Addition Of Peat Research Articles

The simultaneous addition of chitosan and peat enhanced the removals of antibiotics resistance genes during biogas residues composting

Direct reuse of biogas residue (BR) has the potential to contribute to the dissemination of antibiotic resistance genes (ARGs). Although high-temperature composting has been demonstrated as an effective method for the harmless treatment of organic waste, there is few researches on the fate of ARGs in high-temperature composting of BR. This research examined the impact of adding 5% chitosan and 15% peat on physicochemical characteristics, microbial communities, and removal of ARGs during BR-straw composting in 12 Biolan 220L composters for 48 days. Our results showed that the simultaneous addition of chitosan and peat extended the high-temperature period, and increased the highest temperature to 74 °C and germination index. These effects could be attributed to the presence of thermophilic cellulose-decomposing genera (Thermomyces and Thermobifida). Although the microbial communities differed compositionally among temperature stages, their dissimilarity drastically reduced at final stage, indicating that the impact of different treatments on microbial community composition decreases at the end of composting. Peat had a greater impact on aerobic genera capable of cellulose degradation at thermophilic stage than chitosan. Surprisingly, despite the total copy number of ARGs significantly decreased during composting, especially in the treatment with both chitosan and peat, intl1 gene abundance significantly increased 2 logs at thermophilic stage and maintained high level in the final compost, suggesting there is still a potential risk of transmission and proliferation of ARGs. Our work shed some lights on the development of waste resource utilization and emerging contaminants removal technology.

Livestock and poultry waste compost as an amendment in medium for pumpkin seedlings

This research evaluated cow dung compost (CDC), goose dung compost (GDC), and duck dung compost (DDC) as peat addition in growing media used for the production of pumpkin seedlings. Commercial substrate (peat: vermiculite: perlite=3:1:1, v/v) was used as the control (CK). The partial addition in peat of each waste compost in the mixtures were 10%, 20%, and 30% (v/v). The results showed that all compost in mixtures increased bulk density, total porosity, electrical conductivity, and mineral content, but negatively affected the pH and organic matter of the growing media compared to CK. CDC in mixture increased ventilation porosity and gas-water ratio and decreased water-holding porosity compared to CK, which was the opposite of the effect of GDC and DDC. The mixtures elaborated with GDC showed better growth, biomass, gas exchange parameters, and physiological indicators of seedling plants than other treatments in varying degrees, which depended on the additional amount of GDC. DDC inhibited plant growth and gas exchange parameters, especially in high addition rate; however, it had a slight promotion effect on chlorophyll content and quality because DDC was rich in minerals. GDC was better than CDC and DDC as a partial addition for peat in the cultivation of pumpkin seedlings.

Thermokinetics and synergistic effect analysis of peat-lignite coal co-pyrolysis

ABSTRACT In this study, the synergistic effect between peat and lignite coal was investigated in terms of kinetic energy and mass loss trends using a thermogravimetric analyzer. Thermogravimetric non-isothermal studies were conducted at different heating rates under inert nitrogen atmosphere. Kinetic analysis was performed using model-free KAS, OFW, and Starink methods and the average activation energies varied between 88.62 kJ/mol and 204.28 kJ/mol. Differential mass loss trends were determined using experimental and theoretical data. An obvious deviation was obtained at a blend ratio of PT:CL40:60. Thus, results revealed that the PT and CL co-pyrolysis has synergistic effects, especially for sample PT:CL40:60. SEM and BET analyses were performed on the coke sample of peat, coal, and PT:CL40:60 blend ratio samples for further analysis. The surface area of peat and coal was determined to be 416 m2/g and 83.06 m2/g, respectively. It was concluded that the porosity and surface area of coal (187.02 m2/g) increased with the addition of peat. The results are expected to be useful in the design of peat biomass and coal co-pyrolysis systems.

