| Autor: |
Watanabe, Kunio, Takeuchi, Megumi, Osada, Yurie, Ibata, Kazumasa |
| Předmět: |
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| Zdroj: |
Soil Science Society of America Journal; Nov/Dec2012, Vol. 76 Issue 6, p1938-1945, 8p |
| Abstrakt: |
Estimating water potential in a relatively dry soil is fundamentally important, not only for predicting soil water flows in arid areas or during the evaporation process, but also for understanding soil freezing processes. A micro-chilled-mirror hygrometer (FINEDEW) that does not require a sampling chamber and has a rapid response time has recently been developed. The sensor head can be inserted into a soil sample. We confirmed that FINEDEW directly and quickly measures soil water potential in the range of less than -500 kPa in soil under near-equilibrium conditions and in the range of less than -1000 kPa in soil under evaporation at room temperature. The FINEDEW hygrometer was also applied to frozen soil at temperatures between -20 and -0.5°C. At equilibrium, regardless of soil type and freezing--thawing processes, the measured potential corresponded to the calculated potential determined using the Clausius--Clapeyron equation. Soil water potential was found to require time to reach equilibrium after a temperature change. This is thought to be because ice in the soil pores required time to acquire a new equilibrium geometry. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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