Evolution Of Nitrogen Research Articles

Characteristics and Evolution of Nitrogen in the Heavy Components of Algae Pyrolysis Bio-Oil.

Algae pyrolytic bio-oil contains a large quantity of N-containing components (NCCs), which can be processed as valuable chemicals, while the harmful gases can also be released during bio-oil upgrading. However, the characteristics of NCCs in the bio-oil, especially the composition of heavy NCCs (molecular weight ≥200 Da), have not been fully studied due to the limitation of advanced analytical methods. In this study, three kinds of algae rich in lipids, proteins, and carbohydrates were rapidly pyrolyzed (10-25 °C/s) at different temperatures (300-700 °C). The bio-oil was analyzed using a Fourier transform ion cyclotron resonance mass spectrometer equipped with electrospray ionization, and the characteristics and evolution of nitrogen in heavy components were first obtained. The results indicated that the molecular weight of most heavy NCCs was distributed in the 200-400 Da range. N1-3 compounds account for over 60% in lipid and protein-rich samples, while N0 and N4 components are prominent in carbohydrate-rich samples. As temperature increases, most NCCs become more aromatic and contain less O due to the strong Maillard and deoxygenation reactions. Moreover, the heavier NCCs were promoted to form lighter compounds with more nitrogen atoms through decomposition (mainly denitrogenation and deoxygenation). Finally, some strategies to deal with the NCCs for high-quality bio-oil production were proposed.

Insights into heterotrophic denitrification diversity in wastewater treatment systems: Progress and future prospects based on different carbon sources.

Nitrate, as the most stable form of nitrogen pollution, widely exists in aquatic environment, which has great potential threat to ecological environment and human health. Heterotrophic denitrification, as the most economical and effective method to treat nitrate wastewater, has been widely and deeply studied. From the perspective of heterotrophic denitrification, this review discusses nitrate removal in the aquatic environment, and the behaviors of different carbon source types were classified and summarized to explain the cyclical evolution of carbon and nitrogen in global biochemical processes. In addition, the denitrification process, electron transfer as well as denitrifying and hydrolyzing microorganisms among different carbon sources were analyzed and compared, and the commonness and characteristics of the denitrification process with various carbon sources were revealed. This study provides theoretical support and technical guidance for further improvement of denitrification technologies.

Corn response to selected soil health indicators in a Texas drought

The phrase “soil health” describes the condition of a soil in terms of its physical, chemical, and biological properties. The relationship between soil health and crop yield is rather complex, and quantifying their spatial characteristics at field scale is often limited in the literature. To explore the significance and spatial characteristics of soil health and its indicators in crop production, field-based research was conducted in 2018 at the Blackland Research Center, Texas with the following objectives: (i) to quantify soil health indicators of the Haney Soil Health Tool across a corn field; (ii) to relate soil health status to drought-year corn yield using geospatial techniques; and (iii) to evaluate the relationship among soil health, corn yield, and soils types. We collected 218 samples from 0 to 10 cm soil depth in a 27-ha field following a 35 m × 35 m grid sampling scheme. Samples were analyzed for water extractable organic carbon (WEOC), total nitrogen, nitrate-nitrogen, ammoniacal-nitrogen, and 24-hr CO2 evolution (1-day CO2). Analyses results were used to calculate a soil health value based on Haney Soil Health Tool. The field had an average soil health value of 8.5 (±2.2), and corn yield of 2.9 t ha−1 (±1.3); however, corn yield was more variable (CV > 43%) than soil health (CV = 26.7%). Overall, soil samples with lower values of 1-day CO2, WEOC, and organic nitrogen indicated a lower soil health value, which generally corresponding to lower corn yield. Corn yield may be weakly predicted by soil health (Corn yield = −0.29 + 0.39 × Soil health value, R2 = 0.28). Soil type and rainfall exhibited measurable effects upon the calculated soil health value; corn yields were greater for Houston Black clay than Austin silt clay under drought-year conditions. The variation in drought-year corn yield can be explained by the soil health and its indicators in Texas Blackland soils. Further research is necessary to verify the relationship in differing soil types, management scenarios, and annual rainfall totals.

