I can recommend two interesting documentaries on this matter.
How Cuba Survived Peak Oil
http://www.powerofcommunity.org/cm/index.php When the Soviet Union collapsed in 1990, Cuba's economy went into a tailspin. With imports of oil cut by more than half – and food by 80 percent – people were desperate. This film tells of the hardships and struggles as well as the community and creativity of the Cuban people during this difficult time. Cubans share how they transitioned from a highly mechanized, industrial agricultural system to one using organic methods of farming and local, urban gardens. It is an unusual look into the Cuban culture during this economic crisis, which they call "The Special Period." The film opens with a short history of Peak Oil, a term for the time in our history when world oil production will reach its all-time peak and begin to decline forever. Cuba, the only country that has faced such a crisis – the massive reduction of fossil fuels – is an example of options and hope
When they didn't have access to oil, they also didn't have access to chemical pesticides. Before they used a lot. Now they had none and the soil was poor. For 3 years the harvest was poor too. They used composted organic foodrests to nutrify the soil each year. Then after 3 years the harvest regained it's richess and now they have better and more food than ever. Without pesticides.
The Secret of El Dorado
New evidence that advanced societies flourished in the Amazon Basin before the arrival of Europeans It was the most notorious wild-goose chase in history: the Conquistadors' search for El Dorado, a fabulous kingdom of gold that Indians said lay hidden in the jungles of the Amazon Basin. But now, at last, archaeologists have uncovered the truth behind that myth. They have found evidence of a huge society, as advanced as the Egyptians or the Incas, right in the heart of the rainforest. And this is more than the story of a lost world rediscovered. For it seems that the people of the real El Dorado possessed a secret with the power to transform our world and their secret in the soil could be the solution to solving famine in the third world and other nations once and for all....
A few million people, for some centuries lived from or within the forest, without destroying it. To maintain such large number of people they had found a way of producing organic fertilizor so they could grow enough crops without impoverishing the soil.
You don't really need pesticides.
They are enforced by the chemical industry - oil industry. The same story as with synthetical nylon fiber instead of
natural hemp fibres.