Fraction Of Manure Research Articles

Impact of an Integral Management System with Constructed Wetlands in Pig Slurry Traceability and GHG/NH3 Emissions

The sustainable management of pig slurry (PS) in intensive farms is essential to reduce adverse environmental impacts and reduce the ecological footprint. If not managed properly, PS can release GHG/NH3 gases into the atmosphere and contaminate waters. This study evaluates the impact of an integral management system with physical and biological stages to mitigate the impact of PS. The system resulted in effective PS traceability, studying its physicochemical properties. The synergism in the whole system allowed a decrease in the most analyzed parameters during the autumn, spring, and summer. The pretreatment contributed significantly to obtaining an appreciable percentage of reduction in the constructed wetlands of SS (99–100%), COD (56–87%), TN (50–57%), and PO43− (88–100%). The emission values (g/m2/day) were 0–2.14 (CH4), 0–473.76 (CO2), 0–179.77 (H2O), 0–0.265 (N2O), and 0–0.195 (NH3), highlighting the raw, separated and manure fractions with the highest values. It is concluded that the system proves to be a practical, low-cost, and efficient technique for the treatment of PS. It significantly reduces the concentration of nutrients, and the intercepted byproducts can be valuable for application to the soil. In addition, the system effectively reduces GHG/NH3 emissions in decanted, purified, and wetland PS fractions.

Antibiotic resistance partitioning during on-farm manure separation and high temperature rotary drum composting

Manure application as fertilizer can increase environmental exposure risk, as antibiotics, antibiotic resistance bacteria (ARB), and antibiotic resistant genes (ARGs) can be transmitted to agricultural fields, and adjacent natural systems. Understanding how specific antibiotics and ARGs respond within different manure fractions during on-farm management is limited. The study objective was to conduct a mass flow analysis determining the fate of antibiotic resistance factors (antibiotics, ARGs, and ARB) through solid-liquid separation, with the solid fraction continuing through a bedding recovery unit (BRU) via high temperature rotary composting for use of the manure solids as dairy cow bedding. The results show that most of the manure mass containing the antibiotic resistance factors went untreated following solid-liquid separation, with 95 % of the mass leaving the separator as a liquid and pumped to a storage lagoon for field application and 5 % proceeding to BRU processing. The tetracyclines and tulathromycin sorbed to the manure solids, while the beta lactams, ampicillin, and benzylpenicilloic acid were only found in the liquid fraction. The removal of antibiotic residuals during the BRU composting was insignificant, yet 40 %-73 % of the antibiotics were in the liquid fraction. The BRU composting was 100 % effective in removing the ARB examined. Five of the eight ARGs (intl1, sul1, tetQ, tetX, and tetM) had significant reduction (>95 %) following the BRU composting treatment. While the three other ARGs (tetW, ermB, and bla2) remained constant despite treatment. This study highlighted the importance of examining manure management from a mass balance perspective and understanding antibiotic resistance risk factors.

Влияние свиного навоза жидкой фракции на формирование элементов продуктивности в агрофитоценозе озимого рапса

The purpose of the research is to study the effect of introduction the liquid fraction of pig manure on the productivity of winter rapeseed in the conditions of the Kaliningrad region. The article discusses the results of research conducted in 2018–2022 in the conditions of Pravdinsky municipal district, Kaliningrad region, on the effect of applying pig manure of liquid fraction on the quality of overwintering of winter rapeseed plants, productivity elements (number of productive stems, weight of seeds per plant) and seed yield. Mercedes and Visby hybrids, zoned for North-West region of Russia, were taken as research objects. During the research period, we observed the overwintering of winter rapeseed plants and counted the number of plants per 1 m2 before the onset of the winter period and in early spring, after the plants began to grow, and calculated the percentage of overwintered plants. In variants with the application of organic fertilizers, in most cases, the percentage of overwintered plants was on average 1–5% higher compared to the control. An evaluation of the research results also showed an increase in the number of productive stems of winter rapeseed plants by 1–3 pcs. in variants with the introduction of the liquid fraction of pig manure compared to the control on both hybrids. The mass of seeds collected from one plant was significantly greater in the variants with the introduction of the liquid fraction of pig manure throughout the entire study period. The analysis of yield showed that in the control options the values were lower compared to the options where the liquid fraction of pig manure was used as fertilizer. The increase in yield for Mercedes hybrid ranged from 36 to 79% over the years of research, for Visby hybrid – from 43 to 84%. Accordingly, the introduction of the liquid fraction of pig manure will increase the yield by 1.5–2.0 times.

