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1.
Sci Total Environ ; 750: 141188, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182162

RESUMO

Scientists have correlated land application of animal wastes as fertilizer with the feminization of fish. Two questions were asked. 1) Under a worst case scenario when animal waste (layer and roaster litter, or farrowing swine slurry) is applied and tilled in 24 h prior to a surface-runoff producing rainfall, will estrogenic equivalents exceed the Lowest Observable Effect Concentration (LOEC) for fish (10 ng/L)? 2) Can calcium concentrations in runoff, measured using a rapid meter-based method, be used as a sentinel of elevated estrogenic activity? In a 3-yr study wastes were surface-applied and incorporated and 24 h later, 1.5 by 3 m plots were subjected to simulated rainfall and again 1 wk. and 3 wk. later. Nutrients in runoff were also measured, and in year 1 total coliforms and E. coli. were assessed. Except for an initial preliminary test run, runoff from all plots and years never exceeded 10 ng/L E2Eq equivalent. Calcium concentrations in runoff were not related to estrogenicity, negating its use as a sentinel marker. Specific estrogens in animal waste and runoff were identified by mass spectrometry with concentrations in runoff dependant on manure source and timing of rainfall. As expected, total coliform and E. coli concentrations in runoff were increased by the application of layer litter. Concentrations of nutrients in runoff would not be expected to result in surface water concentrations higher than guidelines for protection of aquatic species. Animal wastes applied in quantities appropriate for crop nutrient requirements, tilled into the soil surface, in observance of regulations avoiding application within 24 h of a predicted rain event, should not result in estrogen levels of environmental concern.


Assuntos
Escherichia coli , Esterco , Agricultura , Animais , Fertilizantes , Fósforo , Chuva , Suínos , Movimentos da Água
2.
Sci Total Environ ; 750: 141699, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182212

RESUMO

In the attempt to close nutrient cycles, organic fertilizers and soil improvers are getting interest as renewable P sources for crops. However, both the P availability of these compounds for crops and the underlying mechanisms are not fully understood. In this study composts (n = 8), biochars (n = 5), animal manure and processed animal manure (n = 13), digestates and processed digestates (n = 15) and blends of digestates with compost/animal manure/mineral fertilizers (n = 15) were analyzed for chemical composition, organic matter stability and P use efficiency (PUE). Biodegradability (=holocellulose/lignin ratio) proved to be a good indicator for organic matter stability and can successfully replace time-consuming incubation experiments in standard analyses of organic fertilizers. The PUE of digestates, struvites, animal manure products and blends of digestate with compost/animal manure/mineral fertilizers was determined by the NH4+-N, Mg and Fe content of the organic fertilizers. The PUE can be predicted by PUE = 61.34 + 8.59*NH4+-N/P + 42.25*Mg/P - 8.09*Fe/P (R2 = 0.71). As increasing amounts of NH4+-N and Mg stimulate the formation of soluble struvite crystals, increasing PUE is explained by an increasing amount of P as struvite. The PUE of biochars and composts was determined by the Ca/P and Al content of the organic fertilizers. Here, PUE can be predicted by PUE = 88.87-1.07*Ca/P + 6.08*Al/P (R2 = 0.93). As increasing amounts of Ca stimulate the formation of highly stable apatite crystals, increasing PUE is explained by an increasing amount of P in the form of apatite.


Assuntos
Compostagem , Esterco , Animais , Carvão Vegetal , Fertilizantes/análise , Nitrogênio/análise , Solo , Estruvita
3.
Sci Total Environ ; 753: 142011, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32890881

