Brazil’s lower house passed legislation Tuesday night that would loosen restrictions on how small farmers use their land in the Amazon forest. Lawmakers dropped a change that had most worried environmentalists, although critics of the bill still fear it will cause increased deforestation.

Operators of small-scale farms and ranches defend the measure as a way to let them produce to full capacity and boost Brazil’s food output. The measure passed easily 410-63, but is expected to face a tougher fight in the Senate.

The bill would let farmers and ranchers with small holdings work land closer to river banks and to use hilltops. It also provides for an amnesty from harsh fines on farms and ranches of any size that cleared more tree cover than legally allowed, but only for cutting before July 2008. President Dilma Rousseff has vowed to veto that provision.

While they would be freed from penalties already levied, bigger landholders would still have to replant land they cleared beyond legal limits or buy and preserve the same amount of forested land elsewhere to make up for what they cut. In the Amazon, 80 percent of property is supposed to remain untouched forest.

Smaller farmers would not have to replant forest land cleared before July 2008, but would still have to plant trees in areas illegally felled since then.

Legislative leaders dropped a provision — most feared by environmentalists — that would have removed all limits on preserving trees for small farmers and ranchers.

Environmentalists warn that the changes that remain in the legislation would lead to flooding, silty rivers and erosion and say the full package will inflict severe damage on the rain forest, an area the size of the United States west of the Mississippi River that absorbs the greenhouse gas carbon dioxide.

About 20 percent of the Brazilian rain forest has already been destroyed. Farmers, though, say they feel betrayed by the tough environmental rules imposed in the late 1990s, which the agriculture industry says keeps Brazil from meeting its economic potential.

Satellite images from Brazil’s National Institute for Space Research indicated deforestation in the Amazon last year dropped to its slowest pace in 22 years.

Last week, however, the government announced that 230 square miles of deforestation were recorded in March and April, nearly six times more than in the same period last year.

— Associated Press