Kinetics and highly selective N2 conversion of direct electrochemical ammonia oxidation in an undivided cell using NiCo oxide nanoparticle as the anode and metallic Cu/Ni foam as the cathode

Ammonia oxidation and selectivity of nitrogen conversion were investigated over an Ni foam-supported NiCo oxide electrode synthesized using chemical precipitation and calcination. Characterization using XRD, SEM, and XPS determined the crystal phase and oxdiation state of the nano-textured particulate metal oxides. A voltammetry analysis showed that a M(II)/(III) (M = Ni and Co) redox reaction couple mediated the direct electron transfer of the nitrogen species. Batch electrochemical parameters, including the initial concentration of NH3 and the current density, were studied to evaluate the performance of the tested electrodes in the absence of chloride ions. The best N2 selectivity (40%) was obtained on the oxyhydroxide anode (H-Ni50Co50/Ni); further, as paired with an electroless Cu/Ni cathode, the total nitrogen (TN) loss in terms of gaseous nitrogen evolution was 76%. Consecutive kinetics was derived to assess the pathways of the NH3 conversion and the rates of the nitrogen cycle on different electrode pairs, such as Ni – Ni, Ni – Cu/Ni, and H-NiCo/Ni – Cu/Ni sets.

Synthesis of 2-Naphthylselenoacetic Acid Dialkylamides from 4-(2-Naphthyl)-1,2,3-selenadiazole

Under the action of potassium hydroxide, 4-(2-naphthyl)-1,2,3-selenadiazole readily decomposes with the evolution of nitrogen and the formation of potassium 2-(2-naphthyl)ethynylselenolate. Further treatment of the reaction mixture with an excess of secondary amines led to the formation of the corresponding dialkylamides of 2-naphthylselenoacetic acids in 64–92% yield.

Electrochemical advanced oxidation for treating ultrafiltration effluent of a landfill leachate system: Impacts of organics and inorganics and economic evaluation

We treated landfill leachate using electrochemical advanced oxidation processes (EAOPs) with a boron-doped diamond (BDD) anode. Before EAOPs, the leachate was first treated using biological treatment (anoxic–aerobic) and then ultrafiltration (hereafter referred as biopretreated UF landfill leachate). We explored impacts of organics and inorganics (nitrogen – and chloride – species) for various current densities (1–80 mA/cm2). We found that EAOPs enhanced biodegradability (BOD/COD ratio) significantly from < 0.03 to up to 0.78. COD destruction followed a pseudo-first order model, with the rate constant and electric energy per order ranging from 0.91 to 28.29 h−1 and 17.1 to 127.5 kWh m−3, respectively. The current efficiency (CE) was 100% for current density 1 mA/cm2 and CE decreased to 57.8% as the current density increased to 30 mA/cm2. The oxidation priority was in this order: COD > nitrogen – species > chloride – species. The evolution of nitrogen – and chloride – species and their oxidation mechanisms were also investigated. The impact of Fickian diffusion and electrical field driven charged ion transport (EFDCIT) on the total mass transport was examined using the Nernst-Planck equation. We found that the contribution of EFDCIT was similar to diffusion for current densities higher than 64 mA/cm2. Finally, we compared the costs for standalone EAOPs and EAOPs integrated with subsequent biological treatment for biopretreated UF landfill leachate and found that the lowest cost for the latter one that meets the effluent discharge criteria was only 0.76 USD/m3. Our study proved that EAOPs are technically and economically promising technology for leachate treatment.

Structural evolution and mechanical properties of nitrogen doped hydrogenated amorphous silicon thin films

Nitrogen doped hydrogenated amorphous silicon thin films, also recorded as silicon rich hydrogenated amorphous silicon nitride thin films, were deposited by plasma enhanced chemical vapor deposition. The structural evolution and mechanical properties of the films with different nitrogen contents were studied by Fourier transform infrared spectroscopy, Raman scattering spectroscopy, and the density and stress measurement system, respectively. The results showed that with the increase in ammonia gas flow rate from 0.5 SCCM to 20 SCCM, the tensile stress and the density of the films decreased from 600 MPa to 280 MPa and from 2.31 g/cm3 to 2.08 g/cm3, respectively. The hydrogen bonding configurations, hydrogen content, and structural ordering evolution were investigated to reveal the relationship between the structural and mechanical properties of the films. A qualitative model was proposed to explain the role of nitrogen and hydrogen atoms during the film growth.