RESUMO

Reactive nitrogen (Nr) input often induces soil acidification, which may in turn affect bacterial and fungal nitrogen (N) transformations in soil and nitrous oxide (N2O) emissions. However, the interactive effects of soil acidity and Nr on the contributions of bacteria and fungi to N2O emissions remain unclear. We conducted a field experiment to assess the effects of anthropogenic Nr forms (i.e., synthetic N fertilizer and manure) on bacterial and fungal N2O emissions along a soil acidity gradient (soil pH = 6.8, 6.1, 5.2, and 4.2). The abundances and structure of bacterial and fungal communities were analyzed by real-time polymerase chain reaction and high-throughput sequencing techniques, respectively. Soil acidification reduced bacterial but increased fungal contributions to N2O production, corresponding respectively to changes in bacterial and fungal abundance. It also altered bacterial and fungal community structures and soil chemical properties, such as dissolved organic carbon and ammonia concentrations. Structural equation modeling (SEM) analyses showed that the soil properties and fungal community were the most important factors determining bacterial and fungal contributions to N2O emissions, respectively. The fertilizer form markedly affected N2O emissions from bacteria but not from fungi. Compared with synthetic N fertilizer, manure significantly lowered the bacterial contribution to N2O emissions in the soils with pH of 5.2 and 4.2. The manure application significantly increased soil pH but reduced nitrate concentration. The fertilizer form did not significantly alter the bacterial and fungal community structures. The SEM revealed that the fertilizer form affected the bacterial contribution to N2O production by changing the soil chemical properties. Together, these results indicated that soil acidification enhanced fungal dominance for N2O emission, and manure application has limited effects on fungal N2O emission, highlighting the challenges for mitigation of soil N2O emissions under future acid deposition and N enrichment scenarios.


Assuntos
Fertilizantes , Esterco , Agricultura , Bactérias/genética , Fungos , Nitrogênio , Óxido Nitroso/análise , Solo
4.
Sci Total Environ ; 753: 141832, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32891994

RESUMO

Reducing the content of Cd in wheat grains is necessary for human health, especially in alkaline farmland in northern China where a large area of soils is heavily polluted with Cd. A field experiment was conducted to investigate the effects of wheat straw biochar (WB) and maize straw biochar (MB) combined solely with ferrous sulfate (FeSO4) or combined with FeSO4 and pig manure (PFWB and PFMB) on Cd bioavailability in soil and the phytotoxicity of Cd in wheat in an alkaline contaminated soil. The results showed that the application of these treatments decreased the concentrations of CaCl2-extractable Cd by 32.8-60.5% and increased the soil organic matter by 36.8-106.7% compared with those of the control treatment. The acid-soluble fraction of Cd was decreased by 3.7-16.8% but the residual fraction was increased by 1.7-13.7%. Furthermore, the addition of WB and MB increased the soil pH by 0.29 and 0.16 units, respectively, while the other treatments decreased the soil pH by 0.16-0.37 units. The concentrations of Cd in different wheat tissues were decreased in amended soils, and these decreases were positively correlated with CaCl2-extractable Cd and the acid-soluble fraction of Cd. The ability to accumulate Cd was in the order of root>straw>grain. In addition, there was a downward trend in the bio-concentration and translocation factors under different amendments. The amendments of PFWB and PFMB had better efficiency in the immobilization of Cd in soil and the inhibition of Cd uptake of wheat than WB and MB. In addition, the treatments of PFWB and PFMB increased the wheat yield by 14.3-16.2%, and thus have a great application prospect based on the cost-benefit analysis.


Assuntos
Oryza , Poluentes do Solo , Animais , Disponibilidade Biológica , Cádmio/análise , Cádmio/toxicidade , Carvão Vegetal , China , Compostos Ferrosos , Esterco , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Suínos , Triticum
5.
Sci Total Environ ; 753: 142080, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32898812

