Adhering to buffer zones
When farmers are applying fertilisers and pesticides, they need to be aware that they are required to utilise riparian buffer zones to minimise any potential losses to water, Teagasc Soils and Environment Advisor in Castlerea, Kieran Kenny reminds us of the key buffers.
A riparian buffer zone is the area adjacent to rivers, streams, drains, ponds, lakes, turloughs and other bodies of water that intercepts sediment, nutrients and pesticides moving off the field by surface runoff before reaching the waterbody. These potential losses occur following heavy rainfall and are most prevalent on poorly-draining land when the soils are at or close to saturation.
The value of PIP maps
Recently developed maps by the EPA called Pollution Impact Potential (PIP) maps are valuable tools to identify the riskiest areas in the landscape. These risk maps consider the soil drainage potential and stocking rate on the farm, along with the likely pathways, and delivery points for overland flow.
Adhering to regulation
To adhere to regulation, farmers must retain buffer zones alongside all waterbodies. The buffers typically start at 3 metres for chemical fertiliser or pesticides and 5 metres for slurry. However, effective buffer zones located in higher risk areas require a different approach with the use of extended buffers.
These key locations are often the low lying parts of a field where the surface runoff accumulates in highest concentration. The shape and size of targeted buffer zones are determined by the size of the flow pathway and the contribution area.
Ideally, in a grassland situation the high risk buffers should be permanently fenced off and no organic or inorganic nutrients allowed. A well designed and managed riparian buffer will break the pathway and trap the nutrients and sediment. The buffer can be enhanced further by planting broadleaf trees. This will act as a barrier to spray drift, help shade streams and stabilise river banks while the roots will absorb the soil nutrients. These areas also provide a variety of environmental and ecological services, including a habitat for biodiversity, alleviating flood threat, greenhouse gas exchanges and recreational services.
More information
Your own advisor or local Teagasc office can offer support with PIP maps and buffer zones applicable to your farm.
The Agricultural Sustainability Support and Advisory Programme (ASSAP) is an advisory service available to all farmers situated in Priority Areas for Action to support with farming and water quality issues. Find out more about the ASSAP Programme here.