Composting of toxic weed Parthenium hysterophorus: Nutrient changes, the fate of faecal coliforms, and biopesticide property assessment

Vermistabilization of mango tree pruning waste with five earthworm species: A biochemical and heavy metal assessment

Mango tree pruning results in high biomass output, which is a serious agricultural and environmental problem. Vermicomposting is a potential, fast and sustainable tool to address these challenges. For sixty days, the experiment was carried out in six vermireactors containing five earthworm species by Eudrilus eugeniae, Eisenia fetida, Aporrectodea rosea, Lumbricus rubellus, and Lampito mauritii, as well as composting (without earthworm) using mango tree pruning waste biomass along with cattle dung as an instant preferred feeding material for earthworms. The pH, TOC, C/N and C/P ratios of the waste were substantially reduced by the earthworm activity. However, after vermicomposting, the levels of macronutrients (N, P, K, Ca, Mg, S) and micronutrients (Fe, Mn, Zn, and Cu) and microbial count substantially increased. The TOC content of waste was reduced by 42-55%, and the C/N of vermicompost ranged from 5.58 to 11.38. The results showed that earthworm fecundity was highest in vermireactors containing Eudrilus eugeniae and Eisenia fetida. The current study was ultimately determine that vermicomposting using Eudrilus eugeniae or Eisenia fetida is an effective strategy for utilising mango tree pruning waste, ensuring environmental sustainability and improving farmer revenue.

Evaluation of composting parameters, technologies and maturity indexes for aerobic manure composting: A meta-analysis

Aerobic composting is an efficient method to recover nutrients from animal manure. However, there is considerable variability in the management and maturity criteria used across studies, and a systematic meta-analysis focused on compost maturity is currently lacking. This study investigated the optimal range of startup parameters and practical criteria for manure composting maturity, as well as the effectiveness of in situ technologies in enhancing composting maturity. Most maturity indexes were associated with composting GI, making it an ideal tool for evaluating the maturity of manure composts. GI increased with declined final C/N and (Final C/N)/(Initial C/N) (P < 0.01), and therefore a maturity assessment standard for animal manure composting was proposed: a mature compost has a C/N ratio ≤23 and a GI ≥70, while a highly mature compost has a GI ≥90 and preferably (Final C/N)/(Initial C/N) ≤0.8. Meta-analysis demonstrated that C/N ratio regulation, microbial inoculation and adding biochar and magnesium-phosphate salts are effective strategies for improving compost maturity. Specifically, a greater reduction in the C/N ratio during the composting process is beneficial for improving the maturity of compost product. The optimal startup parameters for composting have been determined, recommending an initial C/N ratio of 20-30 and an initial pH of 6.5-8.5. An initial C/N ratio of 26 was identified as the most suitable for promoting compost degradation and microorganism activity. The present results promoted a composting strategy for producing high-quality compost.

Parthenium hysterophorus's Endophytes: The Second Layer of Defense against Biotic and Abiotic Stresses

Parthenium hysterophorus L. is considered an obnoxious weed due to its rapid dispersal, fast multiplications, and agricultural and health hazards. In addition to its physio-molecular and phytotoxic allelochemical usage, this weed most probably uses endophytic flora as an additional line of defense to deal with stressful conditions and tolerate both biotic and abiotic stresses. The aim of this article is to report the diversity of endophytic flora (fungi and bacteria) in P. hysterophorus and their role in the stress mitigation (biotic and abiotic) of other important crops. Various endophytes were reported from P.&nbsp;hysterophorus and their roles in crops evaluated under biotic and abiotic stressed conditions. These endophytes have the potential to alleviate different stresses by improving crops/plants growth, development, biomass, and photosynthetic and other physiological traits. The beneficial role of the endophytes may be attributed to stress-modulating enzymes such as the antioxidants SOD, POD and APX and ACC deaminases. Additionally, the higher production of different classes of bioactive secondary metabolites, i.e., flavonoids, proline, and glutathione may also overcome tissue damage to plants under stressed conditions. Interestingly, a number of medicinally important phytochemicals such as anhydropseudo-phlegmcin-9, 10-quinone-3-amino-8-O methyl ether 'anhydropseudophlegmacin-9, 10-quinone-3-amino-8-Omethyl ether were reported from the endophytic flora of P. hysterophorus. Moreover, various reports revealed that fungal and bacterial endophytes of P. hysterophorus enhance plant growth-promoting attributes and could be added to the consortium of biofertilizers.