Prediction of the release process of the nitrogen-extinguishant binary mixture considering surface tension

Nitrogen used for pressurization in the extinguisher can be partially dissolved in the fire extinguishing agent. Consequently, the evolution of the dissolved nitrogen has a significant effect on the release behavior of the fire extinguishing agent in a rapid process. In this article, a new model was developed to predict the critical pressure of the nitrogen evolution and the release process of the fire extinguishing agent was described in detail. According to the Peng–Robinson equation of state and van der Waals mixing rule, the effect of the dissolved nitrogen on the surface tension of the fire extinguishant was analyzed by considering surface phase and fugacity coefficient. A method to calculate the surface tension of the liquid agent dissolved with nitrogen was proposed. The results showed that the proposed model can determine the accurate critical pressure of the evolution of the dissolved nitrogen and further evaluated whether nitrogen escapes. At different initial filling pressures, in addition, the release process of the nitrogen extinguishant such as CF3I, FC218 (C3F8), HFC125 (C2HF5) and Halon1301 (CF3Br) was well predicted by the fluid release model when taking the surface tension and adiabatic index of the mixture into account. Compared with the previously obtained experimental data, the predictions obtained indicated that the present model can adequately describe the liquid and the gas mixture release stage in the release process of the nitrogen extinguishant.

Suppression of nano-hydride growth on Nb(100) due to nitrogen doping.

Niobium superconducting radio frequency (SRF) cavities enable the operation of modern superconducting accelerator facilities. These cavities do not approach the theoretical performance limits of Nb due to the deleterious effects of surface defects and chemical inhomogeneities such as Nb hydrides. Nitrogen doping is known to consistently increase the cavity performance and inhibit Nb hydride growth, but a comprehensive understanding of Nb hydride growth and suppression is not yet realized. Scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and density functional theory (DFT) calculations presented herein elucidate the real-time, nanoscale structural and electronic evolution of undoped, hydrogen doped, and hydrogen and nitrogen doped Nb(100) due to the growth and suppression of Nb nano-hydrides. DFT calculations in agreement with the experimental data found unique near-surface phases stabilized upon dopant incorporation. The experimental STM and STS results and DFT calculations reported herein provide the first in situ and real-time nanoscale visualization and characterization of the effects of nitrogen doping on Nb hydride suppression and growth. Such information allows for further optimization of nitrogen doping procedures and advances in the performance of SRF materials for next-generation SRF-based accelerators and free electron lasers.

Hydrothermal 15N15N abundances constrain the origins of mantle nitrogen.

Nitrogen is the main constituent of the Earth's atmosphere, but its provenance in the Earth's mantle remains uncertain. The relative contribution of primordial nitrogen inherited during theEarth's accretion versus that subducted from the Earth's surface is unclear1-6. Here we show that the mantle may have retained remnants of such primordial nitrogen. We use the rare 15N15N isotopologue of N2 as a new tracer of air contamination in volcanic gas effusions. By constraining air contamination in gases from Iceland, Eifel (Germany) and Yellowstone (USA), we derive estimates of mantle δ15N (the fractional difference in 15N/14N from air), N2/36Ar and N2/3He. Our results show that negative δ15N values observed in gases, previously regarded as indicating a mantle origin for nitrogen7-10, in fact represent dominantly air-derived N2 that experienced 15N/14N fractionation in hydrothermal systems. Using two-component mixing models to correct for this effect, the 15N15N data allow extrapolations that characterize mantle endmember δ15N, N2/36Ar and N2/3He values. We show that the Eifel region has slightly increased δ15N and N2/36Ar values relative to estimates for the convective mantle provided by mid-ocean-ridge basalts11, consistent with subducted nitrogen being added to the mantle source. In contrast, we find that whereas the Yellowstone plume has δ15N values substantially greater than that of the convective mantle, resembling surface components12-15, its N2/36Ar and N2/3He ratios are indistinguishable from those of the convective mantle. This observation raises the possibility that the plume hosts a primordial component. We provide a test of the subduction hypothesis with a two-box model, describing the evolution of mantle and surface nitrogen through geological time. We show that the effect of subduction on the deep nitrogen cycle may be less important than has been suggested by previous investigations. We propose instead that high mid-ocean-ridge basalt and plume δ15N values may both be dominantly primordial features.

