You can test soil pH at home in a few minutes. Here are four methods, how accurate each is and what to do with the result. pH tells you whether your crop can actually take up the nutrients in the soil, so it is worth knowing before you spend on fertiliser.
In short
- pH 6.0 to 7.0 suits most crops; rice tolerates more acidic soil.
- Strips and sensors give a number; the vinegar test only hints acid or alkaline.
- Test several spots and average them. One spot can mislead you.
- Soil should be moist, not bone dry or flooded.
Four ways to test
| Method | What you get | Accuracy | Best for |
|---|---|---|---|
| DIY vinegar and baking soda | Rough "acid or alkaline" hint | Low | A curious first look |
| Test strips or colour kit | A pH value by colour match | Medium | Gardens and small plots |
| Digital pH meter | A reading in seconds | Medium to high if calibrated | Frequent checks |
| Soil sensor (like SmartSoil 8-in-1) | pH plus nitrogen, phosphorus, potassium, moisture and more | Good field estimate | Farm decisions and tracking |
Steps for a strip or colour kit
- Take soil from 5 to 10 spots, 10 to 15 cm deep, avoiding field edges.
- Mix the samples in a clean container and remove stones and roots.
- Follow the kit: usually mix soil with distilled water, let it settle, then dip the strip or add the indicator.
- Compare the colour to the chart and write down the date and field.
The vinegar and baking soda check
Put two spoons of dry soil in two cups. Add vinegar to one: fizzing suggests alkaline soil. Add water and baking soda to the other: fizzing suggests acidic soil. No fizz in either points to near-neutral. It is a rough hint only.
What your number means
| pH | Meaning |
|---|---|
| Below 5.5 | Strongly acidic: some nutrients are hard to take up |
| 5.5 to 6.0 | Slightly acidic |
| 6.0 to 7.0 | Best range for most crops |
| Above 7.5 | Alkaline: iron, zinc and phosphorus may be less available |
Ask your local adviser before adding lime or sulfur.
How Famo AI helps
With a soil sensor and the Famo AI app, pH, nutrients and moisture show up together, each against a target range, and every test is saved so you see the trend. Read our full soil pH and NPK guide.
Get Famo AI on Google Play or try the live demo, no sign-up needed.
Frequently asked questions
What is a good soil pH for vegetables?
Most vegetables grow best between 6.0 and 7.0. Some, like potatoes, tolerate more acidic soil.
How do I raise or lower soil pH?
Lime raises pH and sulfur lowers it, but the amount depends on your soil. Get a local recommendation and retest afterwards.
How often should I test soil pH?
Before planting, again mid-season and after any big change in fertiliser or lime.
