Floodplain Meadows
Floodplain meadows are a culturally and environmentally rich part of the countryside
What
They provide an array of benefits to society, such as carbon and water storage, abundant wildlife, and have long been valued by farmers for the high yield and quality of the winter fodder they produce.
Floodplain meadows are found alongside rivers on larger flat areas that dry out sufficiently in the summer through well drained soils, that a hay crop can be taken. Forty two percent of floodplains are no longer in connection with their rivers due to flood alleviation and land drainage schemes, therefore there are opportunities to restore floodplain connectivity and floodplain meadows together.
Why
Floodplain meadows are very rare and important habitats. Some of these grasslands support an amazing number of wildflower species as well as providing habitats for many species of birds, invertebrates, amphibians and mammals. They provide very important supplies of pollen and nectar for bumblebees and other insect pollinators. They are particularly noted for supporting breeding curlew in lowland farmland.
As for other wildflower meadows, floodplain meadows were once a common part of the farmed landscape, however many have been converted to arable cropping or intensive grassland, lost through flood alleviation work, gravel extraction or road/house building. They were created by farming to produce winter food for livestock. Some floodplain meadow systems were known as Lammas Meadows, Ings or Hams, where the hay was shared in blocks or strips, and they were communally grazed after the hay cut.
Their situation on a floodplain means they are naturally very fertile even without additional inputs, receiving phosphorus rich sediment through flood deposition. The wide range of flowering plants and grasses provides a highly nutritional crop with an increased protein and mineral content in the forage compared to improved grassland, which make floodplain meadows particularly productive. They were highly valued before the development of artificial fertilisers and were listed as the most valuable of land uses in the Domesday Book because of this natural fertility.
Well-managed floodplain meadows support a wide range of plants, fungi, insects, reptiles and ground nesting birds such as skylarks, curlews, meadow pipits and yellow wagtails.
How
Floodplain meadows that are traditionally cut for hay have developed a flora that is adapted to this management, and it is vital to continue this practice to maintain this plant community. Changing from a meadow to a pasture regime can result in the loss of plants that are not well adapted to being grazed.
Floodplain meadows are managed in a similar way to other meadows, however livestock are generally removed from the meadows in the winter once the soil is saturated. The hay cut tends to be earlier – typically the end of June, in order to maximise the nutrient removal and balance any inputs from flood sediments. Aftermath grazing is still important to open the sward and allow seeds space to germinate, as well as keeping grass growth down.
If the weather has been wet over the summer leading to summer flooding, it is not always possible to cut floodplain meadows. This also results in higher grass growth and eventually a decline in species richness. Where flooding leads to a missed hay cut and reduction in aftermath grazing, it might be prudent to undertake two cuts the following year such as one in mid-late June and a second cut in September if conditions allow, to try and reduce the grass growth.
Livestock are usually excluded from meadows in the autumn, depending on the soil conditions on the site. There should be no livestock on a floodplain meadow in wet conditions as this can lead to soil compaction. There can be spring grazing in some areas, but this should be removed before mid-April. The grass is then allowed to grow until late June/early July, depending on location and weather conditions.
Cutting according to weather conditions, from mid-June onwards means that the hay can be cut as soon as it is ready. In some years, this will be early and in others it will be later. This also ensures a diversity of cutting times which can be beneficial to insects and different seed setting times.
Hay making, where mown grass is cut, left to dry and turned on the ground over a 3-5 day period is the most wildlife-friendly management. It allows ripe seed to fall to the ground and provides time for wildlife to move from the cut field. Haylage production, where mown grass is only partially dried before being wrapped in plastic can be used when the weather turns wet preventing the fodder crop from drying, however if carried out every year will damage wildlife interests.
Leaving un-mown strips along the edges of fields provides late season food for insects, allows later flowering plants to flower, and provides essential shelter for wildlife over the winter. Flower-rich un-mown areas should be rotated each year however other un-mown areas, such as wet areas tricky to harvest, can be kept as more permanent habitats which just receive aftermath grazing.
Grazing
A few weeks after cutting and baling, the meadow may be used for aftermath grazing. Cattle grazing is particularly beneficial as it tramples seed into the ground and removes grass growth allowing light through to aid seed germination. Delaying aftermath grazing until early autumn can allow re-flowering of clovers and bird’s-foot trefoils which provides important late summer forage for bumblebees and other pollinating insects. If aftermath grazing is not undertaken, a mat of vegetation or thatch can build up. It may be possible to remove some of this in winter using chain or tine harrows. No mechanical operations, including harrowing and rolling should take place once birds have started to nest in the spring, or when soil conditions are not suitable.
Timing of autumn and spring grazing, as well as numbers and type of livestock will vary depending on the meadow type. Aim to reduce the height of the sward to between 5-10cm through low level grazing. Heavy spring grazing should be avoided.
Fertilisers and other inputs
Meadows that traditionally received an annual light application of well-rotted farmyard manure should be continued to be managed in the same manner to maintain soil fertility and hay yields. Applications should only be applied where they have been carried out in the past and at less than 12 tonnes/ha annually. This is generally not damaging to wildlife and can provide food for some bird and invertebrate species. Slurry and artificial fertilisers should not be applied as this may reduce the flowering plants that cannot compete against more vigorous grasses.
More information
Specific information about floodplain meadow management: About Meadow Management.
Case studies of restoration efforts: Restoration Case Studies
In practice
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