AHW11Cultivated areas for arable plants

What it actually is

A margin or plot that gets one cultivation and then nothing at all. You work it down in the spring or the autumn to a fine surface, you sow nothing into it, and you leave it until the end of the summer while whatever is in the soil comes up on its own.

GOV.UK's stated aim is fallow cultivated margins or plots with a fine surface suitable for wild arable plants to establish from the soil seed bank when they are cultivated in the spring or autumn, and natural vegetative cover throughout the growing season until the end of the summer. The page sets that in the context of allowing wild arable plants to increase their populations, providing areas for insects such as bumblebees and hoverflies, and summer foraging habitat for farmland birds.

Source: GOV.UK, AHW11 action page, checked 04/08/2026.

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 2 hectares is an illustration.

Is it worth it on your ground?

Step one: what it costs to put in. No seed, because nothing is sown. The cost is a cultivation pass, and we are not going to put a number on that, because it depends on your kit, your soil and how you cost your own hours. So the payment stands at close to its full value, which puts this action in the same small group as AHW5 and AHW7 rather than with the ones that need a seed mix bought before they start.

Step two: what the ground would otherwise return. Gross margins per hectare for England, non-organic, in the 2023/24 crop year. Variable costs have already been taken off these figures, so there is nothing further to deduct.

Source: Farm Business Survey, Crop Production in England 2023/24, Rural Business Research, England, non-organic, 2023/24 column, checked 02/08/2026. The winter wheat figures come from a sample of 572 farms.

The agreement runs three years, so the comparison has to run three years too, and that ground will not be in wheat for all three of them. Three rotations, worked from the crop figures above:

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. These three are illustrations. Work your own out from the same crop figures.

Step three: the gap.

Source: the payment rate at the top of this page set against the rotation averages in step two. The figures are subtraction. The cultivation pass is not in them.

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

The survey reports one winter wheat figure, not first and second wheat separately. A rotation with two wheats in it carries a second wheat at the same gross margin as the first, which is unlikely to be how it turns out on your ground. We have not found a published split to cite, so we have not applied a discount of our own invention. Read the rotation averages as the generous end for the crop, which on a gap this narrow matters more than it does elsewhere.

It is one year, and not a strong one. The same report's 2022/23 column put winter wheat's gross margin at £1,570 a hectare against the £988 above for 2023/24. A three-year decision resting on a single crop year is a shaky thing, and this particular year was the lower of the two. On a strong year the crop would be well clear.

A margin is not the field. If you put this on a margin rather than an in-field plot, the gross margins above are the wrong figures to compare against, because a margin is the shaded, compacted, overlapped ground the yield map goes pale on. Nobody publishes a yield for it, we are not going to invent one, and the comparison to make is that margin's own return rather than the field's.

Where that leaves it. On ground performing at the field average the crop is ahead by roughly £104 to £176 a hectare a year, which on a margin is not a large gap to close. On ground that returns below your own average it closes on its own. What is more likely to decide this action is not the money but the second half of the requirements, because a whole growing season with no cultivation and no boom sprayer over it is a different proposition on clean ground than it is on ground with a grass weed problem, and that is a farm-by-farm question rather than a national one.

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.

The fit needs care on this one. Conservation Evidence assess an action called Leave uncropped, cultivated margins or plots, including lapwing and stone curlew plots, and AHW11 sits inside that description. But the assessment has two halves that behave differently. The plots half is about bare fallow plots for ground-nesting waders, which is the action next door on this site rather than this one. The margins half is AHW11. And most of the nine studies behind the assessment are about birds, where this action exists first of all for wild arable plants. So the graded assessment below covers the practice AHW11 belongs to, and the evidence inside it is largely not about the thing AHW11 is for.

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. This practice comes out at Likely to be beneficial, a category below the top, on 9 studies, with 59 per cent for effectiveness, 55 per cent for certainty, and 15 per cent for harms. Effectiveness scores only the size and direction of the reported effects, and Conservation Evidence say themselves that it does not consider the quantity or quality of the studies. Certainty is the separate score for how many studies there are, how well built they are and how much ground they cover. The harms score is unusual: nearly every action we have written up on this site comes back as harms not assessed, and this one does not.

Source: Conservation Evidence, action 213, Leave uncropped, cultivated margins or plots, including lapwing and stone curlew plots, Farmland Conservation synopsis, checked 22/08/2026. 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. Taking the findings that bear on margins rather than on wader plots: Stevens and Bradbury, across 256 fields on 84 farms in England, found only reed bunting out of twelve farmland bird species strongly and positively associated with uncropped cultivated strips, with no other species showing a strong association in either direction. Field and others, across three English regions, found fallow plots holding significantly fewer seed-eating farmland songbirds than conventional crop fields in summer in two of the three, at around 1 bird a hectare against 2.5 on crops, while the third region ran the other way.

