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【Objective】 Soil problems in southern Xinjiang of China are many and vary, characterized by scarce rainfall, shallow groundwater and high soil salinity. To safeguard crop production, mulched drip irrigation coupled with subsurface drain have been developed as the dominant cultivation in this region. The purpose of this paper is to experimentally study the efficacy of this system in desalinizing cotton fields. 【Method】 A two-year experiment was carried out in a cotton field with shallow groundwater table. Spacing of the subsurface drains varied from 10 m to 30 m, and their buried depth varied from 0.8 m to 1.1 m. Treatment without drains was taken as the control (CK). The field was mulched, and the cottons were drip-irrigated. The effect of the drains on spatiotemporal dynamics of soil salt was measured, and its variation in response to irrigation amounts was analyzed. 【Result】 A lack of drainage system resulted in inter- and intra-annual salt accumulation in the soil surface; installing subsurface drains redu

Reclamation of salt-affected soil has been identified by the FAO as being critical to meet the needs to increase agricultural productivity. This paper reviews commonly used reclamation methods for salt-affected soils, and provides critical identifiers for an effective reclamation practice of salt-affected soil. There are widely used methods to reduce salinity and sodicity of salt-affected soils, including salt leaching, addition of amendments, revegetation using halophytes and salt scrapping. Not all reclamation techniques are suitable for salt-affected land. The reclamation strategy must be tailored to the site, and based on understanding the soil, plant and climate interactions. On some occasions, a combination of techniques may be required for reclamation. This can include salt scrapping to remove salts from the surface soil, the addition of physical amendments to improve soil pore systems and enhance salt leaching, followed by amelioration of soil by chemical amendments to preserve soil physical conditions, and then halophyte establishment to expand the desalinization zone. This study reveals that soil hydro-geochemical models are effective predictive tools to ascertain the best reclamation practice tailored to salt-affected land. However, models need to be calibrated and validated to the conditions of the land before being applied as a tool to combat soil salinity.

【目的】探索暗管排水对南疆盐碱地改良效果。【方法】在南疆高水位盐渍化棉田开展了2 a暗管排水试验。研究了滴灌条件下暗管排水不同间距与埋深对土壤盐分分布及脱盐率的影响，分析了灌溉淋洗定额对土壤盐渍化程度及暗管排水参数的响应，探讨了适宜南疆高水位盐渍化棉田的暗管排水技术参数。【结果】南疆高水位膜下滴灌棉田无排水时，生育期内灌水对土壤盐分淋洗效果不明显；暗管排水条件下，灌水后土壤盐分淋洗脱盐率在10%~30%之间；土壤盐渍化程度越高，盐分淋洗潜力越大，在暗管排水参数与灌水量一致的条件下，灌水淋洗脱盐效果更佳；土壤淋洗效果一致的条件下，暗管排水间距增加，灌水定额增量呈倍数增长；暗管排水间距与埋深减小时，土壤淋洗脱盐率与淋洗效果均提高。【结论】南疆高水位膜下滴灌棉田暗管排水参数建议为间距10 m、埋深0.8 m。

In the Hachirogata reclaimed area, Minamiakita County, Akita Prefecture, Japan, one of the leading agricultural production areas in the country, the agricultural production foundation and facilities are deteriorating significantly, and problems specific to low-lying reclaimed farmland, such as deterioration of water quality and differential settlement of structures, are occurring. This study investigates the effects of salt leaching on the micromechanical behaviour of highly active Hachirogata clay. A leached sample was artificially prepared using a boring sample collected from the Hachirogata reclaimed land, and a micro-indentation test was performed on both non-leached and leached samples. The results of the indentation test confirmed that the electrical conductivity (EC) of Hachirogata clay was highly correlated with cohesion, c, and that the c value dropped sharply when the EC fell below a certain threshold. Therefore, salt leaching leads to a decrease in the cohesion of clay particles by reducing the number of ions in the clay, making the clay easier to deform under load. From the results of this study, it was inferred that localised salt leaching, which changes the micromechanical behaviour of clay, is one of the factors causing ground differential settlement or slip failure. It is expected that such ground problems could be mitigated by identifying locations with low EC values, that is, weak areas in the ground, and implementing countermeasures such as ground improvement or using lightweight embankment materials in those zones.

