caliche

Noun

caliche (countable and uncountable, plural caliches)

1. A crude form of sodium nitrate from South America; used as a fertilizer.
2. A layer of hard clay subsoil or sedimentary rock; hardpan.
   • According to local well drillers, in wells drilled on the high plains a few hundred feet back from the caliche escarpment or in other locations on the high plains in this area no hard caliche or white layer, such as would characterize a soft layer of high lime-carbonate content, is generally...1929, Soil Survey of Potter County, Texas, US Bureau of Chemistry and Soils, page 44
   • Having a layer of caliche at depths of 16 inches and less really puts a damper on the garden site. The caliche does not allow roots to penetrate it (tree roots often take 10 years to break through a caliche layer) nor does this mineral allow water to drain.1985, Julie Behrend Weinberg, Growing Food In the High Desert Country, page 17