AHW3Beetle banks

What it actually is

A bank of soil you throw up across the middle of a field and sow with fine-leaved and tussock-forming grasses, then leave. GOV.UK's stated aim is that there's an in-field raised grassy bank, with tussocky grass allowed to develop. The page sets that in the context of providing habitat for farmland wildlife, protecting soil from erosion and runoff, and supporting an integrated pest management approach.

Source: GOV.UK, AHW3 action page, checked 02/08/2026.

What it pays, and what that comes to

The rate is in the panel at the top of this page, and it is per hectare. A beetle bank is a narrow object, so the cash one bank produces is small even at a high rate:

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. The 400m by 2m bank is an illustration using made-up dimensions, not a scheme figure. GOV.UK sets no width, length or height for a beetle bank. 400 × 2 ÷ 10,000 = 0.08 ha.

Is it worth it on your ground?

Step one: what the seed costs. Two merchants selling mixes badged for this action. Seed goes in once, at the start of a three-year agreement.

Source: both merchants' own listed prices and stated sowing rates, looked up 02/08/2026. Boston Seeds displays prices with a VAT toggle and £110.00 was read in the inclusive-of-VAT state. The Hurrells per-hectare figure is arithmetic on their acre pack: 2.471 acres per hectare × £55.00. GOV.UK names red fescue, tall fescue, timothy and cocksfoot as examples; the Boston mix as listed contains no cocksfoot or timothy and the Hurrells mix as listed contains all four.

What we have not priced. Building the ridge. It is earthmoving, it depends entirely on your soil, your kit and how long the bank is, and we have not found a published figure we would put on a page about money. It is a real cost and it is yours to put in. The same goes for the nuisance of farming round an obstacle that is not on a headland.

Step two: what the action is worth after seed. Taking the annualised seed cost off the payment leaves £727.33 a hectare a year on the Boston mix, or £718.70 on the Hurrells one, before any earthworks.

Step three: 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 bank is static, so it holds the same ground for all three years and the comparison has to be a three-year one. Three rotations, worked from the crop figures above:

Source: arithmetic on the crop gross margins in step three, 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 four: the gap.

Source: the payment rate at the top of this page less the annualised seed costs in step one, set against the rotation averages in step three. The remaining figures are subtraction. Earthworks are not in this table and are your own figure.

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.

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.

The earthworks are missing from the gap. They are a real cost, they land in year one, and we have not priced them. Put your own figure in before you read the gap in step four as a verdict.

Where that leaves it. This is the closest any of these actions comes to matching an arable rotation on money. On the lower rotation figure the gap is under £40 a hectare a year, which on the area a bank actually occupies is a few pounds. The two questions that decide it are whether the field has a wet or awkward line through it that already returns below the field average, and whether you would get value out of the pest-predator side of it, which we are not going to price for you. Against those, put the cost of building the ridge and three years of farming round it.

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.

This is the closest fit between published evidence and a scheme action anywhere on this site.

Conservation Evidence describe the practice they have assessed as grassy mounds about 2 metres wide, running across the middle of large arable fields, made by two-directional ploughing and sown with a mix of grass species, intended to provide habitat over winter for predatory insects such as beetles and spiders, and possibly foraging habitat for birds and habitat for small mammals. That is AHW3 near enough word for word. Better than that, a good deal of the work sets one sown grass against another on the same bank, so the evidence speaks directly to the decision this page has already said is the one that matters, which is what is in the bag.

One qualification before the numbers. Conservation Evidence list 24 studies, and say themselves that those are 24 reports from 12 individual studies. Fifteen of the 24 come from three long-running experiments, one in Hampshire, one in Leicestershire and one across five southern estates, each written up five times over the years as it went on. Read the count as twelve experiments reported thoroughly rather than as 24 separate tests.

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 a category below the top, at Likely to be beneficial, on 24 studies, with 80 per cent for effectiveness, 60 per cent for certainty, and harms not assessed. Effectiveness scores only the size and direction of the effects that were reported, 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, which is where the twelve-experiments point above lands.

