Soil Treatment Research Articles

Estimation of the displacement of soil nailing vertical face structures intended for building undergrounds

ABSTRACT This study proposes a methodology for estimating horizontal displacements in vertical face soil-nailing structures in urban areas, analyzing 20 projects in São Paulo, Brazil. To minimize displacements, post-grouting sectorized injections through polyethylene tubes was used, a methodology routinely adopted in Brazil which gives the soil mass a significant increase in strength and stiffness.To study the effect of the sectorized injections on soil treatment, a three-dimensional computational model using Plaxis 3D software and calibrated through back-analysis according to the displacements of the structures. Additionally, 11 models were tested with variations in nail length, mesh configuration, and geotechnical parameters, considering injection effects. The study provides design and execution guidelines to optimize this technique. Equations derived from the study predict horizontal displacements, which will be used to assess the technical feasibility of the projects in advance and, when they are being executed, to provide performance control within a more precise and realistic margin.

Amending clayey and sandy soils with nano - bio phosphorous for regulating tomato growth, biochemical, and physiological characteristics

Phosphorus is a critical nutrient that significantly enhances tomato production, so maintaining an adequate level of phosphorus plays an essential role in enhancing the growth of tomato by being present in the soil. This study assessed the impact of soil texture and phosphorus content on tomato plant properties using a factorial, complete, randomized design with four replications. Treatments included clayey and sandy soils with varying phosphorus sources: non-phosphorus (P0), calcium phosphate (CaP1 and CaP2), and nano-hydroxyapatite (PN1 and PN2), where 1 indicates a concentration of 0.12 g and 2 indicates a concentration of 0.23 g per 5-kilogram pot of fertilizer. Results indicated that treatments significantly influenced yield parameters such as average fruit weight, juice content, antioxidant activity, and fruit volume. In the clayey soil, CaP2 treatment had a superior effect on yield, average fruit weight, and shoot fresh weight. In comparison with sandy conditions, CaP2 produced a 50% increase in fruit number, 29% increase in average fruit weight, and 91% increase in fruit yield. The treatments then impacted the shoot fresh weight and root length, while the phosphorus concentration appeared to be more dependent on soil type than on phosphorus sources. Similar to the CaP1 and CaP2 treatments, the PN1 treatment in clay soil also resulted in the highest fresh and dry weights of tomato shoots when compared with the control group. Generally, the findings from this study suggest that the use of CaP2 can serve as a reliable method to improve the growth, yield, and fruit quality of tomatoes, especially in clayey soil environments. However, nano-based phosphorous sources need to be tested more to see if they can improve tomato performance in a range of soil conditions. Also, further research should look into the long-term effects of phosphorous interventions on soil health and sustainability.

Performance of poplars and willow grown on soil under wastewater irrigation during the first 2 years of establishment.

Recycling wastewaters as irrigation and fertilization of tree species is a market-driven action for purpose-grown timber plantations that promotes the circular economy. A greenhouse experiment was carried out to investigate the performance of poplar clones (Populus alba L. "20/45", P. nigra L. "62/154", and P. euramericana (Dode) Guinier "92/40") and willow (Salix excelsa S.G. Gmel) grown on soils under tap water irrigation (TWI) or wastewater irrigation (WWI) during the first 2 years of establishment. Results showed that at 2 years after planting, poplars and willow exhibited significantly greater performance when grown in WWI versus TWI (P < 0.05). Likewise, phytoremediation of nutrients along with some heavy metals increased in plant organs of WWI-grown plants relative to their TWI counterparts (P < 0.05). After 2 years of growth and under both conditions (TWI and WWI), P. nigra plants showed the greatest growth and biomass; however, leaf area was the largest for P. alba and P. euramericana plants. Also, P. nigra plants had the highest total contents of copper (Cu) and manganese (Mn), P. alba had the most zinc (Zn), and differences for iron (Fe) were negligible across species. In contrast, total contents of nickel (Ni) and chromium (Cr) were higher for S. excelsa, P. nigra, and P. alba plants, while the lowest values were measured in P. euramericana plants. Across all species and soil treatments, the translocation factor (TF) was greater than 1 for Mn, Cu, and Zn, indicating phytoextraction and phytoaccumulation of these elements into leaves and stems, while TF was less than 1 for Fe, lead (Pb), Ni, and Cr, resulting in phytoremediation of these elements as phytostabilization. Differences in tolerance index (TI) values were negligible across species, and TI was greater than 100% after 2 years of growth, indicating that all four species are suitable for phytoremediation applications with urban wastewaters having similar heavy metal concentrations as in the present study. Nevertheless, given the combination of enhanced growth, biomass, and heavy metal accumulation (Mn, Cu, Cr, and Ni), P. nigra plants exhibited the greatest phytoremediation potential of four tested species.