Comparative Study on the Effects of Different Soil Improvement Methods in Blueberry Soil

Soil improvement methods can result in changes in the microbial community in blueberry soil. Bacterial communities play an important role in soil fertilizer and plant nutrient acquisition. In this study, the response of microbial community composition, microbial function, and the nitrogen (N) cycle to different improvement methods was analyzed using high-throughput sequencing to investigate the best soil improvement method from a microbial perspective. The results showed that the highest microbial diversity was observed in the treatment involving peat combined with mushroom bran (T2), followed by the peat combined with acidified rice husk (T2) both in the rhizosphere and roots. The dominant phyla were Proteobacteria and Actinobacteria both in the blueberry rhizosphere soil and roots. Interestingly, Acidobacterium and Paludibaculum, belonging to the Acidobacteria phylum, exhibited the most significant influence and were most predominant in the T2 treatment rhizosphere soil. The T2 treatment promoted the growth of N fixation functional bacteria both in the rhizosphere soil and roots. At the module level, the T2 treatment enhanced N fixation and suppressed the assimilatory and dissimilatory nitrate reduction reactions, denitrification, and nitrification in the blueberry rhizosphere. Additionally, the T2 treatment increased the abundance of root endophytic microbes involved in N fixation. Overall, our findings suggest that the addition of peat combined with acidified rice husk is the optimal soil improvement method for blueberry cultivation.

Surge of native rare taxa in tailings soil induced by peat bacterial invasion

The pivotal role of the native bacterial community in maintaining soil health, particularly in degraded tailings environments, is often overlooked. This study utilized peat, rich in microorganisms, to investigate its impact on soil function and native bacteria response in copper tailings-soil. Through 16S rRNA gene sequencing, changes in nutrient cycling, organic matter decomposition, and microbial activity were assessed post one-year peat remediation. Results from FEAST and cluster analysis revealed that peat-derived species disproportionately influenced tailings microbial community remediation, supported by the microbial invasion theory. Tailings responded positively to these species, with optimal function achieved at 5 % peat dosage. Peat biomarkers (Actinobacteriota, Bacteroida, Chloroflexi, and Firmicutes) played key roles in heavy metal removal and nutrition fixation. The Random Forest model and co-occurrence network highlighted contributions from native rare species (Dependentiae and Latescibacterota) activated by peat addition. These insights underscore the resilience of rare taxa and provide a foundation for soil health restoration in tailings areas. By emphasizing the importance of peat as a potential exogenous solution for activating indigenous microbial functions, these findings offer valuable insights for developing effective and sustainable remediation strategies in mining-affected regions.

Ecological Assessment of Drilling Sludge and Development of a Method for their Bioremediation in Western Siberia

The article considers the issue of bioremediation of drilling sludge. The aim of the research is studying of the microbiological processes occurring in soils based on drilling sludge, with their subsequent application for the biological stage of reclamation of disturbed lands. Microbiological characteristics of drilling sludge and four samples of soils based on it with the addition of diatomite, dolomite flour, peat, gypsum, glauconite, humic preparation Rostock in different proportions were studied. Crops were shown on agarized medium: meat-peptone agar (MPA), starch-ammonia agar (SAA), Munz medium, Chapek medium, depending on the determined group of microorganisms. The total number of microflora, the number of saprophytes, microorganisms growing on starch-ammonia agar (SAA), hydrocarbon-oxidizing bacteria (PSB), micromycetes and actinomycetes were estimated. The mineralization coefficient is calculated. The total number of microflora in the samples ranged from 51 to 271 million CFU/g. The share of saprophytes was 16.724.8% of the total amount of microflora. The proportion of microorganisms growing on SAA was 15.6-36.6%. The minimum number of PSB was 2.0 million CFU/g of soil; the maximum was 22.0 million CFU/g. The mineralization coefficient varies from 0.81 to 1.63, which indicates different rates of mineralization processes. The number of micromycetes determined on the Chapek medium ranged from 0.01 to 3.33 million CFU/g, on SAA from 0.03 to 10.4 million CFU/g. At the same time, the number of micromycetes is much lower than the number of bacteria, which is normal for soils. The number of actinomycetes varied from 0.2 to 7.3 million CFU/g. The largest number of actinomycetes was noted when peat and humic preparation Rostock were introduced. The share of actinomycetes in the total number of microflora on the SAA ranged from 0.6 to 14%. There is a development of the total number of microflora, an increase in the diversity of microbocenosis, which indicates a decrease in the concentrations of water-soluble salts, petroleum products and the presence of an additional food source in the form of peat. Based on the data obtained, a conclusion was made about the possibility of using soils based on drilling sludge with the addition of peat and humic preparation Rostock for the reclamation of disturbed lands.

Comparison of carbon and nitrogen accumulation rate between bog and fen phases in a pristine peatland with the fen-bog transition.

