Time slurry spreading to reduce nutrient losses
Richard Crowe, Countryside Management Branch, Department of Agriculture and Rural Development (DARD)
Slurry can provide a valuable range of nutrients for crop growth - but needs to be applied at the right time to avoid losses to the environment and be available to the growing grass or crop. Effectively used, slurry can reduce the need for 'bought in' fertiliser.
However, spreading slurry when soil and weather conditions are not appropriate can potentially lead to high losses of nutrients, including nitrogen and phosphorus.
Across Northern Ireland, the efficiency of use of nitrogen on farms is very low, with only 15-20 percent of nitrogen inputs yielding crop or animal products. The remainder is lost to the wider environment - air, soil and water.
According to the Code of Good Agricultural Practice for the Prevention of Pollution of Water, losses of nutrients can be minimised, and risk to the environment reduced, by not spreading slurry when:
- Soil is waterlogged.
- Land is flooded or likely to flood.
- The soil has been frozen for 12 hours or longer in the preceding 24 hours.
- Land is snow covered.
- Heavy rain is forecast within 48 hours.
Research indicates that the greatest risk of run-off and loss of nutrients from slurry, due to low crop growth, poor soil conditions and high rainfall, is from October to February.
The Protection of Water Against Agricultural Nitrate Pollution Regulations (Northern Ireland) 2004, which came into operation on 29 October 2004, require the Department of the Environment, together with the Department of Agriculture and Rural Development, to establish and apply an action programme to regulate farming activities throughout Northern Ireland in order to reduce and prevent pollution from agricultural sources.
The action programme will give statutory effect to a series of measures many of which are already recommended as best practice in DARD's Code of Good Agricultural Practice for the Prevention of Pollution of Water. The overall aim is to achieve improved water quality in Northern Ireland through the promotion of improved water quality in Northern Ireland through the promotion of good farming practice and the more efficient use of nutrients on farms. An immediate financial benefit will be a reduction in the need to apply inorganic fertiliser.
Don't lose out - make effective use of the valuable nutrients in slurry, and minimise the risk of pollution. For further information about pollution prevention, contact Countryside Management Branch staff at your local DARD office.