Onion waste recycling by vermicomposting: nutrients recovery and agronomical assessment

Vermicomposting is an efficient technology to treat organic wastes and recover nutrients for agricultural purposes. The aim of this work was to assess the feasibility of vermicomposting to treat onion waste and the resulting vermicompost as an agricultural input. Onion waste from the food industry was mixed with cow dump and vermicomposted for 154 days at the pilot scale. The evolution of temperature, moisture, pH, electrical conductivity and total nitrogen was monitored during the vermicomposting process. Finally, the vermicompost was characterized to assess its potential use in agriculture. The vermicomposting process was carried out at moisture around 85% and maximum temperature of 33 °C. The pH decreased throughout the process, while the electrical conductivity increased. Total nitrogen concentration decreased during the first days but then was constant. The final vermicompost was a mature material (C/N = 13), with considerable carbon content (15.7%), lightly basic and with low electrical conductivity. Nutrient equilibria were 1:8:3 with appreciable content of other nutrients such as Ca, Mg and S. Toxic elements were in low concentration and below the legal threshold. The vermicomposting of onion waste with cow dump is a feasible technology to treat this waste and produce a valuable agricultural input to close the nutrient circle.

Intervention of Nitrogen Evolution on Species Diversity of Broad-leaved Forest Plants in Xianweng Mountain

Nitrogen evolution is one of the important factors driving biodiversity change. It is generally believed that the species diversity structure will be changed, and under the conditions of exogenous nitrogen addition, grasses and deciduous shrubs have a competitive advantage over hybrid grasses and evergreen shrubs. For the competition between plants in the same life type, the interaction between different life-type plants is not involved. Therefore, from the changes in forest ecosystem structure and nitrogen elements, the response of different life-type plants to nitrogen evolution can be further explored. The lower plant species of the deciduous broad-leaved forest-Mongolian carp are studied, and different gradients of nitrogen (0, 40, 80, 120 kg N·ha−1·yr−1) are added to the four gradients of extraneous nitrogen effects of nitrogen evolution on forest biodiversity in the north temperate zone. The results of five-year continuous nitrogen addition experiments showed that nitrogen addition significantly reduced the species richness and diversity of understory plants, and changed the species composition of the community. Nitrogen addition increased the species richness of shrub plants and diversity, reduced the richness of herbaceous plants, and reduced the important value of grasses and increased the important value of hybrid grasses. The study showed that long-term nitrogen addition significantly changed the species composition of understory plants, and the response of different life-type plants to nitrogen addition was also different.

The Effect of Drying Temperature on Nitrogen Loss and Pathogen Removal in Laying Hen Manure

Exhaust air from the poultry houses or ambient hot air are normally utilized to dry the laying hen manure extensively in the summer in China. The drying process can not only reduce the moisture of lay hen manure but can also have a degerming effect. However, the ammonia emission is considered as one of the major issues of laying hen manure drying and air pollution scouse. Then, it is not clear that whether the ammonia emission increased using the hot ambient air to dry laying hen manure in summer and whether increasing the temperature can inactivate more bacteria during low temperature drying process. Therefore, the main works of this study were to investigate the evolution of ammonium nitrogen (NH4-N) content, organic nitrogen (Org-N) content, and total bacteria count vs. time during the low-temperature drying process of laying hen manure at different drying temperatures. The results showed that increasing drying temperature can reduce the energy consumption of the manure drying system, but can increase the loss of NH4-N. The Org-N content among the three drying temperatures within same drying time was not significantly different (p &gt; 0.05), which suggested that increasing the temperature did not accelerate the degradation of Org-N during low-temperature drying process. Low-temperature drying had weak destruction of bacteria in laying hen manure and the end dried manure still had a great number of bacteria.

Effects of calcium on the evolution of nitrogen during pyrolysis of a typical low rank coal

