Case Study: Using hay strewing as a technique to create species-rich grassland

Author: Jennifer Palmer

Farm: High Burnham Farm, Epworth

Aims

High Burnham is a large (+300ha) arable farm.  As part of the RSPB’s Axholme and Idle Farmland Bird Initiative¹ (Lincolnshire), an opportunity was identified to revert an arable field corner to a species-rich meadow.  The 1.7ha field corner sits within the base of a large L-shaped arable field.  Because of the clay-based soil type, the field corner lay wet so was deemed unsuitable for arable cropping hence it was left out of production for four years.

The low-lying field corner lends itself to a pastoral management and is less than 200m from Rush Furlong Meadow SSSI.

This will be the only parcel on the holding managed as grassland.  It is anticipated that hay will be cut by a local contractor used by the Lincs Wildlife Trust and aftermath grazing will be carried out by a local grazier.

Management

Verbal advice and a written proposal were provided to the landowners on species-rich grassland establishment and management.  The RSPB’s Hay Meadow and Arable Reversion topic sheets were used to supplement this verbal and written advice.  The landowners understood the principles of grassland management through knowledge of a local grassland SSSI.

Hay strewing is a tried-and-tested method for enhancing the botanical diversity of species-poor grassland² and can also be used to create diverse grasslands on arable land³.  It entails taking freshly cut ‘green hay’ from a local donor site and, on the same day, strewing (spreading) it onto a suitable receptor site.  It is a cost-effective method and ensures that the received seeds are of local provenance.

Two donor sites were identified and Lincolnshire Wildlife Trust kindly donated and cut the hay from Sedge Hole Close, a damp meadow (MG4 National Vegetation Community) containing cowslip, great burnet, lesser knapweed, oxeye daisy and cuckooflower.  Natural England consent would have been required for using SSSI hay.

Loading a trailer with green hay at East Lound with Matt Cox Lincs Wildlife Trust

Technical advice was followed to ensure the receptor site’s soil was suitable, through testing phosphorus (P) levels.  The soil sample results showed a P Index of 1 (low) so was deemed acceptable.  The farmer prepared the site by spraying off weeds using herbicide and creating a create a fine, firm and level seedbed, avoiding looseness at depth.

The site has no historical significance.

Because the donor site is an NVC MG4 vegetation community, containing abundant great burnet, we followed advice from a floodplain grazing meadow conference (attended by Helen Norford of Yorkshire Wildlife Trust) to spread the hay at reasonable depth (up to 10cm).

Once strewn, in the first year the vegetation growth should be cut up to 4 times and then the grassland should be treated as a traditional hay meadow thereafter.

Because the donor site was smaller than the receptor site (0.9 and 1.7ha respectively) we found that we had a deficit of green hay for the receptor field and a ratio of 1:1 (as recommended by Dr Duncan Westbury) would have worked better.  Partners therefore plan to revisit, survey and repeat if necessary next year.

Black grass growth will also be re-sprayed off this year.

The cost of the green hay was free as it was donated by Lincolnshire Wildlife Trust.

There was a minimal fuel and labour cost incurred by the farmer transporting the two loads of green hay from the donor site to the receptor site.

Achievements

Breeding skylarks have been recorded in adjacent fields during RSPB bird surveys and breeding skylarks are also recorded at Rush Furlong SSSI so the parcels should attract skylarks.  The parcel also offers potential lapwing nesting habitat, providing the additional scrape excavation works are undertaken. There are records of yellowhammers in the hedges and reed buntings nesting in the adjacent OSR crop.

Sitting within the Humberhead Levels NCA, the project meets multiple NCA priorities - the creation of lowland meadow (biodiversity priority) and permanent grassland (landscape priority).

Advice for other farmers

Don’t be tempted to miss out the soil testing step! If phosphorous index is anything above low, species-rich grassland creation may not be viable for your site at this moment in time.

Ground preparation is really important and if strewing onto established grassland, really open up the sward so that lots of bare ground is showing.

Orchids may take several years before they appear so don’t be disheartened if nothing happens for the first few years.

Expect to have to consider repeating the method to ensure a diverse sward.

