The farmers have threatened to renew their roadblocks
Argentina's lower house of Congress has approved a controversial package of taxes on agricultural exports.
Farmers are strongly opposed to the measures and have staged widespread protests over the past four months, resulting in riots and food shortages.
They had threatened to renew roadblocks if the measures were approved.
Argentina is one of the world's top producers of soya, grains and beef and the government wants a bigger share of the profits, it says to fight poverty.
Farmers say such high taxes are crippling.
The vote of 129 to 122 came after a heated 17-hour debate in Congress. The Senate is due to consider the measure in coming days.
The BBC's Daniel Schweimler in Buenos Aires says the country is now waiting with bated breath to see whether farmers will accept the vote, which most commentators say is unlikely, or start rebuilding their roadblocks.
Late on Friday, some concessions were made to smaller farmers who would pay less tax.
But our correspondent say that is unlikely to be enough and Argentina remains divided - between city and countryside, rich and poor, pro and anti-government.
Eduardo Buzzi, president of the Argentine Agrarian Federation, said his group would continue to fight the taxes.
"We're still playing in the first half. In the second half, we're going to play in the Senate and we'll go to the courts, even to the Supreme Court," he said.
Farmers lifted their roadblocks when President Cristina Fernandez de Kirchner sent the issue to Congress.