This study aims to investigate the effects of calcium on the migration of nitrogen in coal (coal-N) to N-containing gas species, particularly, NH3 and HCN (volatile-N) in volatiles, as well as the chemical transformation of the N in char during coal pyrolysis under different temperatures. The pyrolysis experiments of Shengli brown coal and its derived coal samples loaded with different contents of calcium were conducted under 600–800 °C in a novel fluidized bed reactor. The experimental results showed that during coal pyrolysis, the generation of NH3 is mainly derived from secondary reactions among volatiles, tar and char with the catalytic effect of mineral matter, especially calcium in coal. Increasing pyrolysis temperature from 600 to 800 °C could enhance the release of N in coal to volatiles. Meanwhile, the increased pyrolysis temperature could also inhibit the generation of NH3 while facilitating the formation of HCN. The release of HCN is more sensitive to pyrolysis temperatures. Specifically, under higher pyrolysis temperatures, more N-containing structures in coal would become thermally unstable and crack into HCN; On the other hand, higher pyrolysis temperature could also enhance the decomposition of N in coal to N-containing species in tar or N2, thus reducing the release of HCN and NH3. Nitrogen in tar could either undergo secondary decomposition reactions, generating NH3, HCN, N2 and other N-containing species in gas phase, or experience condensation polymerization by forming macromolecular structure and be retained in char at high pyrolysis temperatures. Calcium could significantly restrain the release of N from coal, thus reducing the yields of NH3 and HCN. During coal pyrolysis, calcium catalytically enhances the fracture and combination of chemical bonds, generating abundant free radicals. These free radicals could continuously attack N-containing structures and consequently release the N-containing gaseous products, such as NH3, HCN, N2 etc., resulting in the decrease of N in char. Calcium also plays important roles in nitrogen transformation in char during coal pyrolysis by catalytically intensifying the transformation of N in char from pyridinic nitrogen (N-6) and pyrrolic nitrogen (N-5) to quaternary type nitrogen (N-Q) during coal pyrolysis.

Thermal evolution and migration behavior of ion-implanted nitrogen in ZnO:In-N films

Thermal evolution and migration behavior of nitrogen (N) dopants in indium (In) doped ZnO films implanted with high-dose N ions (ZnO:In-N) were investigated by means of experiment and first-principles calculations. The results demonstrate that N-dopants have poor thermal stability, which has a significant impact on N local chemical states. In particular, two different temperature regions can clearly be distinguished in the annealing process. At low-temperature region, the interaction of substitutional nitrogen (NO) acceptor and interstitial nitrogen (Ni) starts to occur, which leads to a decrease in NO acceptor and the formation of additional molecular nitrogen at oxygen site [(N2)O]. In contrast, at high-temperature region, annealing favors energetically the generation of abundant oxygen vacancies near the surface and simultaneously induces the serious out-diffusion of N-dopants. Combined with the calculated migration barriers, oxygen vacancies are deemed to assist the out-diffusion of N-dopants via a vacancy mechanism. This work provides insights into the formation and evolution of different N-related defects and their interaction with intrinsic defects.

New Heterometallic Co(III) Pivalate Complexes with 1,3-(CH2)3(NH2)2

The reactions of the complex [Co(DAP)2(Piv)2] · Piv (Ia), where Piv is the pivalate anion, DAP is 1,3-diaminopropane, with Cd(II) and Li(I) pivalates afford heterometallic compounds, molecular complex [CdCo(DAP)2(Piv)5] (I) and polymeric complex [LiCo(DAP)2(Piv)4]n (II) (CIF files CCDC nos. 1908223 and 1908224, respectively). According to X-ray photoelectron spectroscopy, the electronic structure of cobalt ions in complexes Ia and I corresponds to low-spin Co(III) surrounded by strong-field ligands. The thermal destruction of I and II, studied by synchronous thermal analysis, includes stages of desorption of solvate molecules, destruction of the 1,3-diaminopropane molecule with nitrogen evolution, and degradation of carboxylate anions. The final product of thermolysis of I is the complex oxide CdCoO2.

Effects of activation on the properties of electrospun carbon nanofibers and their adsorption performance for carbon dioxide

Microporous carbon nanofibers were prepared by stabilization, carbonization, and activation of electrospun polyacrylonitrile-based nanofibers. The average fiber diameters of activated electrospun carbon nanofibers (AECNF) samples, ranging from 280 to 500 nm, generally decreased with increasing activation degree. The evolution of nitrogen was observed during the fabricated processes, and the predominant nitrogen functionalities were shifted to those at higher binding energies when the activation degree increased. The N/C ratios on the surface of the samples were affected significantly by the activation temperature and activation time. The AECNF samples were featured with microporosity and the ultramicropores were also newly formed with increasing activation degree. It was expected that the activation process involved a three-step predominant reaction: the transformation from ultramicropores to submicropores, the micropore enlargement reaction followed by the micropore formation reaction. The equilibrium CO2 adsorption capacities could achieve 1.2 mmole/g (0.15 atm) and 3.2 mmole/g (1 atm) at 298 K. The CO2 uptake at low partial pressure and ultramicroporosity of the adsorbents were related to the isosteric heat of adsorption. The AECNF samples for CO2 adsorption had an energetically heterogeneous surface and Freundlich equation provided a satisfactory fit. Synergetic effects of microporosity and nitrogen content of AECNF on CO2 uptakes at low pressure were observed.

