The only way to economically protect eroding rangelands worldwide is to do what nature does and have the land grow its own protection.

To do this, nature's forces must be able to

• Plant seeds and establish young plants to cover bare ground and replace old plants that die
• Grow enough plant material to protect the soil surface
• Knock down standing growth and place it on the soil as litter (mulch)
• Build soil.

Tallgrass prairie does an excellent job of protecting soil. The combination of grasslands, grazers, and predators to kept herds bunched and moving, built soils up to 2.7 meters (9 feet) deep over vast areas of North America.

Once grazed by bison and elk, this prairie outside Salina, Kansas, U.S.A. is now maintained by longhorn cattle, which are managed to imitate wild grazers.