By Duncan Bartlett
Business Daily, BBC World Service
Japan's government gives farmers four times market value for rice
Rice was once so important to Japan's culture that it was worshipped as a god.
Yet the economic problems now facing Japan's rice farmers make it almost impossible for them to make money.
As a result, the Japanese government subsidises the industry and tries to stop imports of foreign rice.
Other nations complain these practices breach world trade rules, but it could be very hard for the rice farmers to manage without such help.
Take the village of Matsunoyama, 300 kilometres north of Tokyo. Even in late March, while the cherry blossoms appear in the south of Japan, snow lies thick on the Matsunoyama's rice fields.
Heavy snow hampers rice cultivation in winter in many parts of Japan
Farmer Keichi Obuchi, 72, complains that it is hard to earn a living in the snow and he is uncertain about its future.
"I have been a rice farmer for 40 years," Obuchi says. "But I can't imagine rice farming surviving here for ever. It is increasingly harder to make money. The number of farms has declined a lot."
He continues: "It will be hard to continue rice farming as a business, given the uncertain situation over the government subsidies.
"Personally, I have no heir to take over my farm after I retire. So, I don't know what will happen to my farm."
His daughters have long left the village, where the population has fallen from 50,000 to 2,800 within the past 50 years.
It is a similar story in other parts of Japan. Around Yokohama for example, many rice farms have been swept away by the tide of urban development.
Farmers have agreed to sell their paddy fields to companies developing new homes and hotels, dramatically changing the landscape.
Fearing the loss of the rice fields altogether, the government of Japan attempts to protect the industry in two ways.
Firstly, it blocks nearly all imports of cheap foreign rice from countries like China and America.
Secondly, the government pays farmers four times the market value for their rice and then sells onto the shops at a loss.
This costs Japanese tax payers nearly $2bn a year.
The US claims the Japonica strain of rice it grows in California would be popular with the Japanese and cheaper than the home-grown variety.
"We are certainly sensitive to the Japanese view of the cultural and food-security importance of rice production in Japan," says Michael Rue from the California Rice Commission.
"But our total production of rice only represents a small percentage of what Japan consumes and produces, so California is not a threat to the existence of the Japanese rice industry."
"However, we would like to have the freedom to market our product to their consumers - much as they do with many of the products that come from Japan to the US."
Australia and China would also like to get a larger share of Japan's rice market and want Japan to end its import restrictions and subsidies.
But the farmers of Japan realise they would probably lose their livelihoods if they had to compete with a flood of cheap imported rice.