undersoil

1. New irrigation and undersoil heating systems were also installed at the same time as the2003 work.
   在2003年的那次大修中，新的灌溉系统和地热系统也被安装上了。
2. Suitable conditions of application, rainwater balance calculation and rainfall runoff intensity of undersoil are key issues in rainwater utilization engineering which are studied along with compiling Code of Design and Practice for Rainwater Utilization in Buildings and Sub-districts.
   雨水利用工程的适用条件、水量平衡计算、下垫面径流系数的确定等是《建筑与小区雨水利用工程技术规范》编制中需要解决的关键技术。
3. Studies on the Forest Humus Layer and Its Impact on the Quantity of Undersoil Moisture
   凋落物层对渗入底土水分数量影响的研究

noun

1. the layer of soil between the topsoil and bedrock

   Synonym:    subsoil