Juxtaposing the quality of compost and vermicompost produced from organic wastes amended with cow dung

Composting is a propitious technology to change bio-degradable solid waste into organic fertilizers. Considering this, five types of organic waste viz., leaf litter (Tectona grandis), water hyacinth (Eichhornia crassipes), cauliflower waste (Brassica oleracea var. botrytis), coir pith, and mushroom spent waste were composted with and without the use of earthworm (Eisenia fetida). The reaction (pH) and electrical conductivity of compost and vermicompost ranged from 6.98 to 7.45 and 6.97 to 7.36, 0.11 to 0.21 dSm^-1, and 0.11 to 0.25 dSm^-1, respectively. The chemical oxygen demand both the compost and vermicompost ranged from 687 to 1170 mg l^-1 and 633-980 mg l^-1 respectively. Cation exchange capacity (CEC) ranged from, 75 to 121 (c mol (p+) kg^-1, and 80 to 127 (c mol (p+) kg^-1, respectively. The C:N of compost and vermicompost varied from 16:1 to 33:1 and 12:1 to 19:1, respectively. The organic carbon content was decreased (18.3-38.7%), while secondary and micronutrient contents increased over the initial concentration. The NH₄⁺ and NO₃^- content of compost and vermicompost ranged from 270 to 510 mg kg^-1 and 230-430 mg kg^-1, 560 to 105 mg kg^-1, and 690-1100 mg kg^-1, respectively. The nitrification index (NH₄⁺/NO₃^-) ranged from 0.3 to 0.9 in composts and 0.3 to 0.6 in vermicomposts. The dehydrogenase and urease activity varied from 685 to 1696 μg g^-1 hr^-1 and 938-2549 μg TPF g^-1 day^-1 respectively. The bacteria, fungi and actinomycetes population were 2-3, 0.3-0.7 and 3-8 times more in vermicompost over the corresponding compost. This study confirmed that compared to compost, vermicompost showed better nutrients and microbial properties.

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.

Performance assessment of in-vessel composter through heavy metal immobilization and humification of Parthenium hysterophorus

The bioconversion of Parthenium hysterophorus was performed through rotary drum composter and examined the mechanism of humification and heavy metals immobilization in the process. The 20th day compost contains a significant increase in humic substances of 28.7% compared to the initial day mix. The bioavailable fractions of heavy metals have reduced by 30 to 55% in the 20th day compost compared to the initial day mix. The leaching potential of cadmium has been reduced by 69% in the 20th day compost. The immobile fractions (F5) of Cd, Ni and Pb have been increased to 100, 99 and 78% in the 20th day compost. The mitotic index was increased by 1.7 and 51.6% in 25% dosed compost extract compared to the control and P. hysterophorus extract respectively. The transition of heavy metals to immobile fraction indicated the biodegradation capability of P. hysterophorus through rotary drum composting.

Deciphering waste bound nitrogen by employing psychrophillic Aporrectodea caliginosa and priming of coprolites by associated heterotrophic nitrifiers under high altitude Himalayas

Himalayan ecosystem is characterized by its fragile climate with rich repositories of biodiversity. Waste collection and disposal are becoming increasingly difficult due to topographical variations. Aporrectodea caligenosa, a versatile psychrophillic soil dweller, is a useful biocatalyst with potent bio-augmented capability for waste treatment at low temperatures. Microcosm experiments were conducted to elucidate the comprehensive nature of biogenic nitrogen transformation to NH₄⁺ and NO₃⁻ produced by coupling of earthworm-microbes. Higher biogenic recovery of NH₄⁺-N from coprolites of garden soil (47.73 ± 1.16%) and Himalayan goat manure (86.32 ± 0.92%) with an increment of 14.12 and 47.21% respectively over their respective control (without earthworms) with a linear decline beyond 4th week of incubation was reported. NO₃^–-N recovery progressively sustained in garden soil and goat manure coprolites during entire incubation with highest 81.81 ± 0.45 and 87.20 ± 1.08 µg-N g⁻¹dry weight recorded in 6th and 5th week of incubation respectively and peak increments as 38.58 and 53.71% relative to respective control (without earthworms). Declined NH₄⁺–N in coprolites at low temperature (15.0 ± 2.0 °C) evidenced increased nitrification rates by taking over the process by abundant nitrifying microbes. Steady de-nitrification with progressive incubation on an average was 16.95 ± 0.46 ng-N g⁻¹ per week and 21.08 ± 0.87 ng-N g⁻¹ per week compared to 14.03 ± 0.58 ng-N g⁻¹ per week and 4.50 ± 0.31 ng-N g⁻¹ per week in respective control treatments. Simultaneous heterotrophic nitrification and aerobic denitrification (SHNAD) was found to be a prominent bioprocess at low temperature that resulted in high and stable total nitrogen and nitrate accumulation from garden soil and goat manure with relative recovery efficiency of 11.12%, 14.97% and 14.20%; 19.34%. A. caligenosa shows promising prospects for mass applicability in biogenic N removal from manure of Himalayan goat.

