P. K. R. Nair, Univ of Florida, 118 Newins Zeigler Hall, PO Box 110410, SFRC, IFAS, Gainesville, FL 32611
After being ignored in the single-commodity paradigm of agricultural and forestry development, agroforestry––the age-old practice of growing crops and trees together––has now come of age as a robust, science-based, integrated discipline, thanks to 25 years of research efforts worldwide. Agroforestry offers a unique set of opportunities for arresting land degradation and providing ecosystem services in both low-income- and industrialized nations. Noteworthy among such practices that are used in tropical environments include incorporation of fast-growing, nitrogen fixing trees and shrubs in agricultural fields to improve soil fertility and minimize erosion hazards, and use of appropriate tree and shrub species for reclamation of salt-affected and other degraded lands. Establishing trees as windbreaks in agricultural fields to arrest wind erosion is a well established practice in both tropical and temperate regions. Recent studies at the University of Florida have shown the importance of silvopastoral systems (integrating trees with forage and livestock production) as a particularly relevant approach to enhancing water quality and carbon sequestration, and therefore a best management practice for ranchers. It is projected that agroforestry practices could have an impact in addressing these land-management problems in an estimated 1.9 billion hectares of degraded land in developing countries alone.