Variation of soil physical-chemical characteristics in salt-affected soil in the Qarhan Salt Lake, Qaidam Basin

Abstract

Soil salinization has adverse effects on the soil physical-chemical characteristics. However, little is known about the changes in soil salt ion concentrations and other soil physical-chemical characteristics within the Qarhan Salt Lake and at different soil depths in the surrounding areas. Here, we selected five sampling sites (S1, S2, S3, S4, and S5) alongside the Qarhan Salt Lake and in the Xidatan segment of the Kunlun Mountains to investigate the relationship among soil salt ion concentrations, soil physical-chemical characteristics, and environmental variables in April 2019. The results indicated that most sites had strongly saline and very strongly saline conditions. The main salt ions present in the soil were Na + , K + , and Cl -. Soil nutrients and soil microbial biomass (SMB) were significantly affected by the salinity (P<0.05). Moreover, soil salt ions (Na + , K + , Ca 2+ , Mg 2+ , Cl -, CO 3 2-, SO 4 2-, and HCO 3 -) were positively correlated with electrical conductivity (EC) and soil water content (SWC), but negatively related to altitude and soil depth. Unlike soil salt ions, soil nutrients and SMB were positively correlated with altitude, but negatively related to EC and SWC. Moreover, soil nutrients and SMB were negatively correlated with soil salt ions. In conclusion, soil nutrients and SMB were mainly influenced by salinity, and were related to altitude, soil depth, and SWC in the areas from the Qarhan Salt Lake to the Xidatan segment. These results imply that the soil quality (mainly evaluated by soil physical-chemical characteristics) is mainly influenced by soil salt ions in the areas surrounding the Qarhan Salt Lake. Our results provide an accurate prediction of how the soil salt ions, soil nutrients, and SMB respond to the changes along a salt gradient. The underlying mechanisms controlling the soil salt ion distribution, soil nutrients, and SMB in an extremely arid desert climate playa should be studied in greater detail in the future.

Arbuscular mycorrhizal fungi affect the expression of PxNHX gene family, improve photosynthesis and promote Populus simonii×P. nigra growth under saline-alkali stress

“…At the same time, the content of reactive oxygen species can exceed the threshold, destroy the biofilm such as cell membrane and thylakoid membrane, degrade chlorophyll, and inhibit the activity of PS I and PS II ( Zhang et al., 2020b ). On the other hand, excessive can cause the precipitation of Ca 2+ and Mg 2+ by forming insoluble carbonate minerals in the soil, which reduces the bioavailability of these nutrient ions by the root system ( Hui et al., 2022 ). Therefore, effective actions need to be taken to help plants alleviate the negative effects from saline-alkali stress.…”

Modeling of Water, Heat, and Nitrogen Dynamics in Summer Maize under Broad Furrow Irrigation and the Mechanism of Enzyme Activity Response

“…Nitrogen movement, encompassing convection, molecular diffusion, and hydrodynamic dispersion, is intricately tied to water movement within the soil, thereby influencing nitrogen distribution [33]. Fertilizer concentration, closely related to soil infiltration capacity [34], affects water movement by altering this capacity. Furthermore, water status and phase changes in soil critically determine its thermal properties.…”

Characteristics of Soil Salinity and Water-Salt Transport in the Vadose Zone of Salt-Impacted Regions with Variable Permeability

“…Salinization of soil, recognized globally as a critical resource and soil issue, has garnered widespread attention from various sectors of society (Farifteh et al, 2005;Sheng et al, 2010;Wang et al, 2018;Qian et al, 2019). Soil salinization refers to the process where soluble salts in the soil rise with capillary water and accumulate on or near the surface after water evaporation (Hui et al, 2022). This phenomenon is primarily influenced by natural factors such as soil parent material, climate conditions, groundwater levels (Ma, 2011), and anthropogenic irrigation practices (Su et al, 2022), with d irect and significant impacts on agricultural production (Fu et al, 2023).…”