The scientific use of sodium carboxymethyl cellulose (CMC) to improve the production capacity of saline–alkali soil is critical to achieve green agriculture and sustainable land use. It serves as a foundation for the scientific use of CMC to clarify the water and salt transport characteristics of CMC-treated soil. In this study, a one-dimensional soil column infiltration experiment was carried out to investigate the effects of different CMC dosages (0, 0.2, 0.4, 0.6, and 0.8 g/kg) on the infiltration characteristics, infiltration model parameters, water and salt distribution, and salt leaching of saline–alkali soil in Xinjiang, China. The results showed that the final cumulative infiltration of CMC-treated soil increased by 8.63–20.72%, and the infiltration time to reach the preset wetting front depth increased by 1.02–3.96 times. The sorptivity (S) in the Philip infiltration model and comprehensive shape coefficient (α) in the algebraic infiltration model showed a trend of increasing first and then decreasing with CMC dosage, revealing a quadratic polynomial relationship. The algebraic model could accurately simulate the water content profile of CMC-treated soil. CMC enhanced the soil water holding capacity and salt leaching efficiency. The average soil water content, desalination rate, and leaching efficiency were increased by 5.18–15.54%, 21.17–57.15%, and 11.61–30.18%, respectively. The effect of water retention and salt inhibition on loamy sand was the best when the CMC dosage was 0.6 g/ kg. In conclusion, the results provide a theoretical basis for the rational application of CMC to improve saline–alkali soil in arid areas.

Tissue engineering aims to develop artificial human tissues by culturing cells on a scaffold in the presence of biochemical cues. Properties of scaffold such as architecture and composition highly influence the overall cell response. Electrospinning has emerged as one of the most affordable, versatile, and successful approaches to develop nonwoven nano/microscale fibrous scaffolds whose structural features resemble that of the native extracellular matrix. However, dense packing of the fibers leads to small-sized pores which obstruct cell infiltration and therefore is a major limitation for their use in tissue engineering applications. To this end, a variety of approaches have been investigated to enhance the pore properties of the electrospun scaffolds. In this review, we collect state-of-the-art modification methods and summarize them into six classes as follows: approaches focused on optimization of packing density by (a) conventional setup, (b) sequential or co-electrospinning setups, (c) involving sacrificial elements, (d) using special collectors, (e) post-production processing, and (f) other specialized methods. Overall, this review covers historical as well as latest methodologies in the field and therefore acts as a quick reference for those interested in electrospinning matrices for tissue engineering and beyond.

There is a lack of research on the effect of humic acid on salinity adsorption and leaching of saline-alkali soil. We used humic acid as a modifier. Saline soil adsorption and leaching tests were carried out in the laboratory and the field to study the effect of humic acid on water, salt, and wheat yield in coastal clay saline soil. Compared to the CK (non-humic acid treatment), the laboratory tests show that soil water content, salt adsorption, salt leaching, and salt removal efficiency, all showed a trend of increasing first and then decreasing, with the increase of humic acid, and increased by 0.1–1%, 0.5–4%, 3–11%, and 1–8% under T1-T8 (humic acid treatments), respectively. Field tests show that in all humic acid treatments soil salinity in 0–20 cm and 0–60 cm was reduced, and the water content and wheat yield was increased, compared to CK. When the humic acid content was 0.149 g/kg (T2 treatment), the soil salt removal effect and wheat yield were optimized. Overall, humic acid can effectively reduce the salinity in clay saline soil, improve its ability to hold water, and inhibit salt accumulation and soil salinization. This research contributes to the improvement of saline-alkali soil in the Yellow River Delta.