Source: Conservation Evidence, action 651, Create beetle banks, Farmland Conservation synopsis, checked 06/08/2026. 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. Fourteen reports from eight studies, from Denmark and the UK, found beetle banks give some benefit to farmland biodiversity. Sixteen reports from eight studies looked at invertebrates: five reports and a review found positive effects on invertebrate numbers, on their distribution, or on ground beetle density and diversity in spring and summer but not in winter; six reports from three replicated studies found the numbers varied with which grass was sown; two found the effect varied between invertebrate groups; and five replicated studies found lower numbers or no difference against other habitats. Six studies looked at birds: two reviews and a replicated controlled trial found benefits, though in combination with other measures rather than from the bank alone; two found mixed effects; and one replicated study of 12 farmland bird species across 84 farms found none of them associated with beetle banks either way. On plants, a replicated paired controlled study and a review found lower plant species richness on banks in summer, and that where grass margins as a group benefited plants the effect was not pronounced on the banks. A controlled study and a review found banks acted as nest sites for harvest mice. 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". The individual studies run from 1987 to 2010, so every one of them predates this scheme and this action.

Source: Conservation Evidence, action 651, key messages and supporting evidence from individual studies, checked 06/08/2026.

What we have not found. Nothing measuring the ridge itself, so nothing on the soil erosion and runoff part of the action's stated aim. Nothing putting a figure on what the predators are worth in the crop, as against what they do on the bank. And nothing measuring AHW3 itself.

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

Start with the grass, because it is the thing the studies test hardest and the thing you buy. Thomas and others, on two Hampshire banks sown with four grasses, found densities of predatory invertebrates of up to 150 a square metre in the first winter and over 1,500 a square metre in the second, against 26 to 29 a square metre out in the field. Within that, creeping bent held the fewest in the first winter, 39 a square metre against 66 to 102 for the other three grasses and 30 on bare ground. In the second winter Yorkshire fog held more than creeping bent and perennial rye grass on both banks. MacLeod, following the same bank for seven winters, recorded ground beetle densities of 11 to 110 a square metre in cock's-foot against 3 to 15 in creeping bent and 2 to 11 in perennial rye grass, with cock's-foot and Yorkshire fog holding the highest densities of predators, though not always significantly so. In a later write-up of the same experiment, money spiders and wolf spiders were also higher in those two tussock-forming grasses, and the perennial rye grass plots had been so thoroughly invaded by cock's-foot by the sixth winter that they were dropped from sampling.

Collins and others found the same shape of result on two Leicestershire banks. Predatory invertebrates came out at 2,045 a square metre in false oat grass, 1,492 in red fescue, 1,380 in crested dog's-tail and 1,060 in naturally regenerated vegetation. Ground beetle density was two and a half to three and a half times higher in cock's-foot than in any other treatment, and spider density was higher in cock's-foot than in red fescue or naturally regenerated ground. By the last year of that study, ground cover stood at 90 per cent for false oat grass, 75 per cent for red fescue, 70 per cent for cock's-foot and timothy and 10 per cent for crested dog's-tail, and the three grasses that held up best were the taller ones that formed dense cover in the bottom 30 centimetres. In an earlier report from the same estate, false oat grass, cock's-foot and timothy held the highest densities of the five grasses tried.

Then age, which is the finding most relevant to a three-year agreement. Thomas and others, comparing 22 beetle banks aged under one year to fourteen years against paired conventional margins, found plant species richness on the banks rose with age until older banks held a similar number of species to the margins, while the cover of tussocky grasses stayed high and did not fall away with age. In a companion paper, older banks held higher abundances of grasshoppers and bushcrickets, and in another, older banks had higher invertebrate diversity, with diversity tracking the number of plant species present. Thomas and others also found that three years after establishment, total predator densities and both ground beetle and spider community composition on the banks were no different from those in natural field boundaries. MacLeod's seven-winter record found two peaks in predator density, in the second and the sixth winter after establishment. The banks in the age comparison had received no active management, or very little, since they were sown.

On what the predators then do, Thomas found the ground beetle Demetrias atricapillus concentrated on and within 3 metres of the bank in mid-spring, at 12 individuals a square metre, before spreading evenly out to 60 metres into the crop later in May, with money spiders more abundant on the bank than in the crop and some dispersal into it. In a later study, the ground beetle species that overwinter in boundaries clustered near the banks and the hedgerow in March, spread out, then clustered again in July. A review of practices affecting ground beetles found three studies, two UK and one Danish, showing higher ground beetle numbers in arable fields close to beetle banks.

