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In 2019, the experiment was carried out at Jordan University of Science and Technology (JUST). Various soil amendments, including biochar and compost, both with and without the combination of poultry manure, were employed. The experimental design followed a completely randomized layout, with seven distinct treatments: T1 - soil (control), T2 - Biochar (3%) (BC), T3 - compost (3%) (Comp), T4 - poultry manure (3%) (PM 3% (38.2 ton/ha)), T5 - Biochar (3%) + poultry manure (60 ton/ha) (BC+PM 60 ton/ha), T6 - compost (3%) + poultry manure (60 ton/ha) (Comp+PM 60 ton/ha), and T7 - poultry manure (60 ton/ha) (PM 60 ton/ha). The assessment encompassed the examination of various physicochemical characteristics of the soil, including bulk density, porosity, water holding capacity, pH, and EC. Morphological and physiological measurements comprised plant shoots and roots' height and length, leaves number, shoots and roots' fresh and dry weight, leaf relative water content, and chlorophyll content. Additionally, the chemical composition, encompassing crude fibers, crude fats, antioxidant activities, total phenols, flavonoids content, and minerals was evaluated. Physicochemical results revealed that (BC+PM 60 ton/ha) excelled in water holding capacity and porosity, whereas PM 60 ton/ha exhibited the optimal soil pH. In terms of morphological results, (Comp+PM 60 ton/ha) and (PM 3% (38.2 ton/ha)) demonstrated superiority in plant height, shoot fresh and dry weight. The application of (BC) outperformed in root fresh and dry weight and leaf relative water content, while (Comp) exhibited the highest root length. Poultry manure applications scored higher values in chlorophyll content, with (BC+PM 60 ton/ha) recording the highest among them. Chemical analysis revealed that crude fibers were highest with the application of (PM 3% (38.2 ton/ha)), while (control) recorded the highest antioxidant activities, total phenols, and total flavonoids. In terms of minerals content in shoots, (Comp+PM 60 ton/ha) demonstrated the highest nitrogen content. Phosphorus, Potassium, magnesium, and calcium were most abundant in (BC+PM 60 ton/ha). Moreover, PM (60 ton/ha) exhibited the highest sodium content. Notably, the (BC+PM 60 ton/ha) application excelled in physiochemical soil properties, excluding soil pH and EC, while also demonstrating superior mineral content in lettuce plants, except for sodium.

Maize cultivation is under the growing threat of charcoal rot (Macrophomina phaseolina). Chemical control of diseases imparts serious health hazards to humans and the ecosystem. Biochar as an alternative disease management approach has been under consideration of the researchers for some time now. The biochar utilized in this study was derived from maize stalks and cobs. Crystallographic structure, inorganic minerals content and size of maize biochar were analyzed by powder X-ray diffractometer, while scanning electron microscopy revealed rough, irregular, tubular structure of the biochar surface. EDX spectra revealed that the maize biochar composition was dominated by 'C' followed by 'O'. The current study was designed to determine the synergistic effect of maize biochar (MB), and biocontrol agent (BCA) Trichoderma viride as soil amendments on the suppression of M. phaseolina. In vitro bioassays were conducted to check the efficiency of antagonistic effect of Trichoderma spp., in combination with maize biochar. On the basis of maximum mycelial growth inhibition T. viride was selected for a glasshouse experiment. Maize plants were grown in pots containing a mixture of soil with MB at application at the rate of 3 and 6% (v/v) separately, associated with or without T. viride. Treatments amended with 3% MB inoculated with M. phaseolina significantly reduced the percentage disease severity index by 40%. While in the presence of T. viride, 3% MB showed maximum disease suppression and a minimum percentage severity index i.e. 60 and 20%, respectively. Highest nitrogen contents were 18.4 g kg−1 observed in treatment 6% MB, while highest phosphorus and potassium contents were 3.11 and 15.2 g kg−1, respectively in the treatment with 3% MB. Conclusively, the effect of variable concentrations of maize biochar and T. viride as soil amendment was evident on the development of charcoal rot, growth and physiology of maize plants. According to the available literature, our report is the first on the implementation of biochar in synergism with T. viride to suppress the charcoal rot in maize. [ABSTRACT FROM AUTHOR]

Adding organic soil amendments can improve the physical and hydrological properties of soil, subsequently enhancing fertility for better crop production. In this study, spent Arabica and Columbian coffee wastes and their respective biochars were evaluated as soil amendments to improve the physical and hydrological properties of loamy sand soil and enhance maize (Zea mays L.) crop growth. Spent Arabica coffee (AC) and Columbian coffee (CC) wastes were collected and transformed into biochar through pyrolysis process at 550 °C with a residence time of 3 h and pyrolysis rate of 5 °C per minute. The AC and CC derived biochar were termed as ABC and CBC, respectively. The produced soil amendments were applied to soil at 0% (control), 1%, 3%, and 5% in a column setup. The moisture characteristics, including water infiltration, evaporation, and water retention, were investigated. Thereafter, the prepared amendments were applied to loamy sand soils at 0% (control), 1%, 3%, and 5% (w/w) application rates. Maize growth was then observed for a period of 30 days under greenhouse conditions. Results of the column trials showed that ABC and CBC applied at 5% reduced the cumulative water evaporation by 57%–66% and cumulative infiltration by 124%–181% compared to control. Likewise, 5% application of ABC and CBC resulted in 101 to 130% higher water retention in loamy sand soil. Results of the greenhouse experiment showed that 5% application of ABC and CBC amendments resulted in root biomass of 2.12 and 2.38 g, respectively, as compared to 0.51 g in control treatment. Similar treatments resulted in shoot biomass of 9.70 and 9.93 g respectively, as compared to 7.37 g in control. Likewise, 5% application of CBC and ABC increase plant height from 15.71 to 30.94 cm in ABC and 33.23 cm in CBC. Overall, 5% application of coffee waste-derived biochars significantly reduced water evaporation and infiltration, while increasing soil water retention and maize plant height, root biomass, and shoot biomass. Therefore, spent coffee waste-derived biochar could effectively be employed to improve physical and hydrological properties of loamy sand soils for better crop productivity. [ABSTRACT FROM AUTHOR]

Enhanced weathering of terrestrial rock material is a promising method for the removal of anthropogenic CO2 emissions from the atmosphere. Herein, we demonstrate that an ameliorated mining waste product can be effectively weathered in the soil environment when used as a soil amendment in conjunction with the cultivation of fast-growing willows (Salix matsudana Koidz. χ S. alba L. "Austree") in a pot study environment. Utilizing this locally sourced amendment minimizes emissions associated with grinding and transportation of enhanced weathering materials. Results showed that the willows were able to tolerate the relatively high metal concentrations of this amendment and sequester inorganic carbon (C) through the production of bicarbonate in soil solution. During the period of peak plant growth (10 weeks after planting), alkalinity measurements of soil solution from pots with willows and the addition of 25% by mass mine waste product indicated an additional 10 mg of inorganic C sequestration per liter of leached soil solution compared to unamended soils with willows. This represents 4.5 times the inorganic C sequestration rate of unamended soils. The addition of ameliorated mining waste also increased the pH of the soil solution by up to two units (pH of 6 in control vs. pH of 8 with the addition of 25% by mass mineral amendment). In addition to inorganic C sequestration, weathering of the ameliorated mining waste product may also provide base cations (such as calcium and magnesium) which could improve soil fertility. These results are encouraging for future investigation of ameliorated mine waste rock to sequester carbon and enhance the production of willows grown for ecosystem services and phytotechnologies. [ABSTRACT FROM AUTHOR]

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]

In recent years, microbial inoculants have showed a great potential to replace chemical fertilizers as a new generation of soil amendment agents, however, the understanding of their effects on nutrient cycling within plants and rhizosphere microbial diversity are still limited. In this study, the rhizosphere growth-promoting bacteria MQB12 was used to inoculate Vigna radiata to evaluate the effects of external inoculants on plant transcriptomics and rhizosphere soil microbial diversity. Enrichment analysis using GO and KEGG revealed significant enrichment in DNA-binding transcription factor activity, transcriptional regulatory factor activity, and phenylpropanoid biosynthesis among the differentially expressed genes. MQB12 inoculation positively responded to phosphorus starvation response, increased the expression of phosphorus starvation response genes (PHT/PAP), enhanced the synthesis of ethylene and salicylic acid to cope with external stress, and improved the expression of plant disease resistance genes to strengthen the disease resistance of plants to pathogens. At the same time, microbial diversity analysis further revealed the positive effect of MQB12 inoculum. MQB12 inoculum enriched beneficial flora, improved flora abundance, changed the structure and diversity of V. radiata rhizosphere microbial community, enhanced the interconnections between the flora, and positively promoted growth. MQB12 was found to adjust the microflora of the rhizosphere, which subsequently changed the environment for plant colonization. This change led to the enrichment of beneficial bacteria and removal of pathogenic bacteria, which positively affected the internal pathways of plants. Additionally, changes in gene expression levels of plants resulted in the formation of different phenotypes and various metabolites, further influencing the formation of rhizosphere microbial communities through close contact between roots and soil. This study provides new insights into the effects of microbial agents on plant growth and root environment construction and is conducive to the further development and application of microbial agents. [ABSTRACT FROM AUTHOR]