RESUMO

The use of sulfuric acid (SA) for reducing greenhouse gases (GHGs, mainly CH4) emissions in manure management encounters with problems related with safety issue and increased H2S emissions. In the present study, citric acid (CA) as an alternative to SA was assessed in the lab-scale experiment at various dosages (pH 5.0-7.0), and then confirmed in the pilot-scale tank (effective volume of 30 ton). During 35 d of pig slurry (PS) storage at 30 °C, it was found that the CA addition to initial pH down to 6.5 could lead negligible reduction, while 85-99% and 48-72% reduction of CH4 and H2S emissions were achieved at pH ≤ 6.0, respectively. The similar reduction performance was confirmed (control vs. pH 6.0) in the pilot-scale test, but, interestingly, two times higher CH4 emissions of 123.7 kg CO2 eq./ton PS was detected caused by the automatic temperature increase (≥35 °C). The pH of acidified PS did not exceed 6.5 during the whole storage period, while it was maintained 7.3-7.7 in the control. A continuous AD reactor fed with acidified PS exhibited a higher CH4 yield of 10.0 m3 CH4/ton PS, compared to the control (5.7 m3 CH4/ton PS), due to the preservation of organic matters and added CA. In overall, about 8.5 [(4.4, storage) + (4.1, biogas)] kg of CH4/ton PS was generated from raw PS and it was reduced to 7.8 [(0.7, storage) + (7.1, biogas)] kg of CH4/ton PS by CA-acidification. Despite the carbon footprint for manufacturing CA, it was calculated that GHG reduction of 107 kg CO2 eq./ton PS could be attained by CA-acidification. In terms of economic profit, it was estimated that 6.3 USD/ton PS can be gained by CA-acidification, while it was 2.4 USD/ton PS in case of control.


Assuntos
Biocombustíveis , Gases de Efeito Estufa , Animais , Ácido Cítrico , Esterco/análise , Metano/análise , Suínos
6.
Sci Total Environ ; 752: 142162, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33207525

RESUMO

The present study compared the effects of adding shrimp shell powder (SSP) at four levels comprising 0% (CK), 5% (L), 10% (M), and 15% (H) on the abundance of antibiotic resistance genes (ARGs) and the bacterial community succession during swine manure composting. The relative abundances of 5/11 ARGs were reduced in CK, and 7/11 in H. Moreover, the removal rate was enhanced by adding SSP. Thus, H decreased the total abundance of ARGs by 32.68%, whereas CK increased it by 6.31%. Redundancy analysis indicated that mobile genetic elements (MGEs) (46.6%) and the bacterial community (31.1%) mainly explained the changes in ARGs. H enhanced the removal of MGEs, prolonged the thermophilic phase, stabilized copper and zinc, and retained nitrogen. LEfSe analysis and non-metric multidimensional scaling indicated that the bacterial community changed in the composting process, and it was optimized by H. The abundances of the potential bacterial co-hosts (such as Lactobacillus, Corynebacterium_1, and Ornithinicoccus) of ARGs and MGEs were lower and the decomposition of organic matter was higher in H compared with CK. Thus, composting with 15% SSP can reduce the risk of ARGs and improve the practical value for agronomic application.


Assuntos
Compostagem , Animais , Antibacterianos , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Esterco , Suínos
7.
Sci Total Environ ; 754: 142180, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920410

RESUMO

Residues from hydrogen sulfide (H2S) removal in biogas filters contain sulfur (S) in various forms (sulfate, sulfide, elemental S) that, if properly stored, is potentially valuable as crop fertilizer. We investigated 1) the turnover of the S compounds from filter materials during storage in untreated and digested cattle manure (CM), and 2) the S fertilizer replacement value (SFRV) of the filter materials applied in pure form or mixed manure with and without storage. The S filter materials from four H2S removal processes (biological and physical-chemical) containing mostly sulfate and/or elemental S were added to untreated CM or digested CM and stored at 10 °C for six months. Afterwards, a pot experiment was established to assess the S availability in an oil-seed rape (Brassica napus) crop. Microbial reduction of sulfate into sulfide took place rapidly after 69 days storage of untreated CM. A lower reduction rate was observed in digested CM mixtures. After six months, 68% and 32% of the initial sulfate content were still present in mixtures containing the S filter materials from biological desulfurization with digested CM and untreated CM, respectively. Sulfate reduction was inhibited for 120 days when digested CM was mixed with S saturated solution from an ash filter, probably due to high pH (≥8.2) and redox potential (>-100 mV) levels. Oppositely, elemental S was immediately and simultaneously both reduced and oxidized. Relatively low losses of total S were observed during the present storage conditions. Despite S turnover, the SFRV of CM and digested CM significantly increased from 15-19% (of total S applied) to 56-90% when S filter materials were added. The storage of S filter materials in digested manure reduced the risk of sulfide production and potential S volatilization. The S filter materials were a valuable source of plant-available S.


