CSAM3Herbal leys

What it actually is

A ley with more in it than grass. GOV.UK's stated aim is that there is an established herbal ley with a mixture of grasses, legumes and herbs or wildflowers to provide varied root structures, and areas of flowering plants from late spring and during the summer months. The page says the action is designed to produce a high volume of forage with minimal use of inorganic fertiliser, to improve resilience to drought, and to help improve and maintain the soil's structure, carbon, biology and fertility.

Grazing and cutting are both permitted on the established ley.

Source: GOV.UK, CSAM3 action page, checked 02/08/2026.

Our own way of putting that, which adds no requirement beyond what the GOV.UK action page sets out: the difference from the fallow actions is that this one is not a set-aside. Something comes off it, and the forage is written into what the action is for.

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 20 hectares is an illustration.

Is it worth it on your ground?

Step one: what the seed costs, and how many times you buy it. As with the legume fallow, the timing requirements put two sowings inside the three years. You establish by early autumn within 12 months of the start date, maintain the ley in the same place for a period of time that can reasonably be expected to achieve the action's aim, which GOV.UK says will usually be the end of the second summer after sowing, and then re-establish by early autumn, at the same place or a different one.

Source: Boston Seeds' own listed price and stated sowing rate for the CSS2 Herbal Ley SAM3 mix, looked up 02/08/2026. The site displays prices with an inclusive and exclusive of VAT toggle and £115.00 was read in the inclusive state. The timing that produces two sowings is from the GOV.UK CSAM3 action page, checked 02/08/2026. The rest is arithmetic on those figures.

Step two: what the action is worth after seed. Taking the annualised seed cost off the payment leaves £147.33 a hectare a year, before cultivation and drilling.

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 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 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 seed cost in step one, set against the rotation averages in step three. The remaining figures are subtraction.

The rest of this section is Tilth's own reading of the arithmetic above. It is not scheme guidance and it is not sourced from Defra or the RPA.

Two things to set against the rotation figures. The survey reports one winter wheat figure, not first and second wheat separately, so a rotation with two wheats in it carries a second wheat at the same gross margin as the first. We have not found a published split to cite, so we have not applied a discount of our own invention. And it is a single crop 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.

But that gap is missing the output, and on this action the output is the point. Unlike a fallow, a herbal ley produces grazing and forage, and the action is written on the basis that you will graze or cut it. What that is worth depends on whether you have stock, whether you can let the keep, and what you would otherwise be buying or growing to feed them. We have not found a published figure for the value of herbal ley grazing that we would put on a page about money, and we are not going to invent one.

Where that leaves it. On a pure arable farm with nowhere for the forage to go, the payment is the whole return, the gap above is the gap, and it is a wide one. On a farm with stock, or with a neighbour who wants the grazing, the payment is a top-up on an enterprise that stands on its own, and the comparison against an arable rotation is answering the wrong question. Both are legitimate readings of the same action, and which one applies to you is not something a website can know.

What you actually have to do

Establish a herbal ley from a seed mix containing at least one grass species, at least two legume species and at least two herb or wildflower species. On land at risk of erosion, use establishment techniques that minimise soil erosion and runoff. Once the ley is established you must maintain it, which GOV.UK puts as managing it in a way, and for a period of time, that can reasonably be expected to achieve this action's aim. You must also minimise the use of inorganic fertilisers containing nitrogen, which GOV.UK says will usually be no more than around 40 kilograms of nitrogen per hectare per year.

GOV.UK's advice section suggests a considerably richer mix than the minimum, in the region of five grass species, four legume species and four herb species, and suggests resting the ley from grazing or cutting for around at least five consecutive weeks between early May and late July. That advice is explicitly not part of the requirements. The requirement is the one grass, two legumes and two herbs or wildflowers.

Establish the herbal ley by early autumn, within 12 months of the action's start date. Maintain it in the same place for a period of time that can reasonably be expected to achieve this action's aim, which GOV.UK says will usually be the end of the second summer after sowing. Re-establish it by early autumn, at the same location or a different one, and maintain it to the end date.