Study on the effect of cinder ash as an auxiliary additive mineral in hydrated lime treatment for expansive sub-grade soil in road construction

Expansive soils pose significant challenges to road construction globally due to their tendency to expand and contract with changes in moisture content, leading to pavement failure. In the construction industry, finding an economical and cost-effective alternative to conventional road construction materials is crucial. The use of a natural cinder ash and hydrated lime mixture as reinforcement has proven to be effective in addressing this issue. Cinder ash, a readily available waste material in countries like Ethiopia, is adaptable and water-resistant, making it an ideal choice for reinforcing expansive soil. This article investigates the strength performance of a cinder ash and hydrated lime mixture as a reinforcement material for expansive soil. The study involves mixing 0%, 20%, 25%, 30%, and 35% of cinder ash with soil stabilized with 2–5% hydrated lime. Expansive soil samples are prepared according to the ASSHTO & ASTM method and tested for compressive strength, California bearing ratio, bulk density, and water absorption. The findings reveal a 448.62%, and 374% increase in compressive strength and California Bearing Ratio respectively for the specimen containing 5% hydrated lime and 35% cinder ash, cured for 28 days. The water absorption is minimized at 15.23% for the 5% hydrated lime and 35% cinder ash mixture; while the maximum density of the soil is observed at 1.774 kg/m3 for the optimal combination of 5% hydrated lime and 35% cinder ash mix. The study suggests that using 5% hydrated lime and 35% cinder ash content for the stabilization of expansive soil significantly enhances the strength characteristics of compressed stabilized soil.

Leveraging extensive soil, vegetation, fire, and land treatment data to inform restoration across the sagebrush biome

ContextWidespread ecological degradation has prompted calls for massive global investments in ecological restoration, yet limited resources necessitate efficient application of restoration efforts. In western North America, altered fire regimes are increasing the scale of restoration needed to preserve the sagebrush (Artemisia species) biome but prioritizing and implementing effective restoration is complicated by the vast and heterogeneous sagebrush landscape, which includes gradients in climate, disturbance, and species composition.ObjectivesTo develop spatially explicit and context-dependent estimates of treatment efficacy and sagebrush recovery rates.MethodsWe leveraged a suite of spatio-temporally extensive datasets to evaluate the influence of restoration treatments and environmental conditions on trends in post-disturbance sagebrush cover, with an emphasis on understanding differences between sites recovering naturally and sites receiving restoration treatments. We used estimates from these models to develop spatially explicit projections for sagebrush recovery, conditional on disturbance, restoration practice, and environmental conditions.ResultsWe found seeding Artemisia spp. increased sagebrush cover over time relative to natural recovery, but this relationship depended on spring soil moisture availability and treatment methods. Natural recovery was positively influenced by soil moisture and sagebrush cover and negatively influenced by cumulative burns and annual herbaceous cover, while the influence of perennial herbaceous cover varied with soil moisture.ConclusionsOur results provide biome-wide insights and spatially explicit tools that can inform economic cost-effectiveness analyses, restoration prioritization tools, and other scientific endeavors to ensure managers have the tools and information needed to effectively steward the sagebrush biome in a rapidly changing world.

Study of biotechnological potential of hydrocarbon-oxidizing bacteria from oil-contaminated soils of the Uzen oil field