Assuntos
Sulfeto de Hidrogênio , Esterco , Animais , Biocombustíveis , Reatores Biológicos , Bovinos , Sulfeto de Hidrogênio/análise , Sulfatos , Enxofre
8.
Bioresour Technol ; 319: 124121, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32957045

RESUMO

The study aimed to identify the preference of pathways of humus formation. Five lab-scale composting experiments were established: the control (CK), montmorillonite addition (M), illite addition (I), thermal treatment montmorillonite addition (M-) and thermal treatment illite addition (I-). Results showed humus content was increased by 11.5%, 39.3%, 37.2%, 30.9% and 27.6% during CK, M-, M, I- and I composting. Meanwhile, Redundancy analysis indicated the bands of bacteria community related to humic acid (HA) were more abundant in the M- and I- treatments. Furthermore, structural equation model and variance partitioning analysis demonstrated that M- and I- treatments promoted precursors to synthesize HA by coordinated regulation of biotic pathway and abiotic pathway, the increase of HA in the M and I treatments mainly through the abiotic pathway. In summary, an effective method was proposed to improve humus production by adjusting the preference of biotic and abiotic pathways of humus formation.


Assuntos
Compostagem , Animais , Bentonita , Galinhas , Substâncias Húmicas , Esterco , Minerais , Solo
9.
Bioresour Technol ; 319: 124120, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32957049

RESUMO

This study examined how the addition of modified cornstalk biochar (CB) affected ammonia (NH3) emissions during composting. Four treatments were established, including a control (CK) with layer manure and sawdust only, and the CK mixtures adding 10% HNO3 CB (NA), 10% H2O2 CB (HP) and 10% HNO3- H2O2 CB (MI). As the results showed, NH3 emissions was reduced by 47.83% (NA), 61.69% (HP) and 45.69% (MI) when the modified CB used as a compost additive (P < 0.05). According to the data analysis, the addition of modified CB significantly increased the number of ammonia-oxidizing bacteria (AOB), inhibited urease activity and decreased the abundance of narG and nirS at rising temperatures and high temperatures (P < 0.05). Redundancy analysis demonstrated a negative correlation between NH3 emissions and AOB and a positive correlation with urease activity, narG and nirS. Thus, the modified CB helped reduce NH3 emissions by regulating nitrification processes.


Assuntos
Compostagem , Amônia/análise , Bactérias , Carvão Vegetal , Peróxido de Hidrogênio , Esterco , Nitrogênio/análise , Oxirredução , Solo , Urease
10.
Bioresour Technol ; 319: 124136, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32966968

RESUMO

Vermitransformation of coir pith (CP) into enriched vermifertilizer has been achieved by amending a green-manure plant, Sesbania sesban (SS) for the first time, and cow dung (CD) in five different combinations: T1(1:0:1), T2(4:3:3), T3(5:3:2), T4(5:4:1) and T5(1:1:0). The substrates were 28 days precomposted with Pleurotus sajor-caju followed by 50 days vermicomposting with Eisenia fetida and Eudrilus eugeniae. Results showed a significant reduction in cellulose, lignin, organic carbon, C/N ratio, C/P ratio and an increase in plant nutrients compared to control. The fertilization index and efficiency of nutrient recovery rate were higher in SS and CD amended CP vermicompost, with a maximum in T2(4:3:3) for E. fetida and T3(5:3:2) for E. eugeniae. The activity of dehydrogenase, urease and cellulase, and phytotoxicity assays further revealed vermicompost stability. The study concludes that T2(4:3:3) and T3(5:3:2) combinations respectively for E. fetida and E. eugeniae is suitable for vermitransformation of CP into enriched vermicompost.


