Study Reveals Effect of Salt Crust on Soil Temperature

When soil is covered by salt crust, the energy balance in soil will be changed, hence influencing soil temperature. However, the impact of salt crust on soil temperature remains unclear.

In a study published in Agricultural and Forest Meteorology, a research team led by Prof. HAO Xingming from the Xinjiang Institute of Ecology and Geography (XIEG) of the Chinese Academy of Sciences, investigated the effect of the salt crust on the soil temperature of wet sandy soils.

The researchers carried out a laboratory experiment using sandy soil with a shallow groundwater table. They saturated the soil with fresh water and saline solution (~25%, NaCl), respectively. Salt crust was formed on the soil surface by evaporation, using a halogen lamp. They measured evaporative water loss, salt cover fraction, and temperature throughout the experiment.

Researchers developed a numerical model that accounts for the variation of cover fraction and thickness of the salt crust, as well as the exothermic enthalpy of the salt crust. The salt crust was simulated with boundaries instead of full domains, enabling a reduction in the number of mesh elements.

The model can accurately describe soil temperature changes with the evolution of the salt crust and the temperature in saline soil was found higher than that in salt-free soil. “Saline soil loses less heat than salt-free soil due to the salt crust cover,” said LI Xinhu, first author of this study.

This study can help improve the understanding of energy balance in saline soil and provide new insights into quantitatively describing soil temperature variation with evolving salt crust.

Article link: https://www.sciencedirect.com/science/article/abs/pii/S0168192324004593

Contact

LONG Huaping

Xinjiang Institute of Ecology and Geography

E-mail: longhp@ms.xjb.ac.cn

Web: http://english.egi.cas.cn