ТЕОРЕТИЧЕСКИЕ ИССЛЕДОВАНИЯ ДЛИНЫ ПЕРЕМЕЩЕНИЯ СТРУИ ЖИДКОГО НАВОЗА ПРИ ЕГО ПЕРЕМЕШИВАНИИ В НАВОЗОХРАНИЛИЩЕ

There on large livestock farms a nonbedding method of animals’ keeping is common. At such animals’ keeping, liquid and semiliquid manure is obtained. Such manure during storage into three fractions - upper, liquid and lower is stratified. The upper fraction surface contacts with the environment and therefore dries out and forms a crust. This manure heavier part, under the influence of gravity, settles to the manure storage’s bottom, forming a dense layer during prolonged storage. Thus, there in storage manure mass three fractions of different physical-and-mechanical properties are formed, for each of them extraction the different methods are used, by the corresponding machines implementing. As a result, the metal and energy consumption at manure extracting process by the manure storage is increased, and consequently, so as the agricultural products’ cost. The stored manure technological operation’s extracting can be reduced to an energy minimum by a homogeneous mass forming. This can be solved by the farm manure coming into the manure storage facility mixing. This operation can be implemented by the layers’ active movement by hydraulic or mechanical methods organizing. The hydraulic method only if liquid fractions without mechanical impurities presence at the pump entering by the impeller as working organ for they disable it at acting The most widespread mechanical method of manure fractions movement by a propeller agitator, forming a directional flow during rotation is carried out. These theoretical studies results concerning the liquid manure jet movement formed as a result the mixer agitator action in the medium of manure mass stored in a manure storage facility are presented. The relationship between the length of movement of the liquid manure jet, the angle of elevation of the blade’s helical line, this mixer diameter, its angular velocity and the mixer’s inclination in the relative to the horizontal plane has been established.

In the quest for sustainable management of liquid fraction of manure - Insights from a life cycle assessment

To mitigate the risk of eutrophication and minimize adverse environmental impacts, surplus manure in nitrate-vulnerable zones is frequently divided into a liquid and solid fraction. Managing the liquid fraction (LF) typically presents a greater challenge due to its substantial volume. This study aimed to assess the environmental impacts by region and trade-offs of managing surplus LF with inventory data from pilot facilities using a life cycle assessment (LCA). The LF-treatment technologies assessed were (i) nitrification-denitrification (NDN) with field application of effluent (ii) NDN with ammonia stripping and nitric acid scrubbing as a pre-treatment step followed by polishing in constructed wetlands, and (iii) nutrient up-concentration using vacuum evaporation and/or membrane filtration.The LCA results suggested that 60 to 80 % of the environmental impacts occurred locally. Nutrient up-concentration from LF via membrane filtration (reverse osmosis) and vacuum evaporation indicated a better environmental performance, albeit with high uncertainty when compared to the other scenarios. Although ammonia stripping-scrubbing showed environmental benefits, these were offset by high environmental burdens from fugitive N2O emissions and energy demand during NDN. Furthermore, the study identified that managing the effluent after NDN, a source of potassium (K), requires a nuanced approach from policymakers. Firstly, when K fertilization requirements are not met, direct land application of the effluent as a fertigation source can be a viable option. This minimizes the need for synthetic K fertilizer production and its ensuing freshwater ecotoxicity impacts. However, tertiary treatment of NDN effluent via constructed wetlands can be considered to prevent deterioration of soil from the influx of K. Policymakers are encouraged to engage with local stakeholders to tailor solutions based on these trade-offs. Furthermore, future research should focus on the implications of K on soil quality as well as the life span of nutrient up-concentration technologies for LF.

Does Biochar Stabilize the Bioreactive Carbon Fractions of Swine Manure?

Does Biochar Stabilize the Bioreactive Carbon Fractions of Swine Manure?