Long-term carbon and nitrogen dynamics in peatlands are affected by both vegetation production and decomposition processes. Here, we examined the carbon accumulation rate (CAR), nitrogen accumulation rate (NAR) and δ13 C, δ15 N of plant residuals in a peat core dated back to ~8500 cal year BP in a temperate peatland in Northeast China. Impacted by the tephra during 1160 and 789 cal year BP and climate change, the peatland changed from a fen dominated by vascular plants to a bog dominated by Sphagnum mosses. We used the Clymo model to quantify peat addition rate and decay constant for acrotelm and catotelm layers during both bog and fen phases. Our studied peatland was dominated by Sphagnum fuscum during the bog phase (789 to -59 cal year BP) and lower accumulation rates in the acrotelm layer was found during this phase, suggesting the dominant role of volcanic eruption in the CAR of the peat core. Both mean CAR and NAR were higher during the bog phase than during the fen phase in our study, consistent with the results of the only one similar study in the literature. Because the input rate of organic matter was considered to be lower during the bog phase, the decomposition process must have been much lower during the bog phase than during the fen phase and potentially controlled CAR and NAR. During the fen phase, CAR was also lower under higher temperature and summer insolation, conditions beneficial for decomposition. δ15 N of Sphagnum hinted that nitrogen fixation had a positive effect on nitrogen accumulation, particular in recent decades. Our study suggested that decomposition is more important for carbon and nitrogen sequestration than production in peatlands in most conditions and if future climate changes or human disturbance increase decomposition rate, carbon sequestration in peatlands will be jeopardized.

Enhancing phytoremediation of arsenic-contaminated soil by agronomic practices (drip irrigation and intercropping): Influence of soil organic matter

It is essential to improve the efficiency and economic benefits of phytoremediation. In this study, drip irrigation and intercropping were used to enhance the phytoremediation of arsenic-contaminated soil. Meanwhile, the influence of soil organic matter (SOM) on phytoremediation was investigated by comparing the difference in arsenic migration in soils with or without peat addition as well as the arsenic accumulation of plants. The results showed that hemispherical wetted bodies with a radius of approximately 6.5 cm were formed in the soil after drip irrigation. Arsenic in the center of the wetted bodies migrated to the edge of the wetted bodies. Peat inhibited the upward migration of arsenic from the deep subsoil and increased the phytoavailability of arsenic under drip irrigation conditions. To soils without peat added, drip irrigation decreased the arsenic accumulation in crops (planted at the center of the wetted body) while increased the arsenic accumulation in remediation plants (planted at the edge of the wetted body) compared with the flood irrigation treatment. An increase in soil organic matter of about 36 % was found after mixing 2 % peat in the soil, and correspondingly, arsenic concentrations in remediation plants increased by >28 % in both intercropping treatments with a drip or flood irrigation. Drip irrigation coupled with intercropping enhanced the effect of phytoremediation, and the addition of soil organic matter further improved phytoremediation efficiency.

Carbon-containing additives changes the phosphorus flow by affecting humification and bacterial community during composting

Phosphorus recycling from organic wastes to prepare a fertilizer by composting is promising. The aim of this study was to compare the effect of diverse carbon-containing additives (T1, glucose; T2, biochar; T3, woody peat) on phosphorus (P) fractions transformations, humus formation and bacterial community succession in chicken manure composting. Results showed that orthophosphate monoester was significantly related to the humification process, and glucose or woody peat addition increased the P in humus. Lentibacillus was a key carbon cycle bacteria related to organics stabilization affected by carbon-containing additives. Redundancy analysis and variation partitioning indicated that phosphatase enzyme activity driven by bacterial community and humic substance had 59.7% contribution to P fractions dynamics. The findings highlight an efficient humus-regulation P stabilization way, notably in composting adding glucose to form humus with a better binding ability to labile P forms and phosphatase.

