Best Practice Information Sheets (Westcountry Rivers Trust)

Using vegetation to protect soils

Best Practice
Information Sheet

Buffer zones

IS 2.5.4

Why change?

Soil is the farm's most important resource. By introducing grassed buffer zones to protect your soils from erosion and runoff you could:

  • reduce costs
     
  • minimise the risk of watercourse pollution
     
  • improve crop yields whilst reducing crop damage and inputs
     
  • increase pest predator populations
     
  • protect habitats, e.g. watercourses and hedgerows
     
  • improve wildlife diversity.

Steps to success

  1. Review the current situation by examining the management of soils on your farm. Use a farm map to help consider the condition of your soils on a field-by-field basis and estimate the cost of problems such as soil erosion, runoff and watercourse pollution. Look out for signs of soil damage such as capping, rilling and brown water runoff. Identify the scope for establishing grassed buffer/settlement zones in natural drainageways and alongside important habitats such as watercourses, hedgerows and ancient woodland in order to slow down runoff, increase infiltration, remove nutrients and trap sediment. It is a requirement under Cross Compliance regulations that every farm in receipt of SPS must complete a Soil Protection Review by 2006 and implement this by 2007.
     
  2. Calculate the cost-benefit of these opportunities by considering the benefits of establishing buffer zones versus the cost of problems such as soil and nutrient loss, watercourse pollution, crop damage and reduced yields.
     
  3. Prioritise the protection of vulnerable soils that are most at risk of severe or regular erosion, e.g. sandy soils on steep, long slopes. Tackle fields adjacent to watercourses first to minimise risk of water pollution.
     
  4. Develop an action plan for establishing grassed buffer zones:
    • aim to manage soil erosion and runoff at source through good soil management and appropriate land use
       
    • establish grassed buffers of at least 2-6m wide in erosion-prone areas, and alongside important habitat such as watercourses, hedgerows and ancient woodland
       
    • create permanent grass strips through regeneration of natural vegetation where soil conditions allow, or by reseeding. Use a native seed mix that includes wild flowers and tussocky species such as Cocksfoot, Yorkshire Fog and Timothy to maximise the interception of runoff and also wildlife potential
       
    • mow strips frequently in the first year to encourage establishment, and control volunteer crops or weeds. Manage buffer strips by mowing annually after mid-July when seeds have set, or alternatively leave strips of uncut tussocky cover for small mammals and insects
       
    • avoid spreading buffer zones with pesticides, herbicides, nutrients and fertilisers
       
    • investigate the availability of grants for establishing grassed buffer zones on arable land and grassland. The creation of buffer zones attracts points under ELS / HLS Environmental Stewardship Schemes.
       
    • Under ELS, after 12 months, 2m and 4m buffer strips only need cutting to control woody growth, no more than one year in five. Buffer strips that are 6m require the 3m next to the crop edge to be cut annually and the other 3m only needs cutting to control woody growth, no more than one year in five.
  1. Check your buffers regularly for injurious weeds, as well as the development of runoff pathways and bypass channels.

 

Best Farming Practices: Profit from Change

  

Practical examples

Summary of practical aspects

Aim to manage pollution at source through good management practices and appropriate land use. Implement buffer/settlement zones as a second line of defence.

Ideally the ratio of dry or wetland buffer zone to farmland should be at least 1:100, i.e. 1 hectare of land should is generally needed to treat the run-off from every 100 hectares of farmland.

Assess the possibility of using buffer zones for summer grazing, when other pasture might be unproductive during periods of drought.

Avoid spreading wetland buffer zones with pesticides, herbicides, nutrients and fertilisers.

Investigate the availability of grants for establishing wetland buffer zones on arable land and grassland.

Check your buffers regularly for injurious weeds and development of bypass flow and channelisation.

Actual examples

Farmyard runoff, previously discharging directly into the main river channel was directed into a linear floodplain wetland. The flow was diverted via a small ditch constructed, using a mechanical digger, during farm ditch clearance. The costs were negligible.

An 80% reduction in phosphorus concentration in surface water was measured and suspended sediment concentrations were also greatly reduced especially in the drier tussocky areas.

A footslope wetland downslope of permanent pasture intercepts nutrient rich runoff. The wetland was left undrained and fertilisers and pesticides were not applied. It is self-maintaining with light summer grazing, which brings some economic benefit. The costs are negligible

Such wetlands remove large amounts of nitrogen originating from fertiliser and manure applied to pasture upslope and minimise the risk of water pollution.

 

Left:
dry settlement area for runoff from winter wheat

Right:
footslope wetland intercepts nutrients in runoff

Remember

  • Buffer zones are not a substitute for good soil management at source.
     
  • Aim to minimise soil erosion and runoff by using appropriate land use practices across your farm.
     
  • Use buffer/settlement zones to intercept runoff, and to protect soils and wildlife habitats such as watercourses, hedgerows and ancient woodland.
     
  • Grant aid for buffer zones is available under an Environmental Stewardship Scheme.
     
  • For further information: The Wildlife Trusts (08700 367711), Defra (08459 335577), Environment Agency (08708 506506), ADAS (08457 660085) and ECSFDI (0800 5874079).

 

Disclaimer - Whilst the Westcountry Rivers Trust, its servants and agents (the "Trust") will use its reasonable endeavours to ensure the accuracy of its work, its advice involves matters relating to the natural environment or matters outside its reasonable control. Accordingly, other than personal injury or death arising from its negligence, the Trust will not be liable for any loss or damage howsoever arising directly or indirectly from any act, omission, neglect or default on its part. Funding for updating these information sheets was provided by the Water Quality Division of Defra as part of its England Catchment Sensitive Farming Delivery Initiative. These sheets provide practical information, guidance and recommendations for farmers based on Trust experience. © Westcountry rivers trust, 2007.

 

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