Growing Sweet Potato in Tana River

Soil suitability analysis based on Tana River's nutrient profile

Quick answer

Generally not ideal — Tana River is poorly suited to Sweet Potato. Tana River's soil (pH 6.4, slightly acidic) gives Sweet Potato a suitability score of 34/100. Match fertilizer to Tana River's nitrogen and phosphorus levels for the best result.

Tana River County is a challenging environment for Sweet Potato (soil-match score 34/100) and will need significant amendment before planting. Local soils average pH 6.4 — slightly acidic to near-neutral and inside the 4.5–7 band Sweet Potato prefers, so no lime is usually required. The main gap is phosphorus and potassium — measured at N 1.04 g/kg, P 8.5 mg/kg, K 108 mg/kg against this crop's low/medium/high demand — so the fertilizer plan below prioritises closing those deficits. The county's predominantly sandy soils suit Sweet Potato, which favours sandy loam. Tana River receives approximately 400 mm/year — well below Sweet Potato's minimum of 600 mm — so supplemental irrigation would be essential for this crop. On ShambaIQ's soil-match model, Sweet Potato is the #43 soil match of the 106 crops we assess for Tana River County. Sweet Potato's full potential is about 5,000 kg/acre (~KES 90,000/acre at KES 18/kg), but at Tana River's 34/100 suitability a realistic target here is closer to 2,125 kg/acre (~KES 38,250/acre) unless the constraints above are addressed.

Better matched to Tana River's soil: Sorghum, Cowpeas, and Pigeon Peas — each scores higher on the same soil.

34Suitability score

Soil & climate match

FactorTana River soilSweet Potato needsStatus
pH6.44.57OK
Nitrogen1.04 g/kgmin 0.5 g/kgOK
Phosphorus8.5 mg/kgmin 12 mg/kgLow
Potassium108 mg/kgmin 200 mg/kgLow
Rainfall400 mm600–1,800 mmLow
Altitude200 m0–2,200 mOK

Planting calendar for Tana River

Long Rains· MarchMay

March
Vine Cutting Planting & Basal Fertilizer
April
Weeding & Vine Management
May
Harvesting & Storage

Short Rains· OctoberDecemberMain season here

October
Vine Planting & Basal Fertilizer
November
Vine Trailing & Weeding
December
Harvesting

Dry Season· JanuaryMarch

January
Irrigation & Vine Planting
February
Weeding
March
Harvesting & Vine Multiplication

Top dressing guide

Product
None
Timing
None required
Instruction
Sweet potatoes rarely need top dressing. Excess N promotes vines over tubers.
Bags per acre in Tana River
0

Tana River's nitrogen reads 1.04 g/kg, but the rate stays at zero: Sweet Potato is not top-dressed, for the crop-specific reason above.

Seed varieties for Tana River

Varieties suited to Tana River's 200 m altitude and 400 mm annual rainfall — 1 of 5 sweet potato varieties we list.

KabodeMedium/Dryland
CIP/KALRO · 120-150 days · 3–4 tons/acre
Orange-fleshed; high Vitamin A; drought tolerant.

Economics

Market priceKES 18/kg
Expected yield in Tana River2,125 kg/acre
Estimated revenueKES 38,250/acre
Adjusted for Tana River's 34/100 suitability. Under ideal conditions Sweet Potato can reach 5,000 kg/acre (~KES 90,000/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