Potash

Potash turns a soil analysis into a spreader setting, using the products you actually have in the shed. Entirely on your phone. No account, no signal, no subscription.

WHAT IT ANSWERS
1. What does this field need - build, maintain, or run down?
2. Which bags, and how much of each?
3. And what does that blend get wrong?

THREE TARGETS, ONE PROBLEM
A nutrient calculator does N, P and K as three separate sums. A real shed cannot. Every product carries more than one nutrient, so the product you buy for its phosphate imports its nitrogen whether you wanted it or not.
- DAP is 18-46-0. Ask it for 46 kg of phosphate and 18 kg of nitrogen arrives with it. On a field whose nitrogen is already met, that is an overshoot you never chose - and most calculators will never tell you about it.
- Potash solves the blend from the most constrained nutrient outward, then reports what it could not do: which nutrient is over, by how much, and WHICH PRODUCT forced it.
- Take that product out and the answer changes in front of you. Put a straight in instead and the forcing stops, because a straight carries nothing else.

AN INDEX IS A POLICY, NOT A NUMBER
The same offtake gives three different recommendations depending on where the field sits:
- Below the target index, the field is on BUILD - apply more than the crop removes.
- At it, MAINTAIN - replace exactly what left.
- Above it, RUN DOWN - apply less and let the reserve fall back.
And the target index belongs to the crop: index 2 is on target for a cereal and below target for potatoes, so the same soil figure means two different things.

IT REFUSES RATHER THAN GUESSES
- No soil analysis, and it declines to recommend at all. What it gives instead is pure crop OFFTAKE, labelled as replacement - apply that and the field holds wherever it happens to be, which is a standstill and not advice.
- Below the crop's pH, the blend is withheld entirely and a lime requirement is returned instead, scaled for your soil - because phosphate locks up and potash availability drops, and buying either is buying something the field cannot use yet.
- Where the target cannot be hit with the products selected, it says so and gives the closest blend with the shortfall and the overshoot both named.

WHAT IS IN IT
- The blend canvas: three nutrient measures with the target ruled across each, and any overshoot standing past its own rule
- Field register with area, soil type, crop, expected yield and whether the straw goes
- Soil analyses with pH and the P, K and Mg indices, drawn as the bands they are
- The shed: your own products, each showing what it FORCES in with it
- Spreader settings rounded to the nearest 5 kg, with the total for the field
- Cost per hectare and the whole farm's fertiliser bill
- Insights: area by soil index, lime owed, fields with no analysis, cost by field
- A shipped offtake reference for 14 crops, exportable
- Export to JSON and CSV - and the plan export carries the misses beside the rates
- Hectares or acres; oxide or element; light and dark themes

PRIVACY
No account. No ads. No analytics. No third-party SDKs. No data collected and none shared. The app requests no runtime permissions at all. Its single network request is loading the privacy policy in Settings; everything else works in flight mode.

The offtake and index figures are published guides, not a warranty, and no substitute for an agronomist who has walked the field. Fertiliser use may also be regulated where you farm.