Salinity is a major constraint for plant growth in world areas exposed to salinization. Sorghum bicolor (L.) Moench is a species that has received attention for biomass production in saline areas thanks to drought and salinity tolerance. To improve the knowledge in the mechanisms of salt tolerance and sodium allocation to plant organs, a pot experiment was set up. The experimental design combined three levels of soil salinity (0, 3, and 6 dS m−1) with three levels of water salinity (0, 2–4, and 4–8 dS m−1) and two water regimes: no salt leaching (No SL) and salt leaching (SL). This latter regime was carried out with the same three water salinity levels and resulted in average +81% water supply. High soil salinity associated with high water salinity (HSS-HWS) affected plant growth and final dry weight (DW) to a greater extent in No SL (−87% DW) than SL (−42% DW). Additionally, HSS-HWS determined a stronger decrease in leaf water potential and relative water content under No SL than SL. HSS-HWS with No SL resulted in a higher Na bioaccumulation from soil to plant and in translocation from roots to stem and, finally, leaves, which are the most sensitive organ. Higher water availability (SL), although determining higher salt input when associated with HWS, limited Na bioaccumulation, prevented Na translocation to leaves, and enhanced selective absorption of Ca vs. Na. At plant level, higher Na accumulation was associated with lower Ca and Mg accumulation, especially in No SL. This indicates altered ion homeostasis and cation unbalance.

Bone implants or replacements are very scarce due to the low donor availability and the high rate of body rejection. For this reason, tissue engineering strategies have been developed as alternative solutions to this problem. This research sought to create a cellular scaffold with an intricate and complex network of interconnected pores and microchannels using salt leaching and additive manufacturing (3D printing) methods that mimic the hierarchical internal structure of the bone. A biocompatible hydrogel film (based on poly-ethylene glycol) was used to cover the surface of different polymeric scaffolds. This thin film was then exposed to various stimuli to spontaneously form wrinkled micropatterns, with the aim of increasing the contact area and the material’s biocompatibility. The main innovation of this study was to include these wrinkled micropatterns on the surface of the scaffold by taking advantage of thin polymer film surface instabilities. On the other hand, salt and nano-hydroxyapatite (nHA) particles were included in the polymeric matrix to create a modified filament for 3D printing. The printed part was leached to eliminate porogen particles, leaving homogenously distributed pores on the structure. The pores have a mean size of 26.4 ± 9.9 μm, resulting in a global scaffold porosity of ~42% (including pores and microchannels). The presence of nHA particles, which display a homogeneous distribution according to the FE-SEM and EDX results, have a slight influence on the mechanical resistance of the material, but incredibly, despite being a bioactive compound for bone cells, did not show a significant increase in cell viability on the scaffold surface. However, the synergistic effect between the presence of the hydrogel and the pores on the material does produce an increase in cell viability compared to the control sample and the bare PCL material.

Freshly excavated overburden (spoils) dumped during open-cut coal mining generate saline leachate that can lead to environmental impacts. Predictions of leachate salinity remain uncertain, largely due to incomplete knowledge of responses of spoils to varying moisture conditions. This study carried out column leaching experiments on four spoil types, originating from Queensland, Australia. Following characterisation of the fresh spoil material, four moisture regimes were tested: three wetting-drying conditions with leaching occurring biweekly, weekly, and fortnightly and one completely saturated regime with leaching occurring weekly. Thirty-four leaching cycles were conducted except for one spoil type for which only 12 cycles were completed. Results showed higher EC and leachate ion concentrations from the saturated regime, while among the wetting-drying regimes, the spoil leached on a fortnightly basis resulted in higher salt release for two geochemically similar spoil types. Overall, lower and steady pH was recorded for spoils leached under saturated conditions. Irrespective of spoil type, sodium was the dominating cation contributing to the overall leachate salinity. The paper provides new insights into parameterising leaching models and in the role of water-rock interactions which informs experimental design and conceptualisation of full-scale models.