Drought stress deteriorates agro-ecosystems and poses a significant threat to crop productivity and food security. Soil amended with biochar has been suggested to mitigate water stress, but there is limited knowledge about how biochar affects the physiology and vegetative growth of quinoa plants under soil water deficits. We grew three quinoa (Chenopodium quinoa Willd.) varieties, Titicaca (V1), Quipu (V2), and UAFQ7 (V3) in sandy loam soil without (B0) and with 2% woodchip biochar (B2) under drought conditions. The drought resulted in significant growth differences between the varieties. V3 performed vegetatively better, producing 46% more leaves, 28% more branches, and 25% more leaf area than the other two varieties. Conversely, V2 displayed significantly higher yield-contributing traits, with 16% increment in panicle length and 50% more subpanicles compared to the other varieties. Woodchip biochar application significantly enhanced the root development (i.e., root biomass, length, surface, and projected area) and plant growth (i.e., plant height, leaf area, and absolute growth rate). Biochar significantly enhanced root growth, especially fresh and dry weights, by 122% and 127%, respectively. However, biochar application may lead to a trade-off between vegetative growth and panicle development under drought stress as shown for V3 grown in soil with woodchip biochar. However, V3B2 produced longer roots and more biomass. Collectively, we suggest exploring the effects of woodchip biochar addition to the soil on the varietal physiological responses such as stomatal regulations and mechanisms behind the increased quinoa yield under water stress conditions. [ABSTRACT FROM AUTHOR]

Valorization of peanut shells has recently gained prominence in the context of thermally converting agricultural waste into biochar, a carbon-rich byproduct with significant potential as a soil amendment. The present study delves into understanding the influence of slow (450°C and 500°C) and fast (550°C and 600°C) pyrolysis temperatures with a resident time of 60 and 30 minutes, respectively, on the physico-chemical properties of peanut shell biochar produced in a low-cost kiln. Results of the Scanning Electron Microscopy analysis revealed that increased pyrolysis temperature increased porosity and surface roughness with crystalline deposits. Thermogravimetric analysis showed that increased temperatures contributed to enhanced thermal stability but reduced biochar yield. Pyrolysis temperatures of 450, 500, 550, and 600°C exhibited 32.19, 29.13, 21.8, and 19.43 percent conversion efficiency with organic carbon content of 11.57, 6.48, 8.64, and 7.76 percent, respectively. The intensities of functional groups (C-H and C-O) declined, whereas the intensity of C=C and stable carbon content increased with the rise in temperatures. The concentrations of heavy metals in all biochar samples were below permissible limits outlined by international biochar initiatives. The study concluded that slow pyrolysis at 450°C for 60 minutes resident time is an ideal pyrolytic condition for producing peanut shell biochar in terms of qualitative and quantitative characteristics. [ABSTRACT FROM AUTHOR]

Mortality of tree species around the globe is increasingly driven by hotter drought and heat waves. Tree juveniles are at risk, as well as adults, and this will have a negative effect on forest dynamics and structure under climate change. Novel management options are urgently needed to reduce this mortality and positively affect forest dynamics and structure. Potential drought-ameliorating soil amendments such as nanochitosan - a biopolymer upcycled from byproducts of the seafood industry - may provide an additional set of useful tools for reducing juvenile mortality during hotter droughts. Nanochitosan promotes water and nutrient absorption in plants but has not been tested in the context of drought and heat stress. We evaluated factors affecting mortality risk and rate for dryland Pinus edulis juveniles (2-3 years old) in a growth chamber using a factorial experiment that included ambient and +4°C warmer base temperatures, with and without a 10 day +8°C heat wave, and with and without a nanochitosan soil amendment. The nanochitosan treatment reduced the relative risk of mortality, emphasizing a protective function of this soil amendment, reducing the relative risk of mortality by 37%. Importantly, the protective effects of nanochitosan soil amendment in delaying tree mortality under hotter drought and heat waves provides a new, potentially positive management treatment for tree juveniles trying to survive in the climate of the Anthropocene. [ABSTRACT FROM AUTHOR]

The properties of different organic fertilizers and their potential for stabilizing toxic metals(loids) in soil have not been fully investigated. This study characterized and evaluated three organic fertilizers from different raw materials. The mushroom residue organic fertilizer (MO) had higher C, H, and O contents and more functional groups (-OH, C-H, and C = O). Its application significantly increased pH (1.00 ~ 1.32 units), organic matter (OM) content (26.58 ~ 69.11%), and cation exchange capacity (CEC) (31.52 ~ 39.91%) of soil. MO treatments can simultaneously reduce the bioavailable TCLP-Cd and TCLP-As in soil, solving the difficulties of remediating the combined Cd and As pollution. MO treatments inhibited the migration of Cd and As from soil to plant, promoting plant growth. Redundancy analysis (RDA) revealed that metal(loid) variations in plants were related to soil properties (40.09%) and TCLP-Cd/As (44.74%). Furthermore, the toxic metals(loids) risk assessment for all organic fertilizers was at safe levels. This study provided a valuable reference for choosing organic fertilizers and presented a novel option for the "producing while remediating" of farmlands with low pollution. [ABSTRACT FROM AUTHOR]

Background: Sunflower is an economically important and the fourth most valuable oil seed crop. The study aimed to investigate organic fertilizers as an alternative method of enhancing soil quality and to determine the optimal combination of organic fertilizer treatments for sunflower growth performance and yield. Methods: The sunflower variety BARI Surjamukhi-2 was used in this study. The treatments were applied as T1= Control; T2= Farmyard Manure @ 2 t ha-1; T3= Vermicompost @2 t ha-1; T4= Biochar @2 t ha-1; T5= Farmyard Manure @1 t ha-1+Vermicompost @ 1 t ha-1; T6= Farmyard Manure @1 t ha-1+Biochar @1 t ha-1 and T7= Vermicompost @ 1 t ha-1+Biochar @1 t ha-1. Result: The data showed that application of different organic fertilizer treatments improves soil quality. Organic fertilizer addition had a positive effect on the growth traits like plant height, leaves number plant-1, stem diameter, chlorophyll content, head diameter, fresh and dry seed number head-1, 1,000-seed weight and seed yield. The correlation results strongly agreed that chlorophyll content, fresh seed number, head diameter plant-1 and 1,000-seed weight could be considered as selection indices for high yield of sunflower. This demonstrates the organic fertilizer's capacity to improve sunflower growth and yield, as well as its significant potential to replace chemical fertilizers in the perspective of crop sustainability. [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]

In a nine-year field experiment in a wheat-maize-sunflower cropping system in Hetao Irrigation Area, Inner Mongolia, China, organic amendments applied as straw, manure, green manure, and the combination of green manure and straw increased wheat and maize yield, soil aggregate stability, and soil microbial activity in comparison with chemical fertilizer, without changing greenhouse gas emission intensity. [ABSTRACT FROM AUTHOR]

This research highlights the efficiency of a bioinsecticide based on Streptomyces griseoflavus PAL114 in controlling black bean aphids and its effect on fava beans. Three actinobacterial strains were tested in vitro for their aphicidal activity. The PAL114 strain was then formulated in talc powder and tested again. Formulation processes were performed with four spore suspension densities (102, 104, 106 and 108 spore ml−1) at a rate of 25 ml per 100 g of talc powder. Furthermore, the in vivo effect of bioinsecticide on fava bean plants was studied in pot experiments using two application methods: spray and spray + soil amendment. The results showed that only the PAL114 strain had a highly significant effect on mortality (p =.001). Their high-density formulations at 106 and 108 spore ml−1 induced very highly significant activity (p <.001) for both, with no influence difference exceeding 90% after 58 h. In contrast, the other low-density formulations at 102 and 104 spore ml−1 had no significant effect (p =.322 and p = 1.000, respectively). There was no adverse effect of the bioinsecticide on fava bean; instead, there was an improvement in growth, especially when the spray application was combined with soil amendment. The present study opens up prospects for field studies on the biocontrol of this crop pest. [ABSTRACT FROM AUTHOR]

