Potential utilization of bagasse as feed material for earthworm Eisenia fetida and production of vermicompost

A Critical Review on the Vermicomposting of Organic Wastes as a Strategy in Circular Bioeconomy: Mechanism, Performance, and Future Perspectives

AbstractTo meet the current need for sustainable development, vermicomposting (VC), a natural, eco-friendly, and cost-effective technology, can be a wise selection for the bioconversion of organic wastes into value-added by-products. However, no one has tried to establish the VC technology as an economically sustainable technology by exploring its linkage to circular bioeconomy. Even, no researcher has made any effort to explore the usability of the earthworms (EWs) as a protein supplement while assessing the economic perspectives of VC technology. Very few studies are available on the greenhouse gas (GHG) emission potential of VC technology. Still, the contribution of VC technology towards the non-carbon waste management policy is not yet explored. In the current review, a genuine effort has been made to inspect the contribution of VC technology towards the circular bioeconomy, along with evaluating its capability to bioremediate the organic wastes generated from domestic, industrial, and agricultural premises. The potential of the EWs as a protein source has also been explored to strengthen the contribution of VC technology towards the circular bioeconomy. Moreover, the linkage of the VC technology to the non-carbon waste management policy has been comprehensively demonstrated by highlighting its carbon sequestration and GHG emission potentials during the treatment of organic wastes. It has been observed that the cost of food production was reduced by 60--70% by replacing chemical fertilizers with vermicompost. The implication of the vermicompost significantly lessened the harvesting period of the crops, thereby helping the farmers attain higher profits by cultivating more crops in a single calendar year on the same plot. Furthermore, the vermicompost could hold the soil moisture for a long time, lessening the water demand up to 30-40%, which, in turn, reduced the frequency of irrigation. Also, the replacement of the chemical fertilizers with vermicompost resulted in a 23% increment in the grapes' yield, engendering an extra profit of up to 110000 rupees/ha. In Nepal, vermicompost has been produced at a cost of 15.68 rupees/kg, whereas it has been sold to the local market at a rate of 25 rupees/kg as organic manure, ensuring a net profit of 9.32 rupees/kg of vermicompost. EWs embraced 63% crude protein, 5-21% carbohydrates, 6-11% fat, 1476 kJ/100 g of metabolizable energy, and a wide range of minerals and vitamins. EWs also contained 4.11, 2.04, 4.43, 2.83, 1.47, and 6.26  g/kg (on protein basis) of leucine, isoleucine, tryptophan, arginine, histidine, and phenylalanine, respectively, enhancing the acceptability of the EW meal (EWM) as the protein supplement. The inclusion of 3 and 5% EWM in the diet of broiler pullets resulted in a 12.6 and 22.5% increase in their feed conversion ratio (FCR), respectively after one month. Similarly, when a 100% fish meal was substituted by 50% EWM and 50% fish meal, the FCR and growth rate of Parachanna obscura were increased substantially. The VC of maize crop residues mixed with pig manure, cow dung, and biochar, in the presence of Eisenia fetida EWs, yielded only 0.003-0.081, 0-0.17, and 130.40-189.10 g CO₂-eq.kg^-1 emissions of CO₂, CH₄, and N₂O, respectively. Similarly, the VC of tomato stems and cow dung ensured 2.28 and 5.76 g CO₂-eq.kg^-1 CO₂ emissions of CH₄ and N₂O, respectively. Additionally, the application of vermicompost at a rate of 5 t/ha improved the soil organic carbon proportion and aggravated carbon sequestration. The land application of vermicompost improved micro-aggregation and cut down the tillage, reducing GHG emissions and triggering carbon sequestration. The significant findings of the current review suggest that VC technology potentially contributes to the concept of circular bioeconomy, substantially negotiates potential GHG emissions, and complies with the non-carbon waste management policy, reinforcing its acceptability as an economically sound and environmentally benevolent organic waste bioremediation alternative.

Sustainable organic waste management using vermicomposting: a critical review on the prevailing research gaps and opportunities

Logistic growth of human population, exponential rate in agronomic industries and feeble waste management practices have resulted in the massive generation of organic wastes. Vermicomposting is one of the eco-biotechnological practices to efficiently transform them into stable and nutrient-rich organic manure with the synergetic actions of earthworms and soil microbiota. Vermicompost, a derivative product has the desirable physicochemical traits such as excellent porosity, buffering actions, aeration and water holding capacity. Also the presences of enzymic and microbial secretions contribute to growth and disease resistance of the crops. Owing to the benefits of soil nutrients restoration and effective organic waste management, vermicomposting has gained much attention among the scientific researchers and organic farmers. The present review is intended to provide comprehensive information on the site selection, screening of earthworms, different modes of operation and their desirable micro-environmental conditions. Also, the review has critically identified the prevailing research gaps viz. limited studies on the substrate formulation or optimization designs, poor control on the operational variables, lack of field-level investigations, technological feasibility of scale-up process, economic viability and cost-benefit analysis. Prospective researches can be made on these hotspots to identify the vermicomposting as a successful and profitable business model in the circular economy.

Estimation of the Ability to Decompose Sodium Benzoate by a Bacterium Isolated from Biohumus Eicenia Fetida

The study presents growth kinetics of a BG28 bacterial strain isolated from vermicompost (generated with the use of Eisenia fetida worms). The strain was given a codename BG28. It was revealed that the isolate is capable of using high concentrations of sodium benzoate (up to 15 g/l) as a substrate. At the same time, the rate and division constants of a culture that grows at 5 g/l, 10 g/l, and 15 g/l do not differ. However, the mean and specific increment of BG28 at the end of the logarithmic growth phase is significantly higher in the variant with 5 g/l. It was testified, that with the shortest duration of the logarithmic growth phase on a medium with 5 g/l, the substrate loss constant is higher than in other variants. The difference in the kinetic parameters of the culture at 5 g/l and 10 g/l sodium benzoate is insignificant. With an increase of the substrate concentration to 15 g/l, the duration of the logarithmic growth phase increased significantly, but the sodium benzoate decrease constant was found to be the lowest. During the study of the individual properties of BG28, it was revealed that the strain is capable of growing on benzoic acid. On this basis, it can be assumed that the culture contributes to the degradation of plant residues during vermicomposting. Besides, the isolate grows on a mineral nutrient medium with polyethylene glycol 6000 and liquid paraffin. In the process of the individual properties estimation, it was revealed that the strain is capable of local suppression of the Alternaria brassicicola VKM F-1864 mold growth when co-cultivated on agar nutrient medium.