Assuntos
Esterco , Oligoquetos , Animais , Bovinos , Feminino , Resíduos Perigosos , Resíduos Industriais , Lignina/análogos & derivados , Solo
11.
Bioresour Technol ; 319: 124111, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32971335

RESUMO

Thermophilic microorganisms play vital roles in the composting process. To elucidate how raw materials affect thermophilic microbial community composition and their interactions, the succession of thermophilic bacterial and fungal communities were monitored in reed straw co-composting with four common nitrogen-rich substrates. The results of high-throughput sequencing showed that raw materials and composting process significantly changed bacterial and fungal community composition. Firmicutes and Actinobacteria drove the assembly of bacterial communities, while Ascomycetes drove the assembly of fungal communities. Network analysis indicated that during the composting process, the addition of nitrogen-rich sources abundant in easily degradable substances promoted the complexity of thermophilic microbial network. Moreover, microorganisms mainly exhibited synergistic effects, and inter-kingdom competition was more intense than intra-kingdom competition. Notably, rare species play essential roles in maintaining the network construction. Our findings provided novel insights into thermophilic microbial community assembly and their co-occurrence networks during the composting process.


Assuntos
Compostagem , Lignina , Esterco , Nitrogênio , Solo
12.
Bioresour Technol ; 319: 124139, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32971337

RESUMO

This study was focused on the changes of antibiotic resistance genes (ARGs) and their potential host bacteria during the swine manure composting on sub-scale farms. Eight target ARGs increased 427% on average, with a trend of increase at early stage and decrease at later stage, and the main reduction stage appeared in maturity stage. The abundance of ARGs was mainly affected by the community succession of potential host bacteria. Composting could reduce the abundance of potential host bacteria of ARGs as well as pathogens such as Pseudomonas, and reduce the environmental risks of swine manure. N/C and S levels had a positive effect on the potential host of most ARGs. Prolonging the maturity period would inhibit the growth of potential host bacteria of ARGs during composting, therefore inhibiting the transmission of ARGs.


Assuntos
Compostagem , Animais , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Fazendas , Genes Bacterianos/genética , Esterco , Suínos
13.
Bioresour Technol ; 319: 124149, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32979596

RESUMO

This study investigated the effect of thermal pretreatment (TP) on the lignocellulose degradation and humification during dairy manure composting and the underlying microbial mechanism. The results showed that TP accelerated temperature rise and elevated composting temperature by increasing 26% initial content of simple organics. The degradation of cellulose, hemicellulose and lignin was 78, 10 and 109% higher in thermal pretreatment composting (TPC) than traditional composting (TC), respectively. Moreover, TP significantly improved the humification degree of composts, as indicated by 14 and 38% higher humus content and humification indexes in TPC, respectively. 16S rRNA sequencing showed that TP increased the relative abundance of thermophilic bacteria in TPC, of which Thermobifida, Planifilum, Truepera and Thermomonospora were potentially involved in lignocellulose biodegradation and humification. Canonical correspondence analysis revealed that TP changed the main factor determining the bacterial community evolution from dissolved organic carbon (DOC) in TC to temperature in TPC.


Assuntos
Compostagem , Lignina , Esterco , RNA Ribossômico 16S/genética , Solo
14.
Bioresour Technol ; 319: 124142, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32987278

RESUMO

This study investigated oxytetracycline (OTC) effects on nitrogen (N) transformation and bacterial community diversity during chicken manure composting. The addition of OTC inhibited nitrifying bacteria, resulted in a decrease in the transformation of NH4+-N to NO3--N during composting, and affected in the order T3 (32.76%) > T2 (28.76%) > T1 (17.02%) > CK. The OTC could act as an inhibitor against core microbial growth, leading to a delay effect during composting. 16S rRNA sequencing was employed for the functional prediction, and results indicated the bacterial community related to N transformation reconstructed under OTC stress. The core microorganisms were changed after OTC addition, with the emergence of Bacillus and Thermobifida, which could inhibit the N transformation by network analysis. Therefore, core microorganisms could be regulated to reduce the negative of OTC impacts on N transformation and thus reduce N loss during composting.


