Mature Vermicompost Research Articles

The bacterial community structures in response to the gut passage of earthworm (Eisenia fetida) feeding on cow dung and domestic sludge: Illumina high-throughput sequencing-based data analysis.

Diets are shown to be capable of shaping the gut microbiota of earthworm, while the effects of distinct foods on bacterial communities of different digestive tracts of earthworm are unknown. For this purpose, cow dung (CD) and domestic sludge (DS) were chosen as diets for earthworms (Eisenia fetida), and different gut contents, namely gizzard+foregut area, hindgut, and mature vermi-compost were sampled for Illumina sequencing analysis. We found that there existed significant reductions in bacterial diversity and abundance in the gizzard+foregut area, where there were stable bacteria with the ability of biodegradation of xenobiotics, such as Amycolatopsis, Methylobacterium, Ralstonia, Ochrobactrum, and Sphingomonas. The decreases could be recovered in the hindgut and mature vermi-compost to different extents, suggesting that a bottleneck effect on the bacterial community occurred in the gizzard+foregut area. Beta-Proteobacteria was the most abundant subclass regardless of the different diets, and bacteria affiliated with gamma-, delta- and epsilon-subclasses were taken as food by the earthworms. Vermi-composts based on the various diets should be used differently according to different aims.

Enriched pressmud vermicompost production with green manure plants using Eudrilus eugeniae

Vermicomposting of pressmud with cow dung and nitrogenous green manures (Gliricidia sepium and Leucaena leucocephala) was carried out using Eudrilus eugeniae (50 days). The reduction in pH, total organic carbon, C/N ratio, water-soluble organic carbon (Cws)/Norg and C/P ratios, and a pronounced increase in NPK contents and microbial population in vermicompost were observed. An enhanced TKN of 3.80% and 3.45% was recorded in vermicomposts of pressmud + cow dung + L. leucocephala (2:1:1) and pressmud + cow dung + G. sepium (2:1:1) respectively. The C/N and Cws/Norg ratios in vermicompost ranged from 11.86 to 16.66 and 0.53 to 1.33, respectively. The activity of dehydrogenase, urease, acid and alkaline phosphatase declined towards the end, indicating the progression of vermicompost maturity. The pressmud and green manure substrates promoted more biomass of E. eugeniae, while cow dung with green manure combination favored reproduction. The amendment of cow dung and green manure plants to pressmud (2:1:1 ratio) results in nutrient-enriched vermicompost production.

Analysis and advanced characterization of municipal solid waste vermicompost maturity for a green environment

Rapid demographic expansion along with increasing urbanization has aggravated the problem of solid waste management. Therefore, scientists are seeking waste management methods that are eco-friendly, cost effective and produce immediate results. In the developing world, municipal solid waste (MSW) contains mostly organic substances, therefore vermicomposting could be a better and cost-effective option for waste management. In this study, vermicomposting of organic portion of MSW with cow dung (additive) was performed using Eisenia fetida. The results showed significant (p < 0.001) decline in pH (13.17%), TOC (21.70%), C: N (62.53%) and C: P (57.66%) ratios, whilst total N (108.9%), P (84.89%) and K (21.85%) content increased (p < 0.001) in matured vermicompost. Different enzymatic activities declined during termination phase of vermicomposting experiment with maximum decrease of 41.72 (p = 0.002) and 39.56% (p = 0.001) in protease and β-glucosidase, respectively. FT-IR, TGA, DSC and SEM studies suggested that final vermicompost was more stabilized as compared to initial waste mixture, characterized by reduced levels of aliphatic materials, carbohydrates and increase in aromatic groups possibly due to biosynthesis of humic substances. Both, the conventional (physicochemical and enzyme activity) and advanced techniques depict maturity and stability of the ready vermicompost. However, FT-IR, TGA, DSC and SEM were proved to be more promising, fast and reliable techniques over conventional analyses.

