Why sampling comes first, and how often to do it
Why sampling comes first
Almost every soil and nutrient obligation you've got starts with an analysis result. RB209 recommendations need a P, K, Mg and pH index. Red Tractor wants analysis on a regular cycle. The Farming Rules for Water require your results to be no more than five years old at the time of application.
It's worth knowing what each scheme asks for before you book anyone in, because the requirements differ more than you'd expect between England, Wales and Scotland, and they've all changed recently.
How often
The working standard is at least once every five years for each field or sampling unit. That's what the Farming Rules for Water require in England and what RB209 assumes.
Sample more often where it earns its keep:
- Every three to four years on light land, on fields with variable yields, or where you're correcting a low index and want to see it moving.
- Before a rotation change, particularly going into a crop with a different P and K appetite, or into a legume where pH matters more than people expect.
- After a run of heavy organic manure applications, where P can climb faster than you'd think.
England
- Farming Rules for Water. pH, phosphorus, potassium and magnesium, no more than five years old at the time you apply. This applies to everyone farming in England, in a scheme or not.
- SFI SAM1 and CSAM1. On top of the standard suite, soil organic matter on every parcel entered into the action, tested within the last five years, and kept within five years for the whole of the three year agreement. Retest land as its result reaches five years old. You can take the samples at the same time as your routine Farming Rules for Water analysis.
- Both actions are closed to new applications and neither is in SFI26, but agreements already running still carry the requirement. See our SAM1 and NUM1 guide.
- SFI26 has no soil testing action at all. Nothing in the new offer pays for sampling.
Wales
The Sustainable Farming Scheme made soil testing a universal action, UA1 Soil Health. It applies if you claim on field parcels containing improved land, meaning land that has been reseeded, or limed, or has had inputs.
- A minimum of 20% of your fields containing improved land tested in 2026, or tested in the previous five years.
- From year 2, an average of 20% a year, so every parcel is covered within a five year cycle.
- From 1 January 2026 the analysis must cover P, K, Mg, pH and soil organic matter as a minimum, at an accredited laboratory. Send all your samples to the same lab so the results are comparable.
- Testing done after 1 January 2022 counts towards it, and only had to include P, K, Mg and pH.
- Each year's testing must be finished by 31 December, and results kept on farm for at least five years.
- From 1 April 2026 Farming Connect no longer funds the testing for farms in the scheme, though it still helps interpret the results.
Scotland
Soil analysis is one of the five baselines in the Whole Farm Plan, alongside an animal health and welfare plan, a biodiversity audit, a carbon audit and an IPM plan.
- Two of the five were required by 15 May 2025. All of them are required by 15 May 2028.
- Soil analysis applies to Region 1 land you manage permanently and put artificial fertiliser or organic manure on. Seasonal land and common grazing shares are out.
- Every applicable parcel sampled at least once every five years, and the result must include pH, phosphate, potash and carbon.
- Falling short currently brings a warning letter rather than a cut to your Basic Payment.
Note that Scotland asks for carbon where Wales asks for organic matter. They're related but they aren't the same measurement, and labs report both, so check which one is on the certificate you're paying for.
