Buffer Strips for Fertiliser Applications - Chemical and Organic

Mary Roache ASSAP Advisor Teagasc Mayo

1. Once the growing season arrives farmers begin to apply nutrients to their lands. This can be in the form of chemical fertilisers or organic fertilisers. Organic fertiliser includes soiled water, effluents, farmyard manure, slurry etc. As well as abiding by the regulations governing good practice when deciding to apply these fertilisers the farmer must also know the relevant buffer zones. A buffer zone is a no spread area which is used for the protection of water against pollution.

Picture 1: Mandatory 5m no spread zone adjacent to surface waters for organic manures

2. The loss of nutrients to our waters is causing a decline in water quality. As a country we are required to have all our waters achieving “good status” by 2027 which is a goal we must all work towards. Nitrogen (N) and Phosphorous (P) loss from agriculture are the main nutrients which are prone to loss and contributing to the decline in this regard.

3. Nutrient enrichment occurs when excess nutrients are not retained on land or used by the growing crop and subsequently are lost to water. Phosphorous is most prone to loss from low permeability clay soils or soils which are peaty in nature. This loss occurs through overland flow of water which carries sediment and P into drains and surface waters. Conversely most Nitrogen losses occur from free draining and light soils as N does not bind tightly to soil. The application of more N than the growing plant can take up leads to loss through leaching downwards through the soil to waters.

4. To mitigate against the loss of P to waters we can “Break the Pathway” through the use of buffer strips. A buffer strip may be fenced or unfenced, planted with trees or just grass, but in all cases acts to intercept and take up excess nutrients before they negatively impact on water. Buffer strips are no spread zones for nutrients. Ditches and drains are designed to remove water from fields but act as corridors and connecting pathways for nutrients and so buffer strips should be sited along these areas of potential loss.

5. The following buffer strips must be maintained:

You Must Not Spread:
Chemical fertiliser on land within 2m of surface waters

You Must Not Spread Organic Manure Within:
5m of surface waters (extends to 10m for first 2 and last 2 weeks of the spreading season)
10m of surface waters where the slope towards water exceeds 10%
15m of exposed cavernous or karst features such as swallow holes and exposed rock
20m of a lake shoreline         
25 - 200m of a water abstraction point for human consumption

These buffer strips are the minimum required however if you have land which is sensitive to loss of nutrients you should consider extending the buffer zone to protect water. Please contact you advisor prior to application of fertilisers if you are in any doubt about which buffer zone you should abide by.

Picture 2: 5m+ buffer strip between where the slurry has been spread using LESS and the stream.

Contact details for your local ASSAP Advisor are: Eimear Connery, Teagasc, Midleton 087 9053198