Co-vermicomposting of Wastewater Treatment Plant Sludge and Yard Waste: Investigation of Operation Parameters

Million tons of domestic wastewater treatment plant sludge is produced in each year. Since it increases the volume of the landfill area, the treatment of sludge with vermicomposting is an attractive approach. Vermicomposting of domestic wastewater treatment plant sludge with yard waste was carried out using Eisenia Fetida for 60 days. The effects of Bio-One™ (liquid microbial fertilizer), additives (different mature vermicomposts), recirculation and ventilation on decomposition rate of composting were investigated for composting mixtures. Temperature, moisture content (MC), organic matter (OM), pH, electrical conductivity (EC), total carbon (TOC) and total kjeldahl nitrogen (TKN) were monitored during the composting process. In addition, phototoxicity level and worm number changes of the mixtures were determined. C/N and OM value decreases ranged between 27.56–63.77% and 15.15–43.12%, respectively. It was concluded that vermicomposting process was faster than traditional composting process in terms of decomposition of organic matter. The result C/N ratio was more suitable to use it as soil remedial material in vermicomposting process. It has been shown that Bio-One™ addition has a positive effect on the acceleration of the process. It has been found that the process of recirculation some of the leachate formed during the vermicomposting process is an advantageous. It has been determined that mature vermicompost addition is an effective method. The final worm numbers were higher (except ventilation conditions) than the initial. The positive results of the plant growth tests on the final products in all cases may indicate that the products will not cause any toxic effect in the use as soil conditioning material.

Characterization of humic acids in a continuous-feeding vermicomposting system with horse manure

The increasing numbers of kept horses create problems with processing horse manure as important local waste. This work was focused on horse manure vermicomposting in a real-field continuous-feeding system under controlled conditions, and on the complex study of the maturity and stability of the produced vermicompost. Commonly used simple indicators such as the C/N ratio, N-NH4+/N-NO3− ratio, DOC or ion exchange capacity, and also more advanced spectroscopic and thermoanalytic techniques were used and applied on the humic substances isolated from the vermicompost during its maturation (12 months in total). When compared with the original horse manure, vermicomposting decreased the aliphatic, protein-like, and polysaccharide humic components, whereas vermicomposting increased the aromaticity and contents of oxygen-containing functional groups. The typical tryptophan-like fluorophores in the manure, corresponding to the freshly produced organic matter of biological or microbial origin, were progressively transformed to humic-like fluorophores during vermicomposting. The most thermally labile humic fraction disappeared quickly during the very early vermicomposting stages. The results of spectroscopic and thermogravimetric analyses suggest that stable and mature vermicompost was produced after 6–9 months of vermicomposting, which was also supported by biologically-based maturity indicators.

Vermicomposting of paper industry sludge with cowdung and green manure plants using Eisenia fetida: A viable option for cleaner and enriched vermicompost production

Vermicomposting of paper mill sludge (PMS) with cowdung (CD) and green manure plants, Tephrosia purpurea (TEP) and Gliricidia sepium (GLS) in different combinations (21 days pre-decomposed) was carried out using Eisenia fetida (60 days). Results revealed that electrical conductivity, total Kjeldahl nitrogen, total phosphorus, total potassium and NNO3- levels were higher in vermicomposts generated from PMS + CD with TEP/GLS combination than in composts prepared without earthworms; while total organic carbon, C/N ratio, C/P ratio and organic matter content depicted significant reduction. C/N and C/P of final vermicompost ranged from 13.45 to 22.33 and 15.54 to 28.56 respectively. The total microbial population was significantly higher in CD + TEP/GLS vermicomposts (P < 0.001). Activities of dehydrogenase, urease, acid and alkaline phosphatases during vermicomposting elevated initially and then declined, indicating vermicompost maturity. Also, the seed germination tests with maize and cowpea in vermicomposts of PMS, CD and green manure combination support the maturity and less phytotoxic nature of vermicompost produced. Growth and reproduction of E. fetida explained that the addition of CD along with GLS/TEP significantly created an impact on bioconversion of PMS. The PMS + CD + TEP/GLS (2:1:1 ratio) combination can be used for sustainable PMS utilization through vermicomposting, and enriched vermicompost can also be obtained by the addition of green manure plants.

