A new U.N. report shows that about 5,000 acres (2,000 hectares) of fertile land have been lost each day for the past 20 years due to damage caused by salt, with an area affected equivalent to the size of France (62 million hectares). This is an increase from an already alarming 45 million hectares of damaged fertile land 20 years ago. Methods successfully used to facilitate drainage and reverse soil degradation include tree planting, deep plowing, cultivation of salt-tolerant varieties of crops, mixing harvested plant residues into topsoil, and digging a drain or deep ditch around the salt-affected land.