humic acid   (TTS Sound)

The humic_acid has 1 Senses.

• humic acid
• フミン酸
• a dark brown humic substance that is soluble in water only at pH values greater than 2; "the half-life of humic acid is measured in centuries"
• pH値を2を上回る程度の溶解性のこげ茶色の腐植物質