HAVANA - Cuba's agriculture ministry said Wednesday the country has made considerable headway in conservations programs aimed at curbing soil degradation that poses a serious threat to food supply.

Mario Riverol, top official for soil conservation at the ministry, said the programs cover more than 600,000 hectares of land and include measures such as use of dams, organic fertilizers and a regular rotation of crops.

Studies find more than 40 percent of Cuba's agricultural land has been damaged by erosion and poor drainage, while half of the nation's arable land had been declared unproductive in 2008.

Cuban leader Raul Castro regards food production as a national security issue and has vowed to boost agricultural output.

Cuba relies on imports for over 80 percent of its food supply and this year alone it will cost the poor Caribbean island more than $1.8 billion to import foods.