[1] In 1976, he moved to Germany as a Senior Humboldt Fellow at Goettingen University; there he received a Doctor of Science degree in Tropical Agriculture.

[6] In 1978, Nair joined ICRAF, the World Agroforestry Centre, a CGIAR Institution, which he co-founded, and moved to Nairobi, Kenya, and served as a principal scientist for about 10 years.

[11] He investigated the patterns of light profile and soil-resource utilization in sole stands (monocrop) of coconut plantations in comparison with intercropping systems,[12] which provided a major scientific foundation for the emerging field of agroforestry.

This research was conducted in various tropical ecological regions and resulted in numerous publications, including a book: Soil Productivity Aspects of Agroforestry.

[14] During the 1980s, Nair also spearheaded a global inventory of agroforestry systems, with financial support of the US-AID and collaboration of numerous institutions in Africa, Asia, and Latin America.

[16] In the early 2000s, Nair started focusing his research on soil carbon sequestration in agroforestry systems as a strategy for climate-change mitigation, in collaboration with a group of colleagues from different continents.

In addition to carbon sequestration, Nair has also worked on other aspects of ecosystem services of agroforestry systems including biodiversity conservation, soil-degradation control, and water-quality enhancement in soils.