Biochar from animal manure: A critical assessment on technical feasibility, economic viability, and ecological impact

AbstractAnimal manure has been used to manage soil fertility since the dawn of agriculture. It provides plant nutrients and improves soil fertility. In the last decades, animal husbandry has been significantly expanded globally. Its economics were optimized via the (international) trade of feed, resulting in a surplus of animal manure in areas with intensive livestock farming. Potentially toxic elements (PTEs), pathogenic microorganisms, antibiotic residues, biocides, and other micropollutants in manure threaten animal, human, and environmental health. Hence, manure application in crop fields is increasingly restricted, especially in hotspot regions with intensive livestock activities. Furthermore, ammonia volatilization and greenhouse gas (GHG) emissions during manure storage, field application, and decomposition contribute to air pollution and climate change. Conventional manure management scenarios such as composting and anaerobic digestion partially improve the system but cannot guarantee to eliminate sanitary and contamination risks and only marginally reducing its climate burden. Hence, this review discusses the potential of pyrolysis, the thermochemical conversion under oxygen‐limited conditions as an alternative treatment for animal manure providing energy and biochar. Manure pyrolysis reduces the bioavailability of PTEs, eliminates pathogenic microorganisms and organic micropollutants, and reduces GHG emissions. Pyrolysis also results in the loss of nitrogen, which can be minimized by pretreatment, that is, after removing soluble nitrogen fraction of manure, for example, by digestion and stripping of ammonia–nitrogen or liquid–solid separation. However, conclusions on the effect of manure pyrolysis on crop yield and fertilization efficiencies are hampered by a lack of nutrient mass balances based on livestock unit equivalent comparisons of manure and manure biochar applications. Hence, it is essential to design and conduct experiments in more practically relevant scenarios and depict the observations based on the amount of manure used to produce a certain amount of biochar.

Влияние навозных стоков на почвенные фототрофные микроорганизмы

Soil phototrophic microorganisms (algae, cyanobacteria) play a very important role in functioning of anthropogenic systems. They take an active part in soil self-purification by directly absorbing biogenic elements, as well as by stimulating the activity of mineralizing microorganisms at the expense of disengaged oxygen. The research was carried out at a plough field with sod-podzol soil situated near a large pig-breeding farm. Neutralization took place due to natural microbiological processes during the time of disgorging the liquid fraction in the lagoons. Long-term application of manure runoff from pig-breeding farms into plough soil had an impact on species diversity of phototrophic microorganisms, which was considered in the research. Groups of species tolerant to the impact formed in the soil in course of long-term application of liquid manure fraction. The influence of long-term runoff of manure from pig breeding farms on specious diversity of soil phototrophic microorganisms was assessed. In plough soils affected by liquid manure runoff a group of species tolerant to this impact has formed. Their basis is represented by green algae: Klebsormidium flaccidum, K. nitens, Chlorococcum infusionum, Chlorella vulgaris, as well as by the heterocyst-free cyanobacteria Phormidium autumnale and the diatom alga Hantzschia amphioxys. On the surface of plough soil these species make microscopically marked films, i. e. soil “blooming” takes place. General species diversity of microphototrophs in soil of the experimental site is lower than that of the control site. Jaccard coefficient of the experimental and control sites of the field is 47.8%. Nitrogen-fixing cyanobacteria are not represented in the microphototrophic community; it indicates that the natural microcoenosis is damaged in the plough soils and nitrogen content is high.

Ammonia recovery from organic nitrogen in synthetic dairy manure with a microbial fuel cell

Increasing pressures on the animal and cropland agriculture sectors have led to the realization of problems with animal waste management and ammonia-based fertilizer supply. Bioelectrochemical systems (BES) are a new-age technology that offer a way to address these problems. Microbial fuel cells (MFCs), one type of BES, are traditionally used for electricity generation from microbial degradation of organic matters, but can also be used to recover nutrients from wastes simultaneous with treatment. This research investigated an MFC for ammonia recovery from the organic nitrogen (orgN) fraction of synthetic dairy manure, using the simple amino acid glycine as the orgN source. We used five different synthetic manure compositions to determine their effects on MFC performance, and found minimal sacrifices in performance under orgN conditions when compared to the base condition without orgN. The MFC achieved greater than 90% COD removal in all orgN conditions. Nitrogen (N) removal efficiencies of between 40% and 60% were achieved in orgN conditions, indicating that organic nitrogen can be used as the substrate for ammonia mineralization and further recovery as fertilizer. In addition, we found the MFC was largely populated by electrogenic organisms from the phyla Bacteroidota, Firmicutes, Proteobacteria, and Halobacterota, with organisms in both Bacteroidota and Firmicutes capable of N mineralization present. Lastly, we found that in conditions where orgN is scarce and the only N source provided, microbes preferentially degraded organic matter from other dead organisms, especially as an N source. This increases the concentration of N in the MFC system and introduces important operational constraints for MFCs operated for ammonia recovery from orgN.

