There is increasing concern regarding local concentrated erosion scenarios such as piping and underground cavities due to their catastrophic consequences. In this study, local concentrated erosion was reproduced by placing shaped erodible columns within the triaxial specimens during sample preparation. The preplaced erodible columns (made of glucose) were set similar in regard to their volume fraction but different in configurations. Bender element measurements were performed in dry, the erosion on-going, and post erosion states to evaluate the mechanical behavior of the samples subjected to concentrate particle removal. The influence of concentrated particle erosion on the shear wave velocity, shear strength, dilatancy and peak angle of shearing resistance was revealed and discussed. It is generally concluded that the resultant effect on the mechanical behavior of soils is greater when erodible particles are more localized within a limited region, especially for densely packed soils.

Soil water repellency (SWR) is a dynamic property of soil that depends on a variety of factors. The warming of the climate and more frequent occurrence of droughts can both increase the SWR phenomenon. Land management demands that mitigation measures be continually adapted to strengthen the resilience of ecosystems and risk reduction strategies be refined. The aim of the work is to analyse the persistence and strength of SWR and soil moisture content (SMC) in sandy soil on abandoned agricultural land with a second succession of pine (S1), and in soil used for growing rye (S2). The studies cover the dry period from March 2019 to March 2020. Systematic measurements of SWR and SMC are carried out in two-week intervals for soil at depths of 0-0.05 and 0.35-0.40 m. For the top layer, the average SMC values for S1 and S2 are 7.18% and 11.21%, respectively. The field studies show a more substantial and longer-lasting repellency (extreme SWR classes occurred for 10 months) at the pine site than the studied phenomena in regions with a warmer climate. These studies make it possible to verify the dependence of SWR on SMC for both test sites, and excellent agreement is achieved between the critical SMC threshold for hydrophobicity determined in the laboratory and under field measurement conditions. Based on the indicated water and ethanol sorptivity, the average indices of hydrophobicity (R index) and their course in relation to SMC, are indicated. The average water sorptivity for S1 is 0.266 cm min(-0.5), for S2 is 0.383 cm min(-0.5). The average R index values are 31.91 and 3.97, respectively. These findings suggest that SWR may be a key soil property for identifying the occurrence of risk connected with the drying out of soil, especially in relation to a warming climate.

Open-ended pipe piles are often used for both land and offshore structure foundation because of their relatively low-driving resistance. During driving, soil enters into the open-ended displacement piles, which cause soil plugging. This paper investigates the plugging effect of open-ended piles jacked into sand. A series of tests were conducted in the laboratory on small scale model pipe piles installed in sand with different soil conditions. The effect of pile diameter and degree of saturation on plugging behavior was evaluated. The laboratory test results show that plug length generally increases as pile diameter increases. Furthermore, the plug length decreases with the increase in the value of matric suction. The tests were also conducted with three different types of sands: coarse, medium, and fine sand. The plug length ratio (PLR) was found higher in coarse sand and lower in fine sand. The jacking force for pile driving was evaluated from the model tests, which significantly depends on the plugged length as well as soil properties. The load settlement curve for the piles indicated that the ultimate load-carrying capacity for pipe piles under dry conditions is greater than saturated conditions.

With the increasing demand of high quality infrastructure, the lack of conventional material in cities becomes the main problem. Due to this limitation in conventional material such as ordinary sand that is excavated from the river and harmful for the environment due to the reduction in ground water level, can be partially/fully replaced by M-Sand/Crushed stone rub down as an economic and ecological alternative for sustainable concrete structures. The use of M-Sand is a great effort towards sustainable enlargement in India. The life of a structure is affected by various parameters i.e. moisture content, free surface moisture (real time sample received in the lab), saturated surface dry (SSD), specific gravity, grain size analysis (to find out the sand zone), workability, water-cement ratio, impact value of aggregates etc. In this situation, while code provisions are also not available for M-Sand, a design parametric study has been conceded in the laboratory with respect to all necessary parameters for M-30 grade of concrete with different percentages of Manufactured-Sand which highly affects the design mix of concrete. In this article river or natural sand has been replaced fully and partially by M-Sand/Crushed sand likewise 0.0%, 10%, 40%, 45%, 50%, 55%, 65%, 75%, 85% & 100%. An advanced design mix procedure has been initialized here by using British codes, ACI & IS. It has been observed in the current research that most of the properties of River/Natural Sand and M-Sand/Crushed Sand are similar and it is also concluded that natural sand is able to be partially or full replaced by Manufactured sand as an economical substitute including sustainable construction material in Civil Engineering Construction era 4.0:Janpad Abhiyantriki (Civil Engineering). Copyright (C) 2022 Elsevier Ltd. All rights reserved.

