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In response to the growing demand for environmentally sustainable agricultural practices that enhance production efficiency, this study aimed to determine the optimal application rates of bovine rumen content (CBR) and chicken litter (CCL) as organic composts. Conducted in a controlled greenhouse environment, the research assessed the effects of various doses of these composts on soil chemical and microbiological properties and on the growth and productivity of yellow biquinho pepper (Capsicum chinense Jacq.). The results of this study confirm that organic composts improve soil health and increase the growth and productivity of yellow biquinho pepper. However, while CBR consistently enhances plant growth across a range of doses, CCL shows a dose-dependent response, with the highest fruit production achieved at an application rate of 73.92 Mg ha−1. Although this dose of CCL is beneficial for increasing yield, it also marks a threshold beyond which further increases may lead to negative effects such as nutrient saturation or salt accumulation, potentially resulting in soil toxicity. The study supports the use of CBR and CCL as effective soil conditioners and emphasizes the need to identify the optimal compost dose to efficiently harness the benefits of organic composts in sustainable agricultural practices. [ABSTRACT FROM AUTHOR]

Dog feces are a known source of nutrient, pathogen, and plastic pollution that can harm human and ecosystem health. Home composting may be a more environmentally sustainable method of managing dog feces and reducing this pollution. While composting is an established method for recycling animal manures into low‐risk soil conditioners for food production, few studies have investigated whether household‐scale compost methods can safely and effectively process dog feces for use in backyard edible gardens. A broad range of literature on in situ composting of dog feces is evaluated and compared according to scale, parameters tested, and compost methods used. Studies are analyzed based on key identified knowledge gaps: appropriate compost technologies to produce quality soil conditioner on small scales, potential for fecal pathogen disinfection in mesophilic compost conditions, and biodegradation of compostable plastic dog waste bags in home compost systems. This review also discusses how existing methods and quality standards for commercial compost can be adapted to dog fecal home composting. Priorities for future research are investigation of household‐scale aerobic compost methods and potential compost amendments needed to effectively decompose dog feces and compostable plastic dog waste bags to produce a good‐quality, sanitized, beneficial soil conditioner for use in home gardens. Integr Environ Assess Manag 2024;20:1876–1891. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: A few scientific and community‐based studies have composted domestic dog feces under controlled laboratory conditions or on large outdoor scales, but no studies to date have investigated outdoor, household‐scale dog fecal composting.Commercial products for home composting dog feces are generally designed to be used in‐ground, but burying dog feces can harm human and ecosystem health by concentrating untreated, unstable pathogens and nutrients in the soil.It is currently unknown how nonthermal physical, chemical, and biological factors may affect pathogen reduction and/or plastic degradation and/or disintegration in dog fecal home compost.Future research on home composting dog feces should prioritize investigating compost quality, sanitation, and biodegradation of home compostable plastic dog waste bags in real‐world conditions. [ABSTRACT FROM AUTHOR]

Ensuring food security for the world's growing population while advancing sustainable agriculture and reducing conventional fertilizer use is a major challenge. The objective of this research was to comparatively evaluate the effect of microalgae biomass biofertilizer, derived from the production of Arthrospira platensis DHR 20 (Spirulina) in cattle wastewater under organic management (CW), on the development of arugula. It also examined the microbiological attributes of arugula leaves and the changes in soil chemical properties and structural composition of the soil post-experiment. The experiment consisted of three treatments: T1 – control, with urea application; T2 – CW; T3 – microalgae biofertilizer. The experimental design was completely randomized with seven replications and four plants per plot. The main conclusion of this research is that microalgae biomass biofertilizer presents nutritional potential for arugula, particularly as a source of N (187.5 mg L−1) and K (92.9 mg L−1), and can replace conventional urea fertilizer as a nitrogen source in the cultivation of arugula, with similar plant development quality according to the Dickson Quality Index. According to the SAR, the microalgae biomass biofertilizer and CW do not present soil sodicity restrictions and show a low to moderate level of restriction for soil use in terms of salinity. The average biofixation rate of 0.22 CO2 L−1 d−1 obtained in the study suggests that Spirulina cultivation in CW is suitable for this greenhouse gas biofixation. Leaves from the three treatment groups yielded negative results for the presence of thermotolerant coliforms. Both microalgae biofertilizer and CW acted as soil conditioners, improving its structural quality when compared to soil fertilized with urea. [ABSTRACT FROM AUTHOR]

The persistent reliance on coal has resulted in the accumulation of substantial coal gangue, a globally recognized problematic solid waste with environmental risks. Given the coal gangue properties and global land degradation severity, the resourceful utilization of coal gangue as soil conditioners is believed to be a universally applicable, cost-effective, high-demand and environment-friendly model with broad application prospect. The direct application of raw coal gangue faces challenges of low active beneficial ingredients, inadequate water and fertilizer retention, presence of potentially toxic elements, resulting in limited efficacy and environmental contamination. This paper provided a comprehensive review of various modification methods (including mechanical, chemical, microbiological, thermal, hydrothermal and composite modifications) employed to enhance the soil improvement performance and reduce the environmental pollution of coal gangue. Furthermore, an analysis was conducted on the potential application of modified coal gangue as a muti-function soil conditioner based on its altered properties. The modified coal gangue is anticipated to effectively enhance soil quality, exhibiting significant potential in mitigating carbon emissions and facilitating soil carbon sequestration. This paper provided innovative ideas for future research on the comprehensive treatment of coal gangue and restoration of degraded soil in order to achieve the dual goals of zero-coal gangue waste and sustainable agriculture. [ABSTRACT FROM AUTHOR]

Biochar is a carbon-rich material that has recently received attention due to its increasing agronomical potential. The agricultural utilization of biochar relates to its potential to act in the soil as a soil conditioner; nevertheless, complex information on the direct dependence of biochar's physical properties (texture, particle size) and corresponding leaching and availability of organic molecules (e.g., the polycyclic and heterocyclic organic compounds) and inorganic mineral salts (based on micro- and macroelements) is still inconsistent. Multi-elemental analysis by using inductively coupled plasma atomic emission spectroscopy (ICP-OES) was used to assess the information on the contents and availability of macro- and microelements in studied commercial biochar samples. The results showed a statistically significant indirect relation between an increase in the size fraction of biochar and the content of aqueous-extractable K and Na and the direct relation with the aqueous-extractable Ca, Mg, and P. Compared to the macroelements, the detected contents of aqueous-extractable microelements were almost three orders lower, and the dependence on fraction size was not consistent or statistically significant. In addition, gas chromatography (GC) coupled with mass spectroscopy (MS) was further used to reveal the concentrations of available polycyclic aromatic and heterocyclic compounds in biochar samples. The detected concentrations of these types of organic compounds were far below the certified limits, and a statistically significant indirect correlation with particle size was also observed for all the studied biochar samples. The proposed methodological concept could provide the necessary insights into the description of biochar mineral content and its connection to biochar texture, the physicochemical properties, and the potential of biochar to release nutrients into the soil. These findings could help in the further assessment of biochar as a soil conditioner in modern agriculture. [ABSTRACT FROM AUTHOR]

