About the index
Who is behind Tilth, and why the index exists
Tilth exists to answer one question no UK farmer could answer before: what is fertiliser actually selling for today? This page explains who runs the index, how it is produced, and why you can trust a number that no fertiliser supplier owns.
Why we publish the index
Fertiliser is most arable farms' single biggest input bill, yet the going price has always been private knowledge: quotes vary farm to farm, and published references arrive weekly at best. When the market moves between prints, farmers negotiate blind.
Tilth publishes a free daily estimate of the UK market price for nine fertiliser grades, so any farmer can check a quote against an independent reference before signing. The index is free for everyone and always will be: farmers sharpen it by adding what they actually paid, and suppliers compete on price in the open.
Who runs it
Tilth is operated by Diligo Ltd, a UK company independent of every fertiliser manufacturer, importer and distributor. No supplier owns any part of the platform, funds the index, or sees the number before you do.
Revenue comes from one place only: suppliers pay a commission when a trade completes on the exchange. Nobody pays to move the published price, and the index methodology does not change based on who is buying or selling.
How the index is produced
Each grade's figure is a daily estimate produced by our forecasting model from driver indices: European gas prices, EU agri-food price indices, listed-producer signals and currency movements. The model's output is validated against weekly UK market prints, and farmer-reported prices sharpen it further.
Every published figure carries an uncertainty band, and grades whose model has not yet earned trust are clearly staged rather than presented as settled. The model itself is re-tested continuously: candidate drivers and fitting methods must beat the live model under the same validation before anything ships. The full methodology, data sources, licence and API are documented on our data page.
Independence
We publish the same number to everyone at the same time. We hold no fertiliser stock, take no position on price direction, and earn nothing from prices being high or low. If a figure fails our own validation gate, we withhold it rather than publish a number we do not stand behind.
Talk to us
Questions about the index, the data, or a correction? We answer.