Response of Nitrous Oxide Flux to Addition of Anecic Earthworms to an Agricultural Field

The burrowing and feeding activities of earthworms may have a strong effect on the flux of N2O from agricultural soils. As such, shifts to agricultural management practices that increase the number of earthworms require an understanding of the role of earthworms in N2O dynamics. We conducted a field experiment to examine the effects of addition of anecic earthworms (Lumbricus terrestris) on N2O flux in a field previously planted with corn (Zea mays) in southern Rhode Island, USA. Plots were amended with (15NH4)2SO4 and either 0 (CTL) or 48 L. terrestris m-2 (EW). The flux of N2O, 15N2O and 15N2 was measured over 28 days between October and November 2008. The EW treatment had a significantly higher flux of N2O and 15N2O 1 - 3 days after 15NH4 addition. No treatment effects were observed on 15N2 flux. The addition of earthworms significantly increased (Day 1) and decreased (Day 12) the mole fraction of N2O relative to the CTL. Our results suggest that anecic earthworm additions can increase N2O flux from inorganic fertilizer N amendments, but the effects appear to short-lived.

Enhanced Lead Uptake by an Association of Plant and Earthworm Bioaugmented with Bacteria

Lead(Pb) is recorded as the second most hazardous pollutant of the environment.Previous cases of Pb bioremediation has been reported using single biosystem,but very few reports are available in biological approaches using multi-biosystems to achieve an enhanced bioremoval of Pb.The present study evaluated the capacity of a unique association of Pennisetum purpureum,a hyperaccumulator plant,and Lumbricus terrestris(earthworm)bioaugmented with a Pb-resistant bacterium,obtained from an industrially contaminated site and identified as isolate VITMVCJ1 Klebsiella variicola,to bioremediate Pb.The Pb-resistant gene was amplified in the bacterial isolate VITMVCJ1.The study was conducted for 60 d.Results verified that the bioaugmentation process enhanced1)root and shoot length of the plants,2)chlorophyll content of the plants,and 3)biofilm-producing ability of the microbes from the rhizosphere region of the plants.The total phenolic and flavonoid contents were found to be lower in the plants in the bioaugmented setup.The study also observed a reduction in the toxic effects of Pb on earthworm and plant.The earthworm was used to assess the Pb-induced stress syndrome after exposure to sublethal concentrations of Pb in the soil.A reduction in the content of malondialdehyde,a potential biomarker,on exposure to Pb demonstrated the role of the inoculum to alleviate heavy metal-induced stress in earthworms.All three symbionts accumulated Pb;Pb was accumulated mainly in the root of the plant,and poorly in the shoot of the plant and body mass of the earthworm.The bioaugmentation system exhibited stable and excellent uptake of Pb from the contaminated soils.The results of the present study suggest the positive effect of the synergistic association of the plant and earthworm with appropriate microbes for the bioremoval of Pb.

Investigation on the Mode of Action of the Traditional Chinese Medical Prescription-Yiqihuoxue Formula, an Effective Extravasation Treatment for Cerebral Vascular Microemboli in ApoE-/- mice

Objective: The objective of this study was to investigate the mechanisms underlying anti-embolism and extravasational effects of traditional Chinese medical prescription YiqiHuoxue(YQHX) formula in ApoE-/-mice with cerebral vascular microemboli. Materials and Methods: An ApoE-/-mice model with microemboli was developed by infusing fluorescently labeled heterologous fibrin-rich microparticles into the internal carotid artery of ApoE -/-gene knockout male mice through the common carotid artery. Before microemboli injection, the animals were randomly divided into four groups of 10 animals, treated daily for 6 weeks by intragastric administration: The ApoE-/-control group(physiological saline, 0.2 mL/10 g/d), YQHX group(0.2 ml/10 g/d), clopidogrel group(3 mg/kg/d), and atorvastatin group(3 mg/kg/d);a further group was constituted of normal male C57 BL/6 J mice(with the same genetic background as ApoE-/-mice;normal control group;no treatment;microemboli injection). The mice in each microemboli group were divided into three subgroups, the 2-h, 24-h, and 72-h subgroups, corresponding to the time after microemboli injection. Two hours(or 24 h or 72 h) after microemboli injection, the changes in aortic intima and brain tissue were analyzed by histopathology, the amounts of fluorescent emboli being measured by fluorescence microscopy image analysis. Comparison points included the microemboli induced loss of aorta functions and pathological changes, atherosclerotic plaque, brain ultrastructure and functions, and embolus extravasation. Results: Loss of aorta functions and adverse pathological changes, atherosclerotic plaque, serious damage in brain ultrastructure and functions, and reduced thrombus elimination were obviously serious in microemboli injected ApoE-/-mice. These symptoms were significantly relieved by the YQHX pretreatment:(i) the ratio of thrombus accumulation was increased with a significant decrease in thrombus extravasation in ApoE-/-mice, while YQHX induced an increased thrombus extravasation;(ii) the degree of aortic intimal thickening and brain tissue structural disorders were significantly increased in ApoE-/-mice, but overtly inhibited in the YQHX group;(iii) YQHX restored cell viability and homeostasis in the brain;(iv) YQHX regulated the expression of pro-and anti-inflammatory cytokines in the aorta;and(v) YQHX reduced cortical nerve nuclei pyknosis, edema, liquefaction, and necrosis induced by brain hypoxia, especially in the 24 h and 72 h groups. Conclusions: These findings indicate that the protective effects of YQHX on the brain against microemboli-induced injury may be attributed to the activation of extravasation mechanisms, which are involved in the cerebrovascular injury pathway and constitutively important in the progression of ischemic stroke.

Effects of zero burning waste on the quality of liquid fertilizer and vermicompost

Peatland is an important ecosystem in Indonesia.But in almost every dry season,drained peatlands have been subject to detrimental wildfires.As a response,the government has explicitly prohibited the burning of land since 2016.To clear the land of crop residues and conduct zero burning practices,one alternative method is to utilize the waste biomass to support the cultivation of earthworms(vermiculture).This study examined the quality of liquid fertilizers and compost produced from vermiculture using a completely randomized factorial design,consisting of two treatment factors.The first factor was worm type,with two species used in this research named Lumbricus rubellus and Eudrilus eugeniae.The second factor was the type of feed provided to the worms,comprising no feed(control),vegetable waste,and crop residue waste resulting from zero burning land preparation.The type of feed significantly affected the pH value of the liquid fertilizer produced by the vermiculture but did not significantly affect the nutrient contents(N,P,and K).The combination of the types of earthworms and types of feed significantly affected the pH value of the vermicompost.The combination of worm types and feed types had a significant effect on exchangeable Ca,but not on exchangeable Mg,Na,and K.In combination,green vegetable waste and Lumbricus rubellus produced the greatest effect on soil CEC.However,for Base Saturation,the control(no food)and Eudrilus eugeniae showed the highest value.Types of worms and types of feed had a significant effect on the exchangeable Mg,while the other three parameters made no significant differences.Zero burning waste and Eudrilus eugeniae provide a better exchangeable Ca and Mg.In contrast,no-feeding and Eudrilus eugeniae have a better effect on exchangeable Na and K.Types of worms and types of feed did not significantly affect the weight of worm colonies,but the addition of feed increased the weight of worms with the highest weight resulting from the use of zero burning waste feed.The results showed that crop residue wastes were potentially good as a feed for earthworms.