The desert is spreading in Lambayeque department, on Peru's northern coast, due to the irrigation of rice paddies, a practice that is increasing the salinity of the soils and transforming them into sand dunes like those that already encircle the valleys in the region. We have recorded an excessive and growing concentration of saltpeter in Lambayeque's valleys, warns Servio Cereceda, executive director of the Olmos Tinajones Irrigation Project Directorate.

Cereceda points out that the 430 km of canals built in the area to drain off the water from the paddies has not halted the salinization of the lands because the traditional technique of flooding smaller parcels continues.