80 % or more of the acreage available for manure application on farms shall be cultivated with grass. Farmers benefiting from an individual derogation shall carry out the following measures:
temporary grassland shall be ploughed in spring;
ploughed grass on all soil types shall be followed immediately by a crop with high nitrogen demand;
crop rotation shall not include leguminous or other plants fixing atmospheric nitrogen. This will however not apply to clover in grassland with less than 50 % clover and to cereals and pea undersown with grass.