Revolutionizing biogas generation: Polyethylene tubular digesters for household pig farms

Manure decomposition from animal waste, including farm sludge, is a significant source of methane (CH4) and carbon dioxide (CO2) emissions, aggravating global warming. Addressing this issue is vital for the environment and pivotal in achieving sustainable development goals by combating pollution from agricultural activities. One promising solution is biogas production, which offers threefold benefits including mitigation of global warming, assurance of energy security, and efficient waste management. This can be achieved by optimizing the process using substrates that yield high biogas output while ensuring low water usage and retention. This study focuses on pig farms' biogas potential of liquid and solid manure fractions performed with laboratory-scale batch digesters and enhanced polyethylene tubular digesters for evaluation. From the screening system, the biogas output from pig slurry resulted in CH4 and CO2 in 45 days, achieving 61.44 and 36.35%, respectively. After the initial screening experiment, polyethylene tubular digesters were implemented for biogas production at household pig farms and produced through fermentation in polyethylene tubular digesters under anaerobic conditions and are mainly composed of CH4 (60–64%) and CO2 (29–38%). This study suggested that the pig slurry could be a reliable biomass energy source for biogas and applicable to householders.

Physico-chemical assessment of on-farm bioconversion of organic waste in dairy farms in context to sustainability and circular bioeconomy

ABSTRACT On a milk-producing dairy farm, milk production is correlated with manure production and the number of cattle, and manure is widely used as a soil fertilizer. However, excessive dairy manure production is linked with greenhouse gas emissions and water quality issues. On-farm planning of manure storage and application to enhance soil nutrients are essential in a circular economy to reduce environmental impact, where manure is not landfilled and incinerated. Instead, it creates a nutrient resource for crops and soil. Dairy manure, which is rich in nutrients, is a valuable fertilizer that contains many nutrients such as nitrogen (N), organic matter (OM), phosphorous (P), Potassium (K) and micronutrients. In this work, a pilot field research was conducted between 2016 and 2018 in various parts of California, USA (San Joaquin Valley, Sacramento Valley, Shasta Cascade, and the North Coast of California) to assess physio-chemical characteristics of solid fractions of dairy manure among various dairy farms. A total of 156 samples were collected from the gut (n = 107) and toe (n = 49) of the manure piles across California for determining total solid (TS), volatile solid (VS), temperature, moisture content and carbon-nitrogen ratio (C: N). Here, using the observations of field study and analysis, we show that C: N, OM and MC of solid fractions of dairy manure vary significantly among dairy farms. The average C: N ratio of manure (26–32) among various regions was close to an ideal C: N value of 24:1 for soil microbes to stimulate nutrient release to crops. Manure pH ranged between 7.0 and 8.0, which was close to an optimal pH range for common crops (6.0–8.0). Moreover, considering less cost and surplus availability, manure will likely continue providing a cost-effective organic fertilizer resource compared to commercial chemical fertilizers.

DISPOSAL OF MANURE AT THE PIGGERY USING BIODESTRUCTORS OF DIFFERENT ORIGIN

The development of biotechnological methods of disposal of pig waste products is relevant at the current stage. However, the high cost of investment and operation of such technologies limits their application. Therefore, owners of pig farms are constantly looking for compromise solutions that would, on the one hand, ensure compliance with technological requirements for manure removal, and on the other hand, not pollute the environment. The purpose of the work is to improve existing technologies and develop innovative approaches to biotechnological methods of manure disposal. Scientific research was carried out at the piggery of Agroprime Holding LLC of the Odesa region with a capacity of 30,000 heads per year. The considered technology of using biological preparations De-Scentase and Complesin for descentization of manure in underground baths, manure storages, manure sites of the complex. The content of gases in the manure subfloor bath of the piggery due to the use of biological preparations was determined. The conducted monitoring of unpleasant scents and harmful gases confirmed the expediency of using new methods of neutralizing unpleasant scents. It was established that the reconstruction of the separator station by installing a metal hangar and a water-dispersion filtration chamber ensured the neutralization and release of scentous gases into the environment and did not affect the ecological state of the environment negatively. On the basis of the conducted research, the method of wide application of the biological preparation for the disposal of manure has been developed. The improved technology of manure disposal at the piggery, which involves the addition of the microbial destructor drug Complesin to underground baths, as well as to manure storages and manure sites, helps to reduce the release of harmful gases and accelerates the disposal of manure. The technology of utilization of liquid and solid fraction of manure by using biological preparation and vermiculture is highlighted. The experience of using equipment for underground application of liquid manure to fields is presented.

