Get a fertilizer plan from your own soil test results

If you have a soil test report from a lab, you can enter your actual pH, nitrogen, phosphorus, and potassium values into ShambaIQ and get a fertilizer plan based on your real soil chemistry — not satellite estimates.

The feature is called Lab Soil Override and it's under Advanced Settings in the free ShambaIQ tool.

Enter my soil test results →

How to use your soil test results — 4 steps

1

Open ShambaIQ and choose your location and crop

Go to shambaiq.com/app. Select your county and ward (or tap 'Check my farm' to use GPS). Then choose the crop you want to grow.

2

Expand Advanced Settings and enable lab override

Scroll to Advanced Settings and open it. You will see 'Advanced: Lab Soil Override'. Tick the checkbox labelled 'I have lab results'. The four soil input fields will appear.

3

Type in your soil test values

Enter the four numbers from your report: pH, Nitrogen (g/kg), Phosphorus (mg/kg), and Potassium (mg/kg). ShambaIQ replaces the satellite estimate with your actual measured values.

4

Get your fertilizer plan

Tap 'Get plan'. You receive a fertilizer recommendation built on your real soil chemistry: which product, how many bags per acre, when to apply, and the estimated cost in KES.

Satellite data vs your lab results

Satellite soil data (default)

  • 30m resolution — precise for regional planning
  • Reflects natural soil without amendment history
  • No soil sampling required — instant
  • Best for first-time and general use

Your lab results (override)

  • Measured on a physical sample from your plot
  • Reflects years of fertilizer and lime applications
  • Most accurate if you have a recent lab report
  • Recommended for serious commercial farms

What values does ShambaIQ accept?

pH
dimensionless (e.g. 5.8, 6.2)
No conversion needed. Enter the number directly from your report.
Nitrogen (N)
g/kg
If your report shows %, multiply by 10. Example: 0.15% → enter 1.5
Phosphorus (P)
mg/kg
Olsen or Mehlich-3 method. Most Kenyan labs use Olsen for P.
Potassium (K)
mg/kg
If shown as cmol/kg, ask your lab for the mg/kg equivalent.

Where to get a soil test in Kenya

A proper lab test costs between KES 1,000 and KES 3,500 per sample and takes 3–10 working days. Collect soil from several spots across your farm (zigzag pattern, 0–20 cm depth), mix together, and send a combined 500 g sample.

KEPHIS — Kenya Plant Health Inspectorate Service

Government lab. Offices in Nairobi and regional centres. Most affordable option.

University of Nairobi — Soil Science Lab

Faculty of Agriculture. Accepts external samples. Results include recommended amendments.

Egerton University Soil Lab

Located in Njoro, Nakuru County. Widely used by Rift Valley farmers.

County Agriculture Departments

Trans-Nzoia, Uasin Gishu, Nakuru, and Meru counties run subsidised soil testing. Visit your nearest Sub-County Agriculture Office.

Frequently asked questions

What four values do I need from my soil test report?

pH (no units), Total Nitrogen in g/kg, Extractable Phosphorus in mg/kg, and Extractable Potassium in mg/kg. These are the standard values on reports from KEPHIS, university labs, and most private Kenyan soil labs.

Where can I get a soil test done in Kenya?

KEPHIS is the main government option. University of Nairobi, Egerton University, and JKUAT also run soil labs. Several counties (Trans-Nzoia, Uasin Gishu, Nakuru) offer subsidised testing through their agriculture departments. Costs range from KES 1,000 to KES 3,500 per sample.

Why are lab results better than satellite data?

Satellite data gives accurate averages across a county or ward, but your specific plot may differ — especially if it has received heavy fertilizer applications or amendments over the years. Lab results from a physical sample taken on your farm are the most accurate data you can use.

My report shows nitrogen as a percentage. What do I enter?

Multiply the percentage by 10 to get g/kg. For example, 0.15% nitrogen = 1.5 g/kg.

Does entering lab values affect the location or agrovet data?

No. Your location (county/ward or GPS) is still used to find nearby agrovets and local fertilizer prices. Only the soil nutrient values change — everything else stays the same.