Effects of hydrolyzed polymaleic anhydride addition combined with vermicomposting on maturity and bacterial diversity in the final vermicompost from the biochemical residue of kitchen waste

A large amount of kitchen waste is produced all over the world. Biochemical disposal is an effective method for the reduction and safe utilization of kitchen waste. However, high salinity, low maturity and poor biocompatibility were encountered when utilizing the biochemical residue of kitchen waste (BRKW) as a kind of soil amendment. To reduce the high salinity, accelerate the maturity and improve the biocompatibility in the BRKW, this study used the BRKW as the main feedstock for earthworms after hydrolyzed polymaleic anhydride (HPMA) was added and focused on revealing the effect of HPMA addition combined with the vermicomposting process on the growth of earthworms and on the basic physicochemical properties and the microbial diversity of the derived vermicompost. The results showed that HPMA addition can promote earthworm growth and reproduction. The pH, electric conductivity, organic matter content, C/N and NH₄⁺-N/NO₃^--N were decreased in the final vermicompost, while total nitrogen, total phosphorus and total potassium contents, and the seed germination index were increased. Scanning electron microscopy analysis showed that there was more disintegration in the final vermicompost. Meanwhile, adding the HPMA also helped to decrease the total number of fungi while increasing the populations of nitrogen-fixing bacteria, phosphorus-solubilizing bacteria and potassium-solubilizing bacteria as well as amount of total bacteria and actinomycetes. The vermicomposting process increased the bacterial phyla that promote the degradation of OM, such as Actinobacteria, Firmicutes and Acidobacteria, decreased the pathogenic Enterobacter and increased the bacterial genera that promote the maturity and quality, such as Cellvibrio and Pseudomonas. Thus, HPMA addition combined with vermicomposting can promote the growth of beneficial bacteria that promote the degradation of lignocelluloses and accelerate maturity while inhibiting some potential bacterial pathogens, which helps guarantee the safety of vermicomposting products from BRKW. Hence, employing HPMA to promote BRKW vermicomposting can possibly reduce salt content and improve the maturity and biocompatibility of the final vermicompost. This approach may help realize the safe utilization of BRKW and further promote the biochemical disposal of kitchen waste.

Seaweed (Gracilariopsis funicularis) biochar incorporation into a goat manure–food waste vermicompost for optimized vermidegradation and nutrient release

Vermicomposts are organic fertilizer sources that are being promoted; however, their concentrations of macronutrients such as NPK are very low. This study, therefore, evaluated the effects of amending goat manure–food waste mixture with biochar prepared from seaweed (Gracilariopsis funicularis) at 0% (control), 2, 4, 6, and 8% on vermicompost degradation and macronutrient release. After 10 weeks of vermicomposting, the highest pH of 9.06 was observed within the control, whilst the lowest was 8.7 in the 8% treatment. The electrical conductivity showed a positive relationship with the level of biochar incorporation with the highest of 16.5 mS/cm from the 8% treatment, whilst the lowest was within the control with 6 mS/cm. There were no significant differences between treatments on humification parameters; however, there were significant differences in the changes in a C/N ratio with the final C/N ratio of 14.4, 14.9, 16.7, 15.1, and 14.4 for the control, 2, 4, 6, and 8% treatments, respectively. A higher incorporation rate resulted in the higher concentration of potassium with a value of 32.3 g/kg at week 8. The final percentage change in Olsen P was 19, 14.2, 7.3, 4.1, and 3.0% for the 8%, 6%, control, 4%, and 2% treatments, respectively. An optimized level of 6% to 8% biochar incorporation ratio can be recommended. However, the incorporation of G. funicularis biochar does not seem to influence changes in the vermidegradation efficiency, though it can significantly improve the macronutrients such as P, K, and Mg concentrations as well as the macroelement concentrations.

Vermiremediation of allopathic pharmaceutical industry sludge amended with cattle dung employing Eisenia fetida

The present study aims to vermiremediate allopathic pharmaceutical industry sludge (AS) amended with cattle dung (CD), in different feed mixtures (AS:CD) i.e (AS₀) 0:100 [Positive control], (AS₂₅) 25:75, (AS₅₀) 50:50, (AS₇₅) 75:25 and (AS₁₀₀) 100:0 [Negative Control] for 180 days using earthworm Eisenia fetida. The earthworms could thrive and grow well up to the AS₇₅ feed mixture. In the final vermicompost, there were significant decreases in electrical conductivity (29.18-18.70%), total organic carbon (47.48-22.39%), total organic matter (47.47-22.36%), and C: N ratio (78.15-54.59%). While, significant increases in pH (9.06-16.47%), total Kjeldahl nitrogen (69.57-139.58%), total available phosphorus (30.30-81.56%), total potassium (8.92-22.22%), and total sodium (50.56-62.12%). The heavy metals like Cr (50-18.60%), Cd (100-75%), Pb (57.14-40%), and Ni (100-50%) were decreased, whereas Zn (8.37-53.77%), Fe (199.03-254.27%), and Cu (12.90-100%) increased significantly. The toxicity of the final vermicompost was shown to be lower in the Genotoxicity analysis, with values ranging between (76-42.33%). The germination index (GI) of Mung bean (Vigna radiata) showed a value ranging between 155.02 and 175.90%. Scanning electron microscopy (SEM) analysis showed irregularities with high porosity of texture in the final vermicompost than in initial mixtures. Fourier Transform-Infrared Spectroscopy (FT-IR) spectra of final vermicompost had low peak intensities than the initial samples. The AS₅₀ feed mixture was the most favorable for the growth and fecundity of Eisenia fetida, emphasizing the role of cattle dung in the vermicomposting process. Thus, it can be inferred that a cost-effective and eco-friendly method (vermicomposting) with the proper amendment of cattle dung and employing Eisenia fetida could transform allopathic sludge into a nutrient-rich, detoxified, stable, and mature vermicompost for agricultural purposes and further could serve as a stepping stone in the allopathic pharmaceutical industry sludge management strategies in the future.

Sustainable treatment and nutrient recovery from leafy waste through vermicomposting

The present investigation was carried out to evaluate the vermicomposting potential of two cruciferous vegetables' residual biomasses under laboratory conditions. Cabbage and cauliflower residual biomasses were spiked with 60% cow dung and vermicomposted for 90 days. The results showed a decrease in pH (5.3-9.8%), Total Organic Carbon (36.7-42.8%); increase in Electrical Conductivity (33-99.4%) and ash content (144.7-187.8%) after vermicomposting. Significant reduction in C:N ratio (49.5-76.4%) and C:P ratio (62.8-66.04%), increase in Total Kjeldahl Nitrogen (49.3-85.3%), Total Available Phosphorus (68.2-98.1%), Total Potassium (91.8-120.3%) were observed. FT-IR spectra of the vermicomposts had lesser band heights and peak intensities than raw materials. This evidenced decomposition of organic compounds and vermicompost stability. Germination Index values was calculated to determine the phytotoxicity level. Earthworms' growth and prolificacy was evaluated in terms of biomass gain, cocoons production and worm growth rate. Finally, it was inferred that cruciferous vegetables' biomass can be used for vermicomposting. The cauliflower residual biomass has shown better decomposition efficiency than cabbage residual biomass.