The effect of organic fertilizers on the productivity of winter rapeseed in the conditions of the Kaliningrad region

Winter rapeseed is a valuable oilseed and fodder crop. In the conditions of the Kaliningrad region, the cultivation of winter rapeseed is economically profitable, it is one of the leading crops; it occupies from 15 to 30% in the crop rotation. Conducted research in the Pravdinsky municipal district, on the fields of Pravdinskoye pig breeding JSC in 2018-2020. Winter rapeseed is demanding of nutrients throughout the growing season. Livestock farming is actively developing in the Kaliningrad region; therefore, the study into the application of organic fertilizers to increase crop productivity is of current relevance. Swine manure, which is primarily a nitrogen-potassium fertilizer, is a valuable quick-acting fertilizer. Liquid organic fertilizers are applied during the main fertilizing procedure minimizing odor and increasing application efficiency. The aim of the study was to investigate the effect of pig manure fraction on the productivity of winter rapeseed. All research results confirmed statistical data. Based on the results, conclusions were drawn.

MICROBIOLOGICAL ASPECTS OF RECYCLED MANURE USED IN DAIRY COWS BEDDING – REVIEW

The economic and social value of cattle, especially dairy cows, is continuously increasing and is defined by the number of lactations during the production period or the milk yield of the individual itself. A significant influence on dairy production of dairy cows has housing comfort and therefore maintaining the quality parameters of the dairy farm is essential. The decreasing availability and increasing costs of traditional underlining materials have increased interest in finding and using alternative materials for underlaying. In this review, we focus on the separated fraction of livestock manure, which, after hygienization, can be a suitable bedding material for dairy cows. We identify possible negative impacts and risks in the context of human or animal health. This article also identifies pathogenic microorganisms that can initiate inflammation of the mammary glands in dairy cows and thus reduce the quality of final food products. Farmers using recycled livestock manure as bedding, reduce the total amount of nutrients which become part of the manure stream due to no net addition of nutrients in the form of bedding, thus increasing potential compliance with environmental regulations.

Calculation methods of a combined resourcesaving system of manure removal on pig-rearing complexes

Relevance. The use of liquid fraction of pig manure as technical water for manure removal is a resourcesaving solution. Applying this solution in designing combined resource-saving manure removal systems requires calculation and accounting methods for the manure nutrients and suspended matter, which pass into the solid and liquid fractions during manure separation. The study aimed to develop a methodology for calculating the quantity and quality of manure fractions for the case when a part of the liquid fraction would be used in the manure removal system.Methods. Calculations were based on the data from a pig rearing complex located in the Leningrad region, with 65,100 heads on the complex at any one time. The calculation results were compared with the actual values from the protocols of laboratory analyses.Results. The developed methodology will allow the farm to make a more efficient accounting plan for nutrients passing into organic fertilisers. It will also save up to 47 450 tons of clean water for the manure removal system per year.

Quantifying Antibiotic Distribution in Solid and Liquid Fractions of Manure Using a Two-Step, Multi-Residue Antibiotic Extraction.

Antibiotic distribution and analysis within liquid and solid fractions of manure are highly variable due to each compound's respective physiochemical properties. This study developed and evaluated a uniform method extracting 10 antibiotics from 4 antibiotic classes (tetracycline, sulfonamides, macrolides, and β-lactam) from unprocessed manure, solid-liquid separated manure, and composted solids. Through systematic manipulation of previously published liquid chromatography tandem mass spectrometry methods; this study developed an extraction protocol with optimized recovery efficiencies for varied manure substrates. The method includes a two-step, liquid-solid extraction using 10 mL of 0.1 M EDTA-McIlviane buffer followed by 10 mL of methanol. Antibiotics recoveries from unprocessed manure, separated liquids, separated solids, and heat-treated solids using the two-step extraction method had relative standard deviations < 30% for all but ceftiofur. Total antibiotic recoveries were 67-131% for tetracyclines, 56% for sulfonamide, 49-53% for macrolides, and 1.3-66% for β-lactams. This is the first study to use one protocol to assess four classes of antibiotics in liquid and solid manure fractions. This study allowed for more precise risk assessment of antibiotic transport in manure waste stream applied to fields as a liquid or solid compost.