This study analyzed the effect of the application of a soil conditioner under the trade name of the Agro Mineral Product (AMP) in the winter rapeseed cultivation on the bacterial and fungal abundance, ion concentrations, and electrolytic conductivity of the soil solution. It was demonstrated that the AMP influenced changes in the total abundance of the culturable fractions of the soil bacteria and fungi at each of the tested time points. A stimulatory effect of the preparation on the growth of the soil bacteria and an inhibitory effect on the development of the fungi was observed, particularly at doses of 4 and 8 t·ha−1. A dose of 12 t·ha−1 proved to be the least effective in relation to the development of the soil microbiome. Increasing the AMP fertilization dose above 4 t·ha−1 caused changes in the chemistry of the soil solution (pH, EC, HCO3−, K+, and PO4-P). It is worth noting that this primarily resulted in decreases in the amounts of mobile forms of potassium (from 40.4 mg·dm−3 in the control to 26.7 mg·dm−3 at the 8 t·ha−1 dose) and orthophosphate as phosphorus (from −6.00 mg·dm−3 in the control to 3.75 mg·dm−3 at the 8 t·ha−1 dose) in the soil solution, which resulted in a reduction in the yield of the winter rapeseed (from 4.76 t·ha−1 in the control to 4.61 t·ha−1 at the 8 t·ha−1 and 4.43 t·ha−1 at the 12 t·ha−1 AMP dose). [ABSTRACT FROM AUTHOR]

Soil conditioners can accelerate the recovery of soil physical, chemical, and/or biological quality, thus optimizing soil productivity. The 32 isotope tracing technique was used to determine the contribution of P from soil amendments in the form of lime, biochar, and compost, as well as to study their effects on P fertilization efficiency and corn yield. The treatments included lime, biochar, compost, and combinations of these three materials. The parameters analyzed were corn yield and P contribution from P sources. This study aimed to evaluate the ability of soil amendments to increase P uptake, growth, and yield of corn, as well as to determine the P contribution from lime, biochar, and compost to corn plants using the 32 isotope tracing technique. The results on Ultisol soil from Jasinga, Bogor, showed that the combination of 3 t ha-1 lime + 15 t ha-1 biochar + 15 t ha-1 compost resulted in the highest grain weight of 45.942 g plant-1 . The contribution of P from the carrier materials to the grain of the combination of 3 t ha-1 lime + 15 t ha-1 biochar + 15 t ha-1 compost was 44.945 mg plant-1. In conclusion, the combination of these soil conditioners can increase P availability and corn production on Ultisol soil from Jasinga, Bogor. [ABSTRACT FROM AUTHOR]

Clogging frequently occurs in the cutter head, excavation chamber or screw conveyor when an earth pressure balance (EPB) shield machine is tunneling in soft or silty clay ground with high clay mineral content. In this paper, montmorillonite, kaolinite, and illite were selected as research objects, and molecular dynamics simulation and laboratory experiment were adopted. At the microscopic scale, dynamic contact behavior and interfacial mechanical behavior of the interface between clay minerals and water/surfactant solution was simulated and the interfacial adhesion and conditioning mechanism between clay minerals and water/surfactant solution was revealed. Thus, sodium dodecyl benzene sulfonate surfactant was selected as the main composition of the soil conditioner. Then, the adhesion stress before and after soil conditioning and the contact angles between clay minerals and water/surfactant solution were tested and analyzed at the macroscopic scale. The result shows that the contact angle between droplet and clay mineral surface is an important parameter to characterize soil adhesion. The simulation rules of the microscopic contact angle are consistent with the experiment results. Furthermore, the adsorption energy between microscopic substances is dominated by electrostatic force, which can reflect the adhesion stress between macroscopic substances. Soil adhesion stress can be effectively decreased by adding the surfactant to the soil conditioner. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Grape pomace from Vitis vinifera Asssyrtiko is an important sub‐product of the Greek wine industry. However, its accumulation is a serious problem with a negative environmental impact. Grape pomace is rich in bioactive compounds and its utilization for alternative uses, such as a fertilizer, is an interesting area of research. On the other hand, its high concentration of phenolic compounds inhibits germination processes. Therefore, there is a need to decrease the high phenolic level in grape pomace before it can be used as a fertilizer. The main objective of our study is the fast reduction of polyphenols in grape pomace, and more specifically catechin and epicatechin in Vitis vinifera Assyrtiko. For this purpose, Chlamydomonas reinhardii was used for polyphenol biodegradation in grape pomace extract. It is shown that the bioremediation proceeds very fast, while the final product has a high potential to be used as a soil conditioner. RESULTS: The results of this study identify that after 6 days of cultivation, C. reinhardtii was able to reduce the total polyphenolic amount by 43%, while catechin and epicatechin were decreased by 100%. In addition, it is shown that the final aqueous product is rich in minerals, such as sodium, phosphorus and potassium. CONCLUSIONS: Through this work we were able to develop a method that allows for the efficient decrease of polyphenols in grape pomace. C. reinhardtii biodegrades a sufficient amount of polyphenols in grape pomace with a high rate, while the product obtained 6 days after cultivation contains high concentrations of minerals and low levels of polyphenols. These results suggest that there is a great potential in using the Vitis vinifera Asssyrtiko biodegraded product as a soil conditioner. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

When an earth pressure balance shield passes through soft-upper and hard-lower composite strata, it faces challenges such as cutterhead "mud cake" formation, inefficient muck removal, and tool wear. To address these issues, this study focused on silty clay-completely weathered granite composite strata and conducted laboratory tests on ground conditioning in different strata based on the adaptability and performance of soil conditioners. The study explored the effects of soil conditioners, such as foam agent and bentonite slurry, as well as their improvement methods on soft-upper and hard-lower strata, to determine an optimal ground conditioning scheme and the appropriate addition ratios for shield tunneling in composite strata. The results showed that: (1)Combining a 3% concentration foam agent solution with bentonite slurry at a 1 : 8 ratio yielded good results. (2)The silty clay strata were improved by foam agent. The slump of the muck increased with the foam addition ratio, while the shear strength, cohesion, internal friction angle, and permeability coefficient decreased. The optimal addition ratio of the soil conditioners was between 19. 7% and 22. 8%. ( 3) The completely weathered granite strata were improved using a combination of foam agent and bentonite slurry, which effectively enhanced the flow plasticity and impermeability of the muck. When using only foam, the optimal addition ratio was between 22. 2% and 28. 7%, while the combined foam and bentonite slurry method required a ratio of 24. 3% to 31. 5%. Field application and construction feedback showed that the above improvement scheme effectively enhanced the flow plasticity of the muck, and significantly improved the shield thrust, cutterhead torque and tool wear. [ABSTRACT FROM AUTHOR]

