The Nitrates Directive is designed to prevent pollution of surface waters and groundwater from agricultural sources and to protect and improve water quality, according to Teagasc.
In response to this, tillage farmers are now required to take measures to establish green cover as soon as possible post-harvest to prevent the pollution of waters caused by nitrates.
Shallow cultivation or sowing of a crop/catch crop must take place within 10 days of the baling of straw, or where straw is chopped, within 10 days of harvest.
But, in all circumstances, shallow cultivation or sowing of a crop/catch crop must take place within 14 days of harvesting.
Shallow cultivation is only applicable to the following counties: Carlow; Cork; Dublin; Kildare; Kilkenny; Laois; Louth; Meath; Offaly; Tipperary; Waterford; Westmeath; Wexford; and, Wicklow.
In certain weather conditions, the Minister for the Environment, Climate and Communications, in discussion with the Minister for Agriculture, Food and the Marine, may grant an exemption.
Nitrates Directive
Soil consolidation as an alternative to shallow cultivation may apply in situations following oilseed rape or where the Land Parcel Identification System (LPIS) parcel has been certified by a Farm Advisory System (FAS) approved advisor as containing certain grass weeds (brome species and black grass).
If soil consolidation is practised as an alternative to shallow cultivation, it must also take place within 14 days of harvesting.
A minimum of 20% and a maximum of 25% of cereal land on each holding shall not be subject to shallow cultivation post-harvest to avoid possible negative impacts on farmland bird species. Unless a crop has subsequently been established, this land shall not be subject to the use of any herbicides until at least February 1, in the following year.
Organic
Shallow cultivation does not apply in a number of cases. These include where the farmer is certified organic or where a cereal crop or beans have been harvested after September 15.
Also exempt are situations where a cereal crop has been under sown with another crop.
There is no requirement for shallow cultivation after a root crop or where a winter cereal crop, oilseed rape or beans are due to be sown on the land by October 31.
Another exemption relates to lands that are destined for use by the National Ploughing Association.