KIBBUTZ SDE ELIYAHU, Israel — Beginning next week, Israeli farmers face a strange challenge: How to avoid going bankrupt while observing an ancient biblical commandment ordering them to stop working their fields for a year.

First practiced in an era of primitive scythes, but still in force in an age of GPS-guided combines, the commandment requires Jewish farmers in Israel to let their fields rest every seventh year, just as Jews are required to rest every seventh day. The coming sabbatical starts with the Jewish new year, Rosh Hashana, on the evening of Sept. 12, and continues across the nation until the fall of 2008.

The sabbatical, known in Hebrew as "shmita," sparks arguments between mainstream Israelis and strict ultra-Orthodox clergymen, prods the Jewish state into strange arrangements with Palestinian farmers in Hamas-controlled Gaza, and forces farmers and rabbis to devise creative loopholes that allow fieldwork to continue without violating the law.

Even nonreligious Israeli growers find themselves respecting the biblical directive so they don't lose the business of Orthodox consumers.

According to an official guide for farmers published by Israel's Chief Rabbinate, the commandment makes the point "that we live in a holy and special land that isn't like other countries" and "implants in us the knowledge that this land belongs to the Creator of the Universe."

Beyond the lofty language are real problems for growers like Shaul Ginzberg of Kibbutz Sde Eliyahu, a communal farm in northern Israel.

Ginzberg's kibbutz grows and processes spices, and in a normal year 80 percent of sales are to companies that meet exacting ultra-Orthodox standards for kosher food.

But those customers won't buy anything grown by Jews in Israel this year, potentially a devastating financial blow to the kibbutz's business.

To solve the problem, the kibbutz dispatched Ginzberg to Egypt, Peru, Turkey and Hungary to look into growing spices there and marketing them under the kibbutz's label. Those efforts failed for technical reasons, but the kibbutz did manage to sign a unique agreement in the Netherlands — a Dutch company will provide spices to the kibbutz's customers while the kibbutz exports its goods to the Dutch company's customers in Europe.

But that won't be equal to the usual volume of orders, and the sabbatical year will still be difficult for the spice growers. "If we usually work 12 months of the year, this year we might be working six," Ginzberg said.

Economic reality has made it virtually impossible to obey the sabbatical commandment. Profit margins on most crops are minuscule, and intensive use of every field the norm. No farmer can afford to lose a year's income.

Recognizing this, moderate Israeli rabbis created a legal loophole to help farmers: They can sell their fields or orchards to a non-Jew for the year.

Under this arrangement, farmers can keep working the land because it's technically "owned" by someone who isn't bound by Jewish law. The vast majority of Israeli farmers take advantage of this practice, including those at Sde Eliyahu, who are religiously observant but not ultra-Orthodox.

The loophole allows farmers to make a living, and is good enough for most Israelis.

But ultra-Orthodox Jews, who interpret Jewish law stringently, have declared the loophole a desecration of the sabbatical commandment. Instead, they are willing to pay more for produce imported from abroad or purchased from Arab farmers.

"The Torah says a farmer must leave his fields fallow this year, and also says God will provide for his income. God promises a blessing to those who keep the sabbatical commandment," said Rabbi Meir Bergman, the official in charge of sabbatical observance in the Edah Haredit, an ultra-Orthodox umbrella group.

"With all of the sympathy for the farmers' difficulties, this does not allow us to break the laws of the Torah," he said. He suggested the government set up a charity fund for farmers during the year.

The ultra-Orthodox need for produce grown by non-Jews leads them to Palestinian residents of the West Bank and even growers from the Gaza Strip.