Oyster shell has been studied as effective stabilizer for heavy metals that exist as cationic forms in soil-aqueous system, but its stabilization capacity for arsenic was very low because of its anionic existence forms. Layered double hydroxide (LDH) shows excellent oxyanion As fixation capacity in soil because of interlayer anion (or complex) exchange, but has relatively low fixation capabilities for other heavy metals. Because of different main mechanism to fix arsenic in the stabilizer compared to other heavy metals, there are limitations in applying only a single stabilizer to the site contaminated with both the arsenic and other heavy metals. The use of a powdered type stabilizer in the field could also be limited because of the risk of suffering mass loss, fugitive dust generation, and low sustainability of the stabilization effect. To overcome these problems, the granular and the slurry type of Mg-Fe LDH mixed with oyster shell were manufactured as the stabilizer to fix As, Pb, and Cu in the soil at the same time and their stabilization efficiencies were investigated by field scale demonstration tests in this study. Results from experiments confirmed that when a mixed granular type stabilizer was added into the soil, the extraction reducing efficiency for all three, As, Pb and Cu, from soil was more than 75%, which indicated that the mixed stabilizer has great potential to fix all of them in soil at the same time. In field demonstration tests (a total of 3 test beds; each bed: 3 m × 3 m × 2 m), the concentration of As and Pb in groundwater from treated test beds decreased by more than 60%, and their extraction reducing efficiencies were higher than 40%. Both As and Pb fractionation transition to more stable phases in test beds by the mixed stabilizer was clearly observed, supporting the Mg-Fe LDH mixed with oyster shell could be successfully used as a single stabilizer for sites contaminated with both heavy metals and As. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the context of efforts aimed at reducing carbon emissions, the utilization of recycled aggregate soil mixes for soil stabilization has garnered considerable interest. This study examines the mechanical properties of mixed soil samples, varying by dosage of a soft soil curing agent C, recycled aggregate R content, and curing duration. Mechanical evaluations were conducted using unconfined compressive strength tests (UCS), field emission scanning electron microscopy (FESEM), and laser diffraction particle size meter tests (PSD). The results indicate that the strength of the mixed soil samples first increases and then decreases with higher dosages of recycled aggregate, reaching optimal strength at a 20% dosage. Similarly, an increase in curing agent dosage enhances the strength, peaking at 20%. The maximum strength of the mixed soils is achieved at 28 days under various proportions. The introduction of the curing agent leads to the formation of a flocculent structure, as observed in FESEM, which contributes to the enhanced strength of the soil mixes. Specimens prepared with a combination of 20% R and 20% C, maintained at a constant moisture content of 20%, and cured for 28 days exhibit a balance between economic, environmental, and engineering performance. [ABSTRACT FROM AUTHOR]

Silicate has been proven to be highly-effective at immobilizing soil heavy metals, but the effects of silicate stabilizers on rice grain cadmium (Cd) reduction and rice quality under field conditions are not clear. In this study, a field experiment was conducted over three consecutive years was conducted to examine the Cd reduction in rice grains and to reveal the potential effects of silicate stabilizers on rice grain nutrients, by setting different amounts of bentonite (B), silica‒calcium fertilizer (SC) and zeolite powder (ZP). The results revealed that the application of the B, SC and ZP significantly decreased the soil CaCl2‒Cd concentration (> 39%) and significantly reduced the grain Cd concentration in both early rice (> 70%) and late rice (> 18%) under field conditions; the silicate stabilizers reduced the soil available iron (Fe) but did not limit rice grain Fe nutrition. Additionally, the three silicates promoted rice yield and improved the rice grain Ca and Mg contents; and the application of B increased the amylose concentration of the late rice grains. In conclusion, high amounts of silicate stabilizers did not adversely influence the soil conventional nutrient indices, rice minerals or rice taste, but changes in rice selenium content need attention. Overall, in comparison with lime, silicate stabilizers can improve not only the safety of rice but also the nutritional and taste qualities of rice and are more eco-friendly for long-term use in soil. [ABSTRACT FROM AUTHOR]

This research investigated the production of compost from concentrated latex sludge as a conditioner and studied the properties of the compost in four different experiments using different ratios of composting ingredients: concentrated latex sludge, urea, and cow manure. The different ratios were used were: 3.0:0:0, 2.0:0.5:0.5, 2.0:1.0:0, and 2.0:0:1.0, respectively. All compost formulations were analyzed for their properties, specifically the average of: temperature, moisture content, pH, electrical conductivity, and organic matter. It was shown that a suitable compost fermentation period lasted for 50 days. The properties of the compost derived from concentrated latex sludge included an average temperature range of 29.80-38.06 °C, the percentage of moisture content ranged from 78.92% to 81.82%, pH was between 8.34 - 8.48, electrical conductivity (EC) was 3.18 - 6.13 decisiemens/meter, and quantity of organic matter ranged from 38.51%-42.71%. Among treatments, the compost in the second treatment with the ratio 2.0:0.5:0.5 was found to be the most suitable, showing the greatest economic value and investment return due to its superior N: P: K content which was the highest in the experiment. Specifically, the percentage contents of N, P, K were 4, 0.95%, and 0.39% respectively. In analysis of economical value, the compost yielded a return on investment 48.47% and a net profit of 1,537.80 Baht per production cycle. In conclusion, the production of compost from concentrated latex sludge contained primary micronutrients and had potential for promoting plant growth as a soil conditioner. [ABSTRACT FROM AUTHOR]

Nitrogen-fixing cyanobacterial consortia are an alternative to the indiscriminate use of chemical fertilizers that affect the environment, fix atmospheric nitrogen, and can therefore be used as plant growth promoters, synthesize various substances such as auxins, vitamins, and total proteins, and fix atmospheric biofertilizers and soil conditioners. The present study aimed to obtain and develop, by biotechnological means, two consortia of cyanobacteria isolated from the root and rhizosphere of Carica papaya grown in sandy loam soil. The culture was carried out in Blue Green Medium without modified nitrogen (BG110), with aeration of 0.32 L min−1, at a light intensity of 48.83 μEm−2s−1, and a temperature of 22 ± 2 °C. Two consortia consisting of Nostoc commune, Aphanothece minutissima, Planktothrix sp. (C1), Nostoc commune, Calothrix sp., and Aphanothece minutissima (C2) were isolated and morphologically identified. The effective development of these consortia was verified at the laboratory level by obtaining biomass in dry weight as well as photosynthetic pigments, proteins, carbohydrates, and lipids. Germination parameters were determined in seeds of Cucumis sativus L. var. Market plus treated with the nitrogen-fixing cyanobacteria consortia, obtaining a higher germination percentage (>90%), greater root length (>6 cm), and higher vigour index I (513), II (13.02) for the C2 consortium. This broadens the spectrum of rhizosphere-derived microorganisms with potential as growth biostimulators. [ABSTRACT FROM AUTHOR]

Chrysanthemum, an agricultural economic crop with ornamental, medicinal, and edible values, faces the problem of continuous cropping obstacles in its cultivation. As a potential soil conditioner used to address continuous cropping obstacles (CCOs), the applicability of biochar in chrysanthemum cultivation has become a research hotspot. This study explored the effects of three different types of biochar (rice straw biochar = RB, pig manure biochar = PB, and sludge biochar = SB) on soil for chrysanthemum that had been continuously cultivated for eight years through pot experiments. The results indicate that the addition of biochar significantly reduced soil water loss. Compared with CK, the water retention rates of the SB and PB treatments increased by 25.4% and 18.4%, respectively. In the PB treatment, the contents of available phosphorus (AP) and available potassium (AK) increased by 85% and 164%, respectively. The available nitrogen (AN) content showed the highest increase under the SB treatment. All three types of biochar could improve the pH value of chrysanthemum soil with CCOs (increased by 0.4–5.4%). The results of microbial community diversity showed that, compared with CK, PB and RB slightly reduced the diversity of bacterial communities in chrysanthemum soil with CCOs (by 1.50% and 0.41%, respectively). However, the SB treatment increased the diversity of bacterial communities in chrysanthemum soil with CCOs (by 0.41%). At the same time, SB and PB significantly inhibited the diversity of fungal communities (reduced by 15.15% and 6.67%, respectively), while RB promoted the diversity of fungal communities (increased by 5.45%). Furthermore, the analysis results of bacterial phyla and genera indicated that PB and SB had enhancing effects on the beneficial bacterial phylum Actinobacteriota (8.66% and 4.64%) and the beneficial bacterial genus Nocardioides (23.29% and 9.69%). Additionally, the PB treatment enhanced the beneficial bacterial phylum Firmicutes (7.03%). The analysis results of fungal genera and phyla indicated that PB contributed to an increase in the beneficial fungal phylum Ascomycota (1.51%). RB significantly enhanced the beneficial fungal genus Chaetomium (56.34%). Additionally, all three types of biochar effectively reduced the abundance of the harmful fungal phylum Basidiomycota (30.37–73.03%). In the PB and SB treatments, the harmful fungal phylum Mucoromycota was significantly decreased (by 36.22% and 62.60%, respectively). Finally, all three types of biochar reduced the abundance of harmful fungal genera Acremonium (1.15–35.19%) and Phoma (97.1–98.7%). In this study, we investigated the effect of three kinds of biochar (RB, PB, and SB) on the soil of chrysanthemum continuous cropping through potting experiments and found that they could significantly reduce water loss, enhance water retention, increase the soil nutrient content, improve the pH value, regulate microbial communities, increase beneficial microorganisms, and reduce harmful microorganisms. These results provide a scientific basis for addressing barriers to continuous cropping (CC) while supporting the sustainability of agriculture and the development of agroecology. [ABSTRACT FROM AUTHOR]