Climate change is expected to cause the spread of pathogens and pests in areas where they have not been relevant before, bringing new challenges for cropping systems based on crops diversification by minor cereals. Rye is a minor cereal that contributes to crop species diversity in Central and Eastern Europe, especially in marginal environments unfavourable for wheat production. During 2019-2020, a plant-pest-pathogen interaction profile was observed on Suceveana rye genotype in a randomized complete block design in dry area from Research and Development Station for Plant Culture on Sands Dabuleni in South of Romania. The best protection against leaf rust was provided by Dithane M 45+Bioinsekt (the 1st assessment = 2.98%; the 2nd assessment = 4.86%), while the best control against pests was provided by Mimox+Bioinsekt (the 1st assessment = 0.83%) and Mimox+ Decis Expert 100 EC (the 2nd assessment = 1.03%). For pests and leaf rust control was noticed the synergistic effect of insecticides and fungicides used in the experiment. Negative and significant correlations of attack degrees with grain yield (r =-0.7886**, respectively r = -0.8332**) were noticed.

Desertification is one of global environmental problems, which is faced by human beings. Finding a new sand-fixing material is an effective method to combat desertification. In desert areas, water shortage is one of problems that Didymodon vinealis (D. vinealis) grew. In this study, we built up a special-structured nanocomposite. Attapulgite had chain layered crystal structure and many active hydroxyl groups, which made them have high absorption and retention capacity of water. The optimum ratio of dried D. vinealis to attapulgite-based nanocomposite was proved to be 1:4 and the optimum spraying amount 4 mg DW & BULL;cm-2. The obtained results provided some useful information on the formation of D. vinealis BSCs with the aid of attapulgite-based nanocomposite. In addition, the results would offer a method for the maintenance and management of D. vinealis in desertification control.

Aim. The aim of the research was to identify the influence of the climate factor on the soil processes in sandy podzols in the forest steppe of the Central Russian province. Material and Methods. Traditional methods (soil survey method, profile method, microbiological methods, etc.) and the latest methods (direct measurements [in situ] of soil CO2 emission) of investigation were used. Results. It has been established that soil formation processes in azonal Al-Fe-humus sandy soils are reflexive to variations in climatic parameters of the forest steppe zone. In warmer and arid conditions of the forest-steppe (southern part), sandy sod-podzols are formed, in colder and humid conditions of the forest-steppe (northern part) - sandy podzols. The soddy-podzols of the southern part of the foreststeppe can be characterized by a more humour soil profile, the content of which is 19.2% higher than in the sandy podzols. More over sodpodzols have greater availability of mineral nutrition elements for plants and a higher microbiological activity (the number of bacteria is 12.7 times higher, micromycetes - 10.5 times, actinomycetes - 4.5 times) than sandy podzols. In summer, the rate of CO2 emission in Al-Fe-humus sandy soils in the northern part of the forest-steppe zone reached 9.1 g CO2 m(2)/day, in the southern part - 12.5 g CO2 m(2)/day. Conclusion. Further climate changes, which have an arid trend in the forest-steppe zone, can possibly lead to transformation of sandy podzols into sandy sod-podzols.

