León has worked with communities to retrieve pre-Hispanic traditions of using barriers to prevent hillside erosion. He has helped identify ancient terraced agricultural systems in the region, many in ruins, and helped communities rebuild the barriers using stones from the fields. The resulting flattened areas impede erosion and enhance agricultural production. León pioneered the construction of contour ditches, retention walls and terraces to capture rainfall and prevent erosion on hillsides. Five kilometers of contour ditches have been shown to capture 1,800,000 liters of water after each heavy rain, recharging the aquifers below. An estimated 80 percent of rainfall previously flowed off the land without filtering, thus causing erosion and preventing the refilling of aquifers. León and CEDICAM worked with farmers throughout the region to build hundreds of kilometers of contour ditches.
In order to promote sustainable agricultural practices, León began a program to help farmers convert to natural compost fertilizers and to use native seed varieties. Most farmers in the region now use native seeds. As a result of the public education and seed-saving efforts, the region is becoming a GMO-free zone. León also started a program to promote local foods and traditional indigenous diet, in opposition to the influx of processed foods accelerated by free trade and changes in culture due to immigration. Many small farmers believed that using chemicals was the modern way and by returning to traditional practices they would be seen as ignorant. León taught people to appreciate the role of the small farmer, building prestige and pride into the recuperation of traditional indigenous and small farming methods. He began applying sustainable methods among a small group of farmers and as neighbors saw concrete results, they too converted to sustainable farming.
León and CEDICAM are have worked with more than 1,500 small farmers in 12 communities. They have planted more than one million trees and reforested more than 1,000 hectares. Their sustainable agriculture programs led to the conservation of some 2,000 hectares. Further, they have protected 5,000 hectares with stone terraces and walls, leading to a 50 percent increase in agricultural production and increased topsoil and water retention, resulting in ecological, social and economic benefits. Where in years past only 25 to 30 percent of the land was arable, communities now farm upwards of 80 percent of the land. The contour ditches that prevent run-off of rain water have led to a 50 to 100 percent increase in spring levels. Farmers throughout the area have converted from industrial fertilizers and pesticides to natural compost fertilizers and native seed varieties, and are returning to local foods and a traditional indigenous diet. For a semi-arid zone like the Mixteca, all of these changes have immensely improved lives throughout the region’s communities, leading to less out-migration.
León’s success resulted in interest from other regions and countries. He has shared his experience in water conservation, anti-erosion techniques, and sustainable agriculture at forums throughout Mexico, Central America and the Caribbean, and at various universities and events in the US.