Perhaps you should try some spelling variations:
decrease desertification » areas desertification (Expand search), decrease nitrification (Expand search), jeremoabo desertification (Expand search)
desertification process » identification process (Expand search), identification processes (Expand search)
the decreased » the decrease (Expand search), the deceased (Expand search), the increased (Expand search)
decreased and » decreases and (Expand search), decrease and (Expand search), decreased in (Expand search)
decrease the » decreases the (Expand search), decrease of (Expand search)
and decrease » and decreases (Expand search), and decreased (Expand search), and increase (Expand search)
in decrease » in decreased (Expand search), on decrease (Expand search), pain decrease (Expand search)

You may be able to get more results by adjusting your search query.

• Removing quotes may allow a broader search: (( decrease in decrease desertification process ) OR ( decrease the decreased and decrease ))~.