hardpan
hard.pan \'ha:rd-.pan\ n 1: a cemented or compacted and often clayey layer in soil that is impenetra ble by roots 2: a fundamental part : BEDROCK
hard.pan \'ha:rd-.pan\ n 1: a cemented or compacted and often clayey layer in soil that is impenetra ble by roots 2: a fundamental part : BEDROCK