The damages resulting from frost heaving are the main causes of channel destruction in seasonal frozen soil regions. Over the years, many experimental studies have been performed regarding the channel anti-frost heaving in the Hetao irrigation area. However, there have been few experimental research studies conducted regarding the insulation and anti-frost heave effects of polystyrene boards (EPS) of different thicknesses. Therefore, in order to explore the insulation mechanism and anti-frost heave effects of precast EPS laid under the conditions of different thicknesses, an anti-frost heave test field was established in the Hetao irrigation area for the examination of the ground temperatures, frozen depths, frost heave amounts, and water content change rules. This study’s results showed that, for the laid EPS with thicknesses between 2 and 12 cm, the frost-heave reduction rate ranged from 53.2% to 92.6%; total accumulated temperature warming ranged from 248.65% to 565.93%; and the frozen depth reduction rate was between 59.8% and 75.9%. It was determined that the EPS per cm additions could effectively improve the ground temperatures at a buried depth of 30 cm by 0.78 °C, and reduce the frozen depth by 10.1 cm. Then, by comprehensively considering the positive economic and insulation effects, it was determined that the most appropriate thickness of the EPS laid under the precast concrete slabs in the Hetao irrigation area of Inner Mongolia was 8–10 cm.

In this research study, platforms with different heights were established for the purpose of simulating the different groundwater level conditions. Combined with the prototype channel, the influences of the groundwater level changes on the frost heave deformations in the foundation soil and on the frost heave force of the channel, as well as on the bending moment of the channel section and water content migration of the foundation soil, were studied by the method of mechanical analysis. The research results show that, after a comparative analysis of the ground temperatures in the same layer had been completed, the difference value was found to have been less than 5%. The frost heave of the foundation soil had decreased by 0.15 cm for every 1 cm reduction in the groundwater level. In addition, the maximum frost heave force of the channel was shown to have varied with the change of groundwater level. This study's theoretical calculations determined that the most unsafe groundwater level of a typical channel was 2.61 m. It was concluded that the increase of groundwater level can reduce the amount of soil moisture transfer, while the influence of groundwater level on frost heave of foundation soil can be effectively reduced by laying polystyrene boards.

To investigate the impact of combining aluminum sulfate with straw and irrigation water to enhance soil quality in soda saline–alkali soil, in this study a field experiment was conducted in Tongliao City, Inner Mongolia Autonomous Region, China. With beet IM1162 as the indicator crop, four levels of aluminum sulfate dosage (30, 60, 90, 120 g m⁻²) and four levels of drip irrigation water quota (225, 270, 315, 360 m³ ha⁻¹) were set. The study examined the impact of varying levels of aluminum sulfate and irrigation water on soil water salt and crop yield. Next, using a comprehensive evaluation method, the optimal quantities of aluminum sulfate and irrigation water needed for effective soil improvement were determined. The research findings indicate that the most effective treatment (W2S3) involved an aluminum sulfate dosage of 90 g m⁻² and an irrigation quota of 270 m³ ha⁻¹. This treatment resulted in significant improvements compared to the control (CK) group. Specifically, in the 0–50 cm soil layer, the following improvements were observed: the water storage capacity (SWS) increased by 51.7%; evapotranspiration (ET) increased by 16.2%; water use efficiency (WUE) increased by 55.0%; and irrigation water use efficiency (IWUE) increased by 98.1% (p < 0.05). These results emphasize the importance of optimizing the combination of aluminum sulfate dosage and irrigation water quota to improve soil conditions and crop performance. It is worth nothing that this study highlights the potential for enhancing water use efficiency and crop yield in agricultural practices, which can contribute to sustainable and efficient farming practices. The study results revealed significant improvements in soil quality and crop yield when compared to the control group (CK). Specifically, in the 0–50 cm soil layer: the soil salt content decreased by 19.8%, soil pH increased by 8.7%, and exchangeable sodium percentage (ESP) decreased by 34.0%. Moreover, the crop yield in the treatment group increased significantly, by 32.1%. These findings indicate the positive impact of the intervention on soil health and agricultural productivity. The study employed the game theory combination weighting method to comprehensively evaluate soil water, salt, and various yield indicators. The results showed that the sustainability weight for crop yield reached 0.116, emphasizing the aim of soil improvement: the sustainable enhancement of crop yield. This approach underscores the importance of balanced soil management practices to ensure long-term agricultural productivity and environmental sustainability. The comprehensive evaluation results of grey relation analysis and the TOPSIS coupling model showed that the soil improvement effect score was the highest when the dosage of aluminum sulfate was 61.7–120.0 g m⁻², and the irrigation quota was 250.4–319.4 m³ ha⁻¹, which was the recommended range for the local area. The research findings discussed in the provided sources contribute to the theoretical basis for soil improvement in soda–saline–alkali land.

