Home Publications & Data Book Chapter Nutrient cycling author(s) Friesen, Dennis K. published in1994 regions Colombia original file download full citation Friesen, Dennis Keith. 1994. Nutrient cycling . In: Centro Internacional de Agricultura Tropical. Savannas program: Biennial report 1992-1993 . CIAT, Cali, CO. p. 1-13. (Working document no. 134)