Background: Oil-contaminated soils are one of the significant environmental concerns in Western Kazakhstan. Cleaning soils from oil contamination is becoming extremely important. Biological soil treatment, which uses hydrocarbon-oxiding bacteria for microbiological remediation, is a more environmentally friendly and delicate method of soil treatment than any other currently used technology (physical, chemical, biological). One of the important aspects of microbiological remediation is the use of bacteria endomimic to the treated soil. This guarantees the most effective soil purification, as the bacteria perform in relatively optimal conditions for themselves. The soil of the Mangistau region, especially the coastal regions, is distinctive due to its high mineralisation and low moisture content, which have helped to form a specific microflora that is adapted to these conditions. Aim: The study aims to search and isolate highly effective hydrocarbon-oxidizing bacteria that are native to highly mineralized soils of the Uzen oil field. Materials and methods: The research employs a variety of analytical techniques, including water chemistry analysis and infrared spectrometry, as well as the microbiological culture of aerobic bacteria on liquid and dense media in environments (temperature and salinity) that closely resemble their native ecotopes. Results: Four enrichment cultures of hydrocarbon-oxidizing bacteria were obtained, and three pure cultures of oil-oxidizing bacteria were isolated. Their hydrocarbon-oxidizing efficiency has been studied. On the basis of heavy, extremely viscous paraffinic oil from the Uzen field, their hydrocarbon-oxidizing efficiency was examined. Conclusion: In this study, active enrichment cultures of halophilic hydrocarbon-oxidizing bacteria as well as active accumulative cultures of halophilic and moderately thermophilic aerobic bacteria were obtained. These bacteria are capable of oxidising a wide range of hydrocarbons, including high-molecular polycyclic and sulfur-containing compounds. Their high biotechnological potential will be studied in further studies.

Effects of maize residue and biochar applications on soil δ13C and organic carbon sources in a subtropical paddy rice ecosystem

AbstractThis study investigates the utility of plant δ¹3C natural labeling in predicting the impacts of environmental shifts on carbon cycling within ecosystems, particularly focusing on paddy fields treated with maize (Zea mays L.) residues and biochar. Specifically, it examines how soil δ¹3C and the sources of soil organic carbon (SOC), respond in paddy fields (which cultivate C3 plants like rice) when amended with maize residues, maize biochar, and silica‐enriched biochar (derived from C4 plants). Conducted in the Fuzhou paddy fields, the experiment included control groups and treatment groups with maize residue (4 t ha⁻¹), maize biochar (4 t ha⁻¹), and silicon‐modified maize biochar (4 t ha⁻¹) during both the early and late rice growth periods. The results indicate that all soil treatments increased soil δ¹3C. The application of maize residues notably affected the δ¹3C of the upper soil profile (0–15 cm) differently from the deeper layers (15–30 cm), and it increased soil organic C more than biochar or silicon‐modified maize biochar. Soil available P (AP) and pH emerged as significant factors linking δ¹3C, influencing rice yield through changes in soil physicochemical properties. Unlike maize residues, which reduced rice yields, applications of biochar and silicon‐modified maize biochar increased rice yields. The latter, which was particularly effective in lowering SOC decomposition rates and addressing rice's silica needs, emerged as the preferred option. The study highlights maize biochar and silicon‐modified maize biochar as sustainable alternatives to maize residues for rice cultivation, enhancing soil fertility, carbon pool stability, and yields.

Growth, physiological and N, P, K accumulation responses of Erythropalum scandens Bl. Seedlings under different substrates

Erythropalum scandens Bl. is a medicinal woody vegetable found in southern China and parts of Southeast Asia. Studies have shown improper substrate hindered E. scandens seedling growth, causing water accumulation and nutrient deficiency. In pursuit of an ideal growth medium for E. scandens seedlings during the early stages, this study conducted a pot experiment to identify a mixed substrate with optimal water permeability and fertility. In this study, pure Alfisols soil treatment as the control (CK), and two soilless substrates (peat soil and perlite) were combined with Alfisols soil into different volume ratios, in order to better use soil resources from understory space and balance the texture of mixed substrates. The growth, physiological characteristics and nutrient status of 24-month-old E. scandens seedlings were determined after planting in different mixed ratios. The results showed that as the proportion of peat soil increased in the mix, most indexes exhibited an initial increase followed by a decline, while soluble protein content decreased consistently. Conversely, an increasing perlite ratio resulted in a general decline in most growth and physiological indexes. Root growth, biomass accumulation and chlorophyll content, peaked in the 66.67% Alfisols soil + 33.33% perlite (T4) treatment. Notably, T3 (66.67% Alfisols soil + 33.33% peat soil) showcased the best above-ground growth, while T1 (50.00% Alfisols soil + 50.00% peat soil) excelled in element content accumulation. In conclusion, the cultivation substrate should primarily consist of Alfisols soil, constituting at least 50%. The addition of peat soil enhances above-ground growth and nutrients accumulation, while perlite contributes to robust root development. One third of peat soil and a small amount of perlite can be added to the substrate during E. scandens seedling cultivation, and proper fertilization should also be used in order to increase nutrient accumulation in aboveground and underground parts. This research provides valuable insights into maximizing the potential of E. scandens seedlings through precise cultivation methods.

