The United Nations Food and Agriculture Organisation has just published its first global asessment of the world's land resources.
It finds that most of the potential agricultural land is already being farmed. Of that, 25 percent is assessed as highly degraded, 8 per cent as moderately degraded, 36 per cent stable or slightly degraded and 10 per cent as improving. The degradation takes the form of soil erosion, water depletion and degration, and biodiversity loss.
The dramatic increases in agricultural yields brought about by the 'green revolution' begun in the 1960s have now tailed off and in part the very farming practices introduced by it have themselves resulted in the land and water resource degradation.