BUENOS AIRES, Nov 3 (Reuters) - Argentina's main farming lobbies sounded the alarm on Friday over legislation they say would effectively spike taxes on the sector.

Lawmakers in the South American grains powerhouse are debating an addendum to the 2024 budget that would eliminate a series of fiscal benefits for agricultural producers.

The changes would mean a "super tax" for producers, the Argentine Rural Society and Argentine Rural Confederations said in a statement alongside two other farmer associations.

"This will undoubtedly cause less activity, the disappearance of producers and productive stagnation," the groups said.

Argentina is an important global food exporter and its agricultural associations wield significant political influence.

The proposal was made by Argentina's economy ministry, whose chief Sergio Massa is trying to bring the country's fiscal situation under control as he prepares to compete in a presidential runoff on Nov. 19.

Debate on the budget addendum began in committees in Argentina's lower house last week.

Argentina already taxes exports of soybeans and their derivatives, as well as corn and wheat, a policy to which farming groups have long voiced opposition. (Reporting by Maximilian Heath; Editing by David Gregorio)