Revolutionizing soil and waste treatment: MoS2 nanosheets turbocharge geopolymerization for eco-friendly remediation and self-cementation of arsenic-contaminated soils and municipal solid waste incineration fly ashes

In the face of escalating arsenic pollution and the mounting challenge of municipal solid waste incineration (MSWI) fly ashes, cutting-edge technology has emerged as a game-changer. By harnessing the power of MoS2 nanosheets, a revolutionary approach to double-self-cementation has been unlocked, addressing the limitations of previous methods. Through heterogeneous adsorption, MoS2 nanosheets bolstered the stability of the matrix, leading to a remarkable surge in compressive strengths and a substantial reduction in leaching toxicities of heavy metals. The compressive strengths of the cemented cubes increased as the dosage of nanosheets increased from 0.3 % to 2.4 %, with compressive strengths ranging from 24.34 to 34.21 MPa. The leaching toxicities of Zn, Cu, Cr, Cd, Pb, and As from the solidified matrix correspondingly decreased to 0.32, 0.21, 0.04, 0.01, 0.05, and 0.53 mg/L, respectively. The role played by nanosheets in inhibiting the release and transport of chloride species further underscored their pivotal contribution. Moreover, the study delved into the intricate mechanisms underlying the impact caused by nanoscale materials cementation and geopolymerization systems, shedding light on their dual function as solidification intensifiers and chemical stabilizers. The nanosheet-enhanced double-self process can be appropriately fitted by the JMAK model. The linear nuclei growth of gels controlled the solidification and geopolymerization of the precursor materials and the stabilization of HM contaminants. This groundbreaking research not only elucidates the transformative potential of MoS2 nanosheets but also paves the way for a paradigm shift in the treatment of contaminated soils and waste materials.

Effects of different ratios of nitrogen base fertilizer to topdressing on soil nitrogen form and enzyme activity in sugar beet under shallow drip irrigation

Sugar beets account for 30% of global sugar production each year, and their byproducts are an important source of bioethanol and animal feed. Sugar beet is an important cash crop in Inner Mongolia, China. To achieve high yields and sugar content, it is essential to supply nitrogen fertilizer in accordance with the growth characteristics of sugar beet, thereby enhancing the efficiency of nitrogen fertilizer utilization. A two-year experiment was carried out in the experimental field of the Inner Mongolia Academy of Agricultural &amp; Animal Husbandry Sciences. The impact of varying ratios of nitrogen-based fertilizer to topdressing on nitrate nitrogen and ammonium nitrogen levels in the 20–60 cm soil layer, as well as the activities of protease, urease, catalase, and sucrose in the 20–40 cm soil layer were investigated during the rapid leaf growth period and root and sugar growth period. Results indicated that different ratios of nitrogen-based fertilizer to topdressing significantly influenced the levels of nitrate nitrogen and ammonium nitrogen, and the activities of protease and urease in the 0–20 cm soil layer, with these effects diminishing as soil depth increased. The activities of catalase and sucrose were minimally impacted. Nitrogen was applied at 150 kg/ha during the growth period of sugar beet, according to the growth characteristics of sugar beet to maximize nitrogen utilization efficiency. Topdressing was completed with irrigation at the rapid growth stage. The nitrogen-based fertilizer to topdressing ratio of 6:4 resulted in optimal crop yield and sugar yield of sugar beet under shallow drip irrigation. Additionally, the activities of protease and urease in different soil treatments were significantly different, and the activities of protease and urease in the 0–40 cm soil layer were identified as useful soil physiological indicators for nitrogen utilization in sugar beet.

Cover crops dismantle keystone ant/aphid mutualisms to enhance insect pest suppression and weed biocontrol