Vermicomposting of textile mill sludge employing Eisenia fetida: Role of cow dung and tea waste amendments

Vermicomposting of textile mill sludge (TMS) with cow dung (CD) and tea waste (TW) as amendments was done in seven different combinations using Eisenia fetida for 90 days. Results revealed that pH decreased from 7.68-8.63 to 7.09-7.59. TOC content and C/N ratio reductions were in range of 15.71-20.08% and 39.33-50.05%, respectively (P < 0.05). The macronutrients in the form of TN, TP, and TK increased 0.38-0.64, 1.07-2.27, and 0.56-1.98 times respectively after end of bioconversion process (P < 0.05), among increases in ash content and EC. The biomass and cocoon production of E. fetida increased significantly (P < 0.05), while high mortality rate of earthworms was observed in treatments containing 50% or more TMS content. The bacterial population beneficial for degradation of organic matter increased significantly over initial substrates (0th day) (P < 0.05). Increased humification index in end-product indicated better maturity of vermicompost as observed in treatments containing higher proportions of amendments. The addition of amendments favored earthworm activity which significantly decreased the heavy metal concentration (Fe, Cu, Pb, Zn) in the end-product. The study concluded that sustainable utilization of TMS could be achieved for cleaner and enriched vermicompost production by addition of amendments CD and TW in proportions of 50% and above.

Eisenia fetida for vermiconversion of waste biomass of medicinal herbs: Status of nutrients and stability parameters

Vermiconversion possibility of waste biomass of two medicinal herbs Zingiber officinale and Curcuma longa has been investigated. The Eisenia fetida, an epigeic earthworm was used in the vermicomposting process. The vermicomposting caused shifting in pH towards neutral range, reduction in electrical conductivity, total organic carbon, C/N and C/P ratios whereas1.8-2.73 folds enhancement in macronutrients (TKN, AP, T Ca and T Mg) and ash contents in the substrate mixture. The heavy metals and trace elements content in the vermicompost were found within 3.25-1380 mg/kg and are under the permissible limits of compost applications. Besides, high germination index value in the vermicompost extract indicates loss of phytotoxicity and safe agricultural application potential of the end product. Finally, enhanced growth in Eisenia fetida confirms the application potential of harvested waste biomass as the raw materials for vermiconversion process.

The succession of GH6 cellulase-producing microbial communities and temporal profile of GH6 gene abundance during vermicomposting of maize stover and cow dung

Vermicomposting eco-friendly converts lignocellulosic wastes into bio-organic fertilizer. Cellulose is the most abundant carbohydrate in lignocellulose. Glycoside hydrolase family 6 (GH₆) plays a key role in the early step of cellulose degradation, which is essential for stabilizing lignocellulose. This study intends to quantify the abundance of GH₆ gene and to clarify the succession of GH₆ cellulase-producing microbial communities during vermicomposting. 100% of maize stover (A) and maize stover and cow dung at 60:40 ratio (B) were used. The results showed that different native genera were observed in the starting materials. Cellulomonas and Cellulosimicrobium were dominant genera harboring GH₆ gene. The peak relative abundance of Cellulomonas was 76% and 30% in B and A during vermicomposting phase, and the corresponding values of Cellulosimicrobium was 36% and 37%. Earthworms increased the abundance of GH₆ gene, which reached 1.51E + 09 from 3.46E + 08 copies/g in B. The results partially interpreted promoting effect of earthworms.

Effect of decomposing oil palm trunk fibers on plant growth and soil microbial community composition

Oil palm trunks (OPT) are logged for replantation and the fiber residues are disposed of into the palm plantation area. The fiber residues are expected to increase soil fertility through recycling of carbon and minerals via fiber decomposition. This study investigated the effects of OPT fiber disposal and other lignocellulosic biomass on plant growth and microbial diversity in the soil environment. Four treatment plots were tested: (A) soil+OPT fiber (1:20), (B) soil+sugarcane bagasse (1:20), (C) soil+cellulose powder (1:20), and (D) unamended soil as a negative control. Low plant height, decreased chlorophyll content, and low biomass was observed in corn grown on soil mixed with OPT fiber, cellulose, and sugarcane bagasse, when compared with those of the control. The plants grown with OPT fiber were deficient in total nitrogen and magnesium when compared with those without fiber amendment, which suggested that nitrogen and minerals in soil might be taken up by changing microflora because of the OPT fibers presence. To confirm differences in the soil microflora, metagenomics analysis was performed on untreated soil and soil from each lignocellulose treatment. The microflora of soils mixed with OPT fiber, cellulose and sugarcane bagasse revealed substantial increases in bacteria such as families Cytophagaceae and Oscillospiraceae, and two major fungal genera, Trichoderma and Trichocladium, that are involved in lignocellulose degradation. OPT fiber resulted in a drastic increase in the ratios and amounts of Trichocladium in the soil when compared with those of cellulose and sugarcane bagasse. These results indicate that unregulated disposal of OPT fiber into plantation areas could result in nutrient loss from soil by increasing the abundance of microorganisms involved in lignocellulose decomposition.

Vermicomposting of harvested waste biomass of potato crop employing Eisenia fetida: changes in nutrient profile and assessment of the maturity of the end products

The vermicomposting potential of waste biomass of potato crops that are generated at the time of harvesting was studied employing Eisenia fetida. The experiment was carried out in pots, and two treatments were applied during the study. In the first treatment, only potato plant biomass (PPB) was taken as the raw materials; whereas in the second treatment, a mixture of PPB with cow dung was engaged in the proportion of 5:1. The vermicomposted materials showed a reduction in C/N ratio, humification index, enhancement in nutrients profiles, ash contents, nitrogen-fixing, phosphate, and potassium solubilizing bacterial population. The macronutrient enhancement in the vermicompost samples was recorded 3.8-4.4-fold for total N, 5-5.6-fold in available P, 1.6-fold in total K, 5.2-6.2-fold in total Ca, and 1.6-fold in total Mg contents. The reduction in C/N was found in the range of 92.5-94.4% in the vermicompost samples. The scanning electron microscope (SEM) images showed higher disintegration in the vermicompost products when compared with initial raw material and compost samples. The addition of cow dung significantly enhanced the quality and quantity of vermicompost final products besides positively affecting the earthworm population and biomass by the end of 60 days of experimental trials.

Pilot-scale vermicomposting of sewage sludge mixed with mature vermicompost using earthworm reactor of frame composite structure

To improve the efficiency of sludge vermicomposting, a new cost-effective method is provided. It uses a new earthworm reactor with a frame composite structure for vermicomposting and reuses mature vermicompost to condition the sludge. Under the optimum conditions (proportion of earthworm droppings: 15%; thickness of sludge laying: 6 cm; moisture content of initial sludge mixture: 75%), the method of continuous operation described herein works well and presents three advantages compared with the traditional vermicomposting method: the short time required for vermicomposting (20.25 h); covering a small area (5 m2/t·d); and a low cost. In addition, the vermicompost obtained from sludge vermicomposting shows better stability and maturity (C/N: 14.96; GI: 86.42%; TOC: 188.5 mg/g; ash content: 516.2 mg/g). The investigation of the associated mechanisms, including 3D-EEM, TGA, SEM and microbial community analyses, revealed that the addition of mature vermicompost can speed up the progress of decomposition and humification of organic matter in sludge. The process of vermicomposting and adding mature vermicompost significantly modified the microbial community of sewage sludge, and the changes in microorganisms in vermicompost were related to the microorganisms in the earthworm gut.

