The problem of land degradation is not new. In fact, soil erosion, soil salinity, and related
forms of land degradation have been with us from the time when humans first domesticated
animals, settled, and started to raise crops, at least 7000 years ago. At times, the problem of
land degradation has become so severe that it has contributed to, if not caused, the decline
of great civilizations in such places as China, Mesopotamia, Egypt, North Africa, and
Greece.
Confronted with the problem of land degradation, over the centuries farmers have
developed ingenious strategies and systems of land use and management to protect and
rehabilitate their lands. Many of these have been very effective and the remains of some of
them can still be seen in old terracing systems in several countries, including Yemen,
China, and Peru, as well as in farming systems such as shifting cultivation which is still