Dynamics of organic matter decomposition during vermicomposting of banana stem waste using Eisenia fetida

A better understanding of how dynamics of physical and chemical changes occur during vermicomposting process would be helpful for determining the stability and maturity of vermicompost. For improving the knowledge about this issue several instrumental techniques were used in the present study to analyse the physical and chemical changes as a function of vermicomposting time of banana stem waste (BS) spiked with cow dung (CD) in different proportions using earthworm Eisenia fetida. Chemical analysis by ICP-AES showed gradual increase in the plant nutrients (P, Ca, K, Mg, Fe) up to 60 day of vermicomposting in all the treatments. But among different treatments, K, Mg and Fe were considerably higher in the BS2CD1 blend. The FTIR showed strong NO stretching vibration with increasing BS content signifying the presence of nitrate in the final compost. The TG analysis of final BS-CD composts described the lower mass loss (52–55%) in the final compared to the initial stage due to high level of humification by earthworms. The maturity of the final compost was confirmed by DSC analysis which exhibited lowering of relative intensity of exothermic peaks related to the easily degradable material at 320–330 °C and complex organic moieties at 495–530 °C. Decrease in the humification index (Q4/6, Q2/4, Q2/6) at 60 day confirmed the stability of vermicomposts. All the treatments showed <2 mg CO2-C g−1 vermicompost C day−1 respiration rates and >70% germination indices (GI) for rice and pea seeds. These findings defined a clear comparison between the treatments during vermicomposting in terms of stability and maturity and revealed that BS2CD1 can be utilized as nutrient-rich stable compost for enhanced crop production.

Changes in structure and function of bacterial communities during coconut leaf vermicomposting.

To understand bacterial community dynamics during the vermicomposting of lignin-rich coconut leaves using an indigenous isolate of an epigeic earthworm, Eudrilus sp., we employed amplicon-based pyrosequencing of the V1 to V3 region of the 16S rRNA genes. Total community DNA was isolated from two separate vermicomposting tanks in triplicate at four different stages of the process: pre-decomposition (15th day), initial vermicomposting (45th day), 50-70% vermicomposting (75th day) and mature vermicompost (105th day). Alpha diversity measurements revealed an increase in bacterial diversity till the 75th day, which then declined in the mature vermicompost. Beta diversity comparisons showed formation of distinct, stage-specific communities. In terms of relative abundance, the Acidobacteria, Actinobacteria, Chloroflexi, Gemmatimonadetes, Nitrospirae, Planctomycetes, TM7 and WS3 groups increased until the 50-70% vermicomposting stage (p=0.05). During the same time, the abundance of Bacteroidetes and Proteobacteria decreased. In contrast, the levels of Firmicutes increased throughout the 105-day vermicomposting process. The distribution of the most abundant OTUs revealed that each stage of the vermicomposting process possessed its own unique microbiome. Predictions based on the OTUs present by PICRUSt suggested a functional shift in the microbiome during vermicomposting. Enzymes and pathways of lipid and lignin metabolism were predicted to be initially abundant, but by the end of the process, biosynthesis of secondary metabolites and plant beneficial properties were enriched. The study revealed that bacterial communities undergo a continuous change throughout the vermicomposting process and that certain OTUs associated with specific stages could be targets for further improvements in the process.

VERMICOMPOST AS AN ALTERNATIVE OF MANAGEMENT FOR WATER HYACINTH

Aquatic weeds, such as Eichhornia crassipes (Mart.) Solms (water hyacinth) can be used as raw material for vermicompost. Vermicompost is the product of microbial decomposition of organic waste through the digestive tracts of earthworms. The aim of this work was to use water hyacinth to obtain stable and mature vermicompost. Three treatments were performed for vermicomposting, treatment one with 100 % of water hyacinth, treatment two with 100 % of cow manure and treatment three with 50 % of water hyacinth and 50 % of cow manure. The earthworm used was Eisenia fetida Savigny. Vermicompost was characterized physically, chemically and microbiologically, and measured by indexes of stability and maturity, as well, metal concentrations were detemined. Germination index was obtained with four different seeds: radish ( Raphanus sativus L.), lettuce ( Lactuca sativa L.), cucumber ( Cucumis spp.) and zucchini ( Cucurbita pepo L.). The three different treatments for vermicompost were stable and mature after 110 days with 90 % of E. fetida survival in each treatment . The vermicompost with water hyacinth and water hyacinth plus cow manure had a high pH and electrical conductivity. Radish had the best performance in germination index and the three vermicompost were rich in metals. We conclude that vermicomposting is suitable for managing water hyacinth because it can produce a stable, mature, and rich in nutrients vermicompost, which is useful as organic fertilizer or soil improver.