Performance and mechanism of high-speed vermicomposting of dewatered sludge using a new type of laboratory earthworm reactor

To solve the problem of the traditional vermicomposting cycle being too long, a new type of laboratory earthworm reactor was developed for high-speed vermicomposting of sludge. The earthworm reactor was established based on the model of first creating an optimal living environment for earthworms and then introducing sludge into the environment for vermicomposting. In addition, we selected four different materials to condition sludge to optimize the treatment efficiency and shorten the vermicomposting cycle. The results revealed that the use of the new earthworm reactor for high-speed vermicomposting can shorten the vermicomposting cycle to 61.33 h, which is 1/30 of the traditional method. Compared to the traditional method, the vermicompost obtained from high-speed vermicomposting had better stability and maturity (C/N: 14.96, humification index: 4.69, Germination index: 78.84%, TOC: 88.5 mg/g and ash content: 686 mg/g). Besides, the FT-IR, SEM, EEM, and enzyme activity from the earthworm analysis results show that the addition of vermicompost (raw material) was beneficial to the stability and mineralization of the final vermicompost for dewatered sludge vermicomposting.

Feasibility of vermicomposting for spent drilling fluid from a nature-gas industry employing earthworms Eisenia fetida

This study investigated the vermicomposting of spent drilling fluid (SDF) from the nature-gas industry mixed with cow dung in 0% (T1), 20% (T2), 30% (T3), 40% (T4), 50% (T5), and 60% (T6) ratio employing Eisenia fetida under a 6 weeks trial. Eisenia. fetida showed better growth and reproduction performances in the first three vermireactors (T1-T3), and the mortality was higher in the vermireactors that contained more spent drilling fluid (≥40%). Vermicomposting results in a decrease in total organic carbon, C/N ratio, and an increase in EC, total nitrogen, total phosphorous, total potassium compared to their initial values. The RadViz and VizRank showed that vermicomposting results in a greater impact on the C/N ratio (15.24-35.48%) and EC (7.29-26.45%) compared to other parameters. Activities of urease and alkaline phosphatase during vermicomposting initially increased and then declined suggesting vermicompost maturity. Also, seed germination, mitotic index and chromosomal abnormality assays using cowpea signified that the vermicomposts T2 is suitable for agricultural use due to the lower phytotoxicity and cytotoxicity. The results indicated that SDF could be converted into good quality manure by vermicomposting if mixed up to 20% with cow dung.

Cleaner production of agriculturally valuable benignant materials from industry generated bio-wastes: A review

Bio-wastes from different agro-based industries are increasing at a rapid rate with the growing human population's demand for the products. The industries procure raw materials largely from agriculture, finish it with the required major product, and produce huge bio-wastes which are mostly disposed unscientifically. This creates serious environmental problems and loss of resources and nutrients. Traditional bio-wastes disposal possess several demerits which again return with negative impact over the eco-system. Anaerobic digestion, composting, co-composting, and vermicomposting are now-a-days given importance due to the improved and modified methods with enhanced transformation of bio-wastes into suitable soil amendments. The advanced and modified methods like biochar assisted composting and vermicomposting is highlighted with the updated knowledge in the field. Hence, the present study has been carried to compile the effective and efficient methods of utilizing industry generated bio-wastes for circularity between agriculture - industrial sectors to promote sustainability.

Centrality of cattle solid wastes in vermicomposting technology - A cleaner resource recovery and biowaste recycling option for agricultural and environmental sustainability

The current review reports the importance and significance of cattle solid waste in vermicomposting technology concerning biowaste pollution in the environment. Needy increasing population evokes livestock production resulting in the massive generation of livestock wastes, especially cattle dung. Improper disposal and handling of biowastes originating from agriculture, industries, forests, rural and urban areas lead to nutrient loss, environmental pollution and health risks. Among the organic waste disposal methods available, vermicomposting is regarded as an environmentally friendly technology for bioconversion of agricultural, industrial, rural and urban generated organic solid wastes which are serving as reservoirs of environmental pollution. In vermicomposting of organic wastes, cattle dung plays a central role in mineralization, nutrient recovery, earthworm and microbial activity leading to vermifertilizer production. Even though the vermicomposting studies use cattle dung invariably as an amendment material, its importance has not been reviewed to highlight its central role. Hence, the present review mainly emphasizes the key role played by cattle dung in vermicomposting. Vermiconversion of cattle dung alone and in combination with other biowaste materials of environmental concern, mechanisms involved and benefits of vermicompost in sustainable agriculture are the major objectives addressed in the present review. The analysis reveals that cattle dung is indispensable amendment material for vermicomposting technology to ensure agricultural and environmental sustainability by reducing pollution risks associated with biowastes on one hand, and nutrient-rich benign vermifertilizer production on the other hand.

Valorization of Orange Peel Waste Using Precomposting and Vermicomposting Processes

The industrialization process of oranges generates waste, which is inadequately disposed of; this produces adverse effects on the environment. Among the alternatives for valorization is the vermicomposting process, which consists of the degradation of organic waste through the action of earthworms and microorganisms. Therefore, this research aimed to study this process using orange peel (OP) waste at the laboratory level. For this purpose, it was necessary to determine the degradation conditions through the monitoring of physicochemical parameters (temperature, pH, humidity, organic matter (OM), total organic carbon (TOC), total nitrogen (TN) and the carbon/nitrogen (C/N) ratio). To balance the substrate’s nutrients, load material (LM) that included vegetable waste and eggshells was added to three different mixtures: M1 (50% OP + 50% LM), M2 (40% OP + 60% LM) and M3 (60% OP + 40% LM). To condition the substrate for earthworm (Eisenia fetida) activity, a previous precomposting process was performed. The results showed that all the mixtures fulfilled the requirements for a quality and mature vermicompost; however, the highest concentrations for TN were in the mixtures M1 and M2. The total time required for degradation of the OP waste was 13 weeks.

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.

Vermiconversion of biowastes with low-to-high C/N ratio into value added vermicompost

Seaweed (T1), sugarcane trash (T2), coir pith (T3) and vegetable waste (T4) with cowdung (1:1, w/w) were vermicomposted using Eudrilus eugeniae (50 days). The pH in vermicomposts showed a decrease while electrical conductivity showed increment. The organic matter content, organic carbon, lignin, cellulose, C/N and C/P ratios in vermicompost was significantly lower than compost. Total NPK contents of vermicompost were significantly elevated (P < 0.05) with 12.04-63.75%, 19.05-31.58% and 22.47-42.55%, respectively. The significantly higher growth rate of 1.41 and 7.74 mg/worm/day was observed in T1 on 10th and 50th day respectively, with 23.91 initial C/N ratio; while it was 0.85 and 4.81 mg/worm/day in T4 with 69.81 initial C/N ratio. A similar pattern was reflected in cocoon production, hatchling success and hatchling number/cocoon. Results revealed that vermicompost quality, worm growth, and reproduction depend on C/N ratio. The study suggests that amendment materials like cowdung are necessary to reduce C/N ratio for effective vermicomposting.

