CNUM2Legumes on improved grassland

What it actually is

You get legumes established in improved grassland and keep them there. GOV.UK's list of acceptable legumes runs to red clover, white clover, alsike clover, sainfoin, lucerne and bird's foot trefoil, and you can either add them to the existing grass or sow a fresh mixed sward of grass and legumes together. Once they are established you carry on grazing or cutting the field, managed in a way that could reasonably be expected to achieve the action's aim, which GOV.UK gives as legumes growing from spring until early autumn, managing nutrients more efficiently, protecting the soil surface and structure, supporting soil biology, and minimising nutrient leaching and erosion.

Source: GOV.UK, CNUM2 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 10 hectares is an illustration.

Is it worth it on your ground?

Step one: what it costs to put in. Legume seed and an establishment pass, once, at your own prices: oversowing clover into an existing sward at the cheap end, a full reseed with a mixed ley at the dear end. The action does not require the dear end.

Step two: what the field keeps doing. Everything. The sward is still grazed, still cut, still the same platform it was, so unlike the arable actions on this site there is no gross margin given up. The payment lands on top of a working field.

Step three: what the legumes are worth beyond the payment. This is the unusual part, and it comes from AHDB rather than from us: in a well-balanced and stable grass and clover sward, with 20 to 30 per cent clover, the potential nitrogen supply generated through fixation is equivalent to 180 kg of nitrogen per hectare. AHDB also report the feed side: each 10 per cent increase in sward clover content raises the crude protein of first-cut silage by about 1 per cent, and livestock may eat 20 to 30 per cent more white clover than grass, with liveweight and milk following. Set your own bag nitrogen price against a fixation figure like that and the payment starts to look like the smaller half of the deal. AHDB's caveat travels with it: the nitrogen supply is unpredictable, because clover content moves with the seasons and between years, and the sward develops late in spring.

Source: AHDB, Why use white clover?, knowledge library, checked 23/08/2026. The arithmetic invitation is Tilth's own; price your own nitrogen.

Where that leaves it. A payment for establishing something with an input-saving case of its own, on a field that keeps producing throughout. The real question is not whether the sum works but whether your grassland management can keep legumes alive, which is the subject of the sections below.

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 setting out first. Conservation Evidence assess Create rotational grass or clover leys, which is leys on arable land within rotations, where this action puts legumes into standing improved grassland. And the assessed outcome is wildlife, where this action's stated aim is nutrients and soil. The nutrient case rests on the AHDB material in the money section above, not on anything below.

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. Creating rotational grass or clover leys is in their category Unknown effectiveness (limited evidence), on 3 studies, scored 0 per cent for effectiveness and 10 per cent for certainty. That is a statement about how little has been measured, not a verdict that the practice fails: three studies is a thin file, and the category name says exactly that.

Source: Conservation Evidence, action 643, Create rotational grass or clover leys, Farmland Conservation synopsis, checked 23/08/2026. Cite as Dicks et al. (2020), Farmland Conservation, pages 283 to 321, in What Works in Conservation 2020, Open Book Publishers.

What the three studies found. A controlled Finnish trial found plots undersown with grass and red clover held more spiders and fewer pest insects than a spring barley control, around 28 to 35 spiders per trap against about 5. An old UK study, 1950 to 1956, found one-year ley plots carried significantly fewer earthworm species and numbers than leys left down for three and a half years, which reads as time in the ground mattering more than the sowing. And a replicated UK study across 294 sites found grass leys held the fewest plant species of ten conservation measures compared, at 3.1 species on average, because the sown grass and clover dominate. Fewer plant species is what a productive sward is, and this action does not pretend otherwise.

Source: Conservation Evidence, action 643, key messages and supporting evidence, checked 23/08/2026.

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 643, the note under key messages, checked 23/08/2026.

What you actually have to do

Establish the legumes, by adding them to existing grass or sowing a mixed sward, within 12 months of the start date where the action is static, and maintain them so that legumes are growing from spring until early autumn in each year. Once established, graze or cut as your system runs, managed in a way that could reasonably be expected to achieve the aim. Do not cultivate, or apply fertilisers or pesticides, within 2 metres of the centre line of any hedgerow.

Source: GOV.UK, CNUM2 action page, checked 23/08/2026.

Where it can go

Temporary grassland with the TG01 land use code, or improved permanent grassland with PG01, below the moorland line. SSSIs need Natural England's consent before agreement, and land with historic or archaeological features is not eligible for this action. Rotational or static: it can move with your reseeding or stay put. Total or part of a parcel.

Source: GOV.UK, CNUM2 action page, checked 23/08/2026.

What you can stack it with

The same-area list on the GOV.UK page: the agroforestry actions AGF1 and AGF2, the organic actions OFC1, OFC3, OFM1 and OFM4, the precision actions PRF1 and PRF2, and no-till SOH1. Boundaries take the usual four: CHRW2, BND1, BND2 and WBD2.

Source: combinations, GOV.UK CNUM2 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.

Your herbicide programme is the quiet conflict. The page does not ban pesticides beyond the hedgerow margin, but the requirement is to establish and maintain legumes, and a standard broadleaf herbicide on grassland takes the clover with the docks. Keeping the legumes alive and keeping the usual spray programme are not both possible, and it is the spray programme that has to give. How you handle the docks and thistles instead is a management question the action leaves with you.

Maintain means every year, not year one. Clover famously comes and goes. A sward that had legumes in year one and lost them by year three has stopped meeting the requirement, and AHDB's own caveat about fluctuating clover content is a description of exactly this risk. Grazing management, soil fertility and pH all bear on whether the legumes persist, and they are your levers.

Nitrogen works against the deal twice. Bag nitrogen suppresses clover, and clover replaces bag nitrogen. A field carrying on with its full fertiliser programme is spending money to defeat the thing it is being paid to grow. The action does not set a nitrogen limit, but the agronomy effectively does.

The two metre hedgerow margin is easy to forget on grassland. No cultivation, fertiliser or pesticide within 2 metres of the hedge centre line. On arable fields that margin is a habit; on a grass field that gets a blanket fertiliser pass, it is a spreader-setting detail that needs remembering.

Establishment has a season, whatever the paperwork says. The requirement is within 12 months of the start date, but clover established into a competitive sward wants warmth, moisture and a tight-grazed or freshly cut surface. The workable windows inside those 12 months are your call, and fewer than the calendar suggests.

Keeping the evidence

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

GOV.UK asks for field operations at parcel level with invoices, and photographs or documentation. The seed invoice and the sowing record cover establishment. For the maintain side, a few dated photographs each year showing legumes in the sward between spring and early autumn are the cheapest strong evidence there is, and AHDB publish a simple method for assessing the clover percentage of a pasture if you want a number to note alongside them.

Source: evidence requirements, GOV.UK, CNUM2 action page, checked 23/08/2026; the clover assessment method, AHDB knowledge library, checked 23/08/2026. The suggestion is Tilth's own.

The part only your own ground can answer

The sum on this page turns on your own numbers three times over: what establishment costs you, what your bag nitrogen price is, and whether your grazing keeps the clover alive long enough to collect on either. Those live in your fertiliser records, your reseeding history and your field diary, which is where Tilth keeps them. Request an invite.