Traditional grazing methods entailing the minimum of grazing are questionable, as too are traditional methods of grass conservation, including hay making. Uncontrolled grazing must essentially be wasteful of feed, for at peak periods of growth the pasture becomes over-mature, and this results in poor quality fodder of low value in terms of animal production. The loss of nutrients in hay as normally cured on the ground is again high and the whole process is therefore wasteful. Hay of a kind can be made even in bad weather, but the labour required for making it is excessive and the loss of nutrients serious. Overexploitation of grazing lands triggers soil erosion, desertification, and other processes of degradation. Productivity is quickly diminished, with far-reaching consequences on the local and national economy and on the well-being of the peoples concerned. Traditionally, livestock production is the main use of these areas, but other considerations, such as tourist value of these spacious lands, are also important.
Grazing lands cover about one third of the world's land surface. They include many areas in arid and semi-arid regions, as well as mountainous and high altitude zones which are too steep or too hot, too cold or too dry for intensive cultivation. These lands have low productivity per unit area, and are inherently fragile.
In China 870,000 square kilometres of grassland areas have been degraded due to over- pasturing, reclamation for agricultural use and damage by rodents. An area of 3.67 million square kilometres has been eroded by water and wind.