Understanding Soil pH: What the Number Really Means

Soil pH is one of the first numbers The Soil App shows you, and for good reason: it sets the stage for almost everything else in the soil. It is a measure of how acidic or alkaline your soil is, on a scale from 0 to 14, where 7 is neutral. Most crops are happiest somewhere between 6.0 and 7.0.

Why pH matters more than it looks

pH does not feed your crop directly. What it does is decide how available the nutrients already in your soil are. A field can be rich in phosphorus and still starve a crop if the pH is wrong, because at the extremes those nutrients lock up into forms roots cannot take in. You end up buying inputs to fix a problem that better pH management would have solved for less.

Why it drifts

Soil rarely holds a fixed pH. Rainfall leaches away the elements that buffer acidity, nitrogen fertilisers tend to push soil more acidic over time, and the parent material under your fields has its own baseline. Left alone, many productive soils slowly acidify season after season — slowly enough that you only notice when yields start slipping.

Reading it before you spend

The point of a reading is to act on it before the cost shows up in the harvest. Capture pH alongside your other readings, watch the trend across seasons rather than reacting to a single sample, and let the recommendation account for the crop you are planning. A reading on its own is data; a reading in context is a decision.

That is the whole idea behind keeping readings, recommendations, and records in one place: the next sample starts from everything you already know.