AHW6Basic overwinter stubble

What it actually is

You take a cereal, oilseed rape or linseed crop off, and you leave the stubble where it stands until around mid-February. GOV.UK's stated aim is a post-harvest stubble remaining over the autumn and winter months, providing winter food for seed-eating birds and foraging habitat for farmland wildlife. You must not apply a pre-harvest desiccant to the crop that produces the stubble, and on the stubble itself there is no topping, no grazing, no post-harvest herbicides, and no fertilisers, manures or lime.

Source: GOV.UK, AHW6 action page, checked 23/08/2026.

What it pays, and what that comes to

The rate is in the panel at the top of this page. Multiplied out:

Source: arithmetic on the payment rate shown at the top of this page, which comes from Tilth's copy of the GOV.UK action catalogue and carries its own last-checked date. The 8 hectares is an illustration.

Is it worth it on your ground?

Step one: what it costs to put in. Nothing. There is no seed, no input and no establishment operation. The costs of this action are all things you stop doing, and they are worked through below.

Step two: what the same field could do instead. This action only asks a real question of ground that would otherwise grow a winter crop, because a field going into a spring crop carries a stubble through the winter anyway. Gross margins per hectare for England, non-organic, in the 2023/24 crop year, with variable costs already taken off:

Source: Farm Business Survey, Crop Production in England 2023/24, Rural Business Research, England, non-organic, 2023/24 column, checked 02/08/2026.

Step three: the two cases.

Source: arithmetic on the crop gross margins in step two, from the Farm Business Survey, Crop Production in England 2023/24, checked 02/08/2026, set against the payment rate at the top of this page.

Two things to set against those figures. What follows is Tilth's own reading rather than scheme guidance.

The spring-crop case is not quite money for nothing. The stubble ahead of a spring crop is there anyway, but this action changes how you manage it: no post-harvest herbicide until the action ends around mid-February, no autumn cultivation of a stubble that must remain a stubble, no lime across that window, and no grazing. On clean ground those may cost you nothing. On ground where the autumn spray or the winter sheep keep matters, they are the real price of the payment, and only your own records say what that comes to.

The winter-crop case does not add up on averages, and is not meant to. No one is entering winter wheat ground into an action paying at this rate, and the table says why. Where the sums get closer is a field returning well below the survey averages, and its enhanced sibling AHW7, at ten times the rate, is the version of this action built for taking ground out.

Does it work, and what makes it work better

This section is what we have found in published sources about the practice this action pays for. It is not scheme guidance, it is not Defra's or the RPA's view, and it adds no requirement beyond what the GOV.UK action page sets out. We have named every source and given the date we checked it. What it means for your ground is your decision.

None of the work below is about AHW6 by name. It is about leaving crop stubbles standing over winter, and this action is one way of paying for that practice. The fit here is unusually close: the practice assessed is defined as leaving stubbles until at least February or March, and this action's around mid-February sits at the front edge of exactly that window. Of the actions in this family, this is the one the studies came closest to measuring.

The graded assessment. Conservation Evidence, based at the Department of Zoology at the University of Cambridge, summarises the published studies behind individual conservation actions and has independent subject experts score each one. Leaving overwinter stubbles comes out in their category Likely to be beneficial, on 20 studies. The expert scores behind that are 90 per cent for effectiveness, 50 per cent for certainty, and harms not assessed. Effectiveness scores only the size and direction of the effects that were reported; certainty is the separate score for how many studies there are, how well built they are, and how much ground they cover. A high effectiveness score against a middling certainty score means the reported effects were large and the panel was less sure they carry across everywhere.

Source: Conservation Evidence, action 695, Leave overwinter stubbles, in the Farmland Conservation synopsis, checked 05/08/2026. Cite as Dicks et al. (2020), Farmland Conservation, pages 283 to 321 in What Works in Conservation 2020, Open Book Publishers.

What the studies found, both ways. Thirteen studies from Finland, Switzerland and the UK found evidence of some benefit to plants, insects, spiders, mammals or farmland birds, including higher densities of farmland birds in winter on stubble fields, increased grey partridge productivity, and cirl bunting recovery where stubbles were provided as one of a group of measures together. One UK site comparison found inconsistent or no effects on farmland bird numbers. Three studies found only certain species responded, and two UK studies found different bird species favoured different stubble heights. The strong end includes a 2007 systematic review that found significantly higher winter densities of farmland birds, seed-eating songbirds in particular, on stubble fields than on conventionally managed fields. The weak end includes a survey of 2,046 one kilometre squares of lowland England that found no consistent association between stubbles and farmland bird numbers.

Source: Conservation Evidence, action 695, key messages and supporting evidence, checked 05/08/2026.

Conservation Evidence say themselves that the studies are not directly comparable or of equal value, and that study size, design, reported metrics and relevance to your own situation matter more than "simply counting the number of studies that support a particular interpretation". The individual studies run from 2000 to 2010, so all of them predate this scheme and this action.

Source: Conservation Evidence, action 695, checked 05/08/2026, including the note under key messages.

