_:b1217720 "FAO:http://fao.org/ag/agl/agll/wrb/doc/wrb2006final.pdf"^^ . _:b1217720 . _:b1217720 . _:b1217720 "Durisols are associated mainly with old surfaces in arid and semi-arid environments and accommodate very shallow to moderately deep, moderately well- to well-drained soils that contain cemented secondary silica (SiO2) within 100 cm of the soil surface."^^ . _:b1217720 .