Comparative Performance of Organic Fertilizers in Maize (Zea mays L.) Growth, Yield, and Economic Results

Maize is a major crop grown and consumed in Uganda and it requires a high fertilizer input. However, the existing inorganic fertilizers in the market are often not affordable especially to small scale farmers, which results in decreased maize yields in the country. On the other hand, there is an abundance of unutilized animal manure, which, when treated, can be used to increase maize yields. This study evaluated the response of maize to products of different cattle manure treatment methods as well as inorganic fertilizer. The treatments such as cattle manure stored under shade (T), cattle manure stored in the open (M), cattle manure slurry digestate (S), vermicompost (V), and an inorganic fertilizer, DAP (D) were all applied in completely randomized block plots at an equal application rate of 50 kg N ha−1 with four replications per treatment. Control plots (C) where no fertilizer was applied were also considered. The experiment was done for two planting seasons in 2018. Number of leaves, plant height, cob, and grain yields were used to evaluate the performance of different fertilizer treatments. Economic assessment of all the six treatments was also carried out to determine the economic viability of applying these fertilizers on maize. Maize growth parameters and yields were all significantly increased (p < 0.05) with an application of both organic and inorganic fertilizers when compared with the control. However, there was no significant difference (p > 0.05) in the maize yields under the different fertilizer treatments. Vermicomposting was the most economically viable manure treatment method due to low operating costs and higher returns on investment that are supplemented with the production of chicken fodder (earthworm biomass) and, thus, can be recommended to farmers for production of a fertilizer that increases maize yields with assurance of economic returns.

Vermicomposting of citronella bagasse and paper mill sludge mixture employing Eisenia fetida

The vermicomposting potential of Eisenia fetida on citronella bagasse and paper mill sludge mixture was studied. The experiment was carried out in pots by taking a mixture of citronella bagasse and paper mill sludge in 3:2 ratios. The physico-chemical properties such as pH, conductivity, total organic carbon, nitrogen, phosphorus, potassium, calcium, trace elements and heavy metals were studied in the end products. The ash content, humification index, C/N ratio and scanning electron microscopic analysis were done to understand the maturity of the vermicompost. Results revealed that bioconversion of citronella bagasse and paper mill sludge mixture is accompanied with reduction of C/N ratio and humification index; enhancement of nutrients profile, nitrogen fixing, phosphate and potassium solubilizing bacterial population. SEM analysis showed that there was more disintegration in vermicompost samples than the initial raw materials and compost. Further, earthworm population and biomass has significantly increased by the end of the experimental trials.

Azolla pinnata, Aspergillus terreus, and Eisenia fetida for fasterrecycling of nutrients from wheat straw

A vast amount of surplus wheat straw/stubble (a carbon-rich bioresource) is wasted every year by burning. Harmful gases and residue matter released due to burning cause harmful effects on the environment and human health. Therefore, there is a strong need to recycle this bioresource in a sustainable manner. In the present study, wheat straw (W) was spiked with cattle dung (C), Azolla pinnata (A), and Aspergillus terreus (F) to make eight different treatments (1 kg each), viz. W (1 kg), WC (666 g + 334 g), WA (980 g + 20 g), WF (980 g + 20 ml), WCF (666 g + 314 g + 20 ml), WCA (666 g + 314 g + 20 g), WFA (960 g+ 20 ml + 20 g), and WCFA(666 g + 294 g + 20 ml + 20 g), and subjected to vermicomposting (Vcom) and aerobic composting (Acom). A comparison was made for the time required for degradation and nutrient profile of the products. The fastest recycling of wheat straw/stubble (120 days) was observed in WCA and WCFA, but the nutrient quality of WCA was better (N 18.67, P 3.88, K 38.84 g/kg). In the Acom group, longer time was required for degradation of various mixtures, but in this group also, WCA was degraded first of all (138 days) and yielded a product with the best nutrient quality (N 14.77, P 2.56, K 28.80 g/kg). Maximum growth of E. fetida and maximum number of hatchlings were observed in WCA while the highest cocoon production was observed in WCFA. It was observed that azolla enhanced conversion of wheat straw into a nutrient-rich product for agronomic use. Thus its use will reduce the amount of cattle dung in the mixture and the bulk to be handled by the farmers for ecosafe disposal of surplus straw/stubble. Therefore, this technology can be adopted as an alternative to burning.

Assessment of a Cattle Manure Vermicomposting System Using Material Flow Analysis: A Case Study from Uganda

Growth in cattle population is associated with increased manure generation whose current management in low-income countries is associated with health and environmental problems as well as low utilization rates. This trend can be reversed by promoting better manure management technologies. This study assessed vermicomposting as one of the technologies to manage organic wastes, using the case study in Uganda. A vermicomposting system using cattle manure and earthworms (Eudrilus euginea) was monitored for one year with the harvesting of products (compost, earthworm biomass) after every three months. Vermicompost samples from the beginning of the experiment and after every harvest were analyzed for the following parameters: pH, ash content, volatile and total solids, nutrients N, P, K, and C. Emissions of CO2, CH4, NH3, and N2O were also measured. Material flow analysis was used to determine the flows and retention of nutrients within the system. Results showed that total solids, ash, N, P, and K content significantly increased, while contents of volatile solids and C, as well as the pH, significantly decreased over time. Of the materials that entered the vermicomposting system, 46% went to vermicompost, 2% into earthworms, and 52% was lost to the atmosphere. Substance flow analysis showed that 30% of C went to vermicompost, 69% was emitted to the atmosphere, and 2% ended up in earthworms while 75% of N was transferred to vermicompost, 7% went to earthworms, and 18% escaped into the atmosphere. The cumulative emissions were 102 g CO2 kg−1 waste, 7.6 g CH4 kg−1 waste, and 3.943 × 10−5 g N2O kg−1 waste on a dry basis, while NH3 was not detected throughout the measurement time. Compared to other manure management methods, vermicomposting demonstrated good potential in conserving nutrients as well as reducing greenhouse gas emissions.

Pre-Composting and Vermicomposting of Pineapple (Ananas Comosus) and Vegetable Waste

In the last few years, pineapple (Ananas comosus) has grown to be considered one of the most important fruits worldwide due to its high production and consumption. However, inadequate disposal of the waste it generates, which represents up to 67% of its total weight, can have environmental impacts. Therefore, this study focuses on the degradation of organic waste produced in the industrialized processing of pineapple waste (rinds, crowns and cores), which undergo a process of vermicomposting at a laboratory level. The methodology used included the pre-composting process and vermicomposting through Californian red worms using mixes tested in three different proportions of pineapple waste (PR) and load material (LM) made up of vegetable waste and eggshells. Testing revealed that the pre-composting process for this waste was feasible as a first stage of the degradation process; the characteristics of the pre-composted material allowed a favorable adaptation for both the worms and general degradation. It also showed efficiencies in the removal of organic carbon between 36.40% and 45.78%. Results also showed the total nitrogen content remained between 1.2% and 2.2% and the carbon/nitrogen relation (C/N) had values under 20 as required for high-quality vermicompost.