Two approaches to the synthesis of hydrogels based on polyacrylamide (pAAm) with copolymers were compared in the paper—traditional chemical cross-linking and physical cross-linking with montmorillonite (MMT). The main aim of the work was to find an adequate replacement of the chemical toxic cross-linking agent MBAAm (N,N'-methylene-bis-acrylamide) by using non-toxic—natural clay MMT for synthesis of pAAm gels, which are planned to be used as soil conditioners. A series of hydrogels based on acrylic monomers (acrylamide (AAm), acrylonitrile (AN), acrylic acid (AA)) physically cross–linked by MMT and chemically cross-linked were synthesized. For the synthesized gels, the influence of the synthesis method on the formation of the structure and the mechanism of thermal destruction in the presence of air was analyzed using a set of physicochemical methods: FTIR, XRD, SEM, DSC and TG/DTG. According to FTIR and XRD data, pAAm-MMT and pAAm-AN-MMT samples formed an intercalated/exfoliated structure, whereas pAAm-AA-MMT had an intercalated structure. The endothermic reaction of decomposition of xerogels based on acrylic polymers with and without MMT was observed using DSC and derivative thermogravimetry analyses, coupled with measurement of FTIR spectra of volatile products of thermolysis. All studied composites were relatively thermoresistant, which had three distinct regions of phase transitions and their thermal decomposition occurred at a temperature range 310–465 °C. [ABSTRACT FROM AUTHOR]

Urban construction generates significant amounts of construction residue soil. This paper introduces a novel soil stabilizer based on industrial waste to improve its utilization. This stabilizer is primarily composed of blast furnace slag (BFS), steel slag (SS), phosphogypsum (PG), and other additives, which enhance soil strength through physical and chemical processes. This study investigated the mechanical properties of construction residue soil cured with this stabilizer, focusing on the effects of organic matter content (Oo), stabilizer dosage (Oc), and curing age (T) on unconfined compressive strength (UCS). Additionally, water stability and wet–dry cycle tests of the stabilized soil were conducted to assess long-term performance. According to the findings, the UCS increased with the higher stabilizer dosage and longer curing periods but reduced with the higher organic matter content. A stabilizer content of 15–20% is recommended for optimal stabilization efficacy and cost-efficiency in engineering applications. The samples lost their strength when immersed in water. However, adding more stabilizers to the soil can effectively enhance its water stability. Under wet–dry cycle conditions, the UCS initially increased and then decreased, remaining lower than that of samples cured under standard conditions. The findings can provide valuable data for the practical application in construction residual soil stabilization. [ABSTRACT FROM AUTHOR]

The soil can be managed to improve plant nutrition and resilience under water scarcity. The objective of this study was to evaluate the contribution of soil conditioners, controlled-release fertilizers, and water availability levels to mitigate water scarcity and improve the nutrition of coffee plants. The experiment was conducted in a greenhouse under a randomized block design with four replicates in a factorial scheme (2 irrigation levels × 2 fertilizer types × 5 soil conditioners) of analysis of variance. The factors under study were two irrigation levels (low—40% of water holding capacity, and high—80% of water holding capacity), fertilizer type (conventional and controlled-release), and soil conditioners (coffee husk, gypsum, water-retaining polymer, organic compost, and control without soil conditioner), The characteristics assessed were soil fertility, soil moisture, and nutrient foliar contents. Multivariate analytical methods were used to interpret the results. Soil moisture, chemical attributes, and leaf nutrient contents were analyzed. There was a similarity in the clusters formed by the controlled-release fertilizer treatments, which contribute to plant nutrition. Even under water restriction, the treatments with coffee husk and organic compost were clustered along with soil moisture, favoring the absorption of nutrients. Soil cover with organic compounds improved soil moisture, even under low water availability, which favored plant fertility and nutrition. [ABSTRACT FROM AUTHOR]

Biomass pyrolysis by-products, such as biochar (BC) and wood vinegar (WV), are widely used as soil conditioners and efficiency enhancers in agriculture. A pot experiment was conducted to examine the effects of WV, both alone and in combination with BC, on soil properties in mildly saline soil and on cotton stress tolerance. The results demonstrated that BC and WV application, either individually or together, increased soil nutrient content. The combined application was more effective than the individual applications, resulting in a 5.18–20.12% increase in organic matter, a 2.65–15.04% increase in hydrolysable nitrogen, a 2.23–58.05% increase in effective phosphorus, and a 2.71–29.38% increase in quick-acting potassium. Additionally, the combined application of WV and BC led to greater improvements in cotton plant height, net photosynthetic rate (Pn), leaf nitrate reductase (NR), superoxide dismutase (SOD), and catalase (CAT) activities compared to the application of BC or WV alone. The enhancements in this study varied across different parameters. Plant height showed an increase of 14.32–21.90%. Net photosynthetic rate improved by 13.56–17.60%. Leaf nitrate reductase increased by 5.47–37.79%. Superoxide dismutase and catalase showed improvements of 5.82–64.95% and 10.36–71.40%, respectively (p < 0.05). Moreover, the combined treatment outperformed the individual applications of WV and BC, resulting in a significant decrease in MDA levels by 2.47–51.72% over the experimental period. This combined treatment ultimately enhanced cotton stress tolerance. Using the entropy weight method to analyze the results, it was concluded that the combined application of WV and BC could enhance soil properties in mildly saline soils, increase cotton resistance, and hold significant potential for widespread application. [ABSTRACT FROM AUTHOR]

