About 25 tractors parked outside a distribution centre for supermarket chain Albert Heijn in Zaandam [Peter Dejong/AP Photo]

Amsterdam, July 4 (RHC)-- Farmers in the Netherlands have blockaded supermarket distribution centres in continuing protests against new environmental rules on nitrogen emissions that are likely to put many of them out of business.

Fishers on Monday blocked ports in a show of support for farmers.  The blockade prevented ferries from sailing to almost all the Wadden Islands off the country’s northern coast and caused lengthy delays, shipping companies reported.

The action had been announced in advance, with farmers calling for “the entire country to be paralysed.”   Airports had also made preparation for blockades on access roads. Traffic along most of the country’s dense road network was reported to be normal.

Police said they would intervene if demonstrators moved to block access to Schiphol international airport near Amsterdam.  Over recent weeks, Dutch farmers have engaged in occasionally violent protests against environmental rules aimed at cutting back nitrogen emissions.

While other sectors, including construction, have also been hit, measures to curb the ammonia generated by livestock farming are a significant part of government plans.

Nitrogen emissions are to be cut by more than 70 percent in areas close to nature conservation areas. According to government estimates, this could lead to the shutting down of about 30 percent of livestock farms.

A 2019 ruling by the country’s highest court prompted the government to impose the measures.