Bolivia's leftist president must overcome steep bureaucratic obstacles and fierce political opposition before using his newly won right to seize huge swathes of land held by the country's richest and most powerful families.

Bolivian Indians danced in the capital's streets Wednesday after the passage of President Evo Morales' sweeping land reform bill, which squeaked through the Senate despite a boycott by conservative lawmakers.

Experts say, however, that the government still lacks the institutional capacity to tackle its goal of expropriating a fifth of the country's land — some 77,000 square miles — from the country's elite.

The bill signed by Morales during a boisterous ceremony in the presidential palace allows Bolivia's first Indian president to seize unproductive or fraudulently obtained property for redistribution to the landless poor.

Bolivia's Senate on Wednesday also ratified an open-ended military pact with the government of anti-U.S. Venezuelan President Hugo Chavez, and approved new contracts with foreign petroleum companies, an important step forward for Morales' populist nationalization of his country's petroleum industry.

Nationalization was a tall order for Bolivia's weak and inexperienced state petroleum company, which struggled to assume control of the country's extensive natural gas fields. But after six months of tense negotiations, international companies last month signed the contracts granting South America's poorest country hundreds of millions of dollars in new gas revenues.

The gas nationalization was widely popular at home, with big foreign oil companies making an easy political target for Morales. With land reform, the president has set his sights on powerful land magnates with deep ties to his conservative opposition and both sides seemed prepared for a long, bitter fight.

"Now comes the time for the government to take action, and that is much more difficult," said Miguel Urioste, Director of Fundacion Tierra, a La Paz-based nonprofit group monitoring agrarian reform in Bolivia. "The time for discussion, for accusations, is over."

Urioste estimates it will take a year to build a government agency capable of overseeing a sparsely populated country twice the size of France, and determining which private lands are unproductive and should be seized.

Morales may also face difficulties in setting a fair standard by which to define idle land. While the new law requires the government to check for unproductive lands every two years, Bolivia's soy farmers say their fields need to lay fallow up to five years to properly rotate their crops.

The reform's rocky passage in the Senate could also hamper Morales' effort. The president relied on votes cast by two absent senators' assistants to pass the controversial bill, granting the opposition legal leverage to question the law's validity.

Former Bolivian President Jorge Quiroga, leader of the conservative party Podemos, which led the Senate boycott, said Wednesday that Morales' tactics were "contemptible and disgusting, both legally and morally."

Podemos has accused the senators' assistants of accepting government bribes to pass the law. On Wednesday, the assistants were being guarded by police for their safety.

Agribusiness organizations in the eastern city of Santa Cruz, long opposed to Morales' land reforms, have vowed not to recognize the new law and promised to fight it in court.

Santa Cruz civic leaders broke off talks with Morales' government aimed at avoiding a nationwide strike planned for Friday. The protest was called by opposition groups to protest the president's control of an assembly to rewrite Bolivia's constitution.