In Berlin, dozens of tractors and lorries stationed in the city centre blasted their horns to signal anger at the start of a planned week of action.
Workers in sectors across Germany, from metallurgy and transport to education, have turned to industrial action in recent weeks.
Wage negotiations have taken a bitter turn as Europe’s biggest economy struggles with weak growth and households contend with sharply increased prices.
Rail workers will be next to walk out as they launch a three-day strike on Wednesday. Unions seek a pay rise to compensate for months of painfully high inflation.
Farmers began gathering on Sunday evening at the Brandenburg Gate in the heart of the government quarter in Berlin. The agricultural sector is up in arms over government plans to withdraw tax breaks.
Farm vehicles blocked the centres of cities including Berlin, Hamburg, Cologne and Bremen, with up to 2,000 tractors registered for each protest.
Outside cities, demonstrators targeted motorway access ramps, snarling traffic in a coordinated nationwide show of discontent.
The protest also caused disruption at Germany’s borders with France, Poland and the Czech Republic, backing up traffic at crossing points.
Thousands of protestors had already descended on Berlin to protest against the planned subsidy cuts in December, blocking roads and dumping manure on the street.
The rallies prompted the government to partially walk back the reductions on January 4.
A discount on vehicle tax for agriculture is now planned to remain in place, while a diesel subsidy would be phased out over several years instead of being abolished immediately, the government said.
The farmers, however, have said that the move does not go far enough and urged Berlin to completely reverse the plans, which were announced after a shock court ruling forced the government to find savings in the budget for 2024.