The utilization of hemp residues, obtained after the harvest of hemp flowers, is a potential soil amendment in crop cultivation that might enhance soil health, nutrient availability, and crop productivity. However, more research is required to choose the best agricultural practice for optimizing hemp residue degradations. This study aimed to determine the integrated effects of hemp residues in different soil tillage systems on spring wheat yield. The results of the two-year experiment show that under favorable climatic conditions and soil moisture contents, the highest spring wheat grain yield (6.0 t ha−1) is achieved in plots where hemp residues are plowed in autumn. Similar results are obtained in dry weather conditions, but the yield is lower by more than half—2.3 t ha−1. The influence of residues increases the C content in the soil. The findings advance our understanding of integrated agricultural practices through the utilization of hemp residues for promoting resilient and sustainable crop production systems. [ABSTRACT FROM AUTHOR]

A 2-year field experiment was conducted to test the effects of individual and co-application of biochar and inorganic fertilizer on soil quality using the principal component analysis (PCA) technique. The dry season field experiments were performed with biochar applied at 0 and 20 t ha−1, and fertilizer at 300 and 0 kg ha−1 (control). The factorial combinations of the above-mentioned treatments were subjected to irrigation at 60, 80, and 100% of irrigation amounts (IAs). Soil hydro-physical and chemical properties and grain yield were determined at harvest. Results from the PCA indicated that the soil total nitrogen (N) and moisture content (MC) were the soil properties mostly affecting the grain yield. The amendments' effects on the soil physico-chemical properties and maize yield were in the order control < biochar < fertilizer < biochar + fertilizer. The derived comprehensive soil quality index (CSQI) from the PCA showed that the soil quality increased by 76, 100, and 200% in treatments individually applied with biochar, inorganic fertilizer, and the co-applications. This study therefore showed that the PCA revealed the actual dynamics in soil properties, in terms of the SQI upon the soil amendment addition, as well as their relationship with maize yield under different weather conditions. [ABSTRACT FROM AUTHOR]

Nitrification is the core step of the soil nitrogen cycle and directly affects the nitrogen use efficiency in agricultural systems. Biochar and gypsum are two important soil amendments widely used in coastal saline farmland. However, little is known about their effects on nitrification and ammonia-oxidizing microorganisms. A one-year pot experiment with three treatments including biochar application (BC), gypsum application (SG), and no amendment (CK) was conducted, and the responses of the nitrification rate, amoA gene copies, and the diversity and community structure of ammonia-oxidizing archaea (AOA) and bacteria (AOB) to biochar and gypsum were evaluated. The results indicated that biochar and gypsum application both resulted in alterations to the soil properties. They both had inhibiting effects on nitrification and AOB amoA gene copies, whereas they had no significant effect on AOA amoA gene copies. Biochar had no significant effect on the diversity indexes of AOA, but it significantly reduced the Shannon index of AOB. Meanwhile, gypsum had no significant influence on the diversity indexes of both AOA and AOB. Biochar and gypsum did not significantly affect the community structure of AOA but did induce changes in that of AOB. In detail, biochar significantly enhanced the relative abundance of the dominant cluster Nitrosospira, whereas gypsum led to a notable increase in the relative abundance of unclassified_o_Nitrosomonadales. The Shannon index of AOB had a significant negative correlation with soil TOC, TN, and NH4+ content, and soil pH was the first primary environmental factor that affected the AOB community structure. In conclusion, biochar and gypsum inhibited nitrification by suppressing the activities of AOB and changed the diversities and community structure of AOB by altering related soil properties. [ABSTRACT FROM AUTHOR]

Salt-affected soils are a prevalent issue globally, resulting in a severe degradation of soil sustainability and plant productivity, reducing the area of agricultural land, and affecting food security. Therefore, eco-solutions and remediation approaches are needed. The needed remediation for salt-affected soil can be addressed via engineering, physical, chemical, or biological techniques. Salt-tolerant crops are normally used for the remediation of slight and moderate saline soil conditions. However, no crops, including salt-tolerant crops, can be cultivated in areas with extreme salinity levels (ECe 8–16 dS/m). Therefore, the aim of this study was to investigate the effect of vermicompost and organic amendment on the cultivation of salt-tolerant crops (Sesbania rostrata) in severely salt-affected soil under field conditions in order to improve saline soil and crop productivity. The design of the experiment followed a randomized complete block design (RCBD) with three treatments and four replications: T1, severely salt-affected soil (control); T2, severely salt-affected soil + vermicompost at a ratio of 25:75; T3, severely salt-affected soil + vermicompost + rice husk biochar + coconut coir at a ratio of 25:25:25:25. The results found that using vermicompost and organic amendment improved the soil quality, increased the soil fertility (organic matter and plant nutrients N, P, and K), and reduced the soil salinity. Sesbania rostrate could not grow in severely salt-affected soil (T1) alone, but could grow in the treatments with vermicompost and organic amendments (T2 and T3). The percentage of Sesbania survival per plot was also high in the treatments with vermicompost and organic amendments (T2 and T3). The highest growth rate, flower production, biomass, and root morphology of Sesbania rostrata were found in T3, with severely salt-affected soil + vermicompost + rice husk biochar + coconut coir at a ratio of 25:25:25:25 with a statistically significant difference (p < 0.05). Moreover, the Sesbania flowers treated with vermicompost and organic amendments have a higher nutritional value due to their minerals and vitamins than Sesbania flowers grown without using vermicompost and organic amendments. This study's findings suggest that incorporating vermicompost and organic amendments is a feasible and economical method for enhancing the quality of salt-affected soils in a sustainable manner. The results of this study demonstrate that utilizing vermicompost and organic amendments is a sustainable and economical strategy for enhancing the quality of salt-affected soils and improving yields in severely salt-affected areas, thereby increasing crop production and the nutritional value of the plants as well as helping to increase farmers' income. [ABSTRACT FROM AUTHOR]

Nano-SiO2, a highly acclaimed nanomaterial for enhancing cemented soil, has shown remarkable improvements in the physical properties and microstructure of cemented soil. The organic matter content in soil plays a crucial role in determining the engineering quality of cemented soil, regardless of whether it is in a freshwater or seawater environment. Therefore, when employing Nano-SiO2 as an amendment for cemented soil, it is crucial to consider the influence of different soil types and environmental conditions on the effectiveness of the enhancement. This study presents a scientific approach for enhancing the consolidation of cemented soil by incorporating Nano-SiO2 as an additive in both freshwater and seawater environments. To ensure consistency with practical construction practices, the experiments were divided into freshwater preparation and curing groups, as well as seawater preparation and curing groups. In soils with distinct characteristics, we utilized five different gradient levels of Nano-SiO2 additives and subjected the cemented soil specimens to a 60-day immersion curing process. Subsequently, unconfined compressive strength (UCS) tests were performed on samples that had reached the specified curing age to investigate the alterations in the mechanical properties of cemented soil caused by Nano-SiO2. The internal microstructure and chemical composition of the cemented soil were analyzed utilizing scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The UCS and deformation modulus of cement soil composed of silty clay A and silty clay D with low organic matter content in fresh water environment increased by 109%, 24.7% and 117%, 43% respectively after adding 3.2% Nano-SiO2; In freshwater environments, the cemented soil composed of high-organic-matter content mucky silty clay B, muddy soil C, and dredged silt E experienced respective increases of 16% and − 27%, 2% and 42%, 6% and − 6% in UCS and deformation modulus after adding 3.2% Nano-SiO2; The UCS and deformation modulus of cemented soil with high organic matter content in seawater and freshwater environment increased by 3% and 6% (Soil B), 12% and 67% (Soil C), 23% and 27% (Soil E), respectively, after adding 3.2% Nano-SiO2; The increase of UCS and deformation modulus of cement soil by adding Nano-SiO2 is negatively correlated with the content of organic matter. in the case of cemented soil with high organic matter content in a seawater environment, the specific type of soil not only impacts UCS and deformation modulus of the soil but also influences the effectiveness of enhancement. Due to the organic matter, the rate of hydration reaction in cemented soil is reduced, resulting in a decrease in the formation of pozzolanic reaction products with SiO2. As a result, the improvement in Nano-SiO2 effectiveness is diminished. [ABSTRACT FROM AUTHOR]

