Twenty miles east of Maraba, long after the frontier town's paltry bit of asphalt has given out, a ragged assembly of wood-and-mud-walled shacks stands by the roadside like an abandoned movie set. Most of the houses are empty now, although there are a few chickens, pigs and children in the dirt yards. Occasionally an overladen truck or a high-axled passenger bus lumbers down the cratered highway, pitching up clouds of red dust.

Six months of the year, this highway is impassable due to the torrential winter rains. The other six months it is full of ruts and potholes. Always, the encroaching vegetation of the Amazon jungle threatens to take back the Trans-Amazon Highway, a dirt ribbon cutting 3,000 miles through the Brazilian forest land. The land hardly seems habitable, and certainly nothing that people would fight and die for.

But Vila Uba is one of many villages that sprang up along the highway where for years peasants have come from thousands of miles away in search of a piece of land. Jose Pereira da Silva left a dried-up plot in the drought-stricken Northeast to settle here, in Para State, in hopes of making a better life for his mother and seven brothers and sisters. But in three years he was able only to set up a small bar and grocery.

So da Silva, or "Black Ze" as he was known, and dozens of other landless peasants huddled together one evening in April and decided to occupy an idle corner of Fazenda Uba, an unkempt 10,000-acre cattle and Brazil nut plantation a few miles away.

Shortly after 8 a.m. one morning in June, seven armed men, or pistoleiros, got into Edmundo Virgulino's white taxi and turned in to a logging road on Virgulino's farm, the Fazenda Uba. There, according to witnesses, the gunmen hunted down and assassinated eight squatters who had settled there. Unhindered by the police in Maraba, who possess one old Volkswagen Beetle and three investigators to cover 18 townships, three days later the gunmen swept into Vila Uba and murdered two more squatters, including the peasant leader, Black Ze. The gunmen vowed they would continue their carnage until all 66 squatter families had abandoned the area.

From the fertile pampas of the south to the Amazon frontier, Brazil is living out a deadly land war. The battle is as lopsided as it is intense: fazendeiros, or landowners, and their hired gunmen clash regularly with posseiros, landless squatters who have planted themselves defiantly on some piece of land that is not theirs.

From the time the Portuguese settlers first battled Indians here, there have been land conflicts in the Brazilian backlands. But the scale of bloodletting has increased in recent years. In 1971, the government registered 20 deaths in 109 clashes in the countryside. Ten years later, the figure had jumped to 91. And last year, in nearly a thousand violent incidents, the death toll climbed to 180.

"There is not one of Brazil's 23 states where there is not an acute land conflict," said Brazil's minister of agrarian reform and development, Nelson Ribeiro. Only a thoroughgoing agrarian reform can "prevent the country from becoming, within a decade, an immense battlefield," the minister warned.

Ribeiro ought to know. He is in charge of implementing Brazil's latest and most sweeping land reform program, which proposes to settle 10.6 million landless Brazilians by the end of the century.

Tensions and hopes all over Brazil were boosted when the new civilian government of President Jose Sarney announced its national agrarian reform plan, promising to turn over millions of acres to the poor. Landowners immediately formed pools of funds to buy arms, while the landless in Brazil's overburdened frontier towns began to mobilize to secure a piece of the promised largesse.

Six thousand landless peasants in the prosperous southern farming state of Parana are gathered along roadsides in hopes of pressuring the government into expropriating several large plantations.

"Our guns are polished," said one Parana landowner. Landowners in the southern state Rio Grande do Sul warned that landowners were buying automatic weapons.

"The age of the bow and arrow is over," said Vali Albrecht, coordinator of a farmers' association in that state. Thousands of poor Brazilians who during the recession years emigrated to Paraguay are now pouring back into Brazil. Nearly 6,000 have camped in shabby tent cities on the Brazilian border, in vague hopes of a piece of land.

"In the last 20 years, mechanized agriculture has expelled 29 million people, the equivalent of the population of . . . Argentina, from the countryside," said agricultural economist Geraldo Muller. The Brazilian cities have borne the brunt of the rural exodus, but for the past 15 years, the government has been trying to turn back the tide. During the military governments that ruled from 1964 until this year, the Amazon was thought to be a great escape valve for Brazil's swollen cities -- "a land without men for men without land," the government slogan went.

Brasilia's military leaders invested billions of cruzeiros in hydroelectric dams, mining projects, roads and migration, which lured adventurers, the rootless and unemployed by the droves to the Amazon frontier. And the government admits that it has been unable to keep pace.

Few regions of the country are as tension-ridden as agrarian reform minister Ribeiro's home state of Para, which for years has been the site of bitter disputes between migrants fleeing poverty, a traditional oligarchy of landowners and a new agribusiness elite.

Nearly 50 persons have died in land conflicts in Para in the first six months of this year, according to church statistics.

"Never have we seen this kind of violence," said Maraba's Bishop Alano Pena.