Hydrogels have potential as soil conditioners due to their high capacity to retain water and mitigate soil salinity. However, investigations under saline conditions are necessary because there are losses in both water absorption and salinity mitigation depending on the composition of hydrogel and ions involved in salinity. In this work, we studied a commercial hydrogel in two experiments. The first experiment was conducted in the laboratory to evaluate the absorption by the hydrogel of water with electrical conductivity (EC) of 0.5, 1.5, 3.0, and 4.5 dS m(-1), promoted by NaCI. The second experiment was conducted in a greenhouse in a 2 x 4 factorial scheme (with and without hydrogel x EC of the first experiment). Although salinity reduced water absorption by hydrogel by 84 %, the polymer applied in a sandy soil under saline conditions reduced water losses by 58 %. However, hydrogel did not increase the final soil moisture (- 0.10 g g(-1)). The polymer reduced Na+ concentration in leachate from 1,499 to 1,219 mg at the highest salinity level (4.5 dS m(-1)), but it increased Na+ soil availability by 0.1 mg kg(-1) in comparison with polymer absence. Hydrogel application increased Na+ content in plants from 9 to 13 mg kg(-1) at the highest salinity, while K+ content was 10 to 16 mg kg(-1) lower than that observed without a polymer. Hydrogel 0.07 % (w/w) reduced maize biomass, indicating damage by monovalent ions, compromising the polymer potential under salinity.

The 216 km2 Neuenhagen Millcreeck catch ment can be char ac ter ized as a drought-sen si tive land scape in NE Ger many. It is therefore of fundamental human interest to understand how water that fell as precipitation moves through the unsaturated soils and re charges ground wa ter. Ad di tion ally, a better knowl edge of nu tri ent trans port from soil to ground wa ter is im por tant, es pe cially in land scapes with light sandy soils. For a better un der stand ing of these pro cesses a dual tracer field ex per i ment with bro mide (Br-) and deu te rium (D2O) was car ried out some years ago. The aim of the present study is to use the re sults of this ex per i ment to model tracer trans port in the un sat u rated zone via two dif fer ent con cepts, the clas si cal de ter min is tic advection-dis per sion equa tion and a new sto chas tic ap proach. The ad van tage of the sto chas tic mod el ling method pro posed here for field-scale tracer ap pli ca tion is to pro duce re li able in for ma tion about ex pected to tal sol ute fluxes from the un sat u - rated zone to ground wa ter and about mean tran sit times. More over, this al lows one to eval u ate the mass of sol ute in the soil profile and to determine the range of water velocity fluctuations. Field experiments should be concentrated on estimation of fluc tu a tion of wa ter flow ve loc ity to make sto chas tic mod els more ac cu rate. To sum ma rize, this work con trib utes to new mod -el ling meth ods for the sim u la tion of wa ter and sol ute trans port in un sat u rated sandy soils which are heavily af fected by droughts and irregular hydrological processes in the subsurface.

Geochemical studies examining surface aeolian sediments are significant for understanding Earth's surface processes and determining sediment provenance in arid and semi-arid regions. However, there is limited research on the geochemical comparison of aeolian sediments formed under distinctive tectonic and climatic settings. Surficial sand samples from the Taklamakan Desert and Horqin Sandy Land in northern China were collected, and the major, trace, and rare earth elements (REEs) in the bulk samples, fine fractions (75 mu m) of sand were analyzed. This study aimed to explore the spatial variation in the geochemical composition of aeolian sand and its drivers. The results show that differences between the two regions are primarily caused by the intensity of chemical weathering, sedimentary recycling, and provenance. The mean chemical proxy of alteration (72.3 vs. 77.8) and the Parker's weathering values (37.8 vs. 55.8) both suggest the bulk samples from the Horqin Sandy Land experienced more intense chemical weathering, whereas physical weathering is a dominant process in the Taklamakan Desert. These differences may be attributed to the different climatic conditions in the two regions and the exposure time to weathering. A combination of the index of compositional variability and immobile trace element ratios shows that aeolian sand in the Horqin Sandy Land underwent more intense sedimentary recycling than sediments in the Taklamakan Desert. REEs ratios (such as Cr/V and Y/Ni) and the Al2O3-CaO*+Na2O-K2O (A-CN-K) diagram indicate aeolian sand in the Taklamakan Desert is probably derived from mixed source rocks of tonalite, granite, and granodiorite. Eu anomaly vs. (La/ Yb) N diagrams suggest that the primary source-rocks contributing to the coarse and fine fractions in the Horqin Sandy Land are different but mainly derived from the Great Hinggan Mountains. Differences in the provenance of the fine- and coarse-grained fractions are primarily controlled by interactions between wind and fluvial systems. This study confirms that surface processes and sediment provenance in drylands of northern china have distinct spatial differences, implying that geochemical signatures in aeolian sand need to be interpreted in the specific climatic and tectonic contexts.