What the sources say makes it work better. All of the following comes from the studies listed on that same Conservation Evidence page, and it is a description of what was found rather than advice from us. Barley stubbles came out ahead of wheat twice: across 122 stubble fields in central England, linnet, skylark, reed bunting and corn bunting were found more frequently on barley stubbles than wheat, with 51 per cent weed cover against 40; and across 205 fields in south Devon, barley stubbles following a low-input herbicide regime carried roughly four times the seed abundance and broadleaved weed cover of wheat or conventionally managed stubbles. The same Devon study found stubbles grazed over winter carried significantly lower densities of seed-eating birds, which runs the same way as this action's grazing prohibition.

Source: Conservation Evidence, action 695, supporting evidence from individual studies, checked 05/08/2026.

What you actually have to do

After harvest, leave the stubble from a cereal crop other than maize or sorghum, oilseed rape or linseed, until around mid-February. Do not apply a pre-harvest desiccant to the crop that produces the stubble. On the stubble area, do not top it or graze it, do not apply post-harvest herbicides, and do not apply any fertilisers, manures or lime.

You also have to identify the land as not being at risk of soil erosion or surface runoff, and keep written evidence that you have. GOV.UK says that evidence can come out of a soil management plan produced for the earlier soil assessment actions.

Do it in each year of the 3 year duration. If the action's start date makes the first year too late, start within 12 months of it. In the final year, run to around mid-February or the action's end date, whichever comes first.

Source: GOV.UK, AHW6 action page, checked 23/08/2026.

What you cannot do on it

No pre-harvest desiccant on the crop. On the stubble: no topping, no grazing, no post-harvest herbicides, no fertilisers, manures or lime.

Source: GOV.UK, AHW6 action page, checked 23/08/2026.

Where it can go

Agricultural land below the moorland line, on arable land used to grow cereals other than maize or sorghum, oilseed rape or linseed, registered with an arable land cover and a compatible land use code, and identified by you as not at risk of soil erosion or surface runoff. SSSIs need Natural England's consent before agreement. Land with historic or archaeological features needs an SFI HEFER first. Total or part of a parcel.

It can be rotational or static: it can move within your crop rotation in years two and three, or stay put. It is not one of the ten limited area actions, so it does not draw on the 25 per cent cap.

Source: GOV.UK, AHW6 action page, checked 23/08/2026. The limited area list, GOV.UK, SFI26 scheme rules and guidance, section 4.5, checked 23/08/2026.

What you can stack it with

The compatibility lists are on the GOV.UK action page, set out separately for actions on the same area and actions on the boundaries of the parcel. The same-area list includes the agroforestry actions AGF1 and AGF2, the arable wildlife actions AHW5, AHW10 and AHW11, no use of insecticide CIPM4, no-till SOH1, the summer cover crop SOH3, and the precision actions PRF1, PRF2 and PRF4. The boundary list includes hedgerow management CHRW2, the wall and bank actions BND1 and BND2, and ditch management WBD2.

Source: GOV.UK, AHW6 action page, checked 23/08/2026.

Things worth watching

This section is Tilth's own reading of where this action is easy to get wrong. It is not scheme guidance, it is not sourced from Defra or the RPA, and none of it adds a requirement beyond what the GOV.UK action page sets out.

The desiccant rule looks backwards in time. The prohibition is on the crop that produces the stubble, not on the stubble. The decision that determines whether a field can go into this action is made before the ground is a stubble at all, and it lands with whoever plans the pre-harvest spray.

No herbicide means no herbicide. There is no grass weed exception here as there is in AHW7. A stale seedbed programme that relies on spraying the stubble off in autumn does not fit this action, and the first chance to spray comes when the action's window ends around mid-February.

The grazing ban reaches the sheep. On mixed farms, winter keep on stubbles is worth real money, and this action removes it for the fields entered. That cost does not appear in any table above because it is entirely a matter of your own stocking.

Mid-February is "around", not a date. GOV.UK gives no calendar date. That is more room than a fixed date, and it also means there is nothing to point at afterwards except what you actually did and when.

The lime window. No lime on the stubble area means an autumn application on those fields waits for the action to end. On ground with a liming plan, that is a scheduling question worth answering before entry rather than after.

The cheap and dear siblings share a family but not a job. The same field in AHW7 pays ten times as much, but takes the ground out for a full cropping year and draws on the shared 25 per cent limited area cap. This action fits in front of a spring crop and draws on no cap. They are different tools, and the money section above is the honest comparison between them.

Keeping the evidence

Also Tilth's own reading. GOV.UK sets the requirements; what follows is a practical suggestion about record keeping.

Two records. First, the erosion and runoff assessment, which GOV.UK explicitly says you must keep in writing, and which can come out of an existing soil management plan. Second, evidence of what happened on the field: operations records and invoices at parcel level, and photographs, given as the examples.

Source: GOV.UK, AHW6 action page, checked 23/08/2026.

Like the rest of its family, this is largely an action of not doing things, and there is no invoice for a spray you did not make. The useful record is the negative one: a spray and operations record for the parcel across the whole window showing what went on it, which is also the record showing what did not, and dated photographs, because a stubble in September and a stubble in February are different pictures.

The part only your own ground can answer

The whole question with this action is which of the two cases in the money section your field is actually in, and what the not-doings cost on your ground: the autumn spray you would have made, the sheep you would have turned out, the lime that now waits. None of that is in a national survey. It is in your own field records, which is where Tilth keeps it, next to the operations record that shows the stubble stood untouched. Request an invite.