Quick answer

Yes, with the right inputs — Tharaka Nithi is moderately suited to Arrow Root. Tharaka Nithi's soil (pH 4.99, strongly acidic) gives Arrow Root a suitability score of 63/100. Apply agricultural lime before planting to unlock phosphorus and lift the score.

Tharaka Nithi County is a solid choice for Arrow Root, with a soil-match score of 63/100. At an average pH of 4.99 the soil is strongly acidic, below Arrow Root's preferred 5–7 range; agricultural lime will lift pH and unlock phosphorus the crop cannot otherwise access. Nitrogen (1.23 g/kg), phosphorus (19.6 mg/kg) and potassium (211 mg/kg) all meet Arrow Root's requirements, so a maintenance fertilizer programme is enough. Arrow Root prefers clay loam soils, while Tharaka Nithi is largely sandy loam, so drainage and organic-matter management matter more here. Arrow Root's full potential is about 5,000 kg/acre (~KES 275,000/acre at KES 55/kg), but at Tharaka Nithi's 63/100 suitability a realistic target here is closer to 3,938 kg/acre (~KES 216,590/acre) unless the constraints above are addressed.

63Suitability score

Soil & climate match

FactorTharaka Nithi soilArrow Root needsStatus
pH4.9957Adjust
Nitrogen1.23 g/kgmin 0.8 g/kgOK
Phosphorus19.6 mg/kgmin 12 mg/kgOK
Potassium211 mg/kgmin 200 mg/kgOK
Rainfall900 mm1,000–2,000 mmLow
Altitude1,100 m0–1,800 mOK

Top dressing guide

Product
CAN
Timing
3 months after planting
Instruction
Apply in a ring around the plant. Arrow Root is a long-season crop and benefits from one mid-season application.
Bags per Acre
0.5

Recommended seed varieties

Nduma LocalMedium/Highland
KALRO · 270-365 days · 2.5–4 tons/acre
Traditional variety; good corm size; suited to wet highland areas.

Economics

Market priceKES 55/kg
Expected yield in Tharaka Nithi3,938 kg/acre
Estimated revenueKES 216,590/acre
Adjusted for Tharaka Nithi's 63/100 suitability. Under ideal conditions Arrow Root can reach 5,000 kg/acre (~KES 275,000/acre) — attainable here only after the climate and soil constraints below are addressed.

Preferred textureClay 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