Desertification is thought to be principally due to

If this question is from Weather Climate and the Biosphere part 4 then the answer to it would be that it is due to overgrazing by animals and due to poor agricultural practices i. e the grazing in the area was not regulated and it lead to decrease in the amount of grass holding the soil together and sand lost its moisture and became desert and other reason is explained as if the wrong type of agricultural practices are followed then it would lead to loss of all important nutrients like nitrogen from soil when will eventually lead to desertification