Nitrogen and the Sustainable Village

Use of synthetic nitrogen fertilizer has increased 15-fold over the past 50 years, helping triple world grain production in support of doubled human populations (Constant and Sheldrick, 1992). While synthetic N has boosted grain production in the past, the high yields of many modern N intensive cropping systems now appear unsustainable (Cassman et al., 1995). Moreover, N fertilizers are increasingly harming both local and global environments (Galloway et al., 1995; Ma, 1997).