Composting Reduces the Vitality of H9N2 in Poultry Manure and EMCV in Pig Manure Allowing for an Environmentally Friendly Use of These Animal Wastes: A Preliminary Study.

In our study, we monitored the inactivation of two important viruses that are critical in animal husbandry throughout the world. To evaluate the influence of the composting process on inactivation of avian influenza virus (H9N2) in poultry manure compost (PMC) and Encephalomyocarditis virus (EMCV) in pig (swine) manure compost (SMC), the H9N2 and EMCV were injected in dialysis cassettes and buried in two different manure compost piles of poultry and pig manure, respectively. The highest temperature achieved in the PMC and SMC piles during the test period were 75 °C and 73.5 °C, respectively. At the completion of the composting for 168 h, inactivation effect appeared to be more sensitive in H9N2 than EMCV. The vitality of H9N2 decreased by 6.25±0.35 log10TCID50/mL to 0.0 log10TCID50/mL within 1 h of the composting. The vitality of EMCV decreased from 7.75±0.35 log10TCID50/mL to 1.50 log10TCID50/mL within 24 h of starting the composting process. However, the activation of EMCV was not decreased (from 7.75±0.35 to 7.50±0.71 log10TCID50/mL) in the control treatment (not inserted in composts) after 168h, while the activation of H9N2 in dialysis cassettes was significantly decreased (from 6.25±0.35 log10TCID50/mL to 2.00±0.6 log10TCID50/mL). Our study demonstrated the effectiveness of the composting treatment in inactivating the viruses studied, which was not the case with air treatment.

Growth and elemental uptake of Rhodes grass (Chloris gayana) grown in a mine waste-contaminated soil amended with fly ash-enriched vermicompost.

Vegetation cover in mine waste-affected soils is necessary to ensure sustainability of these fragile ecosystems. This study evaluated the potential of fly ash-enriched vermicompost (FV) to improve growth of Chloris gayana in a gold mine waste-affected soil. The treatments in the study were based on optimizing phosphorus supplied as vermicompost at 20 mg P and 40 mg P per kilogram soil which were compared to triple super phosphate (TSP) applied at 40 mg P/kg. The 40-mg P/kg FV treatment resulted in 38.4%, 164% and 182.5% significant increase in shoot height, shoot biomass and root biomass, respectively, relative to the control. The increased biomass was reflected in the plant tissue analysis where 40 mg P/kg FV had high P, Ca, Mg and K, though not significantly different to the 20-mg P/kg FV treatment. Amendment effect had no influence on plant tissue N, Pb, Cd and As. Chloris gayana uptake of Fe, Mn, Zn and Cr was significantly reduced with addition of the vermicompost, whereas Cu and B were significantly increased in the 40-mg P/kg FV treatment relative to the control though the increases did not exceed the critical concentration limits of these elements. Therefore, re-vegetation of mine waste-contaminated soils can be achieved with addition of FV at a rate of 40 mg P/kg FV. However, more studies may need to be done under field conditions to further evaluate the effectiveness of such vermicomposts in improving the re-vegetation capacity of mine waste-contaminated soils.

Positive effects of compost and vermicompost produced from tannery waste-animal fleshing on the growth and yield of commercial crop-tomato (Lycopersicon esculentum L.) plant.

Accumulation of solid waste has intensified with the increase in world population and industrialization. Most importantly, wastes of animal origin such as animal manures and tannery wastes are a major under-utilized resource in most countries with potential for utilization in crop production. This study evaluated the potential of solid state hydrolyzed tannery animal fleshing (SSF-ANFL) and submerged state hydrolyzed tannery ANFL (SmF-ANFL) vermicompost and compost amended soils on the growth, yield and chemical characteristics of tomatoes. It was interesting to observe that of most measured parameters, the SSF amended treatments resulted in significantly (P < 0.05) the highest measurements compared to the SmF amended treatments. On average, the SSF vermicompost resulted in a 10%, 8.9% and 14% higher plant height, stem girth and leaf numbers, respectively, compared to other treatments combined. It was also noteworthy that, for the same parameters, the SSF-ANFL based treatments resulted in a 7.7%, 10.1% and 7.4% higher plant height, stem girth and leaf numbers, respectively, relative to the SmF-ANFL based treatments. The study demonstrates the potential of animal fleshing based vermicomposts as nutrient sources in crop production.

Inoculation of fly ash amended vermicompost with phosphate solubilizing bacteria (Pseudomonas fluorescens) and its influence on vermi-degradation, nutrient release and biological activity.

Due to the crucial role played by microbes during vermicomposting, deliberate inoculation of composts with specialized microbes as a way of further optimizing the vermicomposting process has been suggested. This study evaluated the potential of inoculating fly ash - cow dung - waste paper vermicompost with phosphate solubilizing bacteria (P. fluorescens) in improving vermi-degradation, nutrient mineralization and biological activity. Incorporation of E. fetida plus P. fluorescens accelerated the biodegradation process as indicated by the significant decrease in C/N ratio (P = 0.0012) resulting in a final C/N ratio of 11 compared to the control which had C/N ratio of 18. Inoculation with P. fluorescens resulted in improved availability of Olsen P which amounted to 48.3% more Olsen P relative to the control. The inoculation also caused a big decrease in alkaline phosphatase activity but yielded the highest FDA activity. Inclusion of E. fetida with or without P. fluorescens did not significantly influence microbial growth, however, these two treatments had relatively more colony counts compared to the control. It is concluded that the interaction of E. fetida earthworms with P. fluorescens can optimize vermi-degradation, nutrient release and biological activity during vermicomposting of fly ash- cow dung - waste paper substrate. It would be interesting to establish whether Pseudomonas species inoculated at different rates, or their combination with nitrogen fixing bacteria would have the same or better effects on the vermicomposting of fly ash- cow dung - waste paper substrates.