Investigation of rice straw and kitchen waste degradation through vermicomposting

This study investigated the effect of vermicomposting on the degradation of rice straw and kitchen waste. Different ratios of straw and kitchen waste mixtures were used as feedstocks. After vermicomposting the substrates for 45 days under 20-25 °C moisture 60%, the vermicomposting resulted in a significant increase in phosphorous (31.38-55.89%) and potassium (33.40-63.15%), whereas a decrease was seen in TOC (38.24-43.49%) as well as TN (9.01-32.52%). The growth rate of earthworm (Eisenia foetida) was obtained in all feedstocks, the optimal rice straw/kitchen waste ratio for the earthworm growth was 3/2, excessive kitchen waste as negative impacts on the growth of earthworms. The result indicated that vermicomposting rice straw and kitchen waste with Eisenia foetida promoted nutrition content in a short period of time.

A comparative study of pig manure with different waste straws in an ectopic fermentation system with thermophilic bacteria during the aerobic process: Performance and microbial community dynamics

In the present study, ectopic fermentation systems were treated with both solid and liquid waste from livestock. Then, the various physicochemical properties and compositions of microbial communities in different waste straws treatments were compared. The addition of thermophilic bacteria was beneficial to the decomposition of litter, and it improved the fermentation process. Proteobacteria, Bacteroidetes, and Firmicutes were the predominant types in the fermentation vessels, and the presence of the phyla Proteobacteria and Bacteroidetes was correlated with factors prevailing in the mature phase. Furthermore, pig manure with sawdust, rape stem, and rice chaff and pig manure with sawdust, rice straw, and rice chaff vessels had higher concentrations of dissolved nitrogen, which were conducive to the conversion of fermentation wastes into useful fertilizer. These results demonstrate the feasibility of using rape stem and rice straw as padding materials during the treatment of both liquid and solid livestock waste in ectopic fermentation systems.

Azolla pinnata, Aspergillus terreus and Eisenia fetida for enhancing agronomic value of paddy straw

In the present study rice straw (R, control) was mixed with Cowdung (C), Azolla (A) and cellulolytic fungus Aspergillus terreus (F) in different combinations viz. RC, RA, RF, RCF, RCA, RFA and RCFA and subjected to aerobic composting (Acom) and vermicomposting (Vcom - with Eisenia fetida). It was found that addition of azolla and cattledung to two parts straw(RCA-666: 314:20 g) caused fastest degradation (105 days), gave maximum population buildup of E. fetida (cocoons, hatchlings and worm biomass), highest decline in pH, EC, TOC and C/N ratio and maximum increase over control in N(17.72%), P(44.64%), K(43.17%), H (7.93%), S (14.85%), Ca(10.16%), Na(145.97%), Fe(68.56%), Zn(12.10%) and Cu(32.24%). Rice straw (R) took longest time for degradation i.e. 120 and 140 days and had lowest content of nutrients in Vcom as well as Acom group. RCFA was also converted into Vcom at the same time but other parameters were less than RCA except for highest content of B (19.87%), Mg(21.27%) and Mn (5.58%). Bioconversion of three parts straw (RCA-735:245:20 g) was also faster (110 days) with vermicomposting than all the mixtures of Acom group (130–140 days) but nutrient content was slightly less than RCA with 2 parts straw. The results show that azolla reduces dependence on cattledung for recycling the carbon rich rice straw and enhances its agronomic value.

Scanning electron microscopy for analysing maturity of compost/vermicompost from crop residue spiked with cattle dung, Azolla pinnata and Aspergillus terreus

Rice straw and wheat straw were mixed with cattle dung (C), Azolla pinnata (A) and Aspergillus terreus (F) and subjected to aerobic composting and vermicomposting. Eight different mixtures were made as R, RC, RA, RF, RCF, RCA, RFA and RCFA and W, WC, WF, WA, WCA, WCF, WFA and WCFA. Ratio of straw and cattle dung was kept as 2:1, and weight of cattle dung was reduced proportionally when Azolla (20 g) or fungus (20 ml) was added in a mixture. Surface structural morphology of the initial and final mixtures was analysed with SEM. Initial samples showed larger particle size with a coarse surface, less compaction and arrangement of biomass as a dense meshwork of lingo-cellulosic fibres. Final samples showed smaller particle size, compaction and several pores per unit area. Electron micrographs clearly show enhancement of degradation and better texture with the addition of fungus, Azolla or cattle dung to the straw. Azolla and cattle dung when added separately, enhanced degradation and compaction, but the mixtures with fungus showed degradation with no compaction. Maximum homogeneity and smallest particle size of RCFA and WCFA indicated that addition of Azolla and fungus along with cattle dungenhanced degradation of straw and enhancement was remarkably more when the mixtures were subjected to vermicomposting. This is a first report highlighting vermicomposting of the straw mixed with Azolla and fungus along with cattle dung for obtaining a better quality product suitable for agricultural use. Parallel variation in C/N ratio and nutrient profile of the mixtures show that SEM helps in determining maturity index of composts.

Investigation on paper cup waste degradation by bacterial consortium and Eudrillus eugeinea through vermicomposting

Disposable Paper cups are a threat to the environment and are composed of 90% high strength paper with 5% thin coating of polyethylene. This polyethylene prevents the paper cup from undergoing degradation in the soil. Hence, in the present study two different approaches towards the management of paper cup waste through vermicomposting technology has been presented. The experimental setup includes 2 plastic reactors namely Vermicompost (VC) (Cow dung + Paper cup waste + Earthworm (Eudrillus eugeinea)) and Vermicompost with bacterial consortium (VCB) (Cow dung + Paper cup waste + Eudrillus eugeinea + Microbial consortia such as Bacillus anthracis, B. endophyticus, B. funiculus, B. thuringiensis, B. cereus, B. toyonensis, Virigibacillius chiquenigi, Acinetobacter baumanni and Lactobacillus pantheries). After treatment the physicochemical parameters were analysed. The results showed that the values of TOC (26.52 and 37.47%), TOM (36.01 and 33.13%) and C/N (15.02 and 11.92%) ratio are reduced in both VC and VCB whereas, the values of pH (8.01 and 7.56), EC (1.2-1.9 µs^-1 and 1.4-1.9 µs^-1), TP (46.1 and 51%), TMg (50.52 and 64.3%), TCa (50 and 64%), TNa (1.39 and 1.75%) and TK (1.75 and 1.86%) have increased. This study substantiates the addition of the microbial consortia augmenting the degradation in VCB reactor by reducing the period of process from 19 to 12 weeks. Further the characterisation of the vermicompost prepared from paper cup with FT-IR shows high degradation of carboxylic and aliphatic group; SEM analysis shows the disaggregation of cellulose and lignin; XRD shows the degradation of cellulose. All these analyses endorse the degradation of the paper cup waste faster with microbes (VCB). Thus, this present study high lights management of the paper cup waste in a relatively short period of time.