Arid environments have become degraded in recent times through human activity highlighting the need for restoration works to reverse this trend. One of the most common forms of restoration works is revegetation. However, revegetation is difficult in the arid zone due to a combination of environmental factors such as low moisture and extreme temperatures, as well as financial and administrative factors. In this review, we investigated the literature describing various methods available for arid revegetation, and assess their utility for revegetation activities. Each of the methods investigated were found to have potential advantages and disadvantages, though some general trends were observed. Two main planting methods were identified, "out‐planting" and "direct seeding." Which of these methods to use depends on the conditions of the project being undertaken. Out‐planting appeared to be the most suited approach to smaller scale projects with higher budget availability, whereas direct seeding was more suited to large scale, lower budget projects. Weed control prior to planting was identified as being critical for success in most works, whereas soil ripping was beneficial for direct seeding projects. Among the soil amendments investigated, water‐holding gels were most likely to be beneficial, whereas fertilizers were riskier due to their potential to reduce drought tolerance and increase weed invasion. Microbial inoculation with mycorrhiza showed high potential to improve plant performance but may be held back by the lack of suitable commercial sources. Newer seed technologies, such as synthetic seed coats and pellets, show promise, but this issue still requires further research and development. [ABSTRACT FROM AUTHOR]

Portulaca oleracea L. is a wild edible plant with high potential for exploitation in commercial cropping systems due to its nutritional value and great adaptability to abiotic stress conditions. The present study aimed to investigate the response of purslane plants grown under drought stress conditions (100%, 80%, and 60% of field capacity (FC)) and the implementation of biostimulant amendments (control without amendment, plant growth-promoting rhizobacteria (PGPR), mycorrhiza, and effective microorganisms (EMs)) for two consecutive years. In the two-year experiment, the greatest height was recorded in plants grown under no-stress conditions and inoculated with PGPR. The highest branch number, and fresh and dry weight of aboveground and underground parts were observed under no-stress conditions at the mycorrhiza treatment. Moreover, mycorrhiza application in plants growing under 100% FC resulted in the highest N, P, total carbohydrates, and vitamin C and the lowest nitrate and proline contents in leaves. Purslane plants grown under 100% FC and inoculated with PGPR treatment resulted in the highest K and total chlorophyll leaf contents. Additionally, growing plants under mild drought stress (80% FC) combined with biostimulant application (e.g., inoculation with mycorrhiza, PGPR, and EM) may improve plant growth characteristics and mitigate negative stress effects. In general, the applied biostimulant amendments alleviated the adverse effects of drought on plant growth and leaf chemical composition indicating the importance of sustainable strategies to achieve high yield and sufficient quality within the climate change scenario. [ABSTRACT FROM AUTHOR]

Beneficial microbes colonizing plant tissues are recognized as a value-added soil amendment for enhancing soil fertility. The present study aimed to evaluate the effects of co-inoculation with plant growth-promoting endophytic actinobacteria and nitrogen-fixing rhizobacteria for improved growth attributes, soil properties, microbial activity, yield, and nutrient uptake of wheat under field conditions for two consecutive years. Three endophytic actinobacterial isolates, Streptomyces sp. strain WR27, Streptomyces sp. strain WR15, and Streptomyces sp. strain WS6 were evaluated alone and in combination with nitrogen-fixing bacteria, Azotobacter in field experiment with recommended fertilization rate in north-western Indian plains. Results of the study indicated that all the growth attributes were higher in treatments receiving microbial inoculants than un-inoculated control. It was also observed that inoculation with actinobacterial isolates significantly increased total number of tillers m−2, spike length, number of grains spike−1, and 1000 grain weight as compared to control. Streptomyces sp. strain WR27 + Azotobacter and Streptomyces sp. strain WR15 + Azotobacter exhibited maximum grain yield (5.7 t ha−1, respectively) as compared to control (5.0 t ha−1). The treatment involving inoculation with Streptomyces sp. strain WR27 + Azotobacter recorded higher nutrient contents. Soil properties were significantly increased by application of actinobacterial inoculants in both years over the un-inoculated control. Furthermore, among different inocula, Streptomyces sp. strain WR27 + Azotobacter dual inoculation exhibited highest response efficiency for all the traits studied. Therefore, the results revealed multiple benefits of plant growth-promoting actinobacteria and Azotobacter inoculation for wheat crop in terms of improved soil properties and macronutrient content without hampering the soil fertility and productivity. Thus, it could be recommended as a plant growth-promoting bacteria for wheat at the recommended level of fertilizer application rates for field use in north-western India. [ABSTRACT FROM AUTHOR]

Insect manure or "frass" has emerged as an alternative nutrient source for alleviating the dependence on fossil fuel-based fertilizers, reducing food waste, and promoting food security. Yet, research on insect frass chemical composition is in its infancy. Here, we assessed the chemical properties of yellow mealworm (Tenebrio molitor L.) frass compared with poultry litter (PL). Insect frass was obtained from the National Biological Control Laboratory (NBCL; IF-L) and an insect-rearing company (IF-C). PL was collected from facilities in Arkansas (PL-AR) and North Carolina (PL-NC). Samples were analyzed for pH, electrical conductivity, macro- and micronutrients, heavy metals, pathogens, and indicator microorganisms. On average, insect frass had 43% and 47% higher C and N than PL, respectively (P  < 0.05). Considering a 5 mg/ha application rate, IF-C can supply 159 kg N/ha, twice the N supply of PL-AR (78 kg/ha). IF-L had a 53% higher P supply than PL-NC. Mean K, Ca, S, and micronutrient contents were higher in PL than in frass (P  < 0.05), whereas As, Cd, Cr, and Pb were nearly absent in frass. Chemical composition and pathogens in fertilizer sources were largely affected by insect-rearing substrate and supplements used in poultry and insect production. Insect frass utilized in this study had optimum C and N rates relative to PL, suggesting a promising soil amendment for improving soil health and C sequestration, thus contributing to sustainable agricultural intensification and reuse of food waste in circular economies. [ABSTRACT FROM AUTHOR]

Soil contamination and its impact on human health are growing concerns worldwide due to anthropogenic activities, as soil plays a central role in the absorption of pollutants, including petroleum hydrocarbons. Conventional soil remediation techniques can have significant environmental impacts. Sustainable approaches are therefore needed, and bioremediation has emerged as a promising alternative. The addition of poultry manure, which is rich in nutrients and microorganisms, is a valuable resource for enhancing bioremediation processes. In this study, we investigated the use of stabilized and composted poultry manure in different proportions for the remediation of a tropical soil artificially contaminated with diesel oil. The results showed that both compost and stabilized manure treatments significantly reduced hydrocarbon concentrations in 60 days, with degradation rates ranging from 2.00 (w/w) to 6.96% (w/w) per day. Differences between treatments were observed in the improvement of soil structure and moisture retention. Treatments with lower percentages of compost and manure were the most effective, suggesting their suitability for the remediation of hydrocarbon-contaminated soils. In conclusion, the use of poultry manure as an organic amendment for soil remediation is a sustainable and efficient approach, especially for soils with low organic matter and reduced microbial populations. This research contributes to the development of effective remediation strategies in regions with a history of intensive industrialization and contaminated areas, ultimately promoting environmental sustainability and human health. [ABSTRACT FROM AUTHOR]

Growing degree days (GDDs) and leaf area index (LAI) greatly influence the growth and yield of many crops grown in arid regions. Therefore, variation in LAI due to GDD can provide a theoretical basis for predicting crop growth, water consumption, plant development, and yield in arid agriculture via the development of mathematical growth models. This study described the relationship between plant biomass production and variation in LAI due to GDD in arid regions under different types of irrigation (fresh water and saline water) and soils amended with different substances (manure+sandy soil, compost+sandy soil, clay+sandy soil, and sandy soil). Mathematical models for LAI were established for GDDs. In addition, different water quality irrigation techniques were used as independent variables to calculate the LAI of halophytic plants (Hedysarum scoparium) in arid regions under different soil amendment treatments. Furthermore, mathematical models for plant biomass production were developed by using the LAI and GDDs. For this purpose, Logistic, Gaussian, modified Gaussian, and Cubic polynomial models were used. Modified Gaussian and Cubic polynomial models are the best among all developed models, but Cubic polynomial models are more suitable among all developed models because of their simple quadratic equations that can be solved by using the first derivative. It was observed that with increased salt concentration in the irrigation water, the growth of per plant production decreased. However, soil amendments like manure and compost enhance salt tolerance against salt stress and enable plants to sustain their growth. Furthermore, Hedysarum scoparium attains maximum LAI when its GDD is about 1117.5 °C under both irrigation regimes and in all soil amendment treatments. It was concluded that these predicted mathematical models can provide crucial insights for enhancing production in arid regions by using eco-friendly soil amendments to improve water use efficiency across diverse types of water irrigation. [ABSTRACT FROM AUTHOR]

