Beaty, Harold2021-02-252021-02-251949-09-01https://dr.lib.iastate.edu/handle/20.500.12876/95794<p>The Earth is warmer below the so-called freezeline in the winter than it is on the surface. That means there's heat in the water down there, too.</p>articleisulib-bepress-aws-west146020020060farmscience/vol4/iss3/5Agriculture