Bioremediation and detoxification of industrial wastes by earthworms: Vermicompost as powerful crop nutrient in sustainable agriculture

Vermicompost is the final product of the vermicomposting process involving the collective action of earthworms and microbes. During this process, the waste is converted into useful manure by reducing the harmful effects of waste. Toxicity of industrial wastes is evaluated by plant bioassays viz. Allium cepa and Vicia faba test. These bioassays are sensitive and cost-effective for the monitoring of environmental contamination. The valorization potential of earthworms and their ability to detoxify heavy metals in industrial wastes is because of their strong metabolic system and involvement of earthworm gut microbes and chloragocyte cells. Most of the studies reported that the vermicompost produced from organic wastes contains higher amounts of humic substances, which plays a major role in growth of plants. The present article discusses the detoxification of industrial wastes by earthworms and the role of final vermicompost in plant growth and development.

Dynamic Effects of Initial pH of Substrate on Biological Growth and Metamorphosis of Black Soldier Fly (Diptera: Stratiomyidae)

Edible insects have become a recognized alternative and sustainable source of high-quality proteins and fats for livestock or human consumption. In the production process of black soldier fly (BSF), (Hermetia illucens L. [Diptera: Stratiomyidae]), initial substrate pH is a critical parameter to ensure the best value of insect biomass, life history traits, and quality bio-fertilizer. This study examined the impact of initial pH values on BSF larvae production, development time, and adult longevity. The BSF were reared on artificial diet with initial pH of 2.0, 4.0, 6.0, 8.0, and 10.0; the control was set at 7.0. Final BSF larval weight was significantly greater in substrates having initial pH 6.0 (0.21 g), control 7.0 (0.20 g), and 10.0 (0.20 g) with no significant difference among them, whereas larval weight reared with initial pH 2.0 and 4.0 were lowest at 0.16 g (-23%). Prepupal weight was greatest when larvae were reared on substrates with initial pH 6.0 (0.18 g), control 7.0 (0.19 g), 8.0 (0.18 g), and 10.0 (0.18 g). In contrast, the prepupal weight of larvae reared on diets with initial pH 2.0 was lowest at 0.15 g (-22%). Larval development time was 21.19 d at pH 8.0, about 3 d (12.5%) shorter than that of those reared on diets with initial pH 6.0, 7.0 control, and 10.0. In all treatments, pH shifted to 5.7 after 3-4 d and 8.5 after 16-17 d except for two groups (2.0 and 4.0) where the pH remained slightly acidic 5.0 and 6.5, respectively.

Amelioration and degradation of pressmud and bagasse wastes using vermitechnology

This study evaluated the amelioration of pressmud (PM) and bagasse (BG) wastes by the vermiremediation process. The wastes were spiked with cattle dung (CD) in different concentrations to find out the best proportion supporting maximum earthworm growth and nutrients availability. The highest growth rate was observed in PMBG₅₀ (282.2mg/d/worm) feed mixture. Response surface design of earthworm growth parameters enumerated best concentration of wastes in CD with maximum value of 21.81% for earthworm number, 30.86% for earthworm weight, 27.09% for cocoons, 29.71% for hatchlings and 34.0% for hatchlings weight. Vermicomposting enhanced nutrient parameters like pH (6-8%), total kjeldahl nitrogen (19-48%), total phosphorus (9-67%), total calcium (13-111%), while decrease in total organic carbon (14-32%), electrical conductivity (21-30%), C:N ratio (36-51%), total potassium (9-19%) and total sodium (3-21%). Heavy metals in the final products were found to be under safe limits. SEM micrographs were more fragmented which indicated maturity and stability.

Cellulose decomposition and larval biomass production from the co-digestion of dairy manure and chicken manure by mini-livestock (Hermetia illucens L.)

World trends toward the modern dairies intensification on large production units cause massive animal manure production and accumulation. Improper handling of manure produced by industrial farm operation greatly deteriorates the major environmental media including air, water and soil. The black soldier fly utilizes organic waste and converts it into larvae biomass to be used as livestock feed and into residues to be used as bio-fertilizer. However, due to the high ratio of cellulose, hemicellulose and lignin in dairy manure, this conversion is difficult. Therefore, dairy manure treated with chicken manure was digested by Hermetia illucens. In this paper, we found that the co-digestion process significantly enhanced the larval production, waste mass reduction, rate of larvae conversion, feed conversion ratio, nutrient reduction and fibers utilization. Whereas 40% dairy manure and 60% chicken manure group show better results than other manure mixtures and had a significantly increased the cellulose consumption by 61.19%, hemicellulose consumption by 53.22% and lignin consumption by 42.23% compared with 49.89%, 49.77% and 31.95%, respectively, in the dairy-only manure group. Finally, scanning electron microscopy was used to analyze the structural changes of dairy manure, chicken manure and their co-digestion mixtures. The scan electron microscopy showed the deterioration in the structure of dairy and chicken manure fibers by Hermetia illucens. Moreover, the carbon-nitrogen ratio was decreased in all end products of post vermicomposting. The results suggest that the co-digestion of 40% dairy manure with 60% chicken manure is an appropriate proportion for dairy manure management with the black soldier fly.

Growth and reproductive potential of Eisenia foetida (Sav) on various zoo animal dungs after two methods of pre-composting followed by vermicomposting

Disposal of animal manure without treatment can be harmful to the environment. In this study, samples of four zoo animal dungs and one horse dung were pre-composted in two ways: (a) traditional composting and (b) bokashi pre-composting for 1month, followed by vermicomposting for 3months. The permanence (PEf) and reproductive potential (RP) of Eisenia foetida as well as the quality of vermicompost were evaluated. The PEf values and RP index of E. foetida were higher for samples pre-composted using the traditional composting method (98.7-88% and 31.85-16.27%, respectively) followed by vermicomposting (92.7-72.7% and 22.96-13.51%, respectively), when compared with those for bokashi pre-composted samples followed by vermicomposting, except for the horse dung sample (100% for both the parameters). The values of electrical conductivity (EC), cation exchange capacity (CEC), organic C, total N, available P, C/N ratio, and pH showed that both treatments achieved the norms of vermicompost (<4mScm^-1, 40cmolkg^-1, 20-50%, 1-4%, ≤20, 5.5-8.5, respectively). However, the maturity indices of vermicompost, namely, organic matter loss, N loss, and CEC/organic carbon (OC) ratio indicated that bokashi pre-composting followed by vermicomposting produced the highest values (98.7-70.7%, 97.67-96.65%, and 2.7-1.97%, respectively), when compared with the other method adapted in this study. Nevertheless, further studies with plants for plant growth evaluation are needed to assess the benefits and limitations of these two pre-composting methods prior to vermicomposting.

