Soil Conservtion is the name given to a handful of techniques aimed at preserving the soil. Soil loss and loss of soil fertility can be traced back to several causes, including over-use, erosion, salinization, and chemical contamination. Unsustainable subsistence farming and the slash and burn clearing methods used in some less developed regions can often cause deforestation, loss of soil nutrients, erosion on a massive scale, and sometimes even complete desertification.