n.腐殖质
When the humus has been formed, plants can grow well in it. 一旦腐殖土形成，植物就可以在里面茂盛地生长了。
Humus is dead, decaying organic matter. NOT inorganic fertilizer. 腐殖质是已死的、腐烂中的有机物质。而不是无机肥料。
