The process of raising the world s food has not always been kind to the environment. Yet soil degradation has also been a factor, and one with implications for food production as well. Some of this land was only slightly degraded, but an appreciable amount was damaged severely enough to impair its productive capacity or to take it out of production completely.
Degradation comes in several forms, the best known of which is soil erosion.
Farmland can be degraded in several other ways besides erosion. Physical degradation from mechanical tilling can lead to soil compaction and crusting. Repeated cropping without sufficient fallow periods or replacement of nutrients with cover crops, manure, or fertilizer can deplete soil nutrients. Poor water management on irrigated cropland is a leading cause of degraded farmland. Inadequate drainage can lead to waterlogging of the soil or to salinization, in which salt levels build up in the soil to toxic levels.