One of the main challenges for modern agriculture is to seek methods for improvement of crop growth and quality which is based on the sustainable agriculture to provide the growing population with access to high-quality food. Controlled-release fertilizers (CRF) and slow-release fertilizers (SRF) are the answer to these challenges, as they constitute an alternative means of achieving higher agronomic efficiency relative to traditional fertilizers. The focus of this paper is to review the changes and trends regarding the CRF/SRF, with a particular focus on biopolymer-coated fertilizers, specifically sodium alginate as both the biopolymer for coating and a soil conditioner. The presented literature review reveals the promising prospects related to the necessity of developing fertilizers with a controlled/slow release of minerals, involving materials that provide the appropriate mineral release rate and which are characterized by properties ensuring a substantial reduction in the negative impact on the natural environment. This finds confirmation in the clear tendency for applying biodegradable materials, particularly originating from natural sources, which may become the appropriate materials used for fertilizer coating when considering the new requirements concerning environmental issues. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Ca-based, non-Ca-based additives and recycled solid wastes reduce PI and enhance TD. • These active ingredients improve soil texture via cation exchange and flocculation. • Transition metal oxides catalyze TD of nonchlorinated POPs via two mechanisms. • We also reviewed alkali, solid wastes and nano metals as catalysts to enhance TD. • Additives in photo- and photo-thermal-catalysis and their mechanisms are reviewed. High temperatures and providing sufficient time for the thermal desorption of persistent organic pollutants (POPs) from contaminated clay soils can lead to intensive energy consumption. Therefore, this article provides a critical review of the potential additives which can improve soil texture and increase the volatility of POPs, and then discusses their enhanced mechanisms for contributing to a green economy. Ca-based additives have been used to reduce plasticity of bentonite clay, absorb water and replenish system heat. In contrast, non-Ca-based additives have been used to decrease the plasticity of kaolin clay. The soil structure and soil plasticity can be changed through cation exchange and flocculation processes. The transition metal oxides and alkali metal oxides can be applied to catalyze and oxidize polycyclic aromatic hydrocarbons, petroleum and emerging contaminants. In this system, reactive oxygen species (•O 2 − and •OH) are generated from thermal excitation without strong chemical oxidants. Moreover, multiple active ingredients in recycled solid wastes can be controlled to reduce soil plasticity and enhance thermal catalysis. Alternatively, the alkali, nano zero-valent iron and nano-TiN can catalyze hydrodechlorination of POPs under reductive conditions. Especially, photo and photo-thermal catalysis are discussed to accelerate replacement of fossil fuels by renewable energy in thermal remediation. [Display omitted] [ABSTRACT FROM AUTHOR]

The aim of this study is to analyze the stabilization effects of an expansive soil using three different nontraditional chemical additives, in this case: white cement and nano-silica as admixture, waste granite dust, and a new liquid polymer soil stabilizer (i.e. liquid granite). The engineering properties such as soil consistency, linear shrinkage and soil swelling behaviour of a bentonite treated with these stabilizing agents were investigated. Furthermore, the bearing capacity of the stabilized bentonite was analyzed through the California Bearing Ratio test (BCR) and a laboratory foundation model. The experimental program consisted of three series of tests. In the first series, the tests were performed on an expansive soil reinforced with 2%, 4%, 8%, and 10% of white cement combined with 2% of nano-silica. Another series of tests consisted of samples mixed with different percentages of granite powder (5%, 10%, 15%, and 20%). In the third series, liquid granite as a soil stabilizer was blended with soil specimens at various concentrations (1%, 2%, 3%, and 4%). For all admixtures, the results showed a marked improvement in soil consistency, an important decrease in linear shrinkage, a considerable reduction on the expansion index, and a significant improvement of CBR and soil bearing capacity. Moreover, two empirical correlations were proposed between the bearing capacity parameters (i.e. CBR and Improvement factor) and the expansion index. [ABSTRACT FROM AUTHOR]

Abstract Uncaria rhynchophylla is an important traditional herbal medicine in China, and the yield and quality of Uncaria rhynchophylla can be improved by suitable soil conditioners because of changing the soil properties. In this paper, Uncaria rhynchophylla associated alkaloids and soil microbial communities were investigated. The field experiment was set up with the following control group: (M1, no soil conditioner) and different soil conditioner treatment groups (M2, biomass ash; M3, water retention agent; M4, biochar; M5, lime powder and M6, malic acid). The results showed that M2 significantly increased the fresh and dry weight and the contents of isorhynchophylline, corynoxeine, isocorynoxeine, and total alkaloids. Acidobacteria, Proteobacteria, Actinobacteria, and Chloroflexi were major bacterial phyla. Correlation analysis showed that fresh and dry weight was significantly positively correlated with Acidobacteria, while alkali-hydrolyzable nitrogen, phosphatase activity, fresh and dry weight, corynoxeine, and isocorynoxeine were significantly negatively correlated with Chloroflexi. The application of soil conditioner M2 increased the abundance of Acidobacteria and decreased the abundance of Chloroflexi, which contributed to improving the soil nutrient content, yield, and quality of Uncaria rhynchophylla. In summary, biomass ash may be a better choice of soil conditioner in Uncaria rhynchophylla growing areas.

The present work investigated the effects of different doses of biochar (2.5%, 5%, 10%), a by-product of the pyrolysis of woody biomass, on the growth of oat plants (Avena sativa L., cv "Danko") grown under different crude oil concentrations (0.5%, 1%, 2%, 3%, 6%) added to the soil, evaluating both biometric (i.e. fresh weight) and biochemical (i.e., content of malondialdehyde and proline, and total antioxidant power) parameters. The findings indicate that biochar positively influences the fresh weight of oat plants across all concentrations of crude oil investigated. On the other hand, regarding oxidative stress, measured by malondialdehyde and proline content, biochar led to a significant reduction, with statistical significance observed at biochar concentrations > 2.5% and crude oil levels > 2% (malondialdehyde: ranging from -25% to -38%; proline ranging from -33% to -52%). Soil amendment with biochar increased the total antioxidant power, particularly at biochar concentrations > 2.5% and crude oil levels > 2% (ranging from + 20% to + 98%). These results suggest that biochar has a great potential in mitigating the negative effects of crude oil contamination on plant growth and oxidative stress levels, thereby highlighting its value as a conditioner in contaminated soils. [ABSTRACT FROM AUTHOR]

Soil salinity represents a significant factor affecting agricultural productivity and crop quality. The present study was conducted to investigate the effects of soil conditioner (SC) comprising halotolerant microorganisms on the soil fertility, yield, rice quality, and the physicochemical and structural properties of starch in hybrid rice under saline conditions. The experimental treatments were composed of two high-quality hybrid rice varieties, i.e., 'Y Liangyou 957' (YLY957) and Jing Liangyou 534 (JLY534), and two soil amendment treatments, i.e., the application of SC at control levels and 2250 kg hm−2, or 'CK and SC', respectively. The crop was subjected to a mixture of fresh and sea water (EC 11 dS/m). The results demonstrated that the application of SC significantly enhanced the rice yield under salt stress conditions owing to an increase in the number of grains per panicle. Furthermore, SC was found to be effective in improving the organic matter and soil nutrient content. Furthermore, the application of SC resulted in an improvement in antioxidant defense, higher leaf SPAD values, and greater crop biomass, as well as the translocation of photo-assimilates at the heading stage. The application of SC not only improved the milling and appearance quality but also enhanced the taste value of rice by increasing the amylose and reducing the protein content. Furthermore, the application of SC also decreased the indentations on the surfaces of starch granules and cracks on the edges of the granules. The rice varieties subjected to SC exhibited excellent pasting properties, characterized by reduced proportions of amylopectin short chains and a lower gelatinization temperature and enthalpy of gelatinization. Overall, these findings serve to reinforce the efficacy of soil conditioner as a valuable tool to improve rice productivity and sustainability with improved rice grain quality under saline conditions. [ABSTRACT FROM AUTHOR]

