He is an advocate of sustainable agriculture and is highly critical of large agribusiness corporations such as Cargill, Monsanto, and ADM.
He has conducted most of his research in California and Chile working closely with farmers and workers to implement principles of integrated pest management, intercropping, cover cropping, crop-field border vegetation manipulation, and other sustainable practices of biological control.
He also served for 4 years as the General Coordinator for the United Nations Development Programme’s Sustainable Agriculture Networking and Extension Programme which aimed at capacity building on agroecology among NGOs and the scaling-up of successful local sustainable agricultural initiatives in Africa, Latin America and Asia.
He was Director of the US-Brasil Consortium on Agroecology and Sustainable Rural Development (CASRD), an academic-research exchange program involving students and faculty of UC Berkeley, University of Nebraska, UNICAMP and Universidad Federal de Santa Catarina.
[6] in 2017, he became Honorary Professor of the University of La Frontera[7] Altieri is the author of more than 200 publications, and more than a dozen books[5] including Agroecology: The Science of Sustainable Agriculture (1987, 1995, 2018),[8] Biodiversity and pest management in agroecosystems (1994, 2004)[9] and Agroecology and the Search for a Truly Sustainable Agriculture (with Clara I. Nicholls, 2005).