straw, hollow stem
稈 centers on the dry, hollow stalk of grain plants: straw left after harvest, or the hollow stem itself.
稈 combines 禾 (grain plant) with 旱, which likely contributes the sound and may relate to dryness, fitting the idea of dried grain stalks.
Grain 禾 beside 旱 (dry): picture a dry grain stalk, hollow and ready to be used as straw.
For カン, imagine a can made of hollow straw: can -> カン, and the grain stalk becomes a container.