Field Boundary Technical Factsheets from FWAG

Arable Ditches and Dykes

 

A variety of vegetation can provide habitats for a wide range of species

Ditches and dykes are very important features in arable farming. They allow land to be drained and help to create favourable soil conditions for crop growth. They are also very important features for wildlife, creating a habitat to support many species. Ditches and dykes can form an effective network of wildlife corridors throughout farmland and help to link other important habitats such as woodland, hedgerows and scrubland.

 

In order to effectively drain land, ditches and dykes need to be routinely managed to prevent silt and vegetation building up and restricting the water flow. Sensitive management only working on one bank at a time and cutting/clearing different ditches in different years - will minimise the impact on wildlife and benefit the environment in the long run.

Wildlife benefits of ditches and dykes

Arable ditches and dykes are important features in many parts of the country and provide:

  • An excellent habitat for many mammals, birds, fish, amphibians, reptiles, and invertebrates, some of which are rare farmland species.
  • Unique conditions which can benefit many rare plant species.
  • A network of wildlife corridors across the farm, which act as links between habitats.
  • An important landscape feature in many areas of the country.
  • Cultural and historical significance often marking out ancient boundaries between farms, parishes and counties.

Management advice to benefit wildlife

  • Create a variety of bankside profiles to encourage a greater diversity of species.
  • Where possible the shallower slopes should receive the most sunlight. Gentle slopes on southfacing banks provide excellent habitat for a variety of plants and animals.

 

Where possible exclude stock from ditches to prevent bank erosion

  • Protect watercourses from pesticide and fertiliser contamination. Follow codes of good agricultural practice and adhere to LERAPS regulations.
  • Where possible try to protect watercourses with field margin strips or buffer zones.
  • Consider using set-aside strips adjacent to ditches and dykes. 6-metre strips are now allowed alongside permanent watercourses.
  • Consider creating features to hold water in the ditch to create different habitats. This can be done by inserting wooden boards along the length of the ditch.

Clearing advice to benefit wildlife

Clearing and trimming ditches and dykes is often essential to ensure through-flow of water and adequate land drainage. Maintenance work can be very damaging to local wildlife. The following advice will help to reduce the impact of maintenance work on wildlife:

  • Clear ditches and dykes in the autumn or winter when conditions allow. Clearing in the spring or summer can be more problematic for breeding birds, plants and insects.
  • When cutting the bankside, try to leave 10 - 15 cm of vegetation to provide cover and food sources for animals such as water voles.
  • Clear one side of the ditch at a time. This is sufficient to clear the ditch properly but leaves one side of the bank undisturbed and an area for re-colonisation.

Clear one side of the ditch only. Leave the spoil at the bank edge to dry out before spreading or disposing of it.

  • Try to avoid scraping the side of the bank when clearing a ditch.
  • Leave occasional clumps of vegetation on the cleared bank to help wildlife re-colonise the new bankside.
  • Use regular rotational clearing and cutting so that not all channels are disturbed in the same year.

Further information

For further information including possible grant aid contact your local FWAG Adviser and visit the FWAG website at www.fwag.org.uk.


Every effort has been made to ensure accuracy in the information sheet. However, FWAG cannot accept liability for any errors or omission.
Photographs Richard Knight
Author: FWAG
14.2 Jan 2004

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