S. rostrata was the third highest net mineral N producer followed by X. xylocarpa during the earlier part; and T. indica and P. macrocarpus during the latter part. The non-leguminous residues produced lower N mineralization than their legume counterparts, and several residues exhibited net N immobilization after week 2, while rice straw produced net N immobilization throughout Figure 1b. Azmal et al. 1996 also found that rice straw treated soil had N immobilization throughout the 8-week incubation study. Constantinides and Fownes 1994 found that legumes from a tropical agroforestry
system produced more N mineralization than the non-legumes. The use of fresh organic materials L. leucocephala and S. grandiflora also resulted in higher N mineralization than the use of litter. Constantinides and Fownes 1994 compared the use of fresh materials of many species with their litter counterparts and found that the fresh materials produced higher N mineralization.