Effect of peat and thiol-modified peat application on mercury (im)mobilization in mercury-polluted paddy soil

Mercury (Hg) pollution in paddy soil has gained special attention because methylmercury (MeHg) can accumulate in rice grains. Therefore, there is an urgent need to explore the remediation materials of mercury-polluted paddy soil. In this study, herbaceous peat (HP), peat moss (PM), and thiol-modified HP/PM (MHP/MPM) were selected to investigate the effects and probable mechanism of their application on Hg (im)mobilization in mercury-polluted paddy soil through pot experiments. The results showed that HP, PM, MHP and MPM addition increased MeHg concentrations in the soil, indicating that the addition of peat and thiol-modified peat might increase the exposure risk of MeHg in soil. The addition of HP could significantly decrease the total mercury (THg) and MeHg concentrations in rice, with average reduction efficiencies of 27.44% and 45.97%, respectively, while adding PM slightly increased the THg and MeHg concentrations in rice. In addition, the addition of MHP and MPM significantly decreased the bioavailable Hg concentrations in the soil and THg and MeHg concentrations in rice, with reduction efficiencies of rice THg and MeHg of 79.14∼93.14% and 82.72∼93.87%, respectively, indicating that thiol-modified peat had good remediation potential. The possible mechanism is that Hg can bind with thiols in MHP/MPM and form steady compounds in the soil, reducing Hg mobility in the soil and inhibiting its uptake by rice. Our study showed the potential value of HP, MHP and MPM addition for Hg remediation. Additionally, we must weigh the pros and cons when adding organic materials as remediation agents to mercury-polluted paddy soil.

The Effects of Natural Humus Material Amendment on Soil Organic Matter and Integrated Fertility in the Black Soil of Northeast China: Preliminary Results

The input of exogenous organic materials is an effective way to improve soil organic matter (SOM) content in cropland. The exploration of the impact of new organic materials such as woody peat on black soil fertility can provide an important reference for preventing the degradation of black soil in Northeast China. In this study, the effects of adding woody peat to SOM and the soil-integrated fertility of black cropland were studied by seven treatments (no organic matter addition, CK; crop straw returning, SR; decomposed straw addition, DS; organic manure addition, OM; 6 t/ha woody peat addition, LWP; 10.5 t/ha natural humus material addition, MWP; and 15 t/ha natural humus material addition, HWP). The results show that natural humus material additions (LWP, MWP, and HWP treatments) could significantly increase SOM (increased by 4.79~9.41 g/kg), labile SOM (increased by 2.49~4.52 g/kg), and recalcitrant SOM (increased by 2.13~6.39 g/kg) components, respectively. For comparison, traditional organic material inputs (SR, DS, and OM treatments) had no significant effect on SOM but induced an increase in the labile SOM component in the following year. This study also found that natural humus material additions could improve soil-integrated fertility in a year term, especially in promoting SOM accumulation. However, organic manure amendment showed both the advantage of increasing soil fertility slightly and the disadvantage of increasing soil salt sharply. In conclusion, compared with traditional exogenous organic materials, the natural humus material amendment technique can rapidly increase the total SOM quantity and its different stability components and has a great effect in improving the integrated fertility of black soil. Thus, it is of significance to further study the potential of natural humus material amendment in the fertility of black soil in future.

Humic acid and phosphorus fractions transformation regulated by carbon-based materials in composting steered its potential for phosphorus mobilization in soil

This study investigated the effects of different carbon-based additives including biochar, woody peat, and glucose on humic acid, fulvic acid, and phosphorus fractions in chicken manure composting and its potential for phosphorus mobilization in soil. The results showed that the addition of glucose effectively increased the total humic substance content (90.2 mg/g) of composts, and the fulvic acid content was significantly higher than other groups (P < 0.05). The addition of biochar could effectively improve the content of available phosphorus by 59.9% in composting. The addition of carbon-based materials to the composting was beneficial for the production of more stable inorganic phosphorus in the phosphorus fraction. The highest proportion of soluble inorganic phosphorus components of sodium hydroxide was found in group with woody peat addition (8.7%) and the highest proportion of soluble inorganic phosphorus components of hydrochloric acid was found in group with glucose addition (35.2%). The compost products with the addition of biochar (humic acid decreased by 17.9%) and woody peat (fulvic acid decreased by 72.6%) significantly increased soil humic acid mineralization. The compost products with the addition of biochar was suitable as active phosphate fertilizer, while the compost products with the addition of glucose was suitable as slow-release phosphate fertilizer.

