Eighty per cent or more of the area 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 on sandy soils 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 however will not apply to clover in grassland with less than 50 % clover or to other leguminous plants that are under-sown with grass.