Vice President Bush, after concluding a tour through drought-stricken areas in Africa, declared today that the United States was prepared to contribute half of the emergency food needs this year for the continent's 30 million famine victims.

Speaking to a United Nations special conference on famine relief, Bush said the administration planned to seek funds from Congress to provide 3 million tons of food during this fiscal year. U.S. emergency aid is expected to surpass $1 billion in food, in addition to $788 million in previously planned non-food assistance.

While stressing that "what counts in the short term is getting food to people before they die," Bush said that a cyclical pattern of famine must be broken through the adoption of free-market policies and more sophisticated growing methods to cope with Africa's harsh conditions.

Bush had been slated to return to Washington after his address to the U.N. session, but he will instead travel to Moscow Tuesday as the chief U.S. representative at the funeral of Konstantin Chernenko.

After witnessing what Bush called "the results of ecological disaster and human failure" in the parched African earth, the vice president expounded on the administration's strategy to prevent recurrent starvation by encouraging agricultural rehabilitation carried out by Africans.

"Africans seek our help not because they want to depend on us, but because other models have failed and they want to get back on their own feet," Bush said in his prepared text. "We donors have a responsibility to our own citizens and to Africa alike to give both relief and forms of aid that do not perpetuate dependency."

During his eight-day trip through Sudan, Niger and Mali, Bush said he perceived a new emphasis on policies favoring free agricultural markets across the continent. He said that nearly half of all African countries have embraced some kind of shift to free markets.

He said the removal of price controls in Somalia has instigated a 40 percent jump in sorghum and banana production, and Malawi has become a net exporter of corn after open-market pricing led to a doubling of output.

Bush said the Reagan administration intended to promote this trend through its Food for Progress program, in which non-disaster food will be offered to those nations undertaking to free markets.

Bush said he also felt optimistic that Africa would benefit in decades to come from improved farming techniques, so that sufficient quantities of crops could eventually be raised.

"Africa needs its own Green Revolution," he said. "It needs research to develop new seed varieties appropriate to Africa's fragile soils and its fickle climate."

In Khartoum, Bush said he learned about a drought-resistant strain of sorghum that promises to increase yields by 150 percent. "If Sudanese farmers come to use it for just a quarter of the sorghum they grow, Sudan will feed itself," he contended.

Bush compared the continent's spreading deserts with the phenomenon of the Dust Bowl in the 1930s when the central plains in the United States experienced a prolonged drought.

"People said that land would never produce crops again," Bush said. "Today, an important part of the food America ships to Africa comes from what was once the Dust Bowl. With more research, Africa, too, will reclaim its once productive land."