Ewald and others, across 1,031 agricultural sites in England, found a lower proportion of young grey partridges in the population in 2007 on sites carrying a large area of uncropped but cultivated margins and plots, with no significant relationship to changes in partridge density, brood size or overwinter survival. That study covers margins as well as plots, so it applies here as much as it does to the wader action, and it is the finding most likely to sit behind the harms score above.

On the positive side, Chamberlain and others, surveying 212 cultivated plots on 180 farms, found the probability of birds breeding on a plot rose with the proportion of bare ground present on it.

Conservation Evidence say themselves that 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".

Source: Conservation Evidence, action 213, key messages and supporting evidence from individual studies, checked 22/08/2026.

On the plants, which is what this action is for. The strongest finding we have is not on that page. Critchley and others compared ten conservation habitats across 75 farms in East Anglia and the West Midlands, surveying 294 sites, and recorded the average number of plant species in each. Uncropped cultivated margins came out at 6.3 species, second only to wildlife seed mixtures at 6.7, and ahead of undersown cereals at 5.9, uncultivated margins at 5.5, no-fertiliser conservation headlands at 4.8, spring fallows at 4.5, sown grass margins at 4.4, conservation headlands at 3.5 and grass leys at 3.1. The authors named uncropped cultivated margins, wildlife seed mixtures and no-fertiliser conservation headlands as appearing to be the best options for conserving annual broadleaved plant communities.

Source: Critchley, Allen, Fowbert, Mole and Gundrey (2004), Biological Conservation, read through Conservation Evidence, action 695, checked 22/08/2026.

What we have not found. Nothing measuring AHW11 itself. Nothing testing cultivation in spring against cultivation in autumn, which is the one management choice this action leaves you. Nothing on how the seed bank varies with a field's cropping history, which is the question that decides what comes up. And nothing putting a figure on the cultivation pass.

What the sources say makes it work better. All of the following comes from studies listed on Conservation Evidence, and it is a description of what was found rather than advice from us.

On leaving the ground to itself rather than sowing it, two studies compared the two directly and they say different things. May and Nowakowski, working on sugar beet field margins in the UK, recorded 35 plant species a metre on wildflower-sown margins, 17 on naturally regenerated margins, 15 on grass-sown margins and 6 to 11 on margins left in barley or beet. Differences in invertebrate numbers between the treatments were small, running from over 900 to over 1,700 individuals.

Asteraki and others, across 38 field margin plots in Wiltshire over three years, found sown grassy margins suppressed undesirable weeds while not improving invertebrate numbers against naturally regenerated uncultivated margins. Sown plots carried significantly lower cover of nettle, creeping thistle and blackgrass than the naturally regenerated ones. There was no difference in total invertebrate abundance between treatments, and in the final year there were more predatory beetles in the naturally regenerated plots than in the sown ones.

On the surface itself, Chamberlain's finding that breeding probability rose with the proportion of bare ground on a plot is the one that speaks to what this action asks you to produce.

Source: Conservation Evidence, action 246, supporting evidence from individual studies, checked 22/08/2026, for May and Nowakowski (2003) and Asteraki et al. (2004). Conservation Evidence, action 213, for Chamberlain et al. (2009).

What follows is Tilth's own reading of how those findings sit against this action, and it adds no requirement beyond what the GOV.UK action page sets out.

The Asteraki finding is the one we would read twice before entering ground. Further down this page we flag the soil seed bank as both the mechanism of this action and the thing you spend money fighting. That was our own reading when we wrote it. It now has a study behind it: naturally regenerated margins carried significantly more nettle, creeping thistle and blackgrass than sown ones, in a three-year trial on 38 plots. This action requires you to sow nothing and limits you to weed wiping or spot treatment for a whole growing season. If you have a grass weed problem, that is the finding to weigh, and it is somebody else's measurement rather than our opinion.

The same study cuts the other way too, which is why it is worth reporting whole. The naturally regenerated plots ended up with more predatory beetles than the sown ones, and no worse on invertebrates overall. So natural regeneration is not simply the poorer option with a weed problem attached. It is a different trade: more of what you might not want, and more of what you might.

On the thing this action actually exists for, the evidence is better than the bird studies suggest. Uncropped cultivated margins came second out of ten conservation habitats for plant species richness and were named among the best options for annual broadleaved plants. That is the aim on the GOV.UK page, more or less word for word, and it is supported. Anyone reading the bird findings above and concluding this action does not work has read the wrong half.

The choice the action leaves you is the one nobody has measured. Spring or autumn cultivation is yours to make, the two produce different things from the same soil, and we have found nothing that tests one against the other. On an action whose entire management consists of a single pass, that gap is larger than it looks.

