Takeshi Yamada frowns as he surveys his herd of 28 "wagyu" beef cattle, prized for their marbled meat and fetching as much as ¥1 million per head.

"The government told us to evacuate, but we don't want to leave our cattle behind," said the 62-year-old farmer in Iitate, Fukushima Prefecture. "If we're forced to go, we are worried we won't be able to come back and farm again."

Iitate became a haven for refugees after the March 11 earthquake and tsunami triggered the worst nuclear crisis since Chernobyl by crippling the Fukushima No. 1 nuclear power station 40 km away. Now the government is telling residents of Iitate and three other villages to leave by the end of May because contamination in soil and water has reached dangerous levels.