More than 10,000 Dutch farmers protested in The Hague on Saturday against government plans to limit nitrogen emissions.
The farmers said the new regulations will be the end of many farms.
Many held the national flag upside down.
Farmers in Belgium recently staged similar protests.
On the other hand, thousands of environmentalists blocked a major thoroughfare at the her end of The Hague to protest against tax rules they said encourage the use of fossil fuels. Police used water cannon to disperse a group of about 100 of the activists late in the afternoon.
The pro-farm protesters carried banners reading "No farmers, no food," and "There is no nitrogen 'problem'" during the peaceful demonstration organised by the Farmers' Defence Force group.
Relatively large numbers of livestock and heavy use of fertilizers have led to levels of nitrogen oxides in the soil and water in the Netherlands and Belgium that are higher than European Union regulations allow.
Farm groups said the problem has been exaggerated and that the proposed solutions are unfair and ineffective.