Effect of distillery sewage sludge addition on performance and bacterial community dynamics during distilled grain waste composting

This study evaluated the dynamics of physicochemical characteristics and bacterial communities during the co-composting of distilled grain waste (DGW) and distillery sewage sludge (SS), with DGW mono-composting as a control. Results showed that co-composting with SS significantly improved DGW degradation efficiency (61.38% vs. 54.13%) and end-product quality (seed germination index: 129.82% vs. 113.61%; N + P₂O₅ + K₂O: 9.08% vs. 5.28%), compared to DGW mono-composting. Microbial community analysis revealed that co-composting accelerated the bacterial community succession rate and enhanced the abundance of the phyla Proteobacteria, Firmicutes, Chloroflexi, and Deinococcota by 45.86%, 4.38%, 37.49%, and 15.29%, respectively. Network analysis showed that DGW-SS co-composting altered the interactions among the bacterial genera and improved bacterial community stability. Spearman correlation analysis indicated that the correlation between bacterial genera and environmental factors was more significant in DGW-SS co-composting. Therefore, co-composting of DGW and SS is a suitable strategy for the treatment of solid byproducts from spirit distilleries.

Fungal pretreatment facilitates the rapid and valuable composting of waste cardboard

This study investigates the waste cardboard (WCB) fungal pretreatment (Oligoporus placenta and Tremetes hirsuta) under monoculture and mixed culture and then composting for 35 d after mixing with cow dung in different ratios. Fungal pretreatment caused significant reduction in cellulose (28.3-35.8%), hemicellulose (61.4-68.4%), lignin (67.5-69.3%) content in WCB. Pretreated WCB showed better rates of decrement in total organic carbon (26.02-47.92%), carbon-to-nitrogen ratio (19.4-23.5), and lignocellulose contents, as well as incensement in total nitrogen (40.48-63.31%), total potassium (51.92-73.91%), germination index (88.5-102.0%), and elemental (Cu, Fe, Zn, Cr, and Mn) levels. Dehydrogenases (142-210 µg g^-1h^-1), and β-galactosidase (210-256 µg g^-1h^-1) activities indicates high microbial-mediated mineralization in setups. Results suggested that WCB could be used as a valuable substrate for valuable-added compost preparation after pretreating with a consortium of white-rot fungi.

Post-digestate composting benefits and the role of enzyme activity to predict trace element immobilization and compost maturity

The current study evaluated the quality of agricultural waste digestate by composting or co-composting with biogas feedstock (maize silage, food processing waste, or poultry litter). Temperature, phytotoxicity, C/N ratio, water extractable trace elements, and 14 enzyme activities were monitored. Temperature dropped earlier in digestate and maize silage co-composting pile, reducing time to maturity by 20 days. Composting and co-composting reduced phytotoxicity and C/N ratio, but increased immobilization of Al, Ba, Fe, Zn, and Mn at least by 40% in all piles. All the enzyme activities, except arylsulfatase and α-glucosidase, increased at the maturity phase and negatively correlated with organic matter content and most of trace elements. Post-digestate composting or co-composting with biogas feedstock is a promising strategy to improve digestate quality for fertilizer use, and selected enzyme activities can be indicators of compost maturity and immobilization of trace elements.

Current understanding in conversion and application of tea waste biomass: A review

Along with the increasing consumption of tea and its extracts, the amount of tea waste grows rapidly, which not only results in huge biomass loss, but also increases environmental stress. In past years, interest has been attracted on utilization of tea waste biomass, and a lot of work has been carried out. This review summarized the progress in conversion of tea waste by thermo-chemical and biological technologies and analyzed the property of the derived products and their performance in applications. It was found that biochar derived from tea waste had relatively large surface area, porous structures, and abundant functional groups, and could be used as bio-adsorbents and catalysts and electrochemical energy storage, while the cost of its largescale production should be evaluated. Profoundly, biological conversion, including ensiling and composting, was suggested to be an effective way to develop the tea waste biomass in practice due to its low-cost and specific functions.

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.

Management of banana crop waste biomass using vermicomposting technology

This study reports the vermicomposting of banana crop waste biomass by Eisenia fetida. Cow dung has been used as bulking agent in this study. The experiment was conducted in six vermireactors containing different ratios of banana leaf waste biomass (BL) and cow dung (CD) for 105 days. Earthworm activity significantly reduced pH, TOC, C:N and C:P ratio of the wastes. Whereas macronutrients and micronutrients content increased after vermicomposting. TOC content of wastes reduced by 40-64% and C:N ratio of the vermicomposts was in the range of 8.9-24.3. The benefit ratio for heavy metals (Cu, Fe, Zn, Cd, Pb, Mn and Cr) was in the range of 0.23-3.44. The results indicated that the growth and fecundity of the earthworms was best in the vermireactors having 20-40% BL. Finally, it was concluded that vermicomposting can be included in the overall scheme of banana crop waste management.