Stocking Density Optimization for Enhanced Bioconversion of Fly Ash Enriched Vermicompost.

Although it is widely agreed that stocking density critically affects the rate of vermicomposting, there is no established stocking density for mixtures of fly ash and other waste materials. This study sought to optimize (Savigny, 1826) stocking density for effective biodegradation and nutrient release in a fly ash-cow dung-waste paper (FCP) mixture. Four stocking densities of 0, 12.5, 25, and 37.5 g worms kg were evaluated. Although the 12.5, 25, and 37.5 g worms kg treatments all resulted in a mature vermicompost, stocking densities of 25 and 37.5 g worms kg resulted in faster maturity, higher humification parameters, and a significantly lower final C/N ratio (range 11.1-10.4). The activity of β-glucosidase and fluorescein diacetate hydrolysis enzymes showed faster stabilization at stocking densities of 25 and 37.5 g worms kg, indicating compost stability and maturity. Similarly, a stocking density of 25 g worms kg resulted in the highest release of Olsen-extractable P and (NO + NO)-N contents. The 0-, 12.5-, 25-, and 37.5-g treatments resulted in net Olsen P increases of 16.3, 38.9, 61.0, and 53.0%, respectively, after 10 wk. Although compost maturity could be attained at stocking densities of 12.5 g worms kg, for faster production of humified and nutrient-rich FCP vermicompost, a stocking density of 25 g worms kg seems most appropriate.

Characterization of Matured Vermicompost Derived from Valorization of Palm Oil Mill Byproduct.

The valorization process involves transforming low-value materials such as wastes into high-value-added products. The current study aims to determine the potential of using a valorization process such as vermicomposting technology to convert palm oil mill byproduct, namely, decanter cake (DC), into organic fertilizer or vermicompost. The maturity of the vermicompost was characterized through various chemical and instrumental characterization to ensure the end product was safe and beneficial for agricultural application. The vermicomposting of DC showed significantly higher nutrient recovery and decreases in C:N ratio in comparison with the controls, particularly in the treatment with 2 parts DC and 1 part rice straw (w/w) (2DC:1RS). 2DC:1RS vermicompost had a final C:N ratio of 9.03 ± 0.12 and reasonably high levels of calcium (1.13 ± 0.05 g/kg), potassium (25.47 ± 0.32 g/kg), magnesium (4.87 ± 0.19 g/kg), sodium (7.40 ± 0.03 g/kg), and phosphorus (3.62 ± 0.27 g/kg). In addition, instrumental characterization also revealed a higher degree of maturity in the vermicompost. Ratios of 2921:1633 and DTG2:DTG3 also showed significant linear correlations with the C:N ratio, implying that those ratios could be used to characterize the progression of vermicompost maturity during the valorization process of DC.

Molecular characteristics of humic acids isolated from vermicomposts and their relationship to bioactivity.

Vermitechnology is an effective composting method, which transforms biomass into nutrient-rich organic fertilizer. Mature vermicompost is a renewable organic product containing humic substances with high biological activity. The aim of this study was to assess the chemical characteristics and the bioactivity of humic acids isolated from different vermicomposts produced with either cattle manure, sugar cane bagasse, sunflower cake from seed oil extraction, or filter cake from a sugar cane factory. More than 200 different molecules were found, and it was possible to identify chemical markers on humic acids according to the nature of the organic source. The large hydrophobic character of humic extracts and the preservation of altered lignin derivatives confer to humic acids the ability to induce lateral root emergence in maize seedlings. Humic acid-like substances extracted from plant biomass residues represent an additional valuable product of vermicomposting that can be used as a plant growth promoter.