Chenopodium quinoa Willd. (quinoa), a highly nutritious pseudocereal, is a promising crop to address global food insecurity challenges intensified by population growth and climate change. However, drought stress remains a significant constraint for quinoa cultivation. The plant exhibits several morphophysiological adaptations to water stress conditions, including root system modifications, reduced growth rate, leaf abscission, and stomatal closure. While these adaptations enhance drought tolerance, they can also negatively impact plant growth, potentially through alterations in root architecture, physiological changes, e.g., stomatal regulations, and anatomical changes. Different studies have suggested that soil amendment with biochar, a pyrolyzed organic material, can improve quinoa growth and productivity under drought stress conditions. Biochar application to the soil significantly enhances soil physiochemical characteristics and maintains plant water status, thereby promoting plant growth and potentially mitigating the negative consequences of drought on quinoa production. This review focuses on the current understanding of quinoa behavior under drought stress and the potential of soil amendment with biochar as a management strategy. We summarize existing research on applying biochar-amended soil to alleviate quinoa drought stress. [ABSTRACT FROM AUTHOR]

Biochar is beneficial as a clean, stable, and efficient soil amendment to improve rice quality and yield. However, there are few reports on the effects of no-tillage in combination with biochar application on rice growth, yield, and quality in regenerative rice systems. This study evaluated rice yield, grain quality, multiple antioxidant enzyme activities, and malondialdehyde content under four treatments: rotary tillage alone, rotary tillage + biochar application, no-tillage alone, and no-tillage + biochar. The results showed that the rice yield under no-tillage alone was 15% lower than that under rotary tillage alone, but that biochar application significantly increased rice yield by 10% and 20% under rotary tillage and no-tillage conditions, respectively, which might be attributed to the fact that biochar application increased panicle number, spikelet number per panicle, grain filling rate, and antioxidant enzyme activities. Additionally, biochar application also increased fine rice rate and protein content, meanwhile reducing chalkiness degree and chalky grain rate in both the main-season rice and ratoon-season rice. These results suggest that biochar application could enhance the yield and grain quality of ratoon rice, thus compensating for the no-tillage-induced yield loss. This study reveals the role of biochar in main-season rice and ratoon rice cultivation, providing a valuable reference for improved fertilizer utilization and cleaner agricultural production. [ABSTRACT FROM AUTHOR]

Hydrogels have shown promise in improving soil quality and alleviating plant drought stress. This study investigated the effectiveness of four hydrogel composites composed of polyvinyl alcohol, sodium alginate, and pine or olive tree biochar in improving bean (Phaseolus vulgaris) plant growth and soil microbial activities. The experiment was conducted in natural soil, where biochar–hydrogel composites were applied at a concentration of 0.75% hydrogel per soil weight (w/w) for 35 days under two different moisture conditions: adequate moisture (70% of water holding capacity (WHC)) and drought stress (40% WHC). The results showed variation between hydrogel composites and, more importantly, between water regimes. Under water deficit conditions, biochar–hydrogel composites consistently caused a decrease in plant weight and in chlorophyll (CHL) CHLa/CHLb ratio. Furthermore, antioxidant enzyme activities and malondialdehyde and protein levels generally increased in contrast to the observations at 70% WHC. Regarding microbial activities, the composites reduced soil respiration (12–38%) while promoting phosphatase activity (42–65%) under both moisture regimes. Overall, the introduction of hydrogel composites did not show consistently positive effects on either plants or soil microorganisms. To thoroughly evaluate the efficacy of these hydrogels as soil amendments, further studies are needed, considering different soil types, plant species, and hydrogel application rates. [ABSTRACT FROM AUTHOR]

Composts produced with kiwifruit waste from the calibration process (KW), mixed with 5%, 10%, and 20% wheat straw (WS), were evaluated as crop fertilizers through a pot experiment with lettuce, arranged as a randomized block design. Highest lettuce yields were achieved with 20 and 40 t·ha−1 5%WS compost and 40 t·ha−1 10%WS compost, suggesting that the physical characteristics of the composts increased soil water holding capacity and root growth, whereas chemical characteristics such as pH, organic matter, and nutrient contents contributed to improving soil reaction and nutrient availability. The type of soil amendment used influenced the development of different bacterial consortia in the bulk soil and rhizosphere, leading to increased levels of potentially beneficial bacteria and enhanced levels of relevant functions for plant growth, such as nitrogen fixation. Composted KW as an organic amendment can be used to improve soil quality and the circular economy. [ABSTRACT FROM AUTHOR]

Biochar is a soil amendment that has the potential to effectively improve soil salinization. However, there is a paucity of studies on sodium adsorption using biochar, and the adsorption mechanism remains unclear. To better understand the adsorption mechanism of Na+ on the surface of biochar, both pyrochar and hydrochar were produced at different temperatures. The capacity and influencing factors of Na+ adsorption in biochar were analyzed via batch adsorption experiments. Pore filling dominated the Na+ adsorption in the concentration of the NaCl solution when it was ≤100 mg/L, where wheat straw pyrochar (WB, 3.95–4.94 mg/g Na) and poplar wood chip pyrochar (PB, 0.62–0.70 mg/g Na) presented the release and adsorption of Na+, respectively. When the concentration of the NaCl solution was >100 mg/L, the adsorption capacity of WB (25.44–36.45 mg/g) was significantly higher than PB (4.46–6.23 mg/g). Both the adsorption and release of Na+ in hydrochar was insufficient. In a high concentration of NaCl solution, ion exchange became the key mechanism determining the adsorption of Na+ in pyrochar, in which K+ contributed to more than 94% of the Na+ adsorption. The findings proposed strategies for the structural design of biochar used for Na adsorption. These will promote the utilization of solid biowaste for sodium adsorption and the potential of soil salinization amendment for agriculture in arid lands. [ABSTRACT FROM AUTHOR]

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Pine nutshells (PNSs) are lignocellulosic waste materials with limited use in domestic heating. However, a biorefinery approach may be applied to fractionate PNSs and produce chemicals, materials, and improved solid fuels. In this study, we fractionated PNSs and produced antioxidant extracts, lignins, polysaccharides, chars, and activated carbons and analyzed their potential applications. Pyrolytic kinetic modeling as an alternative method to chemical fractionation was also tested. The results showed that the PNS contains low amounts of extracts with weak thiobarbituric acid reactive substances (TBARS) antioxidant properties, while its lignin content is remarkable (50.5%). Pyrolytic kinetic modeling was comparable to wet chemical analysis for estimating lignin yield. Moderate-temperature pyrolysis of the PNS resulted in a 23% char yield. The PNS chars showed improved fuel characteristics, retained 36% water, and leached 151 mg/L potassium into the water. The steam activation of PNS biochars at 750 °C resulted in oxygen-enriched activated carbons with specific surface areas up to 467 m2/g. The overall results indicate promising biochar applications of the PNS for soil amendment and supercapacitor uses. [ABSTRACT FROM AUTHOR]

Compost residue enriches soil health with the potential to enhance plant metabolism and hormonal balance, but has not yet been studied. A study was performed to determine how prevailing compost residue induces tomato (Solanum lycopersicum 'Scotia') plant morpho-physiology, phytohormones, and secondary metabolites. Plants were grown in soils with a previous history of annual (AN) and biennial (BI) compost amendments. The controls were soil without compost (C) amendment and municipal solid waste compost (MSWC) alone. The MSWC- and AN-plants had similar and significantly (p < 0.05) highest growth and photosynthetic activities compared to the BI- or C-plants. Total phenolics and lipid peroxidase activity were significantly (p < 0.001) high in BI-plants, while hydrogen peroxide and antioxidant capacity were significantly (p < 0.001) high in AN-plants. MSWC-plants recorded the highest cis-abscisic acid, followed by AN-, and then BI- and C-plants. Cis-zeatin, trans-zeatin, and isopentenyladenine ribosides were detected in the MSWC- and AN-plants but not in the BI- or C-plants. Furthermore, gibberellins GA53, GA19, and GA8 were high in the MSWC-plants, but only GA8 was detected in the AN plants and none in the others. Besides, MSWC plants exhibited the highest content of 1-aminocyclopropane-1-carboxylic acid. Conjugated salicylic acid was highest in the BI-plants, while jasmonic acid-isoleucine was highest in MSWC-plants and C plants. In conclusion, prevailing compost chemical residues upregulate plant growth, phytohormones, and metabolic compounds that can potentially increase plant growth and abiotic stress defense. Future work should investigate the flow of these compounds in plants under abiotic stress. [ABSTRACT FROM AUTHOR]

