Likely organized by farmer protest groups (FDF for example) to protest against emission restriction regulation. They are known for their dangerous stunts, including driving their tractors on the highway and spraying manure on government buildings. These actions are tolerated by the Dutch police, which willingly and purposefully refuses to punish these acts.
Farmers and right wing people in all of Europe are actively being disinformed by Russian intelligence service and either wilfully ignores it or too incompetent to realize it.
It's crazy how much deference is given to farmers compared to every other occupation.
If the garbage men started dumping the contents of garbage bags in public places I bet they will not be given a free pass.