Effects of drilling waste combined with exogenous organic matter on physicochemical properties of aeolian sandy soil and growth of spinach

An indoor potted experiment was carried out to study the application effects of water-based waste drilling mud (WBDM) and drill cuttings combined with humic acid and woody peat in aeolian sandy soil.We analyze their effects on the growth of spinach, in order to provide a reference for the resource utilization of drilling waste and the improvement of aeolian sandy soil. A total of three individual experiments were set up: 4 treatments in the basic group, taking aeolian sandy soil as the control (CK), mixing aeolian sandy soil and drill cuttings at a mass ratio of 1:1, then added with 0, 2%, and 4% WBDM (dry basis) respectively. The basic group treatment was added with 1% humic acid, 1% humic acid+3% woody peat mixture respectively, as the humic acid group and woody peat group. The results showed that in the basic group, drilling waste application significantly increased soil organic matter content (SOM), pH and electrical conductivity, the 2% WBDM significantly promoted the growth of spinach. Humic acid and woody peat reduced soil pH and increased SOM content and electrical conductivity. Plant growth indicators such as plant height, total leaf area, fresh weight and dry weight of the humic acid group were higher than the corresponding treatments in the basic group. The mixed addition of humic acid and woody peat did not affect plant growth. The treatment with the best performance was to add 2% WBDM to the humic acid group, and the SOM was 13.1 g·kg-1, spinach's plant height, total leaf area, fresh weight and dry weight significantly increased by 49.7%, 93.4%, 83.3%, and 34.6% than CK after 40 days of sowing. The application of drilling waste with organic matter could significantly increase SOM content and promote spinach growth. Aeolian sandy soil + drill cuttings + WBDM (2%) + humic acid (1%) was the best combination mode.

THE IMPACT OF SOIL MIXTURES ON BIOMETRIC INDICATORS OF SEEDLINGS AND YIELD OF DIFFERENT SPECIES OF TOMATO IN PAVLODAR CITY CONDITIONS

The article presents data on the effect of soil mixtures on tomato seedlings of two varieties: «Novichok» and «Velmozha», since the right choice of components in the composition of soil mixtures will depend on obtaining healthy, properly formed tomato seedlings. Field soil with addition of peat, biohumus and horse mulch in different ratios was used as the main component in all the variants. According to the data obtained, the greatest biometric indicators tomato seedlings of the two varieties form in the variants with field soil and biohumus (1:1), field soil and horse mulch (2:1). These soils contribute to better growth and development of seedlings, the formation of its more ramified powerful root system, which provides the most favorable conditions for nutrient, water and air conditions, the photosynthetic activity of plants when transplanted into the open field, leading to an increase in productivity by 1,3–2,2 times, depending on the variety. In the variant with peat the tomato seedlings were stunted (4,6–4,9 cm) with a weak root system (1,6–2,2 cm); they were not transplanted to the open ground.

Effects of the Rapid Construction of a High-Quality Plough Layer Based on Woody Peat in a Newly Reclaimed Cultivated Land Area

To implement the balance system of cultivated land in occupation and supplement and to adhere to the principle of “supplement the occupied cultivated land of high quality with the one bearing same quality”, in the thesis, a field experiment was conducted to study the effects of woody peat on soil physical, chemical, and biological properties of the plough layer and its crop yield. Furthermore, the correlation between soil indexes and crop yield under the best fertilization mode through the addition of the natural material of woody peat instead of lengthy cultivation of the plough layer to rapidly construct a high-quality plough layer and solve the practical problem that the natural endowment of newly reclaimed cultivated land is far less than the occupied high-quality cultivated land was explored. The land remediation project of Fuping County, Hebei Province, was taken as the experimental area, and the five most representative and effective datasets were selected and studied. The results demonstrated that the addition of woody peat and rotten straw could reduce soil particle size and bulk density and alleviate soil viscosity and acidification. An increase in soil organic matter, soil microbial biomass carbon (MBC), alkali-hydrolyzable nitrogen, available phosphorus, and available potassium and a decrease in the heavy metal content were also observed. The results indicated that the application of woody peat achieved the expected effect of the rapid construction of a high-quality plough layer. The best mode of fertilization was A2, which provided a good reference for the rapid construction of a high-quality plough layer in the future. The analysis of the correlation between soil indexes and crop yield illustrated that the organic matter content, soil available nutrients, and crop yield had a significant positive correlation; the organic matter content and soil available nutrients showed the same tendency, which suggests that soil organic matter content and soil fertility level are closely related and that soil fertility plays a decisive role in crop yield under the same external conditions. Woody peat exerted an eminent influence on the organic matter content and soil available nutrients to determine the change in crop yield, which provides a reliable basis for future research on land improvement projects to increase crop yield.