Abstract Cover crops are multifunctional tools that mitigate environmental impacts of agriculture, enhance resilience to weather extremes and suppress weeds and arthropod pests. Cover crops provide non‐crop food and habitat resources that attract natural enemies of pests, but their outcomes for pest management are less clear in regions where keystone mutualisms between red imported fire ants and aphids dominate. Here, we manipulate ant exclusion treatments and cover crop treatments (living mulches and terminated cover crops) that vary in food/habitat resources and examine responses of ants, aphids, other herbivores and predators in a cotton agroecosystem. Living mulches reduced both ants and aphids in the crop canopy by 97% and 93%, respectively, relative to bare soil treatments, and terminated cover crops reduced them as well by a lesser degree (~50%). Non‐aphid herbivores occurred in low densities system‐wide and increased in living mulches, whilst native predators had variable responses to cover crops and ant exclusion. Cover crops had no effect on prey removal in the crop canopy, but living mulches tripled rates of weed seed biocontrol, relative to bare soils. Cover crops elicited a shift in fire ant foraging from cotton foliage downward to the soil‐surface, preventing competitive exclusion by keystone ant/aphid mutualists that dominate crop monocultures. Cover crops altered the system‐wide impacts of fire ants: reducing ecosystem disservices (i.e. aphid tending) and enhancing ecosystem services (i.e. weed seed biocontrol). These results provide incentives for cover crop adoption as a regenerative practice in large‐scale commercial agriculture.

Weathering of Buried Standard Pieces of Serpentine under Varied Soil Treatments and Relevant Analysis of Microbial Community Structure

Carbon sink processes related to the weathering of silicate minerals are often accompanied by physical, chemical, and biological effects. In particular, plant-microbe synergistic effects are important for soil mineral weathering, but relevant correlation analyses and quantitative studies remain sparse. In this research, a standard serpentine test specimens (STSs) with specific specifications were used to study serpentine weathering under different environmental conditions (abiotic or biotic) and correlated it with the microbial community structure under the growth of Setaria viridis. The results showed that the environment with growing S. viridis had the strongest weathering capacity for STSs, which was 35 times higher than that of the abiotic environment group, and a significant increase in soil inorganic and organic carbon contents compared with the abiotic environment and the environment without plant growth. The bacteria with strong weathering ability were enriched in the soil of around STSs, such as Pseudomonas spp. and Sphingomonas spp. In addition, the fungal community of Ascomycetes is also heavily enriched, accelerating STSs weathering. The addition of bacterial agent (Bacillus subtilis) further promoted the STSs weathering under the growth conditions of S. viridis. The soil surrounding the buried STSs was also enriched with heavy metal tolerant Massilia spp. and disease suppressing Lysobacter spp., while the abundance of fungi functionally associated with pathotypes was reduced, thereby benefiting plant growth. This study provides basic information for the serpentine bio-weathering coupled with carbon sequestration by using plant-microbe synergistic effects.

The impact of technologies for the development and use of virgin, fallow lands on agroecological stability and soil fertility

Relevance. The research was carried out in order to analyze the impact of technologies for the development of virgin and fallow lands on erosion processes in the steppe zone in the 60s and modern conditions.Methods. The analysis of approaches to the prevention of soil degradation and desertification of the territory is carried out based on materials obtained in the steppe zone of the Republic of Khakassia in the second half of the XX century and in modern conditions. We used the results of the application of technologies for the development of virgin and fallow lands of Tselinnoye LLC in different periods. Information about dust storms was taken from data from the Bey and Shire weather stations. In 1954–1960 when plowing the chernozem of the southern virgin lands, technology was used using plows, huskers and other tillage tools. The lack of adapted ways of developing and using new lands has led to an outbreak of wind erosion of soils over large areas, including in the south-east of the country.Results. The dump system of soil treatment during the mass development of virgin and fallow lands in the 60s, without taking into account soil, climatic and other conditions, led to a strong development of wind erosion. The number of days with dust storms in Khakassia reached up to 4.8–11.6 per year. In modern conditions, the removal of highly ventilated soils from arable lands and the use of strip placement of crops and minimal tillage on the rest of the arable land contribute to increasing the erosion resistance of agricultural landscapes. The use of the Tornado 500 herbicide in August during the development of the deposit reduces the erodibility by 2.5 times, compared with the technology with its introduction in early summer.

Pre-Plant Soil Treatments Influence Tree Performance and Nematode Dynamics in Replanted Cherry Orchards.

