Here is a video in three parts on ecological agriculture in Cuba. It's in Spanish, and the footage is sort of grainy and dull. I don't know why whenever Latin American countries are captured in videos or photos, they look about six times more decrepit and shitty than they really are. The other day I saw a photo of a research center here in Colombia. I've been there in person, and while it's no beauty of a construction, it isn't at all run-down. But in the photo it looked like some beat-up community center in 1980s El Salvador that might appear in a newspaper article about the civil war!
Anyway, here's the video on Cuba. Essentially Cuba went from having one of the world's most industrialized, chemical-intensive farming systems to a totally organic system when the USSR stopped providing cheap machinery and industrial inputs for farming. This transformation was out of necessity, because the necessity inputs simply weren't there anymore. Consequently, Cuba suffered a lot of hunger in the early 90s as it transitioned to a new model of farming. Today the country has solidified a food system based on urban gardening, diversification, and low use of agrochemicals. It's partly out of necessity and scarcity of inputs, but it seems that there now exists a more explicit, considered set of environmental and social values supporting the farming system model.