Vermicomposting manure-paper mixture with igneous rock phosphate enhances biodegradation, phosphorus bioavailability and reduces heavy metal concentrations.

In organic soil fertility management, rock phosphate (RP) is gaining momentum as an acceptable phosphorus source, though much of this P is not bioavailable for plant uptake, particularly in igneous RP. This study evaluated the nutrient solubilization, biodegradation and heavy metal concentration when cow dung - waste paper mixture amended with increasing rates of igneous RP was vermicomposted with E. fetida. The cow dung was optimized to a C/N ratio of 30 using waste paper and amended with RP to provide 0%; 2%; 4% and 8% of elemental phosphorus on a dry w/w basis. Incorporation of RP at 2% and 8% P enhanced compost biodegradation resulting in a 12% and 22% significantly (P < 0.001) lower final C/N ratio, respectively, compared to the control; together with higher humification parameters. Amending the cow dung - waste paper mixture with 2%, 4% and 8% P as rock phosphate, resulted in a 39%; 50% and 65% more resin extractable P, respectively, relative to the control. Similarly, the bicarbonate extractable P, which represents the bioavailable P fraction, increased consistently by 19%; 28% and 33% following 2%, 4% and 8% RP application, respectively. Though incorporation of RP initially resulted in increased heavy metal levels, reductions of 40%; 35%; 35%; 40% and 45% for Cr, Cu, Cd, Pb and Zn, respectively, were observed in the 8% RP treatment after 8 weeks, due to the presence of earthworms. Vermicomposting with E. fetida significantly reduced heavy metals to levels below the maximum permissible concentration of potentially toxic elements in soils after 8 weeks. This study demonstrates the potential of optimized vermicomposting with igneous RP for generating nutrient rich organic fertilizers.

Optimizing the vermicomposting of organic wastes amended with inorganic materials for production of nutrient-rich organic fertilizers: a review.

Vermicomposting is a bio-oxidative process that involves the action of mainly epigeic earthworm species and different micro-organisms to accelerate the biodegradation and stabilization of organic materials. There has been a growing realization that the process of vermicomposting can be used to greatly improve the fertilizer value of different organic materials, thus, creating an opportunity for their enhanced use as organic fertilizers in agriculture. The link between earthworms and micro-organisms creates a window of opportunity to optimize the vermi-degradation process for effective waste biodegradation, stabilization, and nutrient mineralization. In this review, we look at up-to-date research work that has been done on vermicomposting with the intention of highlighting research gaps on how further research can optimize vermi-degradation. Though several researchers have studied the vermicomposting process, critical parameters that drive this earthworm-microbe-driven process which are C/N and C/P ratios; substrate biodegradation fraction, earthworm species, and stocking density have yet to be adequately optimized. This review highlights that optimizing the vermicomposting process of composts amended with nutrient-rich inorganic materials such as fly ash and rock phosphate and inoculated with microbial inoculants can enable the development of commercially acceptable organic fertilizers, thus, improving their utilization in agriculture.

Potential of Effective micro-organisms and Eisenia fetida in enhancing vermi-degradation and nutrient release of fly ash incorporated into cow dung-paper waste mixture.

The interactions between earthworms and microorganisms activity has prompted several researchers to evaluate the potential of artificially inoculating vermicomposts with additional specific microbes, with the intention of enhancing the vermicomposting process. This study evaluated the potential of inoculating fly ash (F)-cow dung-paper waste (CP) mixture (F-CP) with a specialized microbial cocktail called Effective micro-organisms (EM) during vermicomposting using Eisenia fetida earthworms. Inoculation with EM alone did not result in significantly (P>0.05) different changes in C/N ratio and dissolved organic matter (DOC) compared to the control with no EM and E. fetida. A significant interaction between EM and E. fetida presence resulted in greater changes in C/N ratio and DOC, which were not statistically different from the E. fetida alone treatment. It was also noteworthy that the activity of ß-Glucosidase was not influenced by the presence of EM, but was significantly influenced (P=0.0014) by the presence of E. fetida. However, the EM+E. fetida treatment resulted in a rate of weekly Olsen P release of 54.32mgkg(-1) which was 12.3%, 89.2% and 228.0% more that the E. fetida alone, EM alone and control treatments, respectively. Similarly, though higher in the E. fetida plus EM treatment, the phosphate solubilizing bacteria counts were not significantly different (P>0.05) from the E. fetida alone treatment. It is concluded that inoculation of F-CP composts with EM alone may not be beneficial, while combining EM with E. fetida results in faster compost maturity and significantly greater Olsen P release. It would be interesting to evaluate higher optimized rates of EM inoculation and fortifying EM cocktails with phosphate solubilizing bacteria (PSB) on F-CP vermicompost degradation and phosphorus mineralization.