This fertilizer is rich in humic substances, which are very beneficial for plant growth.

humic 来自拉丁语 humus（意为"土壤"），加上形容词后缀 -ic 构成，指"与腐殖质有关的"或"来自腐殖质的"。humic substances 指土壤中由动植物残体分解形成的有机物质，即"腐殖质"。