For better or for worse, Nafta has reshaped Mexico's agricultural sector.

Protests flared in western Mexico this summer as the country's corn growers made a hard push for higher prices on their huge surpluses. Through a combination of subsidies and tight borders the farmers finally secured about 1,600 pesos a ton from the government and consumers for their grain. U.S. corn, meanwhile, would have cost the equivalent of 800 pesos a ton--if it had free access into Mexico.

And under Nafta terms, it soon will. Mexico and the United States are already halfway down the path toward the bold and controversial creation of a common market in agricultural goods--the first one ever between an industrialized and developing country.

The pricing situation in western Mexico is a stark example of the sort of discrepancies between the two countries that make Mexican producers shudder and decry the trade agreement. Many believe that the government, in opening Mexico's farm sector to imports from the world's agriculture juggernaut, the United States, sold the country's farmers down the river.

"Nafta has got to be revised," said Carlos Jaik, a leader of the growers' organization the National Front for the Defense of the Mexican Countryside. "Otherwise, it's going to do away with Mexican agriculture."

If true, time is running short. In 2003, Mexico must fully eliminate normal duties and quotas restricting U.S. imports of semi-sensitive products such as soybeans, wheat and meat. From then, duties on the highly-sensitive products of corn, sugar, dry milk and beans will face an accelerated phase-out ending in 2008 with a common market (reflecting the vulnerability of Mexico's agricultural sector, only used cars received a longer phase-out schedule under Nafta).

But a closer look at Mexico's agriculture reveals a complex, diverse sector--one where some growers are indeed struggling under Nafta's weight, others are making the transition, while the majority are facing hardship unrelated to trade with the United States.

Of Mexico's crops, grains are probably the most vulnerable to imports from the United States, which is the world's largest exporter of corn, sorghum and wheat. And local grain production indeed faces numerous disadvantages compared with the United States. Mexican farms are vastly smaller, their rainfall is less consistent, and the terrain is often uneven. Fertilizer, seeds, equipment and credit are all more expensive in Mexico than in the United States, not to mention that North American logistical and transportation infrastructure is also superior.

Grain's competitiveness is a key issue because of its social impact: The majority of farmers--2.5 million of the total 3.1 million--are grain farmers. But that statistic alone overestimates the scope of the threat posed by U.S. grains. Only a fraction of grain farmers, by some estimates as few as 20%, actually sell their products through commercial channels; the rest are mostly small-scale subsistence farmers who have only limited contact with the wholesale market.

In fact, policymakers are more concerned with creating opportunities for such small farmers to move off the land than they are with increasing their yields or changing their crops.

"When people tell me farmers are leaving the countryside my response is 'Why would you want them to stay?'" said Francisco Gurria, deputy Agriculture secretary during the administration of former President Ernesto Zedillo. "It's an incubator for the wretched."

Average plot sizes are so tiny, he adds, "that planting marijuana wouldn't even be profitable."

Aside from Mexico's commercial corn, another product critically vulnerable to an open border is sugar, where U.S. corn threatens under a different guise. In what is possibly the most botched aspect of the Nafta negotiations, Mexico agreed to give full access to the sugar substitute high fructose corn syrup (HFCS) by 2003. But the United States has extended the tariff phase-out for the entry of Mexican sugar to 2008, restricting a natural outlet for Mexican sugar displaced by HFCS.

HFCS had already ousted sugar from the U.S. soft drink industry a decade before but enjoyed only a modest presence in Mexico prior to Nafta. However, its consumption in Mexico grew quickly after the agreement went into effect until Mexico slapped "antidumping" duties on it in 1998.

Those duties were declared illegal this year by both Nafta and World Trade Organization (WTO) arbitration panels. But although traders estimate that HFCS could displace 40% more Mexican sugar within two years if the duties are removed, there is a widely-held view that both sugar markets are growing quickly enough that, in several years, the U. S. market will have expanded enough to absorb more Mexican surplus created by HFCS displacement--if Mexico's troubled industry and now partly nationalized industry can just hold on that long.

One of the justifications for Nafta's effects on the agricultural sector was the perceived need to move the disproportionately large numbers of Mexicans living in the countryside into other lines of work, in manufacturing, services and food processing. Another was that Mexican farmers, in a free market environment, would presumably choose to grow other crops that were comparatively more competitive against U.S. similars--moving away from basic grains and toward such things as fruits and vegetables. According to government officials, this is already happening. The most recent Economy Secretariat document on Nafta's effect on the agriculture sector notes that vegetable production grew 46% in volume from 1993 to 1999, while fruit production grew 16% in the same period.

But traders, pointing to persistent cases of inefficient grain surpluses like western Mexican corn, say the government has not gone far enough to refocus subsidies for other produce instead of basic grains.

Robert Randolph is a Mexico City-based freelance writer.