Effect of initial soil water content and bulk density on the infiltration and desalination of melting saline ice water in coastal saline soil

Abstract

Laboratory experiments were conducted to investigate the infiltration of melting saline ice water into coastal saline soil with different initial water contents and bulk densities, together with the redistribution of water, salt and salt leaching after infiltration. Three water contents (5, 10 and 15% at a soil bulk density of 1.3 g cm−3) and three bulk density levels (1.2, 1.3 and 1.4 g cm−3 of air‐dry soil) of saline soil were used, with salt‐free ice comprising the control treatment. The results showed that the depth of infiltration with treatment by saline ice was greater than that of salt‐free ice, and increased as the initial soil water content and bulk density decreased. After infiltration, the soil water content in the upper soil layers increased with increasing initial soil water contents and bulk densities. This trend was reversed in the deeper soil layers. After infiltration of the melting ice water, the saline ice treatment resulted in a smaller soil salt content than the salt‐free ice treatment. The salt contents in the upper soil layers decreased with decreasing initial soil water contents and bulk densities. The largest rate of desalting was observed following infiltration of the melting saline ice water into the coastal saline soil with the smallest soil water content and bulk density. These results indicate that although a similar infiltration process was observed when the melting saline ice water and direct saline water infiltrated the saline soil with different soil water contents and bulk densities, the desalting effect of infiltration of the melting saline ice water was greater than that of infiltration of direct saline water and melting salt‐free ice water. Smaller initial water content and bulk density favoured salt leaching under the infiltration of melting saline ice water. Highlights We evaluated infiltration and soil desalination under melting saline ice into saline soil Rate of infiltration and depth increased with decreasing initial soil water content and bulk density. Soil water content in the top soil layer increased with increasing initial water content and bulk density. Rate of desalting increased with decrease in initial water content and bulk density under infiltration of melting saline ice water.

The successive infiltration of various saline waters accelerates the infiltration processes and enhances the salt leaching in a coastal saline soil

“…These factors result in a higher mean infiltration rate of SIRs than DIRs during the whole infiltration process. Moreover, under MIR, the infiltration depth increased with increasing ice salinity at the same infiltration time (Guo & Liu, 2014, 2019; Li et al, 2008). Similarly, the above trends were also observed in this study during the successive infiltration of various saline water samples (Figure 3).…”

“…As a result of the above situation, crop production has not been obtained, and the growth of most plants is limited except for some native halophytes (Chen et al, 2015; Tao et al, 2014). In this context, in recent years, a new practice is developed to improve coastal saline soil by the method of freezing irrigation in winter using local saline groundwater or drainage water in this area (Guo & Liu, 2014, 2019; Li et al, 2008). Under the condition in cold winter, the saline water with salinity higher than 12 g L −1 is irrigated and frozen into saline ice expeditiously on the top of soil surface.…”

“…The previous soil column and field studies have indicated that the infiltration of such meltwater can result in obvious soil salt leaching effect (Guo & Liu, 2015; Li et al, 2008). Meanwhile, both the ice qualities and initial soil conditions impact the soil salt leaching, water distribution and reduction of sodium adsorption ratio (SAR) (Guo & Liu, 2014, 2019). However, the infiltration process plays a major role in determining the soil salt distribution.…”

Development of a soil wetting pattern estimation model for drip irrigation

“…Hence, the presence of low water content in the soil pores increases the time required to fill the pores with water, which in turn reduces the advance of the wetting front and increases the amount of water required (Liu et al 2019;Patle et al 2019;Cheng et al 2021). When the water content increases, the difference in potential energy decreases, which decreases the flow of water, decreases the time required to fill the pores with water, accelerates the advance of the wetting front, and decreases the volume of applied water (Talsma 1974;Or et al 2001;Guo & Liu 2019;Roy et al 2020). This, however, contradicts the concept of dimensionless analysis, in which the advance of the wetting front is proportional to the total volume of applied water [Equation ( 4)].…”

Evaluation of Different Shallow Groundwater Tables and Alfalfa Cultivars for Forage Yield and Nutritional Value in Coastal Saline Soil of North China

“…Life 2022, 12, 217 2 of 14 mismanagement and overexploitation of water resources in some arid or semiarid climates were important reasons for soil salinization [9]. The underlying saline groundwater in this area provides abundant water resources for agricultural production [10] and has a large potential for exploitation and use. At present, the use of shallow groundwater has become an important measure to relieve agricultural freshwater scarcity [11].…”