The retranslocation rates of major nutrients (N, P, and K) in the leaves of three dominantly available indigenous tree species (Hagenia abyssinica, Croton macrostachyus, and Cordia africana) was studied in Gozamn Woreda, North Central Ethiopia. Both green and abscised leaves of these tree species were collected to quantify the retranslocation rates of the major nutrients. Results of the analysis indicated that the retranslocation rates of nutrients in the leaves of C. africana, C. macrostachyus and H. abyssinica were 32 to 56%, 31 to 59%, and 42 to 61% respectively. Specifically, 56 to 61% for N, 54 to 59% for P, and 31 to 42% for K were recorded. Generally, the retranslocation rates of nutrients was in the order of N > P > K and thus leads to the conclusion that there is a difference in the retranslocation rate of nutrients in these species. Application of green manure from these species can therefore improve the availability of N and P in the soil.

Keywords: Cordia africana, Croton macrostachyus, Hagenia abyssinica, Retranslocation, indigenous tree species