As we've already seen, between 1950 and 1990, world fertilizer use increased 10 fold. We saw that production of fertilizer (particularly nitrogen fertilizers) is very energy intensive. Other problems with large fertilizer inputs include adverse effects on water quality and on the inherent fertility of soils.

">>" at the bottom of this page will take you to a discussion of fertilizers and water quality, or click "Navigate" for general information on moving within and among these documents.