@ARTICLE {RISASI:1998, title = {Assessment of N availability of roots of selected woody species and maize}, author = {Risasi, E. L. and Kang, B. and Opuwaribo, E. E. }, journal = {Biological Agriculture and Horticulture}, year = {1998}, volume = {16}, number = {1}, pages = {87--96}, issn = {0144-8765}, }