Co-hydrothermal carbonization (co-HTC) of phosphorus rock (PR) and corn straw (CS) was investigated to prepare hydrochar-based materials as soil conditioners, focusing on the morphological transformation and solid–liquid migration of carbon and phosphorus. Various analytical methods, including elemental analysis, chemical quantification, FT-IR, XRD, 3D-EEM, TG, and XANES, were used to understand the synergistic interactions of PR and CS during co-HTC and determine the properties of the resultant products. The results indicated the acidic solution and humic acid-like substances produced by HTC of CS reduced the crystallinity of the PR and served as the activating agent for PR, allowing the PR to be easily dissolved and reconstituted, producing calcium carbonate and apatite-like materials, and the formation of C–O–PO3, C–PO3, C=O, and O=C–O chemical bonds. At 220 °C, adding 5% PR significantly promoted a 10.3% rise in the yield of CS hydrochar, a 4.3% rise in carbon recovery of CS, and a 4.8% rise in carbon sequestration potential of CS. The formation of Ca–P was notably promoted and the content of AP in co-HTC hydrochar was up to 89.9%, with 39% Hydro-P and 33% CaHPO4. In the case of artificial humic acid (HAa), its content was also remarkably increased by 5.9% in the hydrochar by co-HTC. In addition, the hydrochar produced by co-HTC of CS and PR was composed of carbon with an increased aromatic degree, rich organic matter, and biologically effective mineral nutrient elements and exhibited high stability. The present study provided a promising approach for value-added utilization of waste biomass and low-grade PR towards soil application. Highlights: CSPR hydrochar was prepared by co-HTC of corn straw and phosphorus rock. Co-HTC significantly activated phosphorus rock and increased carbon stability of corn straw. CSPR hydrochar exhibited a high carbon sequestration capacity. Co-HTC increased P effectiveness of phosphorus rock, and reduced greenhouse gas emissions. [ABSTRACT FROM AUTHOR]

Background: Tannia is one of the six most important root and tuber crops grown world-wide. Tannia possess good keeping quality compared to other vegetables. The tubers are considered more nutritious than colocasia and potato. But the crop is still underexploited compared to other tuber crops. Hence the study was undertaken to identify the effect of tillage and nutrition on quality characters of tannia. Methods: A field experiment was conducted at College of Agriculture, Vellayani, Kerala during 2014-15 to study the effect of organic nutrition on quality characters of tannia. The design used was split plot design with four replications. The treatments consisted of tillage and planting methods as main plot treatments (L1-conventional tillage followed by pit system, L2-conventional tillage followed by mound system, L3-deep tillage followed by pit system and L4-deep tillage followed by mound system). The sub plot treatments were combinations of soil conditioners (S1-control, S2-coir pith, S3-rice husk) and two nutrition systems (N1-integrated nutrient management (INM) and N2-organic nutrition). Result: Results of the experiment revealed that the quality characters of tannia was improved by deep tillage to a depth of 30 cm followed by pit system of planting, application of coir pith as soil conditioner @ 500 g plant-1 and organic nutrition (FYM @37.5 t ha-1 + wood ash @ 2 t ha-1). [ABSTRACT FROM AUTHOR]

Sewage sludge is an important soil conditioner, and source of nutrients with a potential for use in agriculture. However, such benefit needs to be weighed against the risks due to the presence of heavy metals, and other substances that may endanger human health, plants, soil and the ecosystem. This research had the objective of evaluating the agricultural potential of sewage sludge together with the risks that may be present in use. Samples of sewage sludge from seven wastewater treatment plants in Eswatini were analyzed for selected physical and chemical parameters, and heavy metal concentrations using commonly established laboratory procedures. The analysis results indicated that, sludge samples exhibited high organic matter content, cation exchange capacity, macro nutrients such as nitrogen and phosphorus and micro nutrients (trace metal elements) needed for plant growth. Anaerobically digested sludge samples showed higher carbon to nitrogen ratio because of biomass loss in the form of methane and carbon dioxide. The heavy metal concentrations are all within safe limits except the sludge from Matsapha area that had levels of chromium, and nickel above regulatory limits. With respect to their heavy metal contents, most of the sludge samples would qualify as Class A sludge ready to be used as organic fertilizer for agriculture without regular monitoring of heavy metals in the soil to which they are applied. The study results indicated the importance of sewage sludge for their agricultural potential through supplementation of both micro and macro nutrients needed for plant growth, for improving the soil properties such as water holding capacity and permeability, through the increase of organic matter content, and retention of nutrients due to the high cation exchange capacity. All these benefits are realized with sewage sludge being a lower cost alternative to commercial fertilizers. Moreover, the low concentration of heavy metals present in the sludge presents lower risk that may arise in the course of utilizing the sludge as agricultural supplement. [ABSTRACT FROM AUTHOR]

The use of waste such as wood ash as an alternative fertilizer in agricultural production can result in an improvement in the chemical and biological characteristics of the soil. The objective of this research was to evaluate the effect of doses and management of wood ash application in the organic matter content and biological attributes of the soil in a Cerrado area cultivated with Urochloa brizantha cv BRS paiaguás. The experiment was performed in randomized blocks, in a 5 × 2 striped scheme, with five doses of wood ash (0, 8, 16, 24 and 32 t ha−1) and two application managements (with and without incorporation to the soil) with four repetitions. The variables analyzed were: soil organic matter content, microbial biomass carbon, basal respiration, qCO2 and β-glucosidase activity. During the evaluations it was observed a reduction of 0.36 g kg−1 of organic matter for each ton of ash applied to the soil, regardless of management. This reduction also occurred in microbial biomass carbon and β-glucosidase activity. initially the ash doses elevated the soil respiration and the metabolic quotient, evidencing a small stress in the soil microbiota, however, in the last evaluation the rates of these two variables remained stable. The application of wood ash, in doses ranging from 16 to 24 t ha−1, can be used as soil conditioner and fertilizer in pastures, because it results in better conditions for the soil. [ABSTRACT FROM AUTHOR]

This study investigated the effects of nano zero-valent iron-modified biochar (nZVI@BC) as a soil amendment on potted rice growth, soil properties, and heavy metal dynamics. Seven treatments with varying amounts of soil conditioner, biochar, and nZVI@BC were applied to potted rice. Results showed that nZVI@BC application significantly improved rice agronomic traits, with the 15 g·kg−1 treatment increasing the panicle formation rate by 15% and 100-grain weight by 8% compared to the control. Soil fertility was enhanced, with available phosphorus increasing from 137 to 281 mg·kg−1 in the most effective treatment. Heavy metal analysis revealed that nZVI@BC application did not increase soil heavy metal content, with Cd levels remaining below 0.3 mg·kg−1 across treatments. Notably, the 10 g·kg−1 nZVI@BC treatment showed potential for slight Cd immobilization, reducing its concentration from 0.32 to 0.26 mg·kg−1. Microbial community analysis showed that nZVI@BC altered soil microbial diversity and composition, with the 10 g·kg−1 treatment resulting in the highest fungal diversity (Chao1 index: 294.219). The relative abundance of the beneficial fungal class Agaricomycetes increased from 40% to 55% with optimal nZVI@BC application. These findings suggest that nZVI@BC has potential as an effective soil amendment for improving rice cultivation while maintaining soil health, microbial diversity, and potentially mitigating heavy metal contamination. [ABSTRACT FROM AUTHOR]

