scholarly journals Comparison of slant open-path flux gradient and static closed chamber techniques to measure soil N<sub>2</sub>O emissions

2019 ◽  
Vol 12 (2) ◽  
pp. 1095-