Towards understanding the stabilization process in vermicomposting using PARAFAC analysis of fluorescence spectra

In this study, fluorescence excitation–emission matrix (EEM) combined with parallel factor analysis (PARAFAC) was employed to trace the behavior of water extractable organic matter and assess the stabilization process during vermicomposting of sewage sludge and cattle dung. Experiments using different mixing ratios of sewage sludge and cattle dung were conducted using Eisenia fetida. The results showed that vermicomposting reduced the DOC, DOC/DON ratio and ammonia, while increased the nitrate content. A three-component model containing two humic-like materials (components 1 and 2) and a protein-like material (component 3) was successfully developed using PARAFAC analysis. Moreover, the initial waste composition had a significant effect on the distribution of each component and the addition of cattle dung improved the stability of sewage sludge in vermicomposting. The PARAFAC results also indicated that protein-like materials were degraded and humic acid-like compounds were evolved during vermicomposting. Pearson correlation analysis showed that components 2 and 3 are more suitable to assess vermicompost maturity than component 1. In all, EEM–PARAFAC can be used to track organic transformation and assess biological stability during the vermicomposting process.

Evaluation of Vermicompost Maturity Using Scanning Electron Microscopy and Paper Chromatography Analysis

Vermicompost was produced from flower waste inoculated with biofertilizers using the earthworm Eisenia fetida. Principal component analysis (PCA) and cluster analysis (CA) were carried out on the basis of physicochemical parameters of vermicomposted samples. From the results of the PCA and CA, it was possible to classify two different groups of vermicompost samples in the following categories: E2 and E5; and E1, E3, E4, and control. Scanning electron microscopy and biodynamic circular paper chromatography analysis were used to investigate the changes in surface morphology and functional groups in the control and vermicompost products. SEM analysis of E1-E5 shows more fragment and pores than the control. Chromatographic analysis of vermicompost indicated the mature condition of the compost materials.

Integrated composting and vermicomposting: a boon to industry for waste clearance

The industrial bio-solid waste management is a global problem which has become even more challenging due to rise in population, industrialisation as well as changes in standard of living. Different waste management options, particularly landfill and incineration have potential adverse effects on environment, health, soil and biodiversity. There are little potential problems of environmental exposures from composting and vermicomposting and very little from recycling. A combine thermophillic composting and the vermicomposting approach bring the advantages of both the process and have been raised as a sustainable means for the proficient utilisation of the agro-industrial processing wastes. And thus, waste gets converted into worth added products which help in recycling organic matter back into the soil to maintain soil structure and richness. Carbon and nitrogen mineralisation and their ratio reflect the degree of maturity of vermicompost and can be a useful tool for quantifying the impact of various organic and inorganic wastes on soil properties. This review focuses on the balanced C:N ratio and supplement used with different agro-industrial wastes which have been tested for bio-degradation in yesteryears as a means of addressing the environmental pollution concerns.

Compost Maturity Assessment Using Physicochemical, Solid-State Spectroscopy, and Plant Bioassay Analysis

The vermicompost produced from flower waste inoculated with biofertilizers was subjected to compost maturity test: (i) physicochemical method (pH, OC, TN, C:N); (ii) solid state spectroscopic analysis (FTIR and (13)C CPMAS NMR); and (iii) plant bioassay (germination index). The pH of vermicompost was decreased toward neutral, C:N ratio < 20; reduced organic carbon with increased nitrogen indicates the compost attains maturity. The final vermicomposts result shows reduction of complex organic materials into simple minerals which indicates the maturity of the experimental vermicompost product than the control. The increased aliphatic portion incorporated with flower residues may be due to the synthesis of alkyl, O-alkyl, and COO groups by the microbes present in the gut of earthworm. Plant bioassays are considered the most conventional assessment of compost maturity analysis, and subsequently, it shows the effect of vermicompost maturity on the germination index of Vigna mungo .

Critical tests for determination of microbiological quality and biological activity in commercial vermicompost samples of different origins

The aim of the present paper was to show that differences in biological activity among commercially produced vermicompost samples can be found by using a relatively simple test system consisting of microorganism tests on six microbiological media and soilless seedling growth tests with four vegetable crop species. Significant differences in biological properties among analyzed samples were evident both at the level of microbial load as well as plant growth-affecting activity. These differences were mostly manufacturer- and feedstock-associated, but also resulted from storage conditions of vermicompost samples. A mature vermicompost sample that was produced from sewage sludge still contained considerable number of Escherichia coli. Samples from all producers contained several potentially pathogenic fungal species such as Aspergillus fumigatus, Pseudallescheria boidii, Pseudallescheria fimeti, Pseudallescheria minutispora, Scedosporium apiospermum, Scedosporium prolificans, Scopulariopsis brevicaulis, Stachybotrys chartarum, Geotrichum spp., Aphanoascus terreus, and Doratomyces columnaris. In addition, samples from all producers contained plant growth-promoting fungi from the genera Trichoderma and Mortierella. The described system can be useful both for functional studies aiming at understanding of factors affecting quality characteristics of vermicompost preparations and for routine testing of microbiological quality and biological activity of organic waste-derived composts and vermicomposts.