Exploring the effects of different additives on the improvement of newly cultivated farmland in mountainous areas can provide rational soil fertilization plans for regions lacking means of production. We conducted a paddy planting experiment in Ankang City, Shaanxi Province. Six treatments were set up, including sole chemical fertilizer (CK); fertilizer + bacteria agent (NB); chemical fertilizer + alginate bio-organic fertilizer (NO); fertilizer + fulvic acid biomass nutrient solution (NF); chemical fertilizer + acid soil conditioner (NC); fertilizer + silicon–calcium–magnesium–potassium fertilizer (NSi). We collected topsoil samples after paddy harvest, analyzed their physical, chemical, and biological properties, and selected indicators to construct a Total Data Set (TDS) and a Minimum Data Set (MDS). The Soil Quality Index (SQI) was used to evaluate the soil improvement effects after different fertilization regimes. The SQI calculated by the TDS and the MDS showed that the SQI after NF treatment was higher than that under other treatments. The SQI based on the TDS (SQITDS) and the SQI based on the MDS (SQIMDS) were significantly positively correlated with yield. The SQI calculated based on both the TDS and the MDS can objectively reflect the soil fertility quality. The paddy yield and total dry matter accumulation were the highest under the NF treatment, and the SQI was the largest. Thus, the effect of chemical fertilizer combined with fulvic acid biomass nutrient solution on soil fertility was the most significant. [ABSTRACT FROM AUTHOR]

In this study, the engineering properties of organic soil (OS) stabilized with pozzolanic cement (PC) were investigated. In tests, 10, 15 and 20% proportions of PC were added to organic soil. Consistency limit, Proctor, unconfined compressive strength (UCS), triaxial (TA), swelling and compressibility tests were performed on the OS stabilized with PC. The addition of PC to OS increased the maximum dry density (MDD) and optimum moisture content (OMC) values. The UCS values for the OS stabilized with PC increased up to day 56 and then there was a reduction in the UCS after day 56. The internal friction angle value increased by 26% and the cohesion intercept value increased by 86% for the OS stabilized with PC. With the increase in the cement content in the OS stabilized with PC, the UCS, internal friction angle and cohesion intercept values increased. Swelling of the OS stabilized with PC rapidly reduced up to day 10, and this reduction slowed after day 10. The compressibility of the OS stabilized with PC increased up until day 10, and this increase slowed after day 10. With an increase in the cement content in the OS stabilized with PC, swelling and compressibility values reduced. As a result of the study, it appears that pozzolanic cement is an effective stabilizer for organic soil. [ABSTRACT FROM AUTHOR]

The contamination of soil with cadmium (Cd) poses a significant risk to both food safety and human health. It is crucial to urgently identify an effective technology for remediating Cd-contaminated soil. In the present study, a novel sulfur modified biochar supported ferrous sulfide (FeS@SBC) composite was fabricated by calcination and hydrothermal method. Indoor culture, column leaching, and pot experiments were employed to examine the immobilization effect of FeS@SBC on Cd in contaminated soil. The outcomes illustrated a significant immobilization effect on the Cd-contaminated soil with the application of FeS@SBC. After incubating the soil with the stabilizer for 28 d, the Cd that was previously highly mobile underwent a transformation into an immobilized state. In the experiment on leaching using simulated acid rain, the treatment with FeS@SBC showed a noteworthy decrease in the cumulative loss and leaching efficiency of Cd when compared to the control experiment. It achieved reductions of 70.9% and 71.6%, respectively. The adsorption and immobilization mechanisms resulted from co-precipitation, ion exchange and surface complexation. In the outdoor pot experiment, after 28 d of growth, the water spinach in contaminated soil treated with FeS@SBC has a better growth compared to the control group, with a biomass increase of 134.95%. Additionally, the values of BCF and TF of Cd decreased by 62.25% and 40.39%, respectively, and the available concentration of Cd in the soil decreased by 23.87%. The FeS@SBC composite shows promise as an effective stabilizer for remediating Cd-contaminated soil. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biopolymers are polymers of natural origin and are environmentally friendly, carbon neutral and less energy-intense additives that can be used for various geotechnical applications. Biopolymers like xanthan gum, carrageenan, chitosan, agar, gellan gum and gelatin have shown potential for improving subgrade strength, erosion resistance, and as canal liners and in slope stabilization. But minimal research has been carried out on cellulose-based biopolymers, particularly microcrystalline cellulose (MCC), for their application in geotechnical and geo-environmental engineering. In this study, the effect of MCC on select geotechnical properties of kaolin, a weak, highly compressible clay soil, like its liquid and plastic limits, compaction behavior, deformation behavior, unconfined compression strength (UCS) and aging, was investigated. MCC was used in dosages of 0.5, 1.0, 1.5 and 2% of the dry weight of the soil, and the dry mixing method was adopted for sample preparation. The results show that the liquid limit increased marginally by 11% but the plasticity index was nearly 74% higher than that of untreated kaolin. MCC rendered the treated soil stiffer, which is reflected in the deformation modulus, which increased with both dosage and age of the treated sample. The UCS of kaolin increased with dosage and curing period. The maximum UCS was observed for a dosage of 2% MCC at a 90-day curing period. The increase in stiffness and strength of the treated kaolin with aging points out that MCC can be a potential soil stabilizer. [ABSTRACT FROM AUTHOR]

The subsidiary of Yunnan Phosphate Group Co., Ltd., Kunyang Phosphate Mine's mining area is the subject of study. The mining of open-pit phosphate mines has caused significant damage to the ecological environment. Therefore, carrying out ecological restoration and green reclamation of the ecosystem in the mining area has become the top priority for current development. This article establishes an evaluation system for ecological restoration indicators, selecting four indicators including vegetation coverage, soil and water conservation, restoration of native plants, and Plant Species Diversity Index to assess the effects of ecological restoration and green reclamation of phosphate mines. The techniques of reconstructing soil ecological structure using phosphate tailings substrate and improving acidic soil with soil conditioner and calcium-magnesium phosphate compound fertilizer were applied. A series of other measures were taken, including: drafting scientific ecological restoration plans; employing physical, chemical, and biological methods for ecological restoration and green reclamation; selecting suitable plant species for planting; enhancing planting techniques; and strengthening post-restoration ecological monitoring and regulation. After ecological restoration and green reclamation, the Ecological Remediation Effect Index (EREI) for the years 2020, 2021, and 2022 were 48.40, 87.38, and 93.23 respectively, indicating significant improvement in the ecological environment. Furthermore, the difficulties encountered during the ecological system restoration process of the mine and the future development directions were summarized, providing practical and guiding significance for ecological restoration and green reclamation of abandoned mining areas both domestically and internationally. [ABSTRACT FROM AUTHOR]

In order to investigate the effects of various treatments on the growth of kenaf in saline soil, this study employed a comprehensive experimental design incorporating a dual approach of soil amendment and mulching techniques. Soil treatment of saline and alkaline land, as well as biological material mulching treatment after sowing kenaf, were conducted. The growth dynamics of kenaf were assessed before the midterm investigation, and the harvest period was examined. Soil physicochemical properties were measured and analysed at different periods. The results show that in the analysis of red sesame yield traits, the differences mainly appeared between soil treatments. There is no significant difference between the different mulching treatments within each soil treatment. In the mid-term study, significant differences were observed in kenaf plant height. Plant height was the most affected by soil conditioners, while other yield traits did not show significant variations. During harvest, only stem thickness and dry weight of a single plant did not show significant differences, whereas other yield traits did. The application of soil conditioners resulted in a 58.15% increase in dry hull yield compared to organic fertilizers and a 22.66% increase compared to regular fertilizers. Soil conditioners also led to higher levels of effective phosphorus, quick-acting potassium, organic matter, and total nitrogen throughout the kenaf growth period compared to organic and regular fertilizers. This is beneficial for enhancing soil quality and reducing soil alkalinity. Combined with the results of kenaf yield and soil physical and chemical properties analysis, it has been proven that the application of soil conditioner has the best effect, followed by the application of compound fertilizer, with organic fertilizer treatment being the least effective. [ABSTRACT FROM AUTHOR]