And the counterweight, which is consistent enough to belong here rather than in a footnote. Against an existing field margin, a bank is not reliably better and is sometimes worse. Thomas and others found rove beetle diversity lower on banks than on paired field margins in both winters studied, the overall catch of chick-food invertebrates lower on 22 banks than on their paired margins, and both the abundance and the species richness of butterflies and moths significantly lower on the banks in June, July and August. In a companion study, chick-food invertebrates came out at 47 individuals from 15 samples on banks against 65 from 15 samples on permanent margins. Collins and others found predator, ground beetle and rove beetle densities higher in one hedge than in one beetle bank across three winters. Moreby found spider and rove beetle densities lower on banks than on the edges of un-grazed pasture, though banks held the highest density of sawfly larvae of the ten edge habitats compared, above hedge bottoms and wheat headlands. Thomas and others found lower summer plant species richness on banks than on conventional margins, with more grass cover but less cover of herbaceous, woody and nectar-providing plants. Barker and Reynolds, across 116 grass strips on 32 farms, found no difference in sawfly larvae between beetle banks and grass strips planted along existing margins. A review of the Pilot Arable Stewardship Scheme found grass margins as a group benefited plants, bumblebees, true bugs and sawflies but not ground beetles, and that none of those benefits were pronounced on the beetle banks.

On birds and mammals the picture is mixed and the strongest-sounding figures are the ones to read most carefully. Murray and others found skylarks used beetle banks more than their availability would predict, and significantly more than unmanaged set-aside or broad-leaved crops, while yellowhammers used them only as expected and less than cereal or wild bird cover. Stoate recorded a 102 per cent rise in nationally declining songbirds on a 3 square kilometre site where beetle banks were created, but alongside hedge management, wild bird cover, supplementary feeding, predator control and reduced chemical inputs, and with no overall difference in bird abundance or species richness against three control sites. A review reported grey partridge populations 600 per cent higher on farms with partridge conservation measures in place, again a bundle of measures rather than banks alone. Ewald and others, across 1,031 sites in the Partridge Count Scheme, found grey partridge overwinter survival significantly and positively correlated with the presence of beetle banks in one of the years studied, with no relationship to brood size or to year-on-year density change. Against all that, a study of 256 fields across 84 farms found none of 12 farmland bird species strongly associated with beetle banks either way. Bence and others counted 117 harvest mouse nests a hectare on beetle banks against 14 a hectare on field margins, without testing the difference statistically, and Thomas and others found the plant litter, dead grass and tussock that gamebirds nest in covered 61 per cent of the banks against 27 per cent of the margins.

Source: Conservation Evidence, action 651, supporting evidence from individual studies, checked 06/08/2026.

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 single most useful thing in this evidence is not whether beetle banks work. It is which grass. Three separate research groups, over twenty years and two counties, arrived at the same short list: cock's-foot, Yorkshire fog, false oat grass and timothy, the tall tussock formers that make dense cover at ground level. Creeping bent came out close to bare ground in one winter, perennial rye grass came bottom or near it everywhere it was tried and had been squeezed out by cock's-foot within six years. The step earlier on this page about reading the species list against the wording of the action is the same point arriving from a different direction, and one of the two mixes priced above contains neither cock's-foot nor timothy.

The comparison the studies keep making is the one to hold on to. Set a beetle bank against the crop and the difference is enormous, up to 1,500 predators a square metre against 26 to 29 out in the field. Set it against a field margin or a hedge and it is no better, and on butterflies, moths, chick-food insects and plant species it is worse. Our reading is that this action is not really paying for the habitat, which you could get from a margin more cheaply and without moving earth. It is paying for where the habitat is. A margin is at the edge of the field by definition, and a big field has a middle that nothing reaches. That is the gap a beetle bank fills, and it is why the spillover studies matter more here than the habitat comparisons do.

The age findings cut both ways against a three-year agreement. Plant richness rose with age, invertebrate diversity rose with age, grasshoppers and bushcrickets rose with age, and one long record found the second peak in predator density in the sixth winter. Three years is where these banks were starting to become what the studies measured, not where they finished. The banks that improved with age had been left alone, which is roughly what this action asks for. Read alongside the earthworks cost, that suggests the money question on this action looks different if you expect the bank to still be there in ten years than if you are pricing three.

