As the soil degrades .
Desertification occurs , farmers are forced to continually move farther out to find new land to farm which repeats the process all over again ; thereby , farmers are exacerbating the clearing of natural forests .
As the soil degrades and desertification occurs , farmers are forced to continually move farther out to find new land to farm which repeats the process all over again ; thereby , farmers are exacerbating the clearing of natural forests .