Quality of Vermicompost Obtained from Residues of Forestry and Livestock

The forestry-livestock waste materials represent a serious ecological problem if they are not handled properly in agricultural activities. Vermicomposting is a biotechnological process with potential to transform such materials into products that can be safely used as soil enhancers. The objective of this study was to evaluate the nutritional characteristics of organic fertilizers obtained from forestry-livestock organic waste materials when they are processed through vermicomposting using “Red Californian Earthworm” (Eisenia fetida). A completely randomized experimental design with four treatments and eight replicates was performed. Treatments (mixtures) included: leaf litter + sawdust (LS), bovine manure + sawdust (BS), rabbit manure + sawdust (RS), and ovine manure + sawdust (OS). Total nitrogen, pH, carbon/nitrogen ratio, organic carbon and nitrates from vermicompost samples were measured and statistically analyzed using SAS v8.2. At the end of the study, all mixtures showed similar characteristics according to the analyzed variables. Carbon/nitrogen ratios decreased in three mixtures to values considered as within the vermicompost maturity stage. Contents of nitrates and total nitrogen were increased. Final pH showed statistical difference among all mixtures. Results indicate that vermicomposting is a viable process for recycling forestry-livestock organic waste materials since it improves their chemical and nutritional characteristics.

Instrumental evidence for biodegradation of tannery waste during vermicomposting process using Eudrilus eugeniae

Animal fleshing (ANFL) is the main solid waste generated during manufacturing leather, which should be disposed friendly to the environment. The effect of epigeic earthworm Eudrilus eugeniae (with and without addition) to transform fermented ANFL in solid state (SSF) and submerged state (SmF) mixed with cow dung and leaf litter into value added product was studied in a vermibioreactor at low residence period (25 days). The products were characterised for pH and C:N ratio and the results were declined at the end of the treatment process with significant reduction in earthworm processed product. The maturity and the chemical changes of the final products were determined using spectroscopic analysis as UV–Visible Spectroscopy in which worm products (vermicompost) reached >5; this indicated that they were well humified. The FT-IR analyses results confirmed the complete mineralisation of polypeptides, polysaccharides, aliphatic methyl groups and lignin, and formation of a deep nitrate band in worm product compared to without worm processed product. Thermogravimetry (TG) and differential scanning calorimetry analyses were carried out in the initial mixture and final products to identify the mass loss and quantitative and qualitative information regarding physical and chemical changes occurred during composting process. The overall results indicated that the maturity of vermicompost (with worms) was in the order SSF > SmF > control. The results indicate that the combination of both fermentation and bacterial/vermicomposting (without worms/with worms) reduced the overall time required for production of well humified organic manure especially with worms.

Vermicompost derived from different feedstocks as a plant growth medium

This study determined feedstock effects on earthworm populations and the quality of resulting vermicomposts produced from different types of feedstocks using different vermicomposting durations. Feedstock combinations (Kitchen Paper Waste (KPW), Kitchen Yard Waste (KYW), Cattle Manure Yard Waste (CMY)), three durations of vermicomposting (45, 68 or 90days), and two seed germination methods (with two concentrations of vermicompost) for radish, marigold and upland cress, served as the independent variables.The worms (Eisenia fetida) doubled their weight by day 68 in KPW and CMY vermicomposts and day 90 KPW vermicompost produced the greatest weight of worms. The direct seed germination method (seeding into soil or vermicompost–soil mixtures) indicated that KPW and KYW feedstocks decreased germination compared to the control, even in mature vermicompost. Seed germination was greater in the water extract method; however, most of the vermicompost extracts suppressed germination of the three seed species compared to the water controls. Vermicomposts from all three feedstocks increased leaf area and biomass compared to the control, especially in the 10% vermicompost:soil mix. Thus, seed germination and leaf area or plant biomass for these three species are contrasting vermicompost quality indicators.