A hardened impervious layer, typically of clay, occurring in or below the soil and impairing drainage and plant growth.
- ‘The simplest way to see if your soil has a hardpan or compaction layer below the surface is to take a metal rod and walk around your property sticking it into the ground.’
- ‘A reader in Tucson says he plays public courses where the greenside bunkers have just a thin layer of sand over hardpan.’
- ‘Depending on torque and speed of specific models, they can be used in conditions ranging from loose, heavy, or rocky soils to hardpan, frost, and asphalt.’
- ‘The stuff you find yourself in is primarily hardpan, glacial till, and some topsoil.’
- ‘A hardpan or impervious layer of soil (called caliche in the Southwest's low deserts) might be the cause.’
We take a look at several popular, though confusing, punctuation marks.