Soil fertility decreases and soil chemical properties change as a result of overgrazing and rangeland degradation. In Mongolia, soil organic matter content in overgrazed areas was 30-50 per cent lower and exchangeable calcium 40-60 per cent low'er than in non-grazing areas. Land degradation was also found to affect physical soil water properties, increasing topsoil temperature and decreasing moisture content. Moreover, topsoil becomes denser and more compact as a result of livestock pressure on the soil surface, increasing bulk and particle density and making the soil more compact.