The magnitude of the ratio of (HA+FA) Se to total Se in order was A horizon > C horizon > W horizon, and that of (FA Se) to (HA+FA) Se was C and W horizons > A horizon.

• 腐殖酸硒 /全硒为A层 >C层 >W层 ,富里酸硒 /腐殖酸硒为C、W层 >A层。