In this two-year field study, the impacts of pre-plant soil management strategies, including soil fumigation, nematicide application, and organic amendments, on the growth and nematode community dynamics on cherry cultivars 'Emperor Francis' and 'Ulster' grafted to 'Mahaleb' rootstock were investigated in a replanted orchard site. In the first year, fumigation with 1,3-dichloropropene - chloropicrin mixture (Telone C-35) led to significantly increased trunk cross-sectional area and canopy height in both cultivars. Pratylenchus penetrans population densities were suppressed only short-term. Plots treated with the fungicide/nematicide fluopyram (Velum® Prime) had P. penetrans reproduction factors below one throughout both years independent of the scion. Additionally, the combined application of Seed Starter 101®, Dairy Doo® compost, and straw mulch reduced the reproduction factor of P. penetrans to below one in the first year. In the same time period, this combinatory treatment had the highest reproduction factor for bacterivore and fungivore nematodes. Based on results of this study, fumigation with Telone® C-35 resulted in improvement of tree establishment and provided effective short-term suppression of P. penetrans. Velum® Prime exhibited longer-term efficacy for the suppression of P. penetrans.

Application of Pyroligneous Acid as a Plant Growth Stimulant Can Improve the Nutritional Value of Soybean Seed

Farmers today are using biochemical treatments to improve their crop yields. Commercialized organic biostimulants exist in the form of pyroligneous acid generated by burning agricultural waste products. During the 2023 growing season, we demonstrated that soil treatment with a commercial pyroligneous acid product, Coriphol™, manufactured by Corigin Solutions, Inc., stimulated plant growth and significantly improved yield with an optimal treatment dose of 2 gal. acre−1. In the present work, we examined the effect of this treatment on soybean nutritional content using seed harvested from the 2023 season. Total mean seed protein content for untreated control plants was 32.26 ± 0.49% of dry mass and increased 10.8% to 35.64 ± 0.64% with treatment. This increase resulted in a net reduction in total free amino acid content, although levels of the essential dietary amino acid, lysine, were boosted 6-fold. Total lipid content was unaffected by treatment with mean levels of 21.61 ± 0.70% of dry mass noted. Treatment, however, reduced saturated fatty acid content by roughly 40%, and reduced the polyunsaturated content of linoleic acid in favor of the monounsaturated fatty acid, oleic acid. Finally, Coriphol™ treatment did not impact seed content of eight essential micronutrients including Na, Mg, K, Ca, Fe, Ni, Cu, and Mo, but did significantly boost Zn and Mn levels. Altogether, these results demonstrate that soil treatment with the growth stimulant Coriphol™ has the potential to improve the dietary nutritional value of soybean.

ANALYSIS OF THE REGULATORY AND LEGAL BASE FOR THE FORMATION OF GENERAL REQUIREMENTS FOR TEST SLOTS FOR THE CHECKING OF DEMINING MACHINES (HUMANITARIAN) BY FUNCTIONAL PURPOSE

The relevance of the chosen topic is determined primarily by the need to organize testing and certification activities, the introduction of international demining standards and NATO standards in humanitarian demining. To assess the suitability of demining machines under the same controlled conditions. This makes it possible to evaluate products under the same conditions and determine the most productive samples. This actualizes the need to define general requirements for test sites for testing mechanized means of humanitarian demining by functional purpose. It is worth improving approaches to the organization and functioning of test sites based on the existing international experience and new domestic developments. In the course of the conducted research, it was established that there is an urgent need to organize demining of territories in Ukraine, both for military tasks and for humanitarian demining tasks. It has been established that the lack of general requirements for test sites for conducting tests and assessing the conformity of demining means approved as a normative legal act is an urgent problem that needs immediate resolution. During the research, a classification of demining tools was carried out, which are divided into machines for detonation, destruction, removal of mines; machines for soil preparation; machines for detecting sources of danger, have different types of working equipment (excavator or bulldozer type) and different types of attached equipment: roller trawls, milling-rotor trawls, knife trawls, chain trawls, fighting trawls, mulchers for soil treatment. In accordance with the set goal, the article developed recommendations for determining general requirements for test areas of demining machines equipment, substantiated the quantitative and qualitative indicators of objects and elements of test areas for conducting certification tests of mechanical (humanitarian) demining equipment according to their functional purpose, which are based on the practices of conducting such works in Ukraine and other countries. The necessity of forming requirements for test areas for assessing the survivability and productivity of demining means is substantiated. In particular, with the definition of requirements for test sites and related infrastructure. Recommendations are given for the placement of the main and additional elements on the test plots. Recommendations were provided and an approximate scheme for the placement of the main objects and elements of test areas for the organization of certification tests was provided, which will allow to ensure the performance of testing and certification tasks at the level established by state and international standards. In general, the substantiation of the requirements for test sites and the adoption of general requirements for test sites at the level of a normative document will allow normalizing the processes of testing samples of mechanized demining equipment and will allow the implementation of mine action tasks in Ukraine at a new, organizationally and practically improved level.

