The Nitrates Directive on Steeply Sloping Ground

A requirement of the Nitrates Directive is that chemical fertiliser and manures must not be applied to steeply sloping land. In the Northern Ireland Action Plan, Department of Agriculture and Rural Development and Department of the Environment  recently agreed with the Commission the definition of ‘steeply sloping’.

Land is steeply sloping where the average incline is 20 percent or more. A slope typically consists of a smaller gradient at the top and bottom, resulting in an overall average incline of less than 20 percent. It is estimated that approximately 3 percent of the agricultural land in Northern Ireland has inclines greater than 20 percent.

Even if an average incline of 20 percent or more exists, fertiliser and manures can still be applied provided that there is not a significant risk of causing water pollution. The factors contributing to these risks include the closeness to water, soil conditions, the ground cover that is present and rainfall.  Therefore, in practice, the requirement to have an average slope of 20 percent in combination with these other risk factors ensures that this particular measure will have limited impact on farmers in Northern Ireland.  No matter what the slope always take care when applying fertiliser or organic manure to avoid run-off.

It should also be noted that current advice from the Health and Safety Executive for Northern Ireland advises that care should be taken for tractors and tankers when slopes exceed 15 percent. Slopes exceeding 17 percent are considered potentially dangerous. The ability of tractors with fertiliser spreaders and tankers to ascend or descend safely on such slopes will depend on a number of factors.  This includes speed, tyre size and inflation and whether or not the tractor is two or four- wheel drive. Most importantly the presence and the effectiveness of brakes on the tractor and the slurry tanker affect the safe ascent and descent on slopes.  

Remember that the objective of the Nitrates Directive is to improve nitrogen efficiency.  Farmers should make better use of nutrients by applying them where land conditions are favourable, thereby reducing the risk to water quality.