And the partridge result applies here rather than only on the wader plots, because the study that found it covered margins as well as plots. If you run partridges, that belongs in the decision. If you do not, it is a footnote, and 15 per cent for harms is a low score rather than a warning.

What you actually have to do

Create a fallow margin or plot by cultivating it in the spring or the autumn, in a way that can reasonably be expected to achieve the action's aim. Manage that fallow cultivated margin or plot in a way that can reasonably be expected to achieve the aim.

Source: GOV.UK, AHW11 action page, checked 04/08/2026.

What you cannot do on it

On the fallow cultivated margin or plot: do not disturb it before the end of the summer months, which GOV.UK gives as usually around the end of August. Do not use it as regular access tracks for vehicles. Do not apply any fertilisers, manures or lime. Do not apply pesticides, except for herbicides to weed wipe or spot treat.

Source: GOV.UK, AHW11 action page, checked 04/08/2026.

Where it can go, and the cap

Arable land used to grow crops, registered as arable land and declared with an arable crop or a leguminous and nitrogen-fixing crop code, along with temporary grassland under TG01 and arable land lying fallow under FA01.

The action is rotational or static, so you can move it for the second and third years or keep it in the same place.

Source: GOV.UK, AHW11 action page, checked 04/08/2026.

AHW11 is one of the ten limited area actions under SFI26. The rule is that the total eligible area you enter into them must not be more than 25 per cent of the total agricultural area of your farm. The other nine are CIPM2, CAHL1, CAHL2, CAHL3, CIGL1, CIGL2, WBD3, AHW7 and AHW9. How the 25 per cent limit works.

Source: GOV.UK, SFI26 scheme rules and guidance, section 4.5, 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 soil seed bank is the mechanism, and it is also the thing you spend money fighting. This action works by letting what is already in the ground come up. On a field with a long history of arable flora that is the whole idea. On a field with a blackgrass or brome problem it is worth thinking through properly, because a growing season with no cultivation and herbicide limited to weed wiping or spot treatment is not the year to find out what is down there. Nobody can answer that from a national figure, and it belongs in the decision at least as much as the £104 to £176 above.

One cultivation, then hands off. The requirement not to disturb it before the end of the summer months rules out the tidying pass. If it looks wrong in June there is nothing you can do about it in June, so the pass that decides how this action turns out is the one you make at the start.

Spring or autumn is a real choice, not a formality. GOV.UK allows the cultivation in either. They produce different things from the same soil and they sit differently in your workload, and the page leaves the choice with you rather than making it for you.

Weed wipe or spot treat, not a boom. If your plan for injurious weeds on this ground involves a sprayer going across it, read that line again before you enter the parcel.

No fertiliser, manure or lime, and lime is on the list. On ground you would ordinarily be liming during those three years, that is worth noticing before rather than after.

Regular vehicle access is out. A margin along a field edge is the natural line for a machine to travel, and the action rules that out on the ground it covers. Look at where your traffic actually goes before choosing which margin this is.

Rotational or static, and the choice has consequences. If it moves, the cultivation decision and the weed judgement are made three times against three different cropping plans. If it stays, the same ground goes uncultivated from spring to the end of August for three years running.

The area you enter is the area you are paid on. Margins and plots are easy to over-estimate. Measure them off the boundary rather than pacing them out.

The 25 per cent cap is shared, not per action. AHW11 draws on the same allowance as CAHL1, CAHL2, CAHL3, AHW9 and the rest of the ten. Total them together before the form is filled in rather than deciding them separately.

If the parcel is an SSSI, or has historic or archaeological features on it, read the eligible land section of the action page against your own parcels. There are extra steps in that part of the page that do not apply to ordinary arable ground.

Keeping the evidence

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

GOV.UK gives field operations at land parcel level with their associated invoices, and photographs or other documentation, as its examples of evidence of what you have done.

This action produces one operation and then a long silence. There is a cultivation and there is no seed invoice, no spray record and no harvest, which makes the dated photograph do more work here than on almost anything else on this site. A cultivated fine surface in April, the same ground in June and the same ground in August are three pictures that between them show the action doing what it is paid for, and there is no other document that shows it. The cultivation date and the position are the other half, particularly if the plot moves each year, because after the end of August there is nothing on the ground to say where it was.

Tilth lets you draw the margin or plot against the boundary you already have and keeps the cultivation date and the photographs against it, with the year attached.

The part only your own ground can answer

Two questions decide this action and neither is in a national survey. The first is the ordinary one: what that particular margin returns when you crop it, because the gap above is small enough that a below-average margin closes it. The second is the one specific to this action, which is what is actually in the seed bank under that margin, and the best evidence you have for that is your own history of what has come up there and what you have had to spray. Tilth keeps the yields, the boundaries and the spray history for each piece of ground in the same place, which is where both answers live. Request an invite.