Dechlorination of Hexachlorobenzene by Ni/Fe Bimetallic Nanoparticles and the Influence of Co-Existing Heavy Metal Ions

Hexachlorobenzene (HCB) is one of the most persistent environmental pollutants of global concern. Ni/Fe nanoparticles, with their small particle size, large surface area, and high reactivity, are a promising candidate for HCB degradation. In this work, we investigated the kinetics and products of the dechlorination of HCB by Ni/Fe nanoparticles and how the presence of heavy metal ions Cd(Ⅱ) and Zn(Ⅱ) influences the reaction. It is found that 400 μg/L HCB can be rapidly removed by 7.5 g/L Ni/Fe nanoparticles and the removal percentage reaches 99% in 48 h. The removal is facilitated by adsorption and sequential dechlorination of HCB, producing PCB, 1,2,3,4-TeCB, and 1,2,3-TCB as the main products, with 1,2,3,5/1,2,4,5-TeCB, 1,2,4-TCB, and 1,2-DCB as the minor products. The addition of heavy metal ions Cd(Ⅱ) and Zn(Ⅱ) does not significantly affect the removal rate of HCB but hinders the adsorption and degradation of the byproducts through competitive adsorption. Additionally, the concentration of both Cd(Ⅱ) and Zn(Ⅱ) decreases rapidly and achieves over 98% removal in 4 h. Our study reveals that Ni/Fe nanoparticles can remove HCB and heavy metals Cd(Ⅱ) and Zn(Ⅱ) concurrently, with the extent of HCB dechlorination reduced compared to that without heavy metal. These findings may inform the application of Ni/Fe nanoparticles in the treatment of water bodies and soil contaminated by both halogenated aromatics and heavy metal.

Environmental and socio-economic evaluation of a groundwater bioremediation technology using social Cost-Benefit Analysis: Application to an in-situ metal(loid) precipitation case study

Bioremediation can be an alternative or complementary approach to conventional soil and water treatment technologies. Determining the environmental and socio-economic impacts of bioremediation is important but rarely addressed. This work presents a comprehensive sustainability assessment for a specific groundwater bioremediation case study based on In-situ Metal(loid) Precipitation (ISMP) by conducting a social Cost-Benefit Analysis (CBA) using two different approaches: environmental Life Cycle Costing (eLCC) and Impact Pathway Approach (IPA). Externalities are calculated in two ways: i) using Environmental Prices (EP) to monetize Life Cycle Assessment (LCA) results and metal(loid)s removed at field scale, and ii) following the IPA steps to determine the social costs avoided by removing arsenic contamination at full scale. The results show that, in the baseline scenario, the project is not socio-economically viable in both cases as the Net Present Value (NPV) is −129,512.61 € and − 415,185,140 € respectively. Sensitivity and scenario analyses are performed to identify the key parameters and actions needed to reach a positive NPV. For instance, increasing the amount of water treated per year to 90 m3 and assuming a 20 % increase in operation costs and a 60 % increase in construction costs can make the project socio-economically viable at the field scale, while a reduction in the social discount rate from a 4 % to a 2 % can lead to a positive NPV at the full scale. The approaches proposed in this work may be useful for practitioners and policymakers when evaluating the environmental and socio-economic impacts of bioremediation technologies at different scales and regions, as well as human health impacts caused by contaminants at the current legal limits.

Bio-fortification with selenium (Se) improves quality and nutrient profile in citrus fruit

