With the collapse of the Soviet Union in 1989 -1990, Cuba suddenly found itself with 60% lower pesticide and 77% lower fertilizer imports, and 50% less petroleum available for agriculture. There was also a drop in food imports by more than 50%. In response to the looming food shortage crisis, as their agriculture was mostly based on large-scale, capital intensive, monoculture farming systems that were heavily reliant on synthetic pesticides and fertilizers (derived from petroleum), and on petroleum itself, the Cuban government launched a national effort to convert the nation’s modern conventional farming system into an organic one that was low-input and essentially self-reliant.
Pesticides and herbicides were replaced by pest, pathogen, and weed control methods that made use of bio-pesticides (such as various bacterial and fungal disease agents the Cubans developed), plant-based pesticides like Neem, natural enemies (such as various parasitic and predatory insects), inter-cropping and crop rotations, and the contributions to weed control made by farm animals. Synthetic fertilizers were replaced by bio-fertilizers (including Rhizobium inoculants for legumes, free-living nitrogen-fixing bacteria, and mycorrhizal fungi), earthworms, compost, animal and green manures, and the integration of grazing animals.
There was also a return to animal traction in place of tractors, because of the unavailability of fuel, tires, and spare parts. Woodlands surrounding farm fields were encouraged, and they provided not only forest products (lumber, fuel wood, fruits, nuts, and honey), but also habitat for insect-eating, and pollinating, birds, insects, and bats. Farms were converted from large, specialized enterprises with one, or at most only a few, products to mixed farming systems producing fruits, vegetables, grains, livestock, and fish. The resulting diversification created a mosaic of land use that served to help buffer against both extreme weather events and infectious diseases in livestock and crops.
In 1993, Cuba greatly reduced the state farm infrastructure, turning farms into cooperatives, a form of worker-owned enterprises, and encouraged the return of urban populations to the countryside. Farmers markets were also re-opened. By mid-1995, the food shortage had been overcome, and the 1996-97 growing season in Cuba recorded its highest-ever production levels for ten of the thirteen basic food items in the Cuban diet. Production came primarily from small farms, and in the case of eggs and pork, from booming backyard production. The proliferation of urban farmers who produce fresh produce has been vitally important to the Cuban food supply, with more than 30,000 hectares (around 74,000 acres) in cities devoted to agriculture, producing more than 3 million tons of fresh vegetables each year for some 11 million people. More than 50,000 tons of food were produced annually during the late 1990s in the city of Havana alone.