Enhancing improved grassland advice for livestock farming
Small modifications to current practices in agriculturally improved grassland may provide significant benefits for wildlife.
Creating a more diverse sward structure, and/or increasing the species diversity of these productive grasslands is beneficial for wildlife, livestock health and also soil health. It is not just wildflower-rich or other more natural semi-natural grasslands that are important for wildlife. Sympathetic management of agriculturally improved grasslands can have significant benefits for wildlife. Many grasslands could be enhanced to provide greater benefit for the farming system and wildlife. Sward diversity could be enhanced by using either a more lenient grazing regime, increasing the species composition (a shift from grass only to a grass and legume mix) or through re-seeding with a diverse herbal ley mix (~10 or more species).
Relaxing grazing at key times and/or increasing the number of species in a grassland sward can be hugely beneficial for wildlife. An increase in the diversity of sward height enhances the habitat for a whole range of wildlife including mammals, insects, amphibians and reptiles. A greater variety of plant food also increases the variety of insects, which coupled with an increased number of seed heads will support a greater variety of mammals and birds.
Lighter grazing will increase sward height and diversity, benefitting many insects including butterflies and grasshoppers, and birds such as yellowhammers and skylarks. It will also increase flowering, providing more pollen and nectar for pollinators to feed on. Even on species-poor grasslands, lighter grazing will allow common wildflowers such as dandelion, buttercup and red clover to flower benefiting pollinators. Flowering dandelions also provide seed for adult and juvenile linnets and goldfinches. In the winter, invertebrate feeders, such as starlings and thrushes, exploit grazed grassland. Retaining some taller grass at this time of the year provides refuges for over-wintering insects and important habitats for amphibians and reptiles.
A pasture with a mix of plants is more beneficial for livestock health and productivity. Furthermore, diverse swards can improve soil health, drought resistance and water infiltration through variation in plant root structure and depth. Research has shown that even a small change from an intensive perennial rye grass sward to a grass and clover or grass-clover-herb mix, can result in large increases in pollinators. In a mixed farming system, these pollinators can provide essential pollination in other areas of the farm.
Small modifications to current practices in agriculturally improved grassland may provide significant benefits for wildlife. This can be done by targeting particular fields or areas within fields and providing a greater variety of plants and grassland structure. An increase in sward height and structure can be achieved by adapting grazing management (for example through lenient grazing), or by leaving some areas to have a long interlude between grazings. An increase in plant diversity can be achieved by reducing inputs and potentially re-seeding or over-seeding.
More lenient grazing of highly improved pastures dominated by one or two agricultural grasses will create a variety of sward heights, beneficial for mammals, amphibians and reptiles. Benefits will be greater on permanent grasslands with some diversity of grasses and broadleaved plants.
Where some flowers are present in the grassland maintaining an average sward height of 10-12cm throughout the grazing season should allow any wildflower species already present to flower. If rotationally grazed, ensure at least 20% of the sward remains above 10cm at the end of each grazing period. This measure will be most appropriate with cattle as it is closer to the standard sward heights of cattle (6-9cm) than sheep (4-7cm). Leaving swards lightly or ungrazed over the May-July period will enable red clover to flower and provide food for pollinators.
Ensuring some taller vegetation remains through the winter provides an important refuge for wildlife, including insects, which allows them to over-winter and complete their lifecycles, for example the caterpillars of moths and butterflies. Areas left uncut or ungrazed can provide vital habitat for insects as well as large quantities of seeds for mammals and seed eating birds.
If sward quality deteriorates severely, return to standard management and leniently graze elsewhere on the farm.
More caution is required before reducing grazing on species-rich grasslands as wildflowers, insects and other wildlife already present are likely to be adapted to the current management regime. It is best not make too rapid or major changes on these grasslands – see Wildflower-rich pastures.
Enriching sward plant diversity
Existing improved pastures can be enriched by over-seeding with legumes or other herb mixes. If the grassland has never been re-seeded please refer to our Restoring wildflower-rich grassland advice. Ensure the existing pasture is cut or grazed tightly and that it is free of aggressive weeds or grasses. Open up the existing sward by harrowing or similar, providing access to the soil and space for the newly sown plants to establish. An over-seeding mix can then be broadcast or shallow drilled before rolling, several times if possible.
If you plan to create a legume-rich or mixed species ley it may be better to start from a clean seedbed – see our Rotational legume and herb-rich swards advice.
To prevent the most vigorous species becoming dominant, the use of fertilisers should be carefully managed to avoid nutrient build-up. Over application can have negative consequences on soil invertebrates. Regular soil testing will help ensure the correct levels of fertiliser are applied and that soil nutrient levels and pH are maintained at optimum levels. Low inputs of fertiliser (less than 50KgN/ha) or manure (5 t/yr) is unlikely to impact on the objective of boosting insects, however farmyard manure is the best fertiliser option from a wildlife perspective as it helps to boost soil invertebrates.
Pesticide and herbicide use should be avoided aside from the spot treatment or weed-wiping of injurious weeds or invasive non-native species. Grassland topping should be avoided as this will remove the varied vegetation structure you are trying to create. Avoid harrowing and rolling during the breeding season which can be damaging to ground nesting birds such as skylark and to amphibians and reptiles.
If you are managing your grasslands for waders it is best to avoid field operations between mid-March and mid June. If that is not possible, time field operations so that they are at least six weeks apart. If the field is not cut, make sure it is grazed back hard in late summer to remove annual growth.
Improved grasslands can also provide suitable habitat for corncrakes. If you are fortunate enough to live in an area with breeding corncrakes, please seek advice on appropriate management.
If re-seeding is required it is preferable to use minimal cultivation methods as this causes less disruption to soil invertebrates such as earthworms. Earthworms improve the structure, drainage and organic matter of the soil which in turn improve the productivity of the grassland.
Permanent buffer strips
Permanent buffer strips around the field edge are particularly valuable for wildlife, especially when positioned adjacent to habitats such as hedgerows, ponds and ditches. These habitats can provide important corridors, allowing wildlife to move between different habitats on your farm (such as woodland and ponds).
Here are some useful case studies and articles about how farmers are putting Farm Wildlife into practice on their farms
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