Genotoxicity reduction in bagasse waste of sugar industry by earthworm technology

The aim of the present study was to assess the genotoxicity reduction in post vermicompost feed mixtures of bagasse (B) waste using earthworm Eisenia fetida. The genotoxicity of bagasse waste was determined by using Allium cepa root chromosomal aberration assay. Bagasse was amended with cattle dung in different proportions [0:100 (B0) 25:75 (B25), 50:50 (B50), 75:25 (B75) and 100:0 (B100)] on dry weight basis. Genotoxic effects of initial and post vermicompost bagasse extracts were analysed on the root tips cells of Allium cepa. Root length and mitotic index (MI) was found to be increased in post vermicompost extracts when compared to initial bagasse waste. The maximum percent increase of root length was observed in the B50 bagasse extract (96.60 %) and the maximum MI was observed in B100 mixture (14.20 ± 0.60) 6 h treatment which was similar to the control. Genotoxicity analysis of post vermicompost extracts of bagasse revealed a 21-44 % decline in the aberration frequencies and the maximum reduction was found in B75 extract (44.50 %). The increase in root length and mitotic index, as well as decrease in chromosomal aberrations indicates that E. fetida has the ability to reduce the genotoxicity of the bagasse waste.

Effects of Different Ratios of Sewage Sludge and Cattle Manure on Growth and Propagation of Eisenia Fetida

Domestic sewage sludge and cattle manure are rich in nutrition elements, but without proper disposal, are harmful to the environment. Here with an indoor culture method, we used Eisenia fetida to dispose different ratios of sewage sludge and cattle manure, and thereby investigated the effects and acting rules of these sludge-manure mixtures on the growth and reproduction of E. fetida. We find these mixtures are food sources for E. fetida, and their physiochemical properties are significantly changed after disposal by earthworms. Paired samples t-test shows the average change after different treatments is -20.37% for total organic carbon, 85.71% for total Kjeldahl N, -6.67% for total P, 8.33% for pH, -24.78% for EC (ms·cm^-1), and -57.10% for C/N ratio. The average growth rate after treatment CD-70 is 9.20 mg·worm^-1·day^-1; the average growth rates of E. fetida on day 0–28, day 29–56, and day 57–91 are 9.33, 11.90 and 6.95 mg·worm^-1·day^-1, respectively, indicating a trend of "rapid—rapidest—slow" growth. Other treatments all show this trend. Though all earthworms developed reproductive rings during the test periods, the appearing time and the cocoon production time both differed among these treatments. The cocoon production amount is maximized to 233 after treatment CD-70. The cocoon production rates are significantly different among these treatments, and the maximum and mean are 0.32 and 0.17–0.32, cocoons·worm^-1· day^-1, respectively. E. fetida can modestly enrich Cd, but is not very effective over Sb or other heavy metals. E. fetida can remove a part of heavy metals from sewage sludge and cattle manure. Generally, the mixtures of sewage sludge and cattle manure can largely affect the growth and propagation of E. fetida in a ratio-dependent way.

Management of Sugar Industrial Wastes through Vermitechnology

The present paper discusses the role of earthworms in recycling of sugar industrial wastes. The wastes generated from sugar industry are pressmud, bagasse, bagasse fly ash, sugar cane trash, sugar beet mud, sugar beet pulp, molasses etc. These wastes when mixed with other organic substrates become ideal mixtures for growth of earthworms. These wastes if stored in open field’s causes contamination in the environment and may cause several diseases in public health. But the governments have been unable to tackle the menace of solid waste pollution due to dearth of appropriate technologies, finance and space. Therefore, environment friendly and cost effective technologies for nutrient recycling or remediation of wastes are being advocated as an alternative means for conserving and replenishing natural resources of the ecosystems. Vermicomposting is one such technology that synergises microbial degradation with earthworm’s activity for reducing, reusing and recycling waste materials in a shorter span of time. Earthworm technology can convert sugar industrial wastes into valuable fertilizing material. The final product (vermicompost) produced during the process of vermicomposting is nutrient rich organic fertilizer with plant available nutrients such as nitrogen, potassium, calcium and phosphorus. In the present study an attempt has been made to document the role of earthworms in reuse of sugar industry waste.

Management of Sugar Industrial Wastes through Vermitechnology

The present paper discusses the role of earthworms in recycling of sugar industrial wastes. The wastes generated from sugar industry are pressmud, bagasse, bagasse fly ash, sugar cane trash, sugar beet mud, sugar beet pulp, molasses etc. These wastes when mixed with other organic substrates become ideal mixtures for growth of earthworms. These wastes if stored in open field’s causes contamination in the environment and may cause several diseases in public health. But the governments have been unable to tackle the menace of solid waste pollution due to dearth of appropriate technologies, finance and space. Therefore, environment friendly and cost effective technologies for nutrient recycling or remediation of wastes are being advocated as an alternative means for conserving and replenishing natural resources of the ecosystems. Vermicomposting is one such technology that synergises microbial degradation with earthworm’s activity for reducing, reusing and recycling waste materials in a shorter span of time. Earthworm technology can convert sugar industrial wastes into valuable fertilizing material. The final product (vermicompost) produced during the process of vermicomposting is nutrient rich organic fertilizer with plant available nutrients such as nitrogen, potassium, calcium and phosphorus. In the present study an attempt has been made to document the role of earthworms in reuse of sugar industry waste.

Earthworms modify microbial community structure and accelerate maize stover decomposition during vermicomposting

In the present study, maize stover was vermicomposted with the epigeic earthworm Eisenia fetida. The results showed that, during vermicomposting process, the earthworms promoted decomposition of maize stover. Analysis of microbial communities of the vermicompost by high-throughput pyrosequencing showed more complex bacterial community structure in the substrate treated by the earthworms than that in the control group. The dominant microbial genera in the treatment with the earthworms were Pseudoxanthomonas, Pseudomonas, Arthrobacter, Streptomyces, Cryptococcus, Guehomyces, and Mucor. Compared to the control group, the relative abundance of lignocellulose degradation microorganisms increased. The results indicated that the earthworms modified the structure of microbial communities during vermicomposting process, activated the growth of lignocellulose degradation microorganisms, and triggered the lignocellulose decomposition.

Vermistabilization of sugar beet (Beta vulgaris L) waste produced from sugar factory using earthworm Eisenia fetida: Genotoxic assessment by Allium cepa test

In the present study, sugar beet mud (SBM) and pulp (SBP) produced as a waste by-products of the sugar industry were mixed with cattle dung (CD) at different ratios on dry weight basis for vermicomposting with Eisenia fetida. Minimum mortality and highest population of worms were observed in 20:80 (SBM20) mixture of SBM and 10:90 (SBP10) ratios. However, increased percentages of wastes significantly affected the growth and fecundity of worms. Nutrients like nitrogen, phosphorus, sodium, increased from initial feed mixture to final products (i.e., vermicompost), while organic carbon (OC), C:N ratio and electrical conductivity (EC) declined in all the products of vermicomposting. Although there was an increase in the contents of all the heavy metals except copper, chromium, and iron in SBM, the contents were less than the international standards for compost which indicates that the vermicompost can be used in the fields without any ill effects on the soil. Allium cepa root chromosomal aberration assay was used to evaluate the genotoxicity of pre- and post-vermicomposted SBM to understand the effect of vermicomposting on the reduction of toxicity. Genotoxicity analysis of post-vermicomposted samples of SBM revealed 18-75% decline in the aberration frequencies. Scanning electron microscopy (SEM) was recorded to identify the changes in texture in the control and vermicomposted samples. The vermicomposted mixtures in the presence of earthworms confirm more numerous surface irregularities that prove to be good manure.