* Work stoppage called just as soy, corn harvesting starts * Most of Argentina's grains are taken by truck to port * Truckers to meet gov't officials late on Tuesday BUENOS AIRES, March 20 (Reuters) - A strike by Argentine truckers disrupted the flow of corn and soybeans to the country's main ports for a second day on Tuesday after union leaders failed to reach a deal with the government. The protest to demand higher pay began early on Monday, just as exporters needed to haul freshly harvested soybeans to port. The FETRA group of trucking companies met with Planning Ministry officials late on Monday, but said the government had failed to guarantee implementation of a minimum hauling tariff agreed after a strike in October. "We need a clear political decision because grains transport is in (a state of) emergency," said Pablo Agolanti, FETRA's vice president. He said talks with government officials would resume on Tuesday evening. Argentina is the world's top supplier of soyoil and a major soybean and corn exporter. The strike comes at a tough time for farmers recovering from a drought earlier in the year that reduced crop yields. Most of the country's crops are trucked from the Pampas farm belt to the export terminals and processing plants that dot Argentina's rivers. But the country's main shipping hubs lacked the usual sound of industrial-sized rigs rumbling in with tonnes of grain destined worldwide. On Tuesday morning, 26 trucks came in to the Rosario grain area, down 99 percent from the previous day, according to Rosario grains exchange. A prolonged strike could have global market implications and hurt Argentina's finances because export taxes on soy and related products account for about 5 percent of state revenue. Spot soy prices in Rosario fell on Tuesday for a second straight session as the strike hit demand from local buyers. Strikes are closely watched by grains traders and bondholders. Cargill, Bunge, Molinos Rio de la Plata, Noble and Louis Dreyfus are among the grains exporters that operate in Argentina. Labor disruptions are common in Argentina because inflation, estimated by private economists at roughly 25 percent annually, has made wage and tariff negotiations increasingly tough in recent years. Officials from a union representing port workers in the Rosario area threatened on Tuesday to strike in early April if they do not reach a new wage deal in the coming days.