We would treat the partridge and songbird headlines with care, and we have written them out above rather than quoting the percentages on their own. A 600 per cent difference and a 102 per cent rise both came from farms doing five or six things at once. The cleaner bird result is the one that found no association at all across 84 farms, and the cleanest positive results in this whole set are about beetles, spiders and harvest mice rather than birds.

What none of it settles is the money. The gap on this page is the narrowest of any action on the site, and nothing in these 24 reports tells you what a beetle bank's predators are worth in the crop around it. That figure would decide the action, and it does not exist.

What you actually have to do

Build a raised earth ridge and sow it with a mix of fine-leaved grasses such as red fescue together with some tussock-forming varieties like tall fescue, timothy and cocksfoot. You can leave gaps of up to around 40m at each end so machinery can get past. Once the grass is established, keep it in a state that could reasonably be expected to meet the aim.

An existing beetle bank counts, provided it meets the requirements and is not already being paid for under another scheme option such as Countryside Stewardship AB3.

Establish the bank within 12 months of the action's start date, then maintain it through each subsequent year. GOV.UK gives no sowing window and no calendar dates for this action.

Source: GOV.UK, AHW3 action page, checked 02/08/2026.

What you cannot do on it

No fertiliser, manure or lime. No pesticides except herbicides to weed wipe or spot treat injurious weeds, invasive non-native species, nettles or bracken. No entering an area that contains a historic or archaeological feature. No double payment on a bank already funded under another scheme option.

Source: GOV.UK, AHW3 action page, checked 02/08/2026.

Where it can go

Agricultural land below the moorland line: arable land used to grow crops, temporary grassland (TG01), or arable land lying fallow (FA01). SSSIs are eligible, but you must give notice to Natural England to get SSSI consent before the Rural Payments Agency can offer you an SFI26 agreement. Land containing a historic or archaeological feature is not eligible at all. Total or part of the parcel. GOV.UK states no area cap and no percentage limit for this action.

Source: GOV.UK, AHW3 action page, checked 02/08/2026.

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 bag and the requirement are two different things. GOV.UK names four grasses as examples and requires a mixture of fine-leaved grasses together with some tussock-forming varieties. Merchants sell mixes under the AHW3 code that differ in composition, including at least one with no tussock-forming cocksfoot or timothy in it. Reading the species list on the bag against the wording of the action is a five-minute job.

The historic feature rule is a hard exclusion, not a caution. On AHW7 and CIPM4, historic and archaeological features come with a HEFER requirement you can work through. On this one GOV.UK says you must not enter any area containing such a feature. Since the action is moving earth, it is worth knowing what your HEFER says before the digger arrives rather than after.

Static means static. The bank stays in the same place for all three years, which is different from the rotational actions. Wherever you put it, you are farming around it until the agreement ends.

No fertiliser means the bank, not the field. The prohibition attaches to the area entered into the action. That is a simple thing to say and a less simple thing to do with a spreader running across a field with a ridge through the middle of it.

GOV.UK sets no dimensions. No width, no height, no minimum length. That means the area you claim is the area you actually build, and the only person who can measure that is you.

The merchant prices above were read inclusive of VAT. Merchant sites can display either basis, and a quote you are given may be on the other one. Worth settling before the figures go into a budget.

Keeping the evidence

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

The action page says to keep evidence of what you have done, and gives field operations at a land parcel level with their invoices, plus photographs or other documentation, as the examples. For a beetle bank that suggests three things worth having: the seed invoice with the mix composition on it, the date and extent of the earthworks, and photographs of the bank taken more than once, since the point of the action is that tussocky grass develops over time and a single photograph on the day it was sown shows bare soil.

The area is the other one. Because there is no prescribed width, the claimed area rests entirely on your own measurement, so a record of how you measured it is worth as much as the measurement.

The part only your own ground can answer

The gap above is small enough that the line you pick decides it, and what that line returns in cropping is not a number any national survey holds. Your own yield maps do. Tilth keeps them alongside the boundaries and lets you hold the bank as a mapped feature with its own measured area. Request an invite.