humic acids

例句：

1. 1. Humic acids are important for soil health and plant growth.
   腐殖酸对土壤健康和植物生长非常重要。
2. 2.The humic acid in the soil helps to improve water retention and nutrient absorption.
   土壤中的腐殖酸有助于提高水分保持和养分吸收。
3. 3. The use of humic acids in agriculture has been shown to increase crop yields.
   农业中使用腐殖酸已被证明可以提高作物产量。