Selenium (Se) is an essential nutrient for the human body. Humans can enhance Se absorption by consuming horticultural plants, particularly fruits. Therefore, there is need for Se biofortification in fruits to meet the human demand for Se. The objective of this study was to determine the optimal Se application rate, application stage and method, and to assess their impacts on improving both the quality and nutrient profile of a sweet orange cultivar 'Hongjiangcheng' (Citrus sinensis (L.) Osbeck). 'Hongjiangcheng’ is a notable variety of mandarin orange, acclaimed for its large size, thin and smooth skin, orange-red flesh, tender and juicy texture, balanced sweetness and acidityand distinctive flavor. A field experiment was conducted at the Qiaotou Town Test Base in Chengmai County, Hainan Province, China. Biofortification of Se was done through foliar and soil application methods. Treatments were: Control (C) with no application of Se, foliar application of 25 (SeF1), 50 (SeF2), 100 (SeF3) and 200 (SeF4) mg/L and soil application of 100 mg/L (SeS1) as well as a combination of 100 mg/L Se in soil along with 50 mg/L Se on leaves (SeS1F2). At start of the experiment, 189 healthy, four-year-old citrus trees of similar size and normal growth were selected. The trees were divided into three groups of 63 each. Each group received the aforementioned treatments at the young fruit, expanding fruit and premature fruit stages. The Se was applied once during each stage before 9:00 am on sunny days. Treatments were arranged in a randomized complete block design with 9 biological replicates (7 treatments × 9 replicates = 63 citrus trees/ application stage). Foliar application of Se at rate of 200 mg/L (SeF4) enhanced total Se content in leaves by 105, 34 and 69 % at young fruit, expanding fruit and premature fruit stages compared to control (p≤0.05). Respective increments in fruits were 264, 22 and 21 %. The total Se content in leaves were 32 and 40 % higher in the SeF4 (foliar) compared to SeS1 and SeS1F2 (soil) treatments across all development stages (p≤0.05), respectively. The respective increments in fruits total Se content were 16 and 52 %. Only at the young fruit stage, the organic Se content in fruits was significantly higher in the SeF4 compared to soil application treatments (p≤0.05). Single fruit weight was enhanced by 16.61, 13.69 and 4.36 g by foliar than soil application at young fruit, expanding fruit and premature fruit stages, respectively. It was significantly higher (155.53 vs. 113.13 g) after application of SeF4 treatment at young fruit stage relative to all other treatments (p≤0.05). The application of SeF4 at the young fruit stage resulted in an increased seed rate (97 %), total soluble solids (28 %) and solid-to-acid ratio (75 %), while titratable acid decreased by 26 % compared to the control. Interestingly, Se application had non-significant effects on the fruit shape index, peel rate and residue rate across all stages (p>0.05). Additionally, a positive correlation was observed between fruit Se content and several quality indices like total soluble solids, solid acid ratio, fruit shape index and fruit weight at young fruit stage (p≤0.05). It is concluded that foliar application of Se at 200 mg/L (SeF4) during young fruit stage improved citrus Se content, its fruit weight and quality indices establishing these fruits as a valuable source of Se-rich food for human consumption.

Integrating Deficit Irrigation Strategies and Soil-Management Systems in Almond Orchards for Resilient Agriculture

This work was conducted over three-year monitoring seasons of three almond cultivars (Guara, Marta, and Lauranne) subjected to deficit irrigation in combination with cover crops in a Mediterranean semiarid area (SW, Spain). Four water–soil treatments were evaluated based on the conjunction of two irrigation strategies: fully irrigated (FI), covering 100% of the ETC, and regulated deficit irrigation (RDI), with two soil-management systems: bare soil (BS) and cover crop based on a mixture of vetch (Vicia sativa L.) and oat (Avena sativa L.) (CC). Throughout the study period in trees, the yield, the stem water potential (Ψstem), leaf nutrient content (N, P, K, Ca, Mg, Na, Fe, Zn, Mn, and Cu) in soils, organic carbon, microbial biomass, fluoresceine diacetate, and enzymatic activities (dehydrogenase, protease, β-glucosidase, and alkaline phosphatase) were determined. In addition, the dry matter and carbon fixation by plant covers were evaluated. For Guara and Lauranne, yield reductions (22 and 26%, respectively) were found for water-stressed (RDI-CC) plots with respect to non-stressed combination (FI-CC) plots, contrasting with cv. Marta, without a significant impact on productivity in all combinations. That is, the RDI (~3.000 m3 ha−1) strategy enabled acceptable productivity, offering promising possibilities for cultivation performance under water-scarcity scenarios. Important differences in Ψstem could be observed and ascribed to irrigation strategies, especially for Guara and Lauranne, but without significant effects due to the soil-management systems applied. No differences were observed in the tree nutritional status due to the presence or absence of CC; however, its presence increased the fixation of atmospheric carbon, which was not the case under BS conditions. Additionally, CC significantly fostered the microbial processes and enzymatic activities, particularly in upper soil layers (0–10 cm) and with plenty of water supply in FI-CC plots and to a lesser extent in RDI-CC plots, which could encourage prominent aspects for soil quality and health restoration. Thus, the cover crop is congruent with RDI to facilitate soil functionality and water savings in a changing climate, contributing to resilient farming systems in the Mediterranean environment.