ADOMA, Zimbabwe — The ragged farmers shout and whistle as the oxen trudge through the drizzle, dragging a rusty plow through sodden fields. Most passing motorists splash by without a second glance.

The withered men look like ordinary peasant farmers. But they have no fertilizer, no irrigation, few seeds and little hope that their crops will flourish in this season of erratic rains.

They are the beneficiaries of President Robert Mugabe's agricultural revolution.

Over the past two years, the government has redistributed nearly all of the country's white-owned farmland to about 300,000 poor black families and 50,000 aspiring black commercial farmers. Of the 4,500 white commercial farmers who once powered the economy by producing tobacco and wheat, about 600 are still trying to farm, mostly on smaller holdings.

Mr. Mugabe, who has led this country since white rule ended in 1980, has hailed the sweeping change as the fulfillment of the black struggle for liberation in Zimbabwe. Many Africans praise him for undoing the legacy of British colonialism, which left a tiny white minority — less than 1 percent of the population — with more than half of the country's fertile land.

But the government's chaotic and violent seizure of white-owned farms has come at a price. The economy is collapsing. The land program, coupled with severe drought, has left half the population in need of emergency food. And so far, Mr. Mugabe has failed to transform the agricultural sector into a viable system that can feed the nation and drive the economy.

Vast stretches of previously productive farmland are no longer in use because about half of the aspiring black commercial farmers have failed to take up their allotted farms since August, when most white farmers were told to leave.

The government, which seized the farms without compensation, still lacks title to most of the land. Many prospective black farmers are reluctant to occupy farms without title deeds because it is nearly impossible to get loans without them.

Meanwhile, thousands of impoverished, resettled farmers are struggling to survive without seed, fertilizer, irrigation and plowing assistance, basic services that the government has promised. The United Nations says that more than half of the government's tractor fleet — which was meant to plow fields for the poor — is out of service because of shortages of spare parts and fuel.

Officials are so short of seed and fertilizer that many small farmers are sitting idle on plots of land they cannot plant. In Manicaland Province, only about 10 percent of resettled farmers have seed and 17 percent have fertilizer. When seeds are available, the government often provides unsuitable varieties.

"In most cases, the maize seed supplied is not suitable for the areas in which they have been distributed," the United Nations said in a recent report. Some newly resettled farmers are also going hungry as the country's food shortages worsen. Aid agencies report that farmers in the district of Gwanda have gone without food assistance from the government for three months. Zimbabwe, once one of Africa's most prosperous nations, is now a country of hungry people.

Much of the trouble stems from the haste in which the government tried to distribute land. In a bid to woo disillusioned black voters, officials scrambled to parcel out land to as many people as possible before the presidential election this year. They did so without much planning or coordination.

Government officials say problems are inevitable in any large land redistribution program, particularly at a time of severe drought, and they promise to set things right. They are already warning would-be black commercial farmers that they will lose their land if they do not occupy their farms.

Officials say they are also stepping up efforts to find inexpensive seed and fertilizer for new farmers.

"We took it for granted that the supplies would be adequate," Mr. Mugabe said this month in an interview with the state-controlled newspaper, The Herald. "It then proved that we were mistaken," he said. "Seed is short, fertilizer is short and tillage is inadequate. We are working on that."

Officials say the long-term benefits of eliminating racial inequities in the economy outweigh any initial problems, no matter how large. Mr. Mugabe has made it clear that changing course is out of the question.

"We are at a stage where things are irreversible, and we are happy for it," Mr. Mugabe said in the Herald interview. "For us, the most valuable resource and source of our wealth is our land."

During the colonial era, British settlers stole the country's best land and forced blacks to move to stony, arid communal areas. Mr. Mugabe, who helped lead the struggle against white rule, has repeatedly promised to return the land to blacks over the past two decades. In the beginning, the British government helped finance Mr. Mugabe's land program in an open acknowledgment of colonial misdeeds. After white rule ended in 1980, the British paid for the purchase of land to resettle thousands of black families.

The British ended their support after complaints of corruption and cronyism in the land program began to emerge in the 1990's. In 1998, Western donors agreed yet again on a plan to finance land reform, but that plan collapsed.

In recent years, Western governments have withdrawn all financial aid, aside from food, from Zimbabwe to protest the land seizures and the attacks on the political opposition.

Several white farmers and dozens of black farm workers have been killed by government-backed militants, while thousands of other black farm workers have been evicted and left homeless. The government has also been criticized for giving prime land to prominent officials and political allies.

Officials here continue to insist that blacks will benefit from land reform in the long term, even though they lack adequate financing. Research from Zimbabwe's early experiments with land redistribution shows that resettled people were typically better off several years after they had been given land, even when they had not received any government support.

"These early problems are inevitable," said Dan Zvobgo, a local official who oversees land reform in the district of Makonde. "It's only a question of time before they are all resolved."

But whether this hasty and poorly coordinated effort will succeed in the long term is hard to judge. Zimbabwe has never attempted such a large land redistribution before. Between 1980 and 1998, about 71,000 families were resettled, officials say.

This time, the government resettled four times as many households in just two years as officials raced to persuade disillusioned black voters to support Mr. Mugabe and his party in national elections.

"It's massive by Zimbabwean historical standards and by international standards," said Rogier van den Brink, a land expert at the World Bank who worked in Zimbabwe until recently.

"A program of this size would need much, much more resources to make it work," Mr. van den Brink said. "To do this type of land reform program in the midst of a macroeconomic crisis is extremely difficult, if not impossible."

But it is happening. Thousands of white farmers have already packed their bags. Some have moved to the cities to wait for the situation to improve. Others have left the country altogether, looking for a new start in South Africa, Mozambique, Britain and Australia.

"Some people are still waiting for some sort of respite, but a lot of people are leaving now," said Colin Cloete, the president of the Commercial Farmers' Union, which once represented 4,500 white farmers. "Many have decided they never will farm again."

In early December, a group of impoverished black farmers asked the authorities to allow a white farmer to stay on his land because he was providing them with water and helping them to plow their fields. Their request was denied. The white farmer was forced to leave and the black farmers were forced to consider their futures.

Manase Machekano, a 35-year-old resettled farmer, said he was losing hope.

"I wish to plant maize, ground nuts and cotton, but I don't have the seeds," said Mr. Machekano, who was wearing a President Mugabe T-shirt. "The seeds are not coming in time, and soon the season will be over."

Tane Zingwa, an old man with four oxen, also complained that assistance has been slow in coming. He has no fertilizer and few seeds. Soon, he will have no water. Still, he continues to put his faith in the government.

"What will happen to us?" Mr. Zingwa said. "I don't know. It's up to the government. The government put us here. The government must look after us."