epiostracum

例句：

1. 1.The epiostracum is a type of soil that contains large amounts of organic matter.
   土化物是一种含有大量有机物质的土壤类型。
2. 2.The epiostracum plays an important role in the growth of plants.
   土化物在植物生长中起着重要的作用。
3. 3.The epiostracum is often used as a fertilizer to improve soil quality.
   土化物常被用作肥料，以改善土壤质量。