By Daniel Schweimler
BBC News, Buenos Aires
Sunflower crops are among the goods being taxed more
Protests by farmers in Argentina are nothing new. But what is new is the scale and ferocity of these latest demonstrations.
In just a few days, farmers and their supporters have brought Argentina to a near standstill and pushed the government of President Cristina Fernandez into a corner she will find difficult to escape from.
The farmers are angry at an increase in taxes imposed on beef, soya and wheat - some amounting to 45%.
The rises were imposed to boost the country's coffers and to help in the fight against inflation, which in recent months has shown signs of getting out of control.
But what pushed the farmers and their supporters out onto the streets was the timing of the increases - just a few days before the soya harvest.
Then, to make matters worse, President Fernandez, in a speech designed to deflate the tension, accused the farmers of being greedy and trying to rob the country.
"I won't bow to extortion," she said.
Some shops are running short of meat and dairy products
That belligerent tone brought city dwellers out onto the streets in support of the farmers, bashing pots and pans in what has become a common Argentine form of protest.
There is a long history of mistrust in Argentina between city and countryside and this show of support from urban dwellers took many, including the government by surprise.
Each day Argentina is seeing more roadblocks erected around the country. Long-distance buses are cancelling services, food is not reaching the towns and cities, and shelves are emptying.
There have been counter-demonstrations in the capital, Buenos Aires, by government supporters who have clashed with farmers. Riot police are stationed at potential flashpoints.
Malcolm Rodman, a farmer and member of the Sociedad Rural, the main agricultural organisation in Argentina, accused the government of shooting itself in the foot.
"They simply don't understand the countryside," he said. "I think things are going to get a lot worse before they get better."
Marcelo Rasetto, a farmer manning a roadblock in the northern province of Santa Fe, said: "There's no going back. What the government did was harsh - it was insolent. And this won't get them anywhere.
"This is not a countryside rebellion. This is a rebellion by the whole interior of the country. The whole interior of the country is saying 'no'."
President Fernandez and the former president, her husband Nestor, are trying to gather their supporters for a show of force.
However, many of their ministers and regional governors are themselves landowners and farmers with loyalties split between the government in Buenos Aires and their constituents and neighbours in the countryside.
The gaucho life is close to Argentines' hearts
Argentina is a country built on agriculture.
Although most Argentines nowadays live in the cities, they idealise the gaucho, the Argentine cowboy, herding cattle on the flat, green plains, the Pampas.
Argentines on average eat 70kg of beef a year, far more than anywhere in the world and the dominant smell across the country at the weekends is that of meat cooking on parrillas or barbecues in back-gardens or balconies.
What happens in the countryside is felt strongly in urban areas.
The farmers also say it was their hard work and investment that helped rescue Argentina from its economic crisis of 2001 and 2002.
They were aided by the high price of soya especially on international markets. Their wheat and beef are also highly sought after.
Adding to the farmers' frustration is their claim that little of the money they pay the government is re-invested in the countryside.
Farmer Marcos Torres told a national newspaper: "The truth is, the government doesn't have a long-term plan for agriculture."
He, like many, is urging the government to admit it was wrong to raise taxes so drastically and to then sit down and negotiate.
The Argentine government says it will not negotiate until the farmers lift their roadblocks. There appears to be little room for compromise. And with both sides planning large demonstrations over the next few days, the tension is only likely to increase.
Meanwhile, the supermarket shelves are emptying and the soya is still waiting to be harvested.