• Compost organic matter was characterized with a color sensor. • Compost organic matter content was differentiated by principal components analysis. • Accurate compost organic matter quantification is possible in seconds. Composted materials serve as an effective soil nutrient amendment. Organic matter in compost plays an important role in quantifying composted materials overall quality and nutrient content. Measuring organic matter content traditionally takes considerable time, resources, and various laboratory equipment (e.g., oven, muffle furnace, crucibles, precision balance). Much like the quantitative color indices (e.g., sRGB R, sRGB G, sRGB B, CIEL*a* b*) derived from the low-cost NixPro2 color sensor have proven adept at predicting soil organic matter in-situ , the NixPro2 color sensor has the potential to be effective for predicting organic matter in composted materials without the need for traditional laboratory methods. In this study, a total of 200 compost samples (13 different compost types) were measured for organic matter content via traditional loss-on-ignition (LOI) and via the NixPro2 color sensor. The NixPro2 color sensor showed promising results with an LOI-prediction model utilizing the CIEL*a* b* color model through the application of the Generalized Additive Model (GAM) algorithm yielding an excellent prediction accuracy (validation R2 = 0.87, validation RMSE = 4.66 %). Moreover, the PCA scoreplot differentiated the three lowest organic matter compost types from the remaining 10 compost types. These results have valuable practical significance for the compost industry by predicting compost organic matter in real time without the need for laborious, time-consuming methods. [ABSTRACT FROM AUTHOR]

The investigation presented a novel finding regarding mitigating stress induced by chlorpyrifos in Eisenia fetida by incorporating biochar derived from rice straw and fly ash as soil amendments. It was observed that phenolic compounds exhibit solubility in methanol, and the methanolic fraction exhibited notable inhibitory effects on lipid peroxidation and displayed antioxidant properties. The defence mechanism of E. fetida, comprising catalase (CAT), peroxidase (POD), ascorbate peroxidase (APX), and various other enzymes, remained effective in neutralizing stressors without disruption when the earthworm was subjected to diverse chemical agents or stressful conditions. These enzymes served as indicative markers of toxicity induced by pesticide exposure, even at sublethal concentrations. The scavenging of free radicals by these enzymes ultimately safeguarded the organism. Fly ash and biochar emerged as two organic alternatives capable of alleviating stress by providing a protective mechanism. In this context, the study examined the impact of biochar and fly ash amendments on earthworm biomarkers. The mortality rate at the median lethal concentration of chlorpyrifos was reduced to less than 50% through 3% and 5% modifications. In contrast to the non-amendment group exposed to sublethal doses, the amendment group exhibited higher levels of oxidative stress and lower protein content. This observation indicated the presence of stress induced by the accumulation of free radicals, which increased in number with higher doses of chlorpyrifos. Moreover, the study highlighted the interconnected nature of total antioxidant capacity and total phenolic capacity values, with a decrease in these parameters signifying a shift in earthworm biomarkers. [ABSTRACT FROM AUTHOR]

Introduction: In recent years, the frequency and intensity of anthropogenic wildfires have drastically increased, significantly altering terrestrial ecosystems worldwide. These fires not only devastate vegetative cover but also impact soil environments and microbial communities, affecting ecosystem structure and function. The extent to which fire severity, soil depth, and their interaction influence these effects remains unclear, particularly in Pinus tabulaeformis forests. Methods: This study investigated the impact of wildfire intensity and soil stratification on soil physicochemical properties and microbial diversity within P. tabulaeformis forests in North China. Soil samples were collected from different fire severity zones (Control, Light, Moderate, High) and depths (topsoil: 0-10 cm; subsoil: 10-20 cm). Analyses included measurements of soil pH, organic carbon (SOC), total nitrogen (TN), and other nutrients. Microbial diversity was assessed using 16S rRNA gene sequencing. Results: Our findings revealed significant variations in soil pH, SOC, TN, and other nutrients with fire severity and soil depth, profoundly affecting microbial community composition and diversity. Soil pH emerged as a critical determinant, closely linked to microbial α-diversity and community structure. We found that fire severity significantly altered soil pH (p =0.001), pointing to noteworthy changes in acidity linked to varying severity levels. Topsoil microbial communities primarily differentiated between burned and unburned conditions, whereas subsoil layers showed more pronounced effects of fire severity on microbial structures. Analysis of bacterial phyla across different fire severity levels and soil depths revealed significant shifts in microbial communities. Proteobacteria consistently dominated across all conditions, indicating strong resilience, while Acidobacteriota and Actinobacteriota showed increased abundances in high-severity and light/moderate-severity areas, respectively. Verrucomicrobiota were more prevalent in control samples and decreased significantly in fire-impacted soils. Chloroflexi and Bacteroidota displayed increased abundance in moderate and high-severity areas, respectively. Correlation analyses illustrated significant relationships between soil environmental factors and dominant bacterial phyla. Soil organic carbon (SOC) showed positive correlations with total nitrogen (TN) and alkaline hydrolysable nitrogen (AN). Soil pH exhibited a negative correlation with multiple soil environmental factors. Soil pH and available phosphorus (AP) significantly influenced the abundance of the phylum Myxococcota. Soil water content (WC) significantly affected the abundances of Acidobacteriota and Actinobacteriota. Additionally, ammonium nitrogen (NH4+-N) and nitrate nitrogen (NO3--N) jointly and significantly impacted the abundance of the phylum Chloroflexi. Discussion: This study highlights the significant long-term effects of anthropogenic wildfires on soil microenvironment heterogeneity and bacterial community structure in P. tabulaeformis forests in North China, 6 years post-fire. Our findings demonstrate that fire severity significantly influences soil pH, which in turn affects soil nutrient dynamics and enhances microbial diversity. We observed notable shifts in the abundance of dominant bacterial phyla, emphasizing the critical role of soil pH and nutrient availability in shaping microbial communities. The results underscore the importance of soil stratification, as different soil layers showed varying responses to fire severity, highlighting the need for tailored management strategies. Future research should focus on long-term monitoring to further elucidate the temporal dynamics of soil microbial recovery and nutrient cycling following wildfires. Studies investigating the roles of specific microbial taxa in ecosystem resilience and their functional contributions under varying fire regimes will provide deeper insights. Additionally, exploring soil amendments and management practices aimed at optimizing pH and nutrient availability could enhance post-fire recovery processes, supporting sustainable ecosystem recovery and resilience. [ABSTRACT FROM AUTHOR]

The agronomic use of compost and biochar as soil amendments may exhibit contrasting results in terms of soil fertility and plant nutrition. The effects of the biennial application of biochar, compost and a blend of compost:biochar (90:10; % dw:dw) on the agronomical performance of an organically managed and well established 25-year-old olive orchard was assessed 5 years after the initial application. The agronomical evaluation was based on the assessment of the soil physical, chemical, and biological characteristics, and the assessment of the soil fertility by both crop production and nutritional status of the orchard, and the bioassay with olive plantlets. Biochar mainly benefited the physical properties (bulk density, total porosity, aeration, water retention capacity) of soil, especially in the top 0–5 cm. Compost and its blend with biochar improved microbial activity, soil nutritional status (increasing the content of soluble organic C, N, and P) and favoured the formation of aggregates in soil. The bioassay conducted with young plantlets confirmed the enhanced soil fertility status in the three amended treatments, particularly in the case of biochar and its blend with compost. However, this effect was not significantly observed in the adult plants after 5 years of application, reflecting the slow response of adult olive trees to changes in fertilization. Based on these results, alongside the desirable long-residence time of biochar in soil and the ready availability of compost, the blend of biochar with compost assayed in this study is defined as a valid strategy for preparing high quality soil organic amendments. [ABSTRACT FROM AUTHOR]

Poultry manure (PM) has demonstrated its potential to enhance crop nutritional quality. Nevertheless, there remains a dearth of knowledge regarding its synergistic effects when combined with wood biochar (B) on the nutrient concentrations in sweet potato leaves (Ipomoea batatas L.) and the mineral content stored in sweet potato storage roots. Hence, a two-year field trial was undertaken during the 2019 and 2020 cropping seasons in southwestern Nigeria, spanning two locations (Owo—site A and Obasooto—site B), to jointly apply poultry manure and wood biochar as soil amendments aimed at enhancing the nutritional quality of sweet potato crop. Each year, the experiment involved different combinations of poultry manure at rates of 0, 5.0, and 10.0 t ha−1 and biochar at rates of 0, 10.0, 20.0, and 30.0 t ha−1, organized in a 3 × 4 factorial layout. The results of the present study demonstrated that the individual application of poultry manure (PM), biochar (B), or their combination had a significant positive impact on the nutrient composition of sweet potato leaves and minerals stored in the sweet potato storage roots, with notable synergistic effects between poultry manure and biochar (PM × B) in enhancing these parameters. This highlights the potential of biochar to enhance the efficiency of poultry manure utilization and improve nutrient utilization from poultry manure. The highest application rate of poultry manure at 10.0 t ha−1 and biochar at 30.0 t ha−1 (PM10 + B30), resulted in the highest leaf nutrient concentrations and mineral composition compared to other treatments at both sites. Averaged over two years, the highest application rate of poultry manure at 10.0 t ha−1 and biochar at 30.0 t ha−1 (PM10 + B30) significantly increased sweet potato leaf nutrient concentrations: nitrogen by 88.2%, phosphorus by 416.7%, potassium by 123.8%, calcium by 927.3%, and magnesium by 333.3%, compared to those in the control (PM0 + B0). The same treatment increased the concentration of sweet potato root storage minerals: phosphorus by 152.5%, potassium by 77.4%, calcium by 205.5%, magnesium by 294.6%, iron by 268.4%, zinc by 228.6%, and sodium by 433.3%, compared to the control. The highest application rate of poultry manure at 10.0 t ha−1 and biochar at 30.0 t ha−1 yielded the highest economic profitability in terms of gross margin (44,034 US$ ha−1), net return (30,038 US$ ha−1) and return rate or value-to-cost ratio (VCR) (263). The results suggested that the application of poultry manure at 10 t ha−1 and biochar at 30 t ha−1 is economically profitable in the study areas and under similar agroecological zones and soil conditions. [ABSTRACT FROM AUTHOR]

