Growing Potato in Machakos

Soil suitability analysis based on Machakos's nutrient profile

Quick answer

Generally not ideal — Machakos is poorly suited to Potato. Machakos's soil (pH 7.03, near-neutral) gives Potato a suitability score of 34/100. Match fertilizer to Machakos's nitrogen and phosphorus levels for the best result.

Machakos County is a challenging environment for Potato (soil-match score 34/100) and will need significant amendment before planting. At an average pH of 7.03 the soil sits above Potato's preferred 4.8–6.5 range, which can limit uptake of phosphorus and micronutrients. The main gap is nitrogen — measured at N 0.82 g/kg, P 31.4 mg/kg, K 338 mg/kg against this crop's high/high/high demand — so the fertilizer plan below prioritises closing that deficit. The county's predominantly sandy loam soils suit Potato, which favours sandy loam. Potato's full potential is about 8,000 kg/acre (~KES 304,000/acre at KES 38/kg), but at Machakos's 34/100 suitability a realistic target here is closer to 3,400 kg/acre (~KES 129,200/acre) unless the constraints above are addressed.

34Suitability score

Soil & climate match

FactorMachakos soilPotato needsStatus
pH7.034.86.5Adjust
Nitrogen0.82 g/kgmin 1.2 g/kgLow
Phosphorus31.4 mg/kgmin 20 mg/kgOK
Potassium338 mg/kgmin 200 mg/kgOK
Rainfall700 mm700–1,500 mmOK
Altitude1,100 m1,500–3,000 mLow

Planting calendar

Long Rains

Month 1
Planting Tubers & Basal Fertilizer (NPK)
Month 2
Earthing Up & Top Dressing (CAN)
Month 3
Pest Control (Blight) & Weeding

Short Rains

Month 1
Planting & Basal Fertilizer
Month 2
Earthing Up & Top Dressing
Month 3
Blight Control

Dry Season

Month 1
Harvesting & Storage
Month 2
Land Resting
Month 3
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
1

Recommended seed varieties

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.
TigoniHighland
KALRO · 90-100 days · 350-450 bags/acre
Late blight resistant; well adapted to cool highland conditions above 2000m.
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.
Clone IG-70Highland
CIP/KALRO · 95-110 days · 380-460 bags/acre
Virus resistant; developed by CIP for highland Kenya; high dry matter content.
Dutch RobijnHighland
KARI-Tigoni · 90-100 days · 310-400 bags/acre
Classic highland variety released 1960s; high tuber uniformity; excellent crisping quality; tolerant to late blight; short dormancy.
Kenya BarakaHighland
KARI-Tigoni · 95-105 days · 280-320 bags/acre
Oblong/round tubers; resistant to late blight and viruses; good storability; table and chips use; released 1973.
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.
LenanaHighland
CIP/KALRO · 90-105 days · 320-400 bags/acre
Late blight tolerant; PVX and PLRV tolerant; dry matter 22%; good for French fries; upper highlands; released 2017.
WanjikuHighland
CIP/KALRO · 100-120 days · 400-480 bags/acre
Extremely tolerant to PVY; late blight tolerant; dry matter 21%; French fries and crisps; 1800-3000m; released 2017.
NyotaHighland
CIP/KALRO · 90-105 days · 280-360 bags/acre
Late blight tolerant; heat tolerant; dry matter 20%; table variety; upper highlands; released 2017.
ChuluHighland
CIP/KALRO · 100-120 days · 280-360 bags/acre
Late blight and PVX tolerant; heat tolerant; dry matter 24%; table and processing; widely adapted; released 2017.

Economics

Market priceKES 38/kg
Expected yield in Machakos3,400 kg/acre
Estimated revenueKES 129,200/acre
Adjusted for Machakos's 34/100 suitability. Under ideal conditions Potato can reach 8,000 kg/acre (~KES 304,000/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(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