In this study, the channel frost heaving actions in the Hetao irrigation area of Inner Mongolia were examined and a field in-situ test platform was established. Then, experimental investigations were conducted regarding the insulating and anti-freeze effects of polystyrene boards under the conditions of concrete bags with different thicknesses. In this study's experiments, concrete bags with different thicknesses were set, along with a test block of polystyrene boards with different thicknesses. The research results showed that by adding 2–5 cm molded bags, the total accumulated temperature increased in the range of 3.93–9.22% and the frost heave rate decreased by between 18.28 and 55.44% concrete, on the basis of 10 cm molded bag concrete. In addition, when 4–8 cm polystyrene boards were laid, the total accumulated temperature increased by 207.63–272.25%, and the frost heave rate decreased by between 71.43 and 96.6%. The absolute slope of the curve fitting of the frost heave rates and the soil temperatures decreased by 44.6–58.7%.

As a new lining technology, mould bag lining technology has been widely used in recent years. In this paper, the channel frost heave in Hetao irrigation area of Inner Mongolia was studied and a field in-situ test platform was established. The experimental study on the insulation and anti-freeze of polystyrene board under the condition of concrete bag with different thickness was carried out by setting the concrete bag with different thickness and the test block of polystyrene board with different thickness. The research shows that the total accumulated temperature increases by 3.93%~9.22% and the frost heave rate decreases by 18.28%~55.44% by adding 2–5 cm mold bag concrete on the basis of 10 cm mold bag concrete. Laying 4~8 cm polystyrene board, the total accumulated temperature increased by 207.63%~272.25%, and the frost heave rate decreased by 71.43%~96.6%. The absolute slope of the curve fitting the frost heave rate and soil temperature decreased by 44.6%~58.7%. Laying polystyrene plate can inhibit the migration of soil water during freezing-thawing period, reduce the formation of frozen front ice intercalation, and thus reduce the damage of channel frost heave.

To alleviate the eutrophication in the Wuliangsuhai watershed and evaluate the pollutant reduction performance of ecological drainage ditches in the Hetao Irrigation District, a controlled field simulation experiment was conducted using synthetic agricultural return-flow water formulated from long-term monitoring data. Three leguminous plant treatments, two microbial substrate treatments, and one control were established to compare the migration and transformation of total nitrogen (TN), total phosphorus (TP), and chemical oxygen demand (COD) in overlying water, sediment, and plants under different hydraulic retention time intervals (0–6 h, 6–12 h, and 12–18 h). The results showed that plant treatments generally improved conventional water quality indicators, with increased pH and dissolved oxygen (DO) and decreased electrical conductivity, salinity, and total dissolved solids, whereas microbial substrate treatments tended to reduce DO. Pollutant reduction performance differed among treatments. Medicago sativa showed the strongest TN removal from overlying water, Microbial biological rope exhibited the best TP removal from overlying water, and Melilotus suaveolens performed best in COD reduction. Among all plant treatments, Astragalus laxmannii exhibited the most stable overall performance and a relatively strong integrated capacity for nitrogen and phosphorus retention. Most TN and TP reduction in overlying water and sediment occurred during the initial hydraulic retention time interval of 0–6 h, whereas TN plant uptake became more evident during 12–18 h. These findings suggest that ecological drainage ditches vegetated with locally adapted leguminous species have potential to mitigate agricultural non-point source pollution in arid irrigation districts. In particular, Astragalus laxmannii appears to be a promising candidate for ecological ditch design in the Hetao Irrigation District. However, this study was conducted under controlled synthetic return-flow conditions rather than with actual field drainage water, and no tracer-based hydrodynamic verification was performed; therefore, the reported hydraulic retention time effects and treatment efficiencies should be interpreted cautiously. Further field-scale validations under real drainage, seasonal variation, and long-term operation conditions are still needed.