ADSORPTION OF OBSOLETE SLUDGE, PEAT, BUCKWHEAT HUSKS AND COMPOSITIONS FROM THEM

The problem of accumulation of obsolete silt deposits at aeration stations is relevant for the whole territory of Ukraine. This can lead to environmental hazards. Therefore, the task of processing silt deposits with the creation of granules based on them with the addition of peat and buckwheat husks.&#x0D; Van Bamelen's tensometric (static) method was used to determine the equilibrium humidity of the experimental samples depending on the relative humidity .&#x0D; As a result of researches kinetic curves of adsorption over obsolete silt deposits, peat, buckwheat husk and the three-component composition created on their basis are received. Kinetic adsorption curves indicate a slow process. The adsorption curves of the three-component composition have the character of curves of obsolete sludge, which have a non-uniform character. The obtained equilibrium humidity does not exceed the standard humidity for fuel pellets. The adsorption isotrams of the three-component composition and its components are determined, from which the equations of experimental and linearized isotrams are obtained. The analysis of experimental isotherms allows to relate them relatively to the isotherms of adsorption IV, which are observed in inorganic oxides and in other porous bodies.&#x0D; For the first time, the adsorption properties of three-component compositions based on peat, sludge and buckwheat husk were studied. The obtained equilibrium humidity of the compositions does not exceed the standard humidity for fuel pellets (is 20%) and is 6 - 7%. Therefore, they can be used for combustion in biomass boilers. The resulting ash can be used for the production of bricks, cement and other building materials. During storage of composite granules in order to prevent loss of their technological properties, it is recommended to maintain humidity at the level of 60 - 70%.

Assessing Soil-like Materials for Ecosystem Services Provided by Constructed Technosols

Urbanization results to a wide spread of Technosols. Various materials are used for Technosols’ construction with a limited attention to their ecosystem services or disservices. The research focuses on the integral assessment of soil-like materials used for Technosols’ construction in Moscow megalopolis from the ecosystem services’ perspective. Four groups of materials (valley peats, sediments, cultural layers, and commercial manufactured soil mixtures) were assessed based on the indicators, which are integral, informative, and cost-effective. Microbial respiration, C-availability, specific respiration, community level physiological profile, and Shannon’ diversity index in the materials were compared to the natural reference to assess and rank the ecosystem services and disservices. The assessment showed that sediments and low-peat mixtures (≤30% of peat in total volume) had a considerably higher capacity to provide C-sequestration, climate regulation and functional diversity services compared to peats and high-peat mixtures. Urban cultural layers provided ecosystem disservices due to pollution by potentially toxic elements and health risks from the pathogenic fungi. Mixtures comprising from the sediments with minor (≤30%) peat addition would have a high potential to increase C-sequestration and to enrich microbial functional diversity. Their implementation in urban landscaping will reduce management costs and increase sustainability of urban soils and ecosystem.

Woody peat addition increases soil organic matter but its mineralization is affected by soil clay in the four degenerated erodible soils