Pulsed Laser Activation of Carbene Bioadhesive Boosts Bonding Strength

AbstractLight‐activated tissue adhesives are limited to low light doses (50 J) and intensities (&lt;1 W cm−2) due to photo‐to‐thermal heat generation. Low intensities have the disadvantage of limited penetration depths with retarded crosslinking kinetics, which impairs carbene‐based crosslinking strategies that compete with nitrogen evolution and gas nucleation. These limitations are circumvented by a trade‐off between high‐intensity activation while reducing the exposure surface area. Continuous or pulsed activation by line scanning the carbene precursor adhesive allows curing a higher surface area/volume ratio while preventing localized heat generation. By optimizing irradiation with a pulsed laser scan, the adhesion strength is improved by 17‐fold over ultraviolet A (UVA) light emitting diodes (LEDs) and is on par with bioadhesive gold standard of topical cyanoacrylates. Overall, this improved method of photo‐activation applies to other industrial and clinical photocuring adhesives where limits on UVA dose constrain exposure intensities.

Partitioning of nitrogen during melting and recycling in subduction zones and the evolution of atmospheric nitrogen

The subduction of sediment connects the surface nitrogen cycle to that of the deep Earth. To understand the evolution of nitrogen in the atmosphere, the behavior of nitrogen during the subduction and melting of subducted sediments has to be estimated. This study presents high-pressure experimental measurements of the partitioning of nitrogen during the melting of sediments at sub-arc depths. For quantitative analysis of nitrogen in minerals and glasses, we calibrated the electron probe micro-analyzer on synthetic ammonium feldspar to measure nitrogen concentrations as low as 500 μg g−1. Nitrogen abundances in melt and mica are used together with mass balance calculations to determine DN(Mica/Melt), DN(Fluid/Mica), and DN(Fluid/Melt). Calculated partition coefficients correspond to expected values for NH4+, which behaves similarly to Rb+ due to its nearly identical size. Nitrogen partitioning between fluid and melt (DN(Fluid/Melt)) and fluid and bulk residue (melt+mica) (DN(Fluid/Bulk)) increase linearly with temperature normalized to pressure. This linear relationship can be used to calculate DN(Fluid/Melt) and DN(Fluid/Bulk) for slab melts from 800 to 1200 °C following: DNFluid/Melt=0.012×T°CPGPa−2.02 and DNFluid/Bulk=0.04×T°CPGPa−8.48.We used these partition coefficients to quantify the amount of N recycled into the mantle as 50 ± 6% of today's atmospheric N. Depending on the rate of mantle N degassing we calculated 4 different scenarios for atmospheric pN2 evolution. All 4 scenarios estimate pN2 to be 8–12% higher at the beginning of the Phanerozoic. These estimates diverge towards the past due to uncertainties in the mechanism and magnitude of N degassing from the mantle. Assuming degassing of N in the past was close to modern degassing rates from MORB, pN2 was up to 40% higher at the onset of plate tectonics at 3–4 Ga. However, degassing rates were probably higher than this: assuming 10× and 20× times higher rates at the onset of plate tectonics leads to pN2 within 20% of modern values. If N degassing from the mantle is increased to 40× the modern MORB rate, pN2 in the Archean would have been 50% lower than today's, which is in accordance with observations from paleoatmospheric studies.

Release of Nitrogen and CO2 evolution from Manures and Fertilizers applied in Soil: An incubation study

Carbon and nitrogen mineralization and urease activity were evaluated under wet and dry climate with input of manures and fertilizers. Results indicates that release of NH4+ and NO3N and CO2 evolution was maximum during 7 to 21 days after incubation (DAI) with recommended dose of fertilizer and decreased later on. Release of N and C took place after 21 DAI where manures applied either with neem cake or fertilizers. The evolution of CO2C and total nitrogen were significantly higher in poultry manure combined with neem cake and FYM as compared to vermicompost along with neem cake. The NH4+N released during the entire incubation period were higher than NO3N. Combination of neem cake, poultry manure and FYM had higher enzyme activity than other treatments. Application of commercial fertilizers registered significantly higher CO2C fluxes upto 35 DAI compared to manures and control. Overall effect of manures applied with neem cake or their combination proved better in the treatments for release of nitrogen. Correlation study between CO2C flux, total N and urease activity showed that a positive relationship (p&lt;0.05) with each others.