Land reform has been on the books since at least 1946, when Brazilian legislators drafted what they called a "magna carta" calling for "the just redistribution of property with equal opportunity for all." Since then, land laws have been written and rewritten while land distribution patterns have become steadily worse.

Today, 2 percent of the country's property owners hold nearly 60 percent of the arable land.

These latifundiarios have enjoyed the benefits of public roads, energy lines and other infrastructure supplied by the government. Forty percent of these holdings are considered idle or unproductive by the government, and therefore subject to redistribution.

Also under scrutiny are the nearly 27 million acres of land owned by foreigners, many of them American investors.

Big landholders have also consistently gotten a break under Brazil's inefficient rural tax collection system. Last year alone, the government failed to collect $4 million owed by residents of rural areas.

On the other hand, nearly 11 million Brazilians have no land or too little to eke out a living. Four million Brazilians are migrant workers who travel in the back of flatbed trucks in search of seasonal labor.

The latest land reform is a revival of a 1964 land statute, written by reformers in the military government. The land statute was effectively buried by subsequent hard-line governments, which had toppled the civilian government of Joao Goulart in 1964 in large part because of a growing clamor for land redistribution.

Now that the civilian government in Brasilia appears to be serious about applying land redistribution laws, owners of large and medium-sized holdings have howled in protest. They have descended by the hundreds on Brasilia, lobbied state governors and legislators and privately pressured for the ouster of one top agrarian reform official.

Three thousand landowners massed in Brasilia in June and denounced the government land reform plan as "unconstitutional, ideologically nebulous and economically unviable."

They blame communists and the activist Brazilian church for inciting squatter invasions, while leading church figures score the plan as too moderate and argue for expropriation of even working plantations.

"There are no unproductive farms here," said Jose Miranda da Cruz, who owns a 30,000-acre cattle ranch in Para. "I warned the government that property owners are arming themselves. With or without blood, we've got to find a way to defend ourselves. The news of land reform set fire to the region."

Late last month, Ribeiro was forced to move his family from the river town of Belem, in the Amazon, to a house under armed guard in Brasilia after three men kidnaped and beat a servant, whom they apparently mistook for Ribeiro's son. Ribeiro attributed the incident to "forces opposed to agrarian reform."

The government's precipitous announcement of land reform may have cost the agrarian reform plan needed allies, particularly in the elite modernized farming sector, which wanted to hear about reduced interest rates and not land redistribution.

"Brazil needs agricultural development not agrarian reform," complained Olacyr de Moraes, owner of the 125,000-acre Itamaraty Farm, the world's largest individually owned soybean plantation. "The government wants to solve unemployment by filling the countryside with illiterate and inexperienced peasants. They are inevitably going to fail.

"While the farmers in the United States are using computers, we are going back to the age of hoes. This plan will send agriculture back to the middle ages," he said.

The government announced only a 30-day discussion period before scheduling implementation of the law that had been dormant for the past 21 years. And the government was taken aback by the ferocity of the reaction.

Minister Ribeiro had to embark on an intense state-by-state lobbying effort to calm irate property holders.

Nor did the government help matters much early this month when President Sarney signed a decree issued by Ribeiro's ministry, targeting the entire locality of Londrina, in wealthy Parana State, for expropriation to resettle families squatting on an Indian reservation. The news, which rocked the town of 300,000, was published in an emergency edition of the daily newspaper at 1 a.m. the next day. The decree was quickly branded a mistake, and in the end only one 4,125-acre spread of land -- and not Londrina's entire 1.95 million acres -- was handed out to the 137 squatter families.

"Are you trying to give me a heart attack?" Parana Governor Jose Richa asked Sarney in a telephone conversation.

"My minister of agrarian reform gives me a heart attack," reportedly answered the chagrined president.

There are some signs of peace amid the gathering war clouds. After the killings at Fazenda Uba in Para, Sarney dispatched agents from the National Information Service, the national secret police, to the traditionally lawless area. No new conflicts have been recorded since.

The government colonization agency allocated nearly half a million dollars in emergency relief for the homeless families who returned from Paraguay.

In the village of Itaipavas, in Araguaia, the Amazon land agency settled a 10-year feud late last month, parceling out nearly 11,000 acres to 51 families that had battled rich farmers for part of a giant cattle ranch. The agency's president, Asdrubal Bentes, has received $14 million to settle 20,000 landless peasants by the end of next year. But, Bentes said, "Three times that number are in need of a solution."

Meantime, most of the squatters have fled Fazenda Uba. Even the village a few miles up the road is half empty. The few who remain huddle about the corner grocery, watching traffic on the dusty highway. No one talks much about agrarian reform these days.

"Every time someone drives up here, my whole body starts to tremble," Manoel Goncalves told a visitor.

Marcos Ferreira Lima shook his head and looked away.

"I don't even want to dream of land anymore," he said.