At the Experimental Farm of El-Gemmeiza, Agric Res. Station, (ARC), Gharbya Governorate (Middle Delta, Egypt), two field experiments were conducted in the winters of 2020/2021 and 2021/2022 to examine the effects of nitrogen fertilization at 50, 75 and 100% of the recommended rate (equal 60, 90 and 120 kg N/fed., respectively) and treated soil with some soil conditioner (humic acid at 10 kg/fad., biochar at 5m³/fed. and humic at 10 kg/fad. + biochar at 5 m³/fad.), beside untreated soil (control) on plant growth, mineral uptake, yield and bulb quality of garlic cv. Sids 40 using a flow irrigation system in clay soil. Fertilizing garlic plants with 100% equal 120 kg N/fed. and treating soil with a mixture of humic acid at 10 kg /fed. and biochar at 5 m3/fed. had a significant effect on plant growth (plant height, number of leaves per plant, both neck and bulb diameter, as well as the fresh and dry weight of the bulb and leaves and the total fresh and dry weight), nitrogen, phosphorus, and potassium percentages, and its uptake by the leaves of garlic plants at 135 days from sowing, and gave the highest values of yield and its components (exportable, marketable yield, total yield/fed., and average bulb weight), as well as bulb quality (N, P, and K, total soluble solids, dry matter content, and pungency). Moreover, the interaction between nitrogen at a rate of 75% RR and the mixture of humic acid and biochar gave the best results for increasing the efficiency of nitrogen use, and the relative increases in the total yield were about (4.97 and 5.38%) compared to the interaction between nitrogen at a rate of 100% RR only in both seasons, respectively and a decrease in mineral nitrogen by 25%. [ABSTRACT FROM AUTHOR]

Copyright of Acta Agronomica Sinica is the property of Crop Science Society of China and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Contaminant soil remediation has potential engineering applications with various stabilization techniques addressing heavy metal contamination. Conventional soil stabilizers, however, have an environmental impact, promoting international research into environmentally friendly alternatives. Using waste byproducts to produce geopolymer binders as new green cementitious materials can provide an environmentally friendly and effective option for soil improvement. Silica-rich wastes have been advanced as a sustainable option for soil stabilization. The effectiveness of alkaline-activated silica-rich wastes in stabilizing cadmium-contaminated soil and its potential engineering utilization remain of profound significance, demanding sustained and rigorous research investigation. Cadmium was immobilized in silty clay soil by rich silica waste products—fly ash, silica fume, and rice husk ash—at various percentages with 4.5 and 6.5-molar alkaline activators. Unconfined compressive strength tests assessed soil behavior, while Toxicity Characteristic Leaching Procedure (TCLP), pH tests, X-ray diffraction, and scanning electron microscope analyses explained cadmium immobilization mechanisms. The experimental results revealed that alkali-activated silica-rich wastes enhanced strength and cementitious properties and reduced cadmium leaching in the contaminated silty clay. The Finite Element Method was also employed to analyze the bearing capacity of the stabilized contaminated soil. The numerical results support the experimental results and confirm increased soil strength and reduced compressibility, endorsing the efficacy of the stabilization techniques and environmental benefits. [ABSTRACT FROM AUTHOR]

In this study, the effects of soil conditioners on the growth and development of melons and the rhizosphere soil environment were explored. The optimal amount of added soil conditioner was screened to solve the practical production problems of high-quality and high-yield thin-skinned melon. The melon variety "Da Shetou" was used as the material. Under the conditions of conventional fertilization and cultivation technology management, different soil conditioners were set up for potted melons. The effects of Pastoral soil (CK), 95% Pastoral soil + 5% volcanic ash soil conditioner (KT1), 85% Pastoral soil + 15% volcanic ash soil conditioner (KT2), 75% Pastoral soil + 25% volcanic ash soil conditioner (KT3), 65% Pastoral soil + 35% volcanic ash soil conditioner (KT4), and 55% Pastoral soil + 45% volcanic ash soil conditioner (KT5) on melon yield, quality, and rhizosphere soil characteristics were investigated. The soil microbial community was analyzed using Illumina MiSeq technology. Compared to CK, KT1, KT3, KT4, and KT5, the KT2 treatment could improve the single fruit yield of melon, increasing it by 4.35%, 2.48%, 2.31%, 5.92%, and 2.92%. Meanwhile, the highest contents of soluble protein, soluble solid, and soluble sugar in the KT2 treatment were 1.89 mg·100 g−1, 16.35%, and 46.44 mg·g−1, which were significantly higher than those in the control treatment. The contents of organic matter, total nitrogen, alkali-soluble nitrogen, nitrate nitrogen, ammonium nitrogen, available potassium, and available phosphorus in melon rhizosphere soil were the highest in the KT2 treatment. Through Alpha diversity analysis, it was found that the Chao1 index, Shannon index, and ACE index were significantly higher in the KT1 treatment than in the control, while, among all groups, the Simpson index and coverage were not significantly different. The dominant bacteria in the six treated samples were mainly Actinobacteriota, Proteobacteria, Cyanobacteria, Chloroflexi, Acidobacteria, Bacteroidetes, Myxomycota, Firmicutes, Gemmatimonadota, Verrucomicrobia, and Planctomycetes, which accounted for 96.59~97.63% of the relative abundance of all bacterial groups. Through redundancy analysis (RDA), it was found that the organic matter, electrical conductivity, available phosphorus, and nitrate nitrogen of melon rhizosphere soil were the dominant factors of bacterial community change at the dominant genus level. In summary, 15% ash soil conditioner applied on melon was the selected treatment to provide a theoretical reference for the application of soil conditioner in facility cultivation. [ABSTRACT FROM AUTHOR]

Biochar is widely used in agricultural production because of its ability to improve the physical and chemical properties of soil and promote crop growth. In this study, a combination of different biochar and lake sediments were used to improve saline soils. The four raw materials, including corn stalk and chicken manure liquefaction product (SMLP), rice husk charcoal (RHC) and two types of sediment (S‐1 and S‐2), which was used to improve the saline–alkali soil, respectively. The most significantly effective applied on the soil was when the composite soil conditioner (CSC) prepared by mixing SMLP, RHC, S‐1 and S‐2 at 5:20:6000:500 t·100 ha−1. The results of soil experiments using the above blending levels showed that the spike weight, plant height and root length of corn increased by 12.49%, 47.17% and 22.10%, respectively, and the pH and electrical conductivity (EC) of soil decreased by 4.83% and 24.02%, respectively. The contents of soil nutrients, soil organic matter (SOM), water content (WC) and soluble cations (K+, Ca2+ and Mg2+) all presented an increasing trend, and the contents of Na+ and soluble anions (Cl−, CO32−, HCO3− and SO42−) of soil showed a downward trend. Accordingly, the composite soil conditioner with biochar and dredged sediment achieves a synergistic improvement in soil physical structure and an increase in nutrient content, which is beneficial for promoting the growth characteristics and yield of corn. [ABSTRACT FROM AUTHOR]