Crossword Clue:

SOLUM a soil layer

AnswerCrossword Clue
SOLUMSoil layer
LOAMSoil layer
HARDPANCompact soil layer
GLEYWet soil layer
HARDPANClay layer under soil
PERMAFROSTLayer of soil that never thaws
HARDPANFirm layer of clay underlying soft soil.