Production of compost with biopesticide property from toxic weed Lantana: Quantification of alkaloids in compost and bacterial pathogen suppression

Toxic weed Lantana camara foliage was composted with cow dung in 2:1 and 1:1 ratio (v/v) and changes in physicochemical characteristics, and faecal coliform bacterial population (Escherichia coli and Salmonella) was estimated for 35 d. Results showed a significant increase in total N (1.48-1.69-folds), Paval (6.87-9.19-folds), and total K (1.08-1.23-folds) content, while a decrease in C/N ratio (1.87-2.13-folds) and total organic carbon (1.12-1.46-folds) after composting process. Germination index (GI) results (> 70 %) suggested the non-toxic property of Lantana compost against tested rapeseed mustard seeds. E. coli and Salmonella population reduced to the safe limit after 35 d composting. Compost extract (sterilized and non-sterilized) (from 2:1 setup) showed about 0.88 - 1.08-, 0.88 - 0.96-, 0.83 - 0.94-, and 0.79-1.08-folds higher inhibition in Xanthomonas citrus, Xanthomonas campestris, Erwinia carotovora, and Pseudomonas aerogenosa, respectively, indicating strong pathogen-inhibiting substances in Lantanacompost. GC-MS analysis of compost extract indicated the presence of isomers of several compounds of biocidal property - hexadecane (9-hexyl and 9-octyl); 2-tridecyl ester; eicosane; tetradecane, heptacosane (1-chloro- and 9-hexyl); heptadecane, octadecane, 3-ethyl-5-(2-ethylbutyl)-, heptacosane, tetradecane, 2,6,10-trimethyl-, etc.). Result revealed that Lantana compost could be used as biomanure with biopesticide properties for sustainable organic farming system.

Vermicomposting of invasive weed Ageratum conyzoids: Assessment of nutrient mineralization, enzymatic activities, and microbial properties

Ageratum conyzoids biomass was vermicomposted with cow dung in 25 (T₂₅), 50 (T₅₀), and 75 (T₇₅) % (v/v) ratios and changes in physicochemical characteristics, enzymatic activities (proteases, dehydrogenases, β-galactosidase and phosphatases), and microbial population (bacterial, fungal, and actinomycetes) was recorded. Vermicomposting caused a decrease in pH, OC_total (27.3-35.3%), but an increase in N_total (59.6-69.9%), P_aval (53.8-148.7%), K_total (32.2-92.43%), and Ca_total (25.5-55.3%). The peaked enzymatic activities were recorded between 5 and 15 d. T₅₀ and T₇₅ showed the highest fold increase in bacteria (2.09-to-2.51), fungi (1.48-to-2.41), actinomycetes (1.52-to-1.79) population. The maximum biomass (883.67-1480 mg), cocoon production (85.33-145.33), and population build-up in earthworm were recorded in setups with a high content of Ageratum. Germination index (>80%) and soil respiration rate suggested the non-toxic impact of vermicomposted Ageratum. Results indicate that Ageratum could be biotransformed into toxic-free manure through vermitechnology.

Vermicomposting of duckweed (Spirodela polyrhiza) by employing Eisenia fetida: Changes in nutrient contents, microbial enzyme activities and earthworm biodynamics

This study investigated the vermicomposting of duckweed (DW) mixed with cow dung in 25 (T₂₅), 50 (T₅₀), 75 (T₇₅), 100% (T₁₀₀) ratio using Eisenia fetida under a 35 d trail. Decrease in pH, organic carbon (33.54-38.25%), C/N ratio (43.6-56.6%), but increase in total N (18.2-42.4%), P_aval (137-187%), and TK (7.76-79.4%) was recorded. Macro-elements (Mg, Fe, Zn, Mn, and Cu) also showed a many-fold increase in vermicomposts. T₅₀ and T₇₅ showed the highest mineralization rates. Activities of enzymes (proteases; dehydrogenases; β-galactosidase; acid phosphatase; and alkali phosphatases) and soil respiration rate was also higher in DW-rich waste mixtures. Seed bioassay test indicates the high agronomic application of DW-based vermicomposts. High earthworm biomass (975-1395 mg) and fecundity rate (1.53-4.07 cocoons worm^-1) was recorded in all vermi-setups suggesting the suitability of DW as a substrate for E. fetida culture.