Over-dose pesticide application disrupts plant physiological processes and soil biological functions; however, the toxicity mechanisms of pesticides and the effectiveness of mitigation measures are still unclear. Our review shows that over-dose of pesticide can cause plant phytotoxicity by enhancing reactive oxygen species and cellular membrane electrolyte leakage, which subsequently decrease chlorophyll biosynthesis, vegetative growth and yield. However, the optimum use of pesticides (insecticides at 0.21 kg a.i. ha-1; herbicides at 1.44 kg a.i. ha-1 and fungicides at =0.4 kg a.i. ha-1) may not interfere with plant physiological functions, while indirectly improving plant nutrients absorption, translocation and yield. In the soil system, pesticide application decreases microbial population by disrupting the microbial metabolism and cellular protein denaturation. Moreover, pesticide application can restrict (by adsorption, etc.) glucose release from organic matter by decreasing the hydrolysis of extracellular enzymes, thereby reducing the labile C source for microbes and resulting in lower soil organic carbon cycling. The pesticide residue can decrease biological nitrogen fixation and nitrogen mineralization by decreasing diazotrophs and saprophytic bacterial population due to cellular hyperkinesis and misfunctions, respectively. Organo-phosphate pesticides can induce oxidative stress to microbes which can affect phosphorus (P) mineralization, but may also enhance P-solubilizing bacterial activities and P availability. The use of biosurfactants, exogenously induced microbes, and soil amendments (e.g., biochar) can effectively remediate pesticide toxicity through solubilization, microbial catabolism and sorption of pesticides by 70%, 78% and 69%, respectively. However, field application of biosurfactants and optimization of biochar characteristics remain challenging for effective pesticide sorption and remediation. [ABSTRACT FROM AUTHOR]

This article examines the impact of artificial exogenous additions on grassland ecosystems, specifically focusing on carbon emissions driven by microbial communities. The authors discuss the concept of the "priming effect" and argue that while exogenous additions can stimulate microbial activity and increase carbon release, the overall impact on soil carbon dynamics is likely to be minor and not result in substantial carbon loss. They emphasize the need for further research to fully understand the ecological significance of the priming effect in the context of global changes. The article also explores the long-term effects of exogenous additions on grassland ecosystems, highlighting the role of different plant species and mycorrhizal fungi in maintaining community stability. The authors conclude that exogenous additions are unlikely to cause large-scale soil carbon emissions, but more research is needed to understand the long-term impacts and develop effective management strategies. [Extracted from the article]

Applying bokashi (Bok) at 10% volume/volume (v/v), biochar (BC) at 10% v/v, and their combination (Bok_BC) as soil amendments significantly enhances citrus nursery production, improving plant growth and soil health, alongside offering notable economic benefits. Our greenhouse experiment evaluated these treatments across two fertilizer doses, at half (700 μS/cm) and full (1400 μS/cm) electrical conductivity (EC) levels, compared to a control mix, demonstrating improved nutrient availability, water retention, growth rates, and potential for carbon sequestration. Based on the results of this experiment, a cost–benefit analysis was performed; the BC treatment yielded substantial savings, particularly in large nurseries where BC at 700 μS/cm electrical conductivity (EC) saved USD 1356.38 per day and the same treatment at 1400 μS/cm EC saved USD 1857.53. These savings stem from increased nutrient contents (N, P, and K) and improved water retention, reducing irrigation; shortened growth cycles due to enhanced growth rates were observed, indirectly suggesting reduced electricity costs for greenhouse operations. Additionally, the increased carbon content within the soil points toward long-term benefits from carbon sequestration, further contributing to the sustainability and economic viability of these practices. These findings highlight the economic advantage of incorporating Bok and BC into soil mixes, providing a cost-effective strategy for enhancing greenhouse agriculture sustainability. [ABSTRACT FROM AUTHOR]

The use of beach-cast macroalgae as a fertilizer (F) or soil amendment (SA) is coming back into focus, due to its highly efficient transformation of CO2, nutrients, salts and minerals from its aqueous surroundings into biomass. This research studied the hydrothermal carbonization (HTC) of Fucus vesiculosus macroalgae to hydrochar and evaluated its feasibility for use in soil applications. F. vesiculosus was submitted to HTC following a full factorial design of experiments with three HTC process parameters varied to assess their impact on the hydrochars: temperature (T: 160, 190, 220 °C), solid content (%So: 20, 35%), and process water recirculation (PWrec: yes and no). In general, F. vesiculosus and its hydrochars were rich in nutrients, but also contained regulated heavy metals. Investigation of the partitioning behavior of inorganic elements between the hydrochars and process water showed that heavy metals like Cr, Pb, Co and Cu tended to accumulate in the hydrochar, unaffected by HTC conditions. Nutrients such as P, N, B, and Mn were primarily found in the hydrochar and could be partially influenced to transfer to process water by changing %So and T. The correlation between the mass fractions of 22 elements in the hydrochar and HTC process parameters was studied. T was the most influential parameter, showing a significant positive correlation for eleven elements. %So and PWrec showed inconsistent effects on different elements. When process water was recirculated, some elements decreased (Ca, Cd, Fe) while others increased (K, Na, B, N) in the hydrochar. Assessment against various regulations and standards for F and SA revealed that F. vesiculosus complied with Cd limit values for most rules including the EURF and B, and was regulated only in the RAL for SA, over the limit value. In contrast, the limit value of Cd for both F and SA applications was surpassed in the 13 hydrochars. The contents of N, P, K, S, and Na in the feedstock and hydrochars complied with European F and SA rules, while they were too high for German rules on SA. The other limits for F rules were achieved (under certain HTC process parameters) except for P (lower than the requirements in F for F. vesiculosus and its hydrochars). Highlights: The brown algae complied with most limit values for Cd content to be applied as soil amendment or as fertilizer. Hydrochars from brown algae did not comply with any Cd limit values. No HTC process condition reduced the Cd content to comply with the requirements. Inorganic mass fractions were mostly influenced by temperature (positively correlated with 11/22 elements), followed by water recirculation (7) and solid content (6). Heavy metals accumulate in hydrochars across all HTC conditions. The partitioning for some elements (e.g., Cd, Co, Cu, W, V) showed no correlation with process conditions. [ABSTRACT FROM AUTHOR]

The implementation of ridge-furrow with plastic film mulching has the potential to enhance crop yields and water productivity, particularly in black soil regions. However, the synergistic impacts of combining ridge-furrow with plastic mulching alongside with various organic amendments on maize yield and nitrogen fertilizer utilization efficiency remain unclear. Using 15N-labeled tracing technology, we investigated fertilizer-N recovery of maize, distribution, fertilizer-N residual in soil, and nitrogen fertilizer loss across six treatments: nonmulched flat with non-organic amendment (FN), non-mulched flat with straw amendment (FS), non-mulched flat with biochar amendment (FBC), ridge-furrow with plastic mulching without organic amendment (RN), ridge-furrow with plastic mulching with straw amendment (RS), and ridge-furrow with plastic mulching with biochar amendment (RBC). The results revealed that ridge-furrow with plastic mulching in comparison to non-mulched flat, led to a significant increase in maize dry biomass accumulation, yield, and the rate of fertilizer-N recovery in maize (NRE) by 8.57%–12.36%, 10.08%–15.13%, and 2.22%–3.18%, respectively. The rate of fertilizer-N residual in soil (NSR) and fertilizer-N loss (NLS) decreased by 0.5%–2.04% and 0.78%–3.21%, respectively. In addition, the straw and biochar amendments under different planting methods promoted NRE in plants and NSR in soil, reducing NLS. Compared with non-organic amendment treatments, the inclusion of straw and biochar amendments resulted in increased NRE and NRS by 1.64%–6.20% and 0.12%–2.18%, while NLS decreased by 1.76%– 7.78%. Biochar amendment treatment exhibited significantly higher nitrogen accumulation and NRE compared to the straw amendment treatment. Overall, ridge-furrow with plastic mulching combined with biochar amendment proved to be an effective method to enhance nitrogen fertilizer utilization of maize in the black soil regions, improving both yield and nitrogen fertilizer utilization efficiency. [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]