Assuntos
Compostagem , Microbiota , Oxitetraciclina , Animais , Esterco , Nitrogênio , RNA Ribossômico 16S/genética , Solo
15.
Bioresour Technol ; 319: 124155, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33035862

RESUMO

In this work, agricultural wastes were treated by composting in an ectopic fermentation bed system (EFBS) with a continuous nitrogen addition technique. With decreasing of NH4+-N concentration and increasing of NO3--N concentration were observed, and activities of protease, urease and nitrate reductase changed significantly during the fermentation process. To elucidate the key microbes and their function in nitrogen-transforming, microbial diversity and clusters of orthologous groups (COGs) in composting materials were evaluated using metagenomic technology. Comparing with ammonification, the COGs involved in nitrification and denitrification were predominant in the composts. The correlation heatmap revealed that Streptomyces predominant in ammonification was significantly affected by contents of N, NH4+-N and NO3--N. Meanwhile, ammonia-oxidizing archaea (AOA) had a positive relationship with moisture. The most abundant genera in denitrification had positive relationships with N and NO3--N. The results indicated that EFBS had functionally diverse microbes and COGs for NH3 removal.


Assuntos
Compostagem , Microbiota , Amônia , Animais , Fermentação , Esterco , Nitrificação , Nitrogênio , Solo , Suínos
16.
Bioresour Technol ; 319: 124197, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33038654

RESUMO

The performance of biochar mediated anaerobic co-digestion (co-AD) of corn stover (CS) and chicken manure (CM) using continuous stirred tank reactor (CSTR) was studied. Results showed that urea pretreated CS (UPCS) and biochar addition in anaerobic digestion (AD) system can improve co-AD. The effect of urea pretreatment is similar to that of biochar addition, and their synergistic effect was apparent under medium and high OLR conditions. When the OLR was 4.2 and 6.3 g VS/L/d, the biochar mediated UPCS/CM co-AD operated stably with the VMP of 2.160 and 1.616 L/L/d, and VMP of the biochar mediated UPCS /CM were 32.8%-89.6% and 27.8%-96.4% higher than other reactors, respectively. The results reveal that urea pretreatment and biochar addition promoted AD process through strengthening the buffer capacity system established by ammonia nitrogen and volatile fatty acids and improving the degradation of lignocellulosic biomass.


Assuntos
Esterco , Zea mays , Anaerobiose , Animais , Biocombustíveis , Reatores Biológicos , Carvão Vegetal , Galinhas , Metano , Ureia
17.
J Environ Manage ; 277: 111395, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33038671

RESUMO

The multi-sectoral metabolisms of substance and energy in rural areas are complex, whose optimization is the key to realize resource recycling and energy cascade utilization. Through Substance Flow Analysis (SFA), we establish a Multi-sectoral Metabolism Analysis Model specific to rural areas (MMAM-rural), and investigated the multi-sectoral metabolisms of Liujiadian Town in Beijing city. We simulate the water, energy and nutrients (carbon, nitrogen and phosphorus) metabolisms of a total of five sectors (water, waste management, livestock husbandry, forestry, and residential sectors), and identify the key metabolic flows significant for improving regional metabolism performance of Liujiadian Town. For further technical path optimization, we construct an index system made up of resource utilization efficiency, environmental burden of production and recycling efficiency, and adopt Scenario Analysis to evaluate the water-energy-nutrient metabolism performance under multiple technical scenarios different from disposals of agricultural waste, livestock and poultry manure, and domestic waste. Results show that, for agricultural wastes disposal, the combination scenario of edible fungi cultivation, anaerobic fermentation and aerobic composting is optimal. For livestock and poultry manure, all pig manure should be composted after anaerobic fermentation. For domestic wastes, food wastes require anaerobic fermentation and composting for optimization. Our study provides a model to evaluate metabolism performance of water-energy-nutrient nexus in rural areas, and raises solutions for optimization in the process of eco-town construction.


