Growing Potato in Kirinyaga

Soil suitability analysis based on Kirinyaga's nutrient profile

Quick answer

Yes — Kirinyaga is well suited to Potato. Kirinyaga's soil (pH 5.31, strongly acidic) gives Potato a suitability score of 83/100. Apply agricultural lime before planting to unlock phosphorus and lift the score.

Kirinyaga County is well suited to Potato, scoring 83/100 on ShambaIQ's soil-match model. Local soils average pH 5.31 — moderately acidic and inside the 4.8–6.5 band Potato prefers, so no lime is usually required. 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. Potato prefers sandy loam soils, while Kirinyaga is largely clay, so drainage and organic-matter management matter more here. On ShambaIQ's soil-match model, Potato is the #16 soil match of the 106 crops we assess for Kirinyaga County. At current prices (about KES 38/kg) and a typical 8,000 kg/acre yield, a well-managed Potato crop here can gross roughly KES 304,000 per acre.

83Suitability score

Soil & climate match

FactorKirinyaga soilPotato needsStatus
pH5.314.86.5OK
Nitrogen1.36 g/kgmin 1.2 g/kgOK
Phosphorus12.5 mg/kgmin 20 mg/kgLow
Potassium177 mg/kgmin 200 mg/kgLow
Rainfall1,300 mm700–1,500 mmOK
Altitude1,500 m1,500–3,000 mOK

Planting calendar for Kirinyaga

Long Rains· MarchMayMain season here

March
Planting Tubers & Basal Fertilizer (NPK)
April
Earthing Up & Top Dressing (CAN)
May
Pest Control (Blight) & Weeding

Short Rains· OctoberDecember

October
Planting & Basal Fertilizer
November
Earthing Up & Top Dressing
December
Blight Control

Dry Season· JanuaryMarch

January
Harvesting & Storage
February
Land Resting
March
Seed Tuber Sprouting

Top dressing guide

Product
CAN
Timing
Week 3–4 after emergence
Instruction
Apply when plants are 15–20cm tall, before earthing up
Bags per acre in Kirinyaga
1

Kirinyaga's nitrogen (1.36 g/kg) already meets Potato's 1.2 g/kg requirement, so this is a maintenance rate.

Seed varieties for Kirinyaga

Varieties suited to Kirinyaga's 1,500 m altitude and 1,300 mm annual rainfall — 6 of 14 potato varieties we list.

ShangiMedium/Highland
KALRO · 80-90 days · 300-350 bags/acre
Very fast cooking; high tuber density per plant.
UnicaDryland/Medium
KALRO · 90-100 days · 350-400 bags/acre
Heat tolerant; highly resistant to late blight.
AsanteMedium/Highland
KALRO · 85-95 days · 320-400 bags/acre
High yielding; good cooking quality; suited to medium altitude 1500-2000m.
Kenya FurahaMedium/Highland
KALRO · 90-100 days · 340-420 bags/acre
Good taste; disease tolerant; KEPHIS certified; consistent yield.
Kenya MpyaMedium/Highland
KALRO · 85-95 days · 300-380 bags/acre
New release; adapted to Central Kenya highlands; good storability.
SherekeaMedium/Highland
KARI/CIP · 90-105 days · 320-380 bags/acre
High yielding; good cooking quality; medium dormancy; suited to highlands 1400-3000m; released 2010.

Economics

Market priceKES 38/kg
Expected yield 8,000 kg/acre
Estimated revenueKES 304,000/acre

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