South Korea announced Friday it would scrap rice import caps from next year, but said high tariffs would be imposed to prevent a damaging surge that would hurt local farmers.
The decision to open the market up was forced by the imminent expiry of a two decade-old deal on rice import quotas that South Korea had secured with the World Trade Organization (WTO).
Even though the move was expected, it remains a divisive and extremely sensitive political issue and was met by angry opposition among farmers' groups, who protested outside the main government complex in Seoul.
"We've come to the conclusion that there is no other alternative but to open up the rice market," Agriculture Minister Lee Dong-Phil told reporters.
"But we will protect the rice industry as best we can by imposing the highest possible tariffs allowed," Lee said.
The tariff will have to be verified by the WTO, but Lee said Seoul would push for a rate "within the range of 300-500 percent".
The current agreement with the WTO provides for mandatory rice imports which this year will amount to nearly 410,000 tonnes -- or around 10 percent of consumption.
In a statement, the Agriculture Ministry said the imposition of steep tariffs meant any increase in imports in the coming years would be "insignificant".
Rice farmers fear the tariffs will swiftly be cut back as the result of free-trade deals with rice exporting nations.
An alliance of South Korean farmers' groups and trade unions issued a statement denouncing the opening of the rice market as a "human disaster".
"We will never accept this unilateral, irresponsible declaration," the organisation said.
At the demonstration outside the government complex, dozens of farmers hurled packets of rice over the walls and waved placards with slogans such as: "Rice is our life" and "Protect our food sovereignty."
Some, wearing black armbands, had their heads shaved on the spot as a gesture of protest.
Im Jeong-Bin a professor at Seoul National University and an expert on trade issues, said the government had no option but to scrap the import caps.
"South Korea depends heavily on trade and it would hardly be able to keep its rice market closed while exporting other goods," Im said.
"Given the international treaties to which it is a party, there was no way it could further delay this move," he added.