Soil erosion exacerbates the reduction of soil organic matter (SOM) and destruction of soil physical structure in agricultural systems, which seriously threatens agricultural ecological environment and global sustainable agriculture development. Owing to rich SOM and nutrients of woody peat results in it’s widely applied in degraded soil for improving land productivity. But how the impacted of woody peat addition on crop growth and soil organic matter (SOM) in different textured degenerated erodible soils are not well understood. Here, along the latitudinal gradient from north to south of China, four typical regional soils collected in Northeast (black soil), Northwest (loessial soil), Central (lou soil) and South (red soil) of China, where suffered strongly soil erosion. Soil clay content was 37.0%, 16.9%, 29.6%, and 38.5% for the black, loessial, lou, and red soils, respectively. We conducted a plot incubation experiment in a fully ventilated, rainproof outdoor greenhouse for planting wheat (Triticum aestivum L.). The study is aimed to investigate the response of different texture eroded soil to crop growth and physiology, soil evaporation and soil organic matter after woody peat addition. Eight treatments have been designed for four soils with two groups. (i) the control group with no woody peat addition, B0, H0, L0 and R0; (ii) woody peat addition group, BW, HW, LW and RW. Overall, the SOM concentration altered wheat growth characteristic and grain yield in the four typical erosion degraded soils. The highest grain yield of winter wheat is 6.5 ± 1.3 g per plot in B0 and 6.5 ± 1.1 g per plot in BW, and the lowest is 0.4 ± 0.1 g per plot in R0 in red soil. But woody peat addition increased the wheat yield or yield variation, the wheat gain yield increased four times with woody peat addition (RW) than control (R0) in red soil. In addition, the results revealed that the SOM content were increased in black soil by 40.4%, in loessial soil by 40.0%, in lou soil by 101.3%, and in red soil by 94.6% when compared to the control treatments at harvest. From sowing to harvest, SOM decreased by 5.1 ± 1.8 g kg-1 (black soil), 9.9 ± 0.9 g kg-1 (loessial soil), 7.6 ± 1.8 g kg-1 (lou soil), and 6.2 ± 1.0 g kg-1 (red soil) in the soils with woody peat addition. Without woody peat addition, SOM decreased by 5.6 g kg-1 (black soil), 4.7 g kg-1 (lou soil), and 0.6 g kg-1 (red soil), but increased by 0.4 g kg-1 in loessial soil. In conclusion, woody peat addition resulted in wheat yield increasing in the degenerated soils, but it’s significant in the red soil with adequate nutrient supply and increased soil acid buffering capacity. Woody peat addition increased the SOM concentration in the four degenerated soils, but a faster decreasing rate of the ΔSOM in coarse-textured loessial soil than others medium-fine texture soils. Therefore, appropriate woody peat application and clay content is more conducive to the protection of SOM. More deeply research should have been focused on the impact of woody peat addition in coarse-textured soil on the soil environment (such as the clay type, content, and soil priming effect, etc.).

The behavior of antibiotic-resistance genes and their relationships with the bacterial community and heavy metals during sewage sludge composting

The main contributors to antibiotic resistance genes (ARGs) profiles during the composting process under the addition of biochar (BC) and peat (PT) were not fully explored. This study investigated the influence of BC and PT amendment on ARGs fate, the bacterial community and heavy metals in sewage sludge compost. Compared to control, BC and PT declined the total abundances of ARGs by 17.6% and 43.0% after composting. Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria were the dominant phyla across the composting process, among which, members of Firmicutes (mainly Bacillaceae) were the potential hosts for multiple ARGs. BC and PT addition declined the abundance of bacterial pathogens such as Bacteroides and Pseudomonas. Besides, the concentrations of copper (Cu), zinc (Zn) and lead (Pb) were less in BC and PT treatments than control on day 40, and these metals displayed significant positive correlations to sul1 and intI1. Furthermore, variation partitioning analysis (VPA) revealed that the bacterial community exhibited the most contribution to the ARG patterns, as much as 34.0%, followed by heavy metals (10.8%) and intI1 gene (1.5%). These results suggested that biochar and peat can reduce the risks of ARGs in sewage sludge mainly by sharping the bacterial composition.

&lt;i&gt;Erythrina crista-galli&lt;/i&gt; L. e turfa na fitorremediação de cobre no solo

A fitorremediação é uma técnica que utiliza plantas, associada ou não com amenizantes de solo para descontaminar áreas contaminadas. O objetivo do trabalho foi avaliar o uso de turfa e Erythrina crista-galli na fitorremediação de solo contaminado com cobre. O trabalho foi desenvolvido em casa de vegetação por 120 dias, utilizando o delineamento experimental inteiramente casualizado, com seis repetições, em arranjo fatorial (2 x 6): com ausência e presença de turfa (200 mL L-1 de solo) e seis doses de cobre no solo (0, 60, 120, 180, 240, 300 mg kg-1).Os parâmetros avaliados foram: altura das mudas, diâmetro do colo, massa seca radicular e aérea, teores e quantidade acumulada de cobre no sistema radicular e parte aérea, índices de qualidade de Dickson, de tolerância e de translocação. Os resultados evidenciaram que a adição de turfa estimulou o crescimento das mudas de Erythrina crista-galli, porém não agiu como amenizante da contaminação do solo com o cobre. A Erythrina crista-galli apresentou baixo potencial fitoextrator de cobre.