Tillage farmers can plant grass along by watercourse buffer zones as a management tool to prevent these margins from being overrun by undesirable weeds.

The necessity to leave at least two metres uncultivated along by official watercourses in tillage fields has given rise to considerable confusion at farm level. The imposition of buffer zones aims to protect watercourses from sediment loss from cultivated ground in order to prevent phosphate loss.

The measure appears to prevent the establishment of grass strips for the long-term management of the buffer zone because it bans cultivation.

But leaving these strips uncultivated in 2015 resulted in big problems, with a range of very undesirable weeds such as wilds oats, sterile brome, cleavers etc, which would quickly spread back out into fields to make bigger problems long term.

Nitrates review

When the nitrates review introduced the two-metre buffer zone measure, provision was made for the once-off establishment of grass swards.

There have been varied opinions as to whether this applies to the planting of grass strips for management purposes or not but now Department of Agriculture staff have confirmed that buffer strips can be sown down with grass for maintenance purposes.

So a once-off cultivation is allowed to establish grass in these two-metre strips beside watercourses. This will help, in time, to slow or prevent problem weeds from growing in the strips and spreading back out into the fields. However, it is essential to get the grass planted very quickly after the strip is cultivated so as to avoid the risk of sediment loss to the watercourse.

In order to manage these grass strips in the first year it is important to plant at least a three-metre strip to enable topping during the growing season.