Late last month, in an incident little noticed outside the Carribbean island this country shares with Haiti, several hundred Haitians rioted and were brought under control only when Dominican soldiers surrounded them.

The Haitians were migrant workers, brought here under contract between their two governments to cut sugar cane.

The harvest over, they spent nearly three weeks waiting for the Dominicans government to take them home, herded into a corral-like barbed wire enclosure without food or sanitary facilities, before they blew up.

The migrants were quickly stopped in their plans to march from the "repatriation" compound just outside this small rural town, to Santo Domingo, 20 miles to the south. But the incident triggered a new round of news stories, protests and promises, both here and in Haiti, about the treatment of Haitians in the Dominican Republic.

Last year, the two countries were denounced before the United Nations for engaging in organized slavery, a charge they heatedly denied.

Three weeks ago, a front-paged article in a leading Santo Domingo newspaper described how taxi drivers in the western Dominican town of Barabona sold Haitians for $2 piece when they could not afford to pay for the trip toward Haiti from the cane fields.

That same week, after a number of returning workers critized their harsh treatment in the Dominican Republic on Haitian radio, the rubber-stamped Congress of President Jean-Claude Duvalier held its first-ever debate on the migrant worker question.

According to the workers -- who were promised Dominican minimum wages under a contract whose secret financial terms also included a $1.6 million cash payment to the Duvalier government for "recruiting costs" -- most of them had to use the bulk of their wages to pay inflated prices for food in the compounds where they were housed during the harvest.

The 14,000 Haitians publicly contracted by the two governments for this year's November-to-July Dominican harvest represent but a small fraction of an estimated 400,000 Haitians working, simply squatting or slowly dying in this country -- most of them illegally.

Even the contract that ostensibly supplies workers only to the State Sugar Council, through which the government owns 12 of the Dominican Republic's 16 major sugar plantations, does not enumerate all the cane cutters it covers. According to sources close to the yearly bilateral negotiations, this year's document also contains a secret appendix "buying" another 2,000 workers for the La Romana plantation -- the country's biggest, owned by U.S.-based Gulf and Western -- and three other plantations privately owned by a Dominican family.

The use of Haitian workers to harvest Dominican sugar -- and the willingness of Haitians to migrate legally or illegally -- are nothing new here. What is new in the past year or two is that anyone here cares enough to question it.

According to some island historians, large-scale movement began early in this century, when the United States occupied both countries, and U.S. sugar companies needed laborers for plantations in the Dominican Republic.

In 1937, after the U.S. Marines had gone, traditional Dominican dislike of their darker skinned neighbors -- who themselves had occupied and ruled this country for more than 20 years in the 19th century -- exploded, and dictator Rafael Trujillo had at least 12,000 Haitians massacred in a three-day orgy of resentment and racism.

But the Dominicans needed sugar, which brings in more than half the country's income, and the Haitians needed jobs. Despite the high Dominican unemployment rate, the backbreaking job of cane cutting traditionally has been considered "Haitian work" here, and few Dominicans are interested in either the low pay or the bad working conditions.

Although the border between the two countries officially has been closed since 1959, ostensibly to curtail contraband trade in cheap Haitian goods, the contraband trade in people flourishes.

Despite heavy military patrols on both sides, some Haitians manage to cross the border on their own. Others come officially under the yearly cane cutting contract. Most, however, reportedly are traded by border officials.

"If I have a coffee farm and need 200 pickers," one informed Dominican explained, "I go to the border and pay $1,000 to some soldier whose salary is $150 a month. He brings them over, I pay the $1.50 a day, give them the earth to sleep on and treat the like animals. That's the way it works."

He estimated that at least 7,000 Haitians enter the country that way annually. Many of them spend years in the Dominican Republic before returning home, if they ever do return.

Economic and racial concerns, plus a desire to keep tabs on foreigners in the country, were the reasons the first contract governing Haitian migration was signed in 1952. More recently, the contracts -- in which wages, housing, health and other benefits are guaranteed -- have served the governments as ostensible proof to be presented to domestic and international critics that they are trying to regulate a situation that even concerned officials on both sides of the border believe is essentially uncontrollable.

An increasingly vocal human rights minority in the Dominican Republic, however, argues that neither the governments nor the landowners are complying with the terms of the contracts. Dominican attorney and Haitian migrnat specialist Ramon Antonio Veras recently declared that "In the entire continent, there are no human beings who receive more cruel treatment than the Haitian braceros in the Dominican Republic, regardless of what the law says."

Haitian communities in the Dominican Republic are a mix of legal and illegal migrants -- some who cut cane or pick coffee, others who simply exist without work. Most Haitians here live on sugar plantations in compounds called bateys. Families live in rows of dirt floored barracks-like houses called barrancones.

Most have no electricity, and use common water and sanitary facilities, many times from the same source. While most nbateys have schools, they usually are adequate for only a fraction of the children.

Although the contract guarantees each cane cutter a metal bed and mattress, such amenities are rare. "It's a business," said one Dominican involved in the process. "The sugar council gives the plantation 8,000 mattresses, and they sell 5,000 of them." Many of the returning Haitians, and human rights activists in the Dominican Republic, say the migrants are beaten and sometimes killed by Dominican soldiers.

The cutters are paid $1.55 per ton of sugar cane. Although some cut as much as three tons a day, the average is much less. Each is then responsible for bringing his harvest to a central weigh-in station before receiving a pay voucher. The trip takes as many as two days out of the working week.

The Haitian government, according to a senior official interviewed in Port-au-Prince, "is very unhappy with the treatment of the workers," many of whom return home with virtually nothing after six months' work.

But volcal critics on both sides contend that the situation suits both governments, and their treasuries. In addition to the $1.6 million Haiti was paid for "recruitment costs" this year, the government also received $251,000 for hiring some 100 inspectors and supervisors to check on conditions in the bateys -- in all a more than half-million-dollar increase over last year's rate.

In addition, the Dominican government deducts $1 from the pay of the Haitians every 15 days and turns it over to the Haitian Embassy in Santo Dominigo. This money -- paid in U.S. currency under contract terms -- is to be turned over to the workers as enforced savings back in Haiti. But, of those Haitians who protested publicly on their return, none could recall having received it.

Complaining about their treatment at the hands of Dominicans soldiers, those who particiapted in the July demonstration said the soldiers repeatedly told them to shut up because "This country paid Jean-Claude [Duvalier] $1,000 for each of you."