Mehlich 3 · desired ranges from the Helena cheat sheet
Soil Test Cheat Sheet
The desired range for every line on a soil report, and — if you type your numbers in — how far each one sits from it.
What “desired” means here. These are the levels where you can start applying crop removal . Above them you can begin cutting back below removal. They are not a level where you can apply nothing.
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Notes on the numbers
Every desired range on this page comes from the cheat sheet. Nothing here is a substitute recommendation — the bars and the distances are arithmetic laid over the sheet’s own numbers.
The summary lists; it does not prioritise. Anything outside its desired range is collected in the order the sheet lists it, with the distance to the nearest edge. There is no severity score and no ordering by urgency, because the page has no sound basis for one — it cannot see that pH gates what sits below it, what a gap costs to close, or which misses a crop will actually answer. Deciding what to do first is yours.
Each bar is a plain linear scale. The end numbers are only a display window chosen to keep the desired band readable; they are not thresholds. A value past the right end pins the needle at the edge and the marker turns into an arrow.
The phosphorus build figure uses the sheet’s own 16-units-per-ppm factor and applies to the Mehlich 3 range only. It sizes the gap; it is not a rate. Bray 1 and Olsen ranges are the sheet’s converted equivalents for the same soil.
CEC is shown with its range but left out of the count. It is a soil property, not something a program changes, so counting it as a problem to fix would be misleading. The same caution applies more loosely to organic matter, which moves over years.
Nitrogen is a PSNT value — sampled around V6 in corn, not a fall or spring soil test. Entering a fall nitrate number here will not mean anything.