Posted: 4 April 2001

Desertification means the degradation of land in dry areas of the world. It is not the spread of existing deserts, but rather the loss and destruction of healthy fertile soils. Loss of topsoil and soil fertility results in declining production of crops and livestock. Overall the problem is caused by people putting too much pressure on delicate soils and ecosytems. The main causes of degradation include:

  • Overgrazing - Too many livestock, such as goats or cows, strip the soil of its vegetation and expose it to erosion by wind and water;
  • Deforestation - Trees hold soil together and help water the land by channeling rainwater into the soil. When they are chopped down, the soil is eroded by the elements and is unable to hold water;
  • Overfarming - Overworking the land eventually drains the soil its nutrients, leaving it unable to produce crops;
  • Poor irrigation practices - Bad irrigation can lead to waterlogging and salinisation of soil.Over one-quarter fo the Earth's land surface has suffered erosion and soil degradation.