Source: GOV.UK, CSAM3 action page, checked 02/08/2026.

What you cannot do on it

Do not use the established ley for storage. Do not apply pesticides to it, except herbicides to weed wipe or spot treat to control injurious weeds, invasive non-native species, nettles or bracken, and except herbicide used to destroy an existing ley in order to re-establish it. Use of inorganic fertilisers containing nitrogen must be minimised, which GOV.UK says will usually be no more than around 40 kilograms of nitrogen per hectare per year.

Source: GOV.UK, CSAM3 action page, checked 02/08/2026.

Where it can go

Agricultural land below the moorland line, on arable land growing crops, temporary grassland (TG01), arable fallow (FA01) or improved permanent grassland (PG01). It can be rotational or static.

Two hard exclusions. GOV.UK says you must not enter any area designated as an SSSI into this action, and you must not enter any area with an historic or archaeological feature into it either. Both are stated as ineligible rather than as consent or notice requirements.

Source: GOV.UK, CSAM3 action page, checked 02/08/2026.

Two things worth drawing out of that, which are ours rather than GOV.UK's and which add no requirement beyond what the action page sets out. The improved permanent grassland cover means the action is not confined to ground in the arable rotation. And the two exclusions are a different answer from the one AHW7, CIPM3, CIPM4 and CNUM3 give, where an SSSI consent or a HEFER is something you can work through.

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 requirement and the advice are different numbers, and they sit close together on the page. One grass, two legumes, two herbs or wildflowers is what you have to do. The five, four and four in the advice section is a suggestion, and GOV.UK says so. Reading the advice as the rule makes the action look more demanding and more expensive than it is; reading the rule and ignoring the advice may make for a poorer ley.

The herb species are the part to count. A mix can be sold as a herbal ley on the strength of its grasses and clovers. The two herb or wildflower species are a stated requirement, so the composition on the bag is the thing to check rather than the name on it.

Two sowings, not one. The timing puts an establishment and a re-establishment inside the three years, so budget the seed twice. On the merchant price used above that is the difference between £115 and £230 a hectare across the agreement.

The nitrogen requirement is a judgement with a number attached to it. GOV.UK asks you to minimise inorganic nitrogen and says that will usually mean no more than around 40 kg a hectare a year. That is not a hard cap in the way a date is a hard date, but it is a figure attached to a requirement, and 40 kg is not much on ground you are trying to get forage off.

SSSI and historic features are outright exclusions here. On AHW7, CIPM3, CIPM4 and CNUM3 those are consent or HEFER requirements you can work through. On this one the page says the land is ineligible. That is a different answer and it is worth reading twice before planning round it.

The forage is part of the return, and only you can value it. The payment on this action sits well below CNUM3's for a legume fallow on the same kind of ground, and the visible difference between the two actions is that this one lets you take something off. If you have no use for the forage, the payment is the whole of your return and the gap above is the gap.

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 asks for evidence of what you have done, with field operations at parcel level and their invoices, and photographs or other documentation, given as examples.

The two seed invoices with their full species breakdowns speak directly to the composition requirement, because the one grass, two legumes and two herbs condition is a claim about what went in the ground and the invoice is the paperwork that records it. After that, the fertiliser record for the parcel is worth keeping deliberately rather than incidentally, since the nitrogen requirement is one of the few places in the action where a number is attached to what you do. Grazing and cutting records are worth having for your own sake as much as anything, since they are what tells you whether the ley is earning its place, and photographs across the season make a case that a February picture on its own does not.

The part only your own ground can answer

The gap above is worked against an arable rotation on national figures, which is the right comparison only if the forage has nowhere to go. What the keep is worth on your farm, and what this particular block returns in cropping, are both numbers that live in your own records rather than in a national survey. Tilth is where we keep them, field by field. Request an invite.