Additional information

¹ The Axholme and Idle Farmland Bird Initiative covered the river catchment area in the Idle Valley and Isle of Axholme, an area of Lincolnshire, South Yorkshire and Nottinghamshire recognised as being nationally important for its farmland bird assemblage.  The project area was one of the RSPB’s Farm Advice Focus Areas and ran from 2012 to 2018 combining farmland bird monitoring and farm conservation advice.
² Natural England Technical Information Note TIN063, Sward enhancement: diversifying grassland by spreading species-rich green hay.  Also through own experience on land owned by the Malvern Hills Trust, following advice from Dr Duncan Westbury of Worcester University.
³ Visit to arable reversion hay strewing site led by Professor Ian Trueman, 15-18 June 2012, FSC Shropshire Wildflower Weekend.
⁴ Natural England Technical Information Notes: TIN035, Soil sampling for habitat recreation and restoration and TIN036, Soil and agri-environment schemes: interpretation of soil analysis.

Case study: Herb-rich leys

Author: Ian Boyd
Farm: Whittington Lodge Farm, Gloucestershire

Aims:

Whittington Lodge Farm has predominately thin Cotswold Brash soils on 280ha, mostly over 800 feet in altitude. The cultivated half of the farm was in a continuous arable system, but average yields meant it was only marginally viable and blackgrass was creeping in.

In 2015, it was decided to undergo organic conversion on all the arable area to combine with the fully organic grassland. Herb-rich leys were introduced into the rotation to build fertility for the organic cereals. They are grazed by an existing and expanded suckler herd of native Hereford cows and calves.

Cattle grazing a herb-rich ley at Whittington Lodge Farm. Image credit: Ian Boyd

Management:

The herb-rich leys contain at least 5 species of grass, 5 legumes and 5 herbs which all add to the biodiversity with varying rooting depth in the shallow soils. They are established by under-sowing in spring barley crops, broadcast with an Opico seeder/harrow once the barley plants have reached the 3 leaf stage. This way the undersown plants are still small enough not to interfere with the barley combining. Grazing can begin in the autumn.

The herb-rich ley can last for 4 years and can be grazed or conserved as hay or silage. It can fit in well with other grasslands like permanent pasture with the management of grazing livestock.

Mob grazing can help achieve the best from the leys. The cattle are moved frequently, usually daily, onto fresh grazing and a back fence stops them eating any re-growth after about 3 days. The adage is that you should not see the cattle’s knees when they go in and you should not see their ankles when they come out. Some of the herbage is eaten, some trampled and some left so that the root structure underneath the plants is maintained and re-growth is rapid.

Then, most importantly, the ley is rested for a couple of months to allow plants to flower and set seed before the next grazing. This will provide habitat for invertebrates, including crop pollinators, and improve soil structure and water infiltration.

Moving the electric fence is a daily commitment but it makes it easier to check and count the stock as they run past.

The cost of seed is significant but no nitrogen is required, and it is possible to incorporate this option into a Countryside Stewardship scheme and claim payments for it.

As the soil organic matter level is improved, more grass will be grown and stocking rates will be able to be increased. This system suits both cattle and sheep on organic and non-organic farms.

Achievements:

There are multiple benefits to herb-rich leys. When terminated, they provide an ideal entry to cereal crops for several years, organic or not. The arable weed spectrum is dramatically reduced, especially blackgrass.
Soil health and organic matters levels will have been increased with large amounts of carbon sequestered into the soil, far more than the effects of methane produced by the cattle.

The nutrient density of the beef will be greater when multiple species and biodiversity are eaten with knock-on health benefits for the cattle and consumer.

The farmland wildlife is a big winner here, with many different plants flowering producing nectar for pollinating insects and producing seed (and insects) for many bird species to eat. Skylarks nest everywhere, hares and roe deer love to graze it. Kestrels and barn owls hunt for short-tailed field voles living in the long grass and snipe are increasingly being seen looking for worms in the winter time.

It really helps to be organised and to have planned the rotational grazing before the start of the season. Access to water, ease of moving electric fences and having the cattle in the right place at the right date all have to be factored in.

This system really suits British native breeds of cattle, which can readily be managed to Pasture-for-Life standards (essentially no grain fed). Pasture-for-Life beef allows the opportunity to brand and market it yourself with a great story for a higher price than the beef commodity market can pay.

www.cotswoldbeef.com