Soil flooding is a serious abiotic stress that can repress plant growth and yield. The intensity of flooding stress is continuously increasing owing to rapid climate change and changes in rain intensity and frequency. Biochar (BC) emerges as an important soil amendment to mitigate adverse impacts of abiotic stress. The role of BC against different stresses is well reported, however, its role under flooding stress is not determined yet. Thus, this experiment was conducted to determine the role of BC on the performance of brassica crops under flooding stress. The experiment was comprised of well-watered (WW) and flooding stress (FS) conditions and biochar application: control, 1% biochar, and 2.5% biochar. The results indicated that flooding stress stunted the plant growth and impaired the photosynthetic pigments, leaf water status, osmolytes yield and yield traits, and oil concentration and increased the electrolyte leakage (EL), hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentration. The application of BC at the rate of 2.5% mitigated the adverse impacts of salinity and upgraded the antioxidant activities (~50-120%), reduced the oxidative stress markets (~70-300%), and increased the leaf water status, photosynthetic pigments, osmolyte accumulation, nutrient uptake, yield traits, and oil contents. In conclusion, BC application can improve the productivity and oil yield of brassica under drought stress by improving plant physiological and biochemical functioning. However, more in depth studies are direly needed to explore the mechanism of BC to induce flood tolerance. [ABSTRACT FROM AUTHOR]

Agriculture plays a fundamental role in India's economy, supporting 70% of rural households. While often perceived as non-productive, agricultural waste harbors materials potentially beneficial to humans through the creation and utilization of biochar in the production and processing of agricultural goods. This study conducts a comprehensive exploration into the advantages and risks associated with biochar application, considering its role as a soil amendment, bioremediation agent, and its broader implications for human health and the environment. Biochar, primarily composed of stable carbon, was initially proposed as a soil amendment to sequester carbon. Efficient resource utilization has emerged as a viable means to address global environmental challenges associated with waste disposal. This review delineates diverse agricultural waste types and sources, identifies related environmental risks, and advocates for government-led measures aligned with circular economy principles to manage such waste. Furthermore, it offers insights into potential management strategies, policy considerations, and practical approaches, fostering sustainable agriculture practices and environmental conservation in India. [ABSTRACT FROM AUTHOR]

The study aim was to optimise the C/N ratio, improve the compost quality, reduce pathogenic bacteria load in the compost, and improve guava yield. Vegetable wastes were mixed with cow dung, grasses, and food wastes in ratios of 4:3:2:1 (w/w) for achieving a C/N ratio of approximately 37. Cocomposting is an important strategy because the mixture of bulking agents can help achieve optimal composting conditions. Experimental results were obtained from a pilot-scale rotary drum reactor with forced aeration. In the reactor, the temperature increased during the thermophilic phase (58±2 °C) and decreased after 10 days (54±2 °C). The pH values moderately increased, then decreased, and were near to neutral after maturation. The results indicated that co-composting of bio-wastes at a C/N ratio of 37.6%±1.02% could be effectively decomposed to reduce the residuals to just 13.6%±1.05% after 28 days. The microbial population increased in both mesophilic and thermophilic stages and decreased at the end of the composting, reflecting stability. The stable compost was applied to the growth of guava plant, and the yield was calculated. The organic compost improved plant growth, fruit yield, and enriched phytochemical compounds in the fruit and peels. The phytochemical compounds improved antioxidant activity in the guava fruits. [ABSTRACT FROM AUTHOR]

The dissemination of antibiotic resistance genes (ARGs) in soil has become a global environmental issue. Vermicomposting is gaining prominence in agricultural practices as a soil amendment to improve soil quality. However, its impact on soil ARGs remains unclear when it occurs in farmland. We comprehensively explored the evolution and fate of ARGs and their hosts in the field soil profiles under vermicompost application for more than 3 years. Vermicompost application increased several ARG loads in soil environment but decreased the high-risk bla -ARGs (bla ampC , bla NDM , and bla GES-1) by log(0.04 – 0.43). ARGs in soil amended with vermicompost primarily occurred in topsoil (approximately 1.04-fold of unfertilized soil), but it is worth noting that their levels in the 40–60 cm soil layer were the same or even less than in the unfertilized soil. The microbial community structure changed in soil profiles after vermicompost application. Vermicompost application altered the microbial community structure in soil profiles, showing that the dominant bacteria (i.e., Proteobacteria, Actinobacteriota, Firmicutes) were decreased 2.62%–5.48% with the increase of soil depth. A network analysis further revealed that most of ARG dominant host bacteria did not migrate from surface soil to deep soil. In particular, those host bacteria harboring high-risk bla -ARGs were primarily concentrated in the surface soil. This study highlights a lower risk of the propagation of ARGs caused by vermicompost application and provides a novel approach to reduce and relieve the dissemination of ARGs derived from animals in agricultural production. [Display omitted] [ABSTRACT FROM AUTHOR]

In light of climate change and increasing global temperatures, it is important to equally prioritize the study of inorganic carbon dynamics in calcareous soils within temperate ecosystems, as has been done for arid or semiarid environments. A significant area of vineyards in Germany is established on calcareous soils. However, the potential influence of inorganic carbon on CO2 emissions in these vineyards has not been sufficiently explored when evaluating the carbon footprint of management practices in relation to carbon storage. Therefore, we aimed to differentiate between organic and inorganic sources of CO2 emissions from six vineyard soils located in the southwest of Germany that had previously received organic soil amendments (OA). Inorganic carbon content varied between 8 and 55 g kg−1 across different sites, with variations observed in the inorganic‐to‐organic carbon ratio. Soil samples were incubated under standard laboratory conditions for 48 h, and the source of emitted CO2 was determined using a two‐end‐member mixing model. The contribution of inorganic carbon to CO2 emissions was influenced by the quantity of inorganic carbon, with an increase in contribution with increasing inorganic‐to‐organic carbon ratio. On average, abiotic sources accounted for 5% to 40% of the emitted CO2 at the different sites, with one site showing no significant contribution of inorganic carbon. CO2 production from inorganic carbon was higher in the subsoil compared with the topsoil, likely related to the higher content of inorganic carbon in the subsoil. Notably, there was no discernible influence of OA on carbonate dissolution. This study emphasizes the significance of considering abiotic sources of CO2 emissions in addition to soil respiration in calcareous soils and highlights the need for further investigation to apply these findings at the field scale. [ABSTRACT FROM AUTHOR]

Elucidating the characteristics and underlying mechanisms of soil organic carbon (SOC) and nitrogen mineralization in the context of sludge addition is vital for enhancing soil quality and augmenting the carbon sink capacity of soil. This study examined the chemical properties, enzyme dynamics, and organic carbon and nitrogen mineralization processes of soil from degraded grasslands on the Loess Plateau at various incubation temperatures (5, 15, 25, and 35 °C) and sludge addition rates (0%, 5.0%, 10.0%, and 20.0%) through a laboratory incubation experiment. The results showed that incubation temperature, sludge addition, and their interactive effects significantly altered the soil enzyme C:N, C:P, and N:P stoichiometries. The cumulative mineralization rates of SOC and nitrogen increased significantly with increasing incubation temperature and sludge addition rate. Principal component analysis revealed a significant linear correlation between cumulative SOC and nitrogen mineralization. Random forest analysis indicated that β-1,4-Glucosidase (BG), β-1,4-N-acetyglucosaminidase (NAG), cellobiohydrolase (CBH), ammonium nitrogen (NO3−), enzyme C:P ratio, alkaline phosphatase (ALP), and incubation temperature were crucial determinants of cumulative SOC mineralization. Structural equation modeling demonstrated that sludge addition, NO3−, NAG, ALP, and enzyme C:P positively impacted SOC mineralization, whereas dissolved organic carbon and BG had negative impacts. Conversely, incubation temperature negatively affected soil nitrogen mineralization, whereas NO3−, available phosphorus, and ALP contributed positively. Sludge addition and temperature indirectly modulated soil net nitrogen mineralization by altering soil chemical properties and enzyme activities. These findings underscore the role of SOC and nitrogen mineralization as indicators for evaluating soil nutrient retention capabilities. [ABSTRACT FROM AUTHOR]