Assuntos
Esterco , Água , Animais , Pequim , Cidades , Esterco/análise , Nitrogênio , Nutrientes , Suínos
18.
Sci Total Environ ; 750: 141719, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32858285

RESUMO

Organic amendments (OAs) application is a practical strategy to improve soil organic carbon (SOC) in agriculture. The present study evaluated the impact of different OAs on the transformation of carbon and the dynamics of microorganisms in a 77-day incubation experiment. The OA treatments applied included wheat straw (U + WS), pig manure (U + PM), compost (U + CP), and improved compost (U + IC), and the no amendment group was the CK. After incubation, the SOC increased significantly in the U + WS group, but the other OA treatments had no significant effect relative to the CK. Among the OA treatments, U + CP and U + IC had lower CO2-C cumulative mineralization and the highest humification of dissolved organic carbon (DOC). U + PM had the lowest SOC content and the lowest aromatization of DOC. Redundancy analyses (RDA) showed that the CO2-C cumulative mineralization directly influenced the DOC, extracted organic carbon (EOC) and microbial biomass carbon (MBC) in all treatments. Proteobacteria positively correlated with SOC and MBC, Bacteroidetes were significantly related to DOC, and Gemmatimonadetes had a significant negative relationship with CO2-C cumulative mineralization. These results showed that U + CP and U + IC were more conducive to carbon sequestration, and U + PM was the most unfavourable during the incubation. Wheat straw played an important role in the steady improvement of the SOC.


Assuntos
Carbono , Solo , Agricultura , Animais , Sequestro de Carbono , Esterco , Microbiologia do Solo , Suínos
19.
Sci Total Environ ; 750: 141422, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32858290

RESUMO

Glyphosate-based herbicides (GBHs) are the most frequently used herbicides globally. They were launched as a safe solution for weed control, but recently, an increasing number of studies have shown the existence of GBH residues and highlighted the associated risks they pose throughout ecosystems. Conventional agricultural practices often include the use of GBHs, and the use of glyphosate-resistant genetically modified crops is largely based on the application of glyphosate, which increases the likelihood of its residues ending up in animal feed. These residues persist throughout the digestive process of production animals and accumulate in their excretion products. The poultry industry, in particular, is rapidly growing, and excreted products are used as plant fertilizers in line with circular food economy practices. We studied the potential effects of unintentional glyphosate contamination on an agronomically important forage grass, meadow fescue (Festuca pratensis) and a horticulturally important strawberry (Fragaria x vescana) using glyphosate residues containing poultry manure as a plant fertilizer in a common garden experiment. Glyphosate in the manure decreased plant growth in both species and vegetative reproduction in F. x vescana. Furthermore, our results indicate that glyphosate residues in organic fertilizers might have indirect effects on sexual reproduction in F. pratensis and herbivory in F. x vescana because they positively correlate with plant size. Our results highlight that glyphosate can be unintentionally spread via organic fertilizer, counteracting its ability to promote plant growth.


Assuntos
Fertilizantes , Herbicidas , Animais , Produtos Agrícolas/genética , Ecossistema , Glicina/análogos & derivados , Herbicidas/toxicidade , Esterco , Plantas Geneticamente Modificadas
20.
An Acad Bras Cienc ; 92(suppl 2): e20180758, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33146271

RESUMO

The production model used in Brazilian pig farms promotes a concentration of animals in small territorial extensions, causing difficulty in disposing of the manure generated, since the economically viable alternative is to use this as an agricultural fertilizer. The objective was to evaluate the effect of swine manure doses on the biological and behavioral parameters in Folsomia candida by ecotoxicological tests. An Ultisol, Oxisol and Tropical Artificial Soil (TAS) were contaminated with 0, 25, 50, 75 and 100 m3 ha-1 of swine manure, to which springtails were exposed for evaluation of mortality, and the doses 0, 10, 15, 20 and 25 m3 ha-1 of swine manure to evaluated reproduction and avoidance. Lethality was observed in all doses as well as all soils, indicating toxicity of the manure. In the reproduction tests dose since 10 m3 ha-1 caused a reduction of juveniles in all soils. Avoidance behavior was observed in all doses of the Oxisol treatments and at 20 and 25 m3 ha-1 in Ultisol treatments. However, in TAS occurred not avoidance response of F. candida. We conclude that the swine manure was toxic to F. candida and the toxicity is dependent on the soil characteristics and the manure concentrations applied.


Assuntos
Artrópodes , Poluentes do Solo , Animais , Brasil , Esterco , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Suínos
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