Feedstock analysis, technical and achievable potential of advanced biofuels, renewable gases and recycled carbon fuels for the Greek transport sector until 2050

We find that there is sufficient technical feedstock availability for Greece to reach its medium-term targets on the production and use of advanced biofuels, renewable gases, electrofuels and recycled carbon fuels for the Greek transport sector. Our analysis suggests that the biomass fraction of municipal solid waste, the biomass fraction of industrial waste, animal manure and sewage sludge, tree prunings, carbon dioxide feedstocks from industrial sources and refuse derived fuels/plastics are feedstocks with sufficient availability until 2050 for the production of renewable fuels and gases for the transport sector in Greece. As a rough indicator, if all the technically achievable feedstocks covered in this study are converted into associated advanced fuels (excluding recycled carbon fuels), this could equate to 7% in 2020, 8.2% in 2030, 9.3% in 2040 and 10.3% in 2050 of the total energy consumed in the transport sector. With policy support, the production of biomethane from the biomass fraction of municipal solid waste, hydrotreated vegetable oil and recycled carbon fuels have possibilities in Greece by 2030, while electrofuels and biomethane from other sources have possibilities by 2040 and lignocellulosic ethanol does not have possibilities in the long run due to limited feedstocks and high costs.

A resistome survey across hundreds of freshwater bacterial communities reveals the impacts of veterinary and human antibiotics use.

Our decreasing ability to fight bacterial infections is a major health concern. It is arising due to the evolution of antimicrobial resistance (AMR) in response to the mis- and overuse of antibiotics in both human and veterinary medicine. Lakes integrate watershed processes and thus may act as receptors and reservoirs of antibiotic resistance genes (ARGs) introduced into the watershed by human activities. The resistome - the diversity of ARGs - under varying anthropogenic watershed pressures has been previously studied either focused on few select genes or few lakes. Here, we link the resistome of ~350 lakes sampled across Canada to human watershed activity, trophic status, as well as point sources of ARG pollution including wastewater treatment plants and hospitals in the watershed. A high percentage of the resistance genes detected was either unimpacted by human activity or highly prevalent in pristine lakes, highlighting the role of AMR in microbial ecology in aquatic systems, as well as a pool of genes available for potential horizontal gene transfer to pathogenic species. Nonetheless, watershed agricultural and pasture area significantly impacted the resistome. Moreover, the number of hospitals and the population density in a watershed, the volume of wastewater entering the lake, as well as the fraction of manure applied in the watershed as fertilizer significantly impacted ARG diversity. Together, these findings indicate that lake resistomes are regularly stocked with resistance genes evolved in the context of both veterinary and human antibiotics use and represent reservoirs of ARGs that require further monitoring.

Membrane-covered composting significantly decreases methane emissions and microbial pathogens: Insight into the succession of bacterial and fungal communities

In this study, the effects of semipermeable membrane-covered on methane emissions and potential pathogens during industrial-scale composting of the solid fraction of dairy manure were investigated. The results showed that the oxygen concentration in the membrane-covered group (CT) was maintained above 10 %, and the cumulative methane emission in CT was >99 % lower than that in the control group (CK). Microbial analysis showed that the bacterial genus Thermus and the fungal genus Mycothermus were dominant in CT, and the richness and diversity of the bacterial community were greater than those of the fungal community. At the end of the composting, the relative abundance of potential bacterial pathogens in CT was 32.59 % lower than that in CK, and the relative abundance of potential fungal pathogens in each group was <2 %. Structural equation models revealed that oxygen concentration was a major factor influencing the bacterial diversity in CT, and the increase of oxygen concentration could limit methane emissions by inhibiting the growth of anaerobic bacteria. Therefore, membrane-covered composting could effectively improve compost safety and reduce methane emissions by regulating microbial community structure.

Organic material as supplementation for substrate in papaya seedlings production

Papaya is among the main fruit species produced in Brazil, representing high socioeconomic importance in productive regions. Changes in production methodologies aim to meet market demands and sector sustainability. In this sense, the use of organic compounds has been successfully used in the production of seedlings. The objective of the study was to evaluate the potential use of different sources of organic material for the composition of substrates used in the production of papaya seedlings, identifying the effects on the emergence and development of plants. Therefore, the treatments were composed of different substrates, namely: T1 – Soil; T2 – 75% soil and 25% chicken litter; T3 - 75% soil and 25% earthworm humus; T4 - 75% soil and 25% tanned cattle manure. When evaluating the characteristics, it was found that substrates composed of the fractions of earthworm humus and cattle manure allowed increases in the characteristics of shoot length, number of leaves, leaf area and stem circumference, while the presence of chicken litter interfered negatively on all the variables studied. It was concluded that organic compounds have the potential to favor the production of papaya seedlings. In this sense, the composition of the substrate alters the emergence and development of papaya seedlings, and the use of a fraction of 25% of earthworm humus allows the formation of seedlings with greater vigor, while the use of chicken litter in this same proportion should be avoided.