Remember Remember The 15 Of September

Where chemical fertiliser remains to be applied it is vital to sow as soon as possible.

Chemical fertiliser can be applied up until 14 September as the Nitrates Regulations state that chemical nitrogen fertiliser must not be applied between 15 September and 31 January. This “closed period” for spreading reflects both environmental factors and economic considerations.

Research shows that nitrogen applied during this period will have a high potential to leach out of the soil into watercourses. Also, the combination of mineralisation, the process by which nitrogen from organic material in the soil becomes available, and falling grass growth ensures that there is adequate nitrogen available in the soil during the autumn. There is no economic justification for nitrogen applications after 14 September.

However, where a requirement can be demonstrated for crops other than grassland, for example, late sown winter oilseed rape, chemical nitrogen fertiliser can be applied during this time. There is no nitrogen requirement for the establishment of grass reseeds or for the seedbed in winter cereals.

For further advice on the Nitrates Regulations contact Countryside Management staff at your local DARD Office.