Soil bulk density (ρ_b) is a critical parameter for describing soil structure and physical processes, yet traditional methods are unable to capture spatial and temporal changes in ρ_b. Recently the thermo–time domain reflectometry (thermo‐TDR) technique has been applied to determine in situ ρ_b on the basis of soil thermal property and water content measurements. Here, we present theory, instrumentation, procedures, and comments for monitoring in situ ρ_b with the thermo‐TDR sensor. We conclude that the thermo‐TDR sensor offers a useful tool for determining ρ_b continuously and nondestructively.

中文翻译：

---

热时域反射法：原位监测土壤容重

土壤堆积密度（ρ _b）是用于说明土壤结构和物理过程的关键参数，但是传统的方法是无法捕捉在ρ时空变化_b。最近的热时域反射（热TDR）技术已经被应用在原位ρ来确定_b土壤热特性和水含量的测量的基础上。在这里，我们目前的理论，仪器仪表，过程和原位监测ρ评论_b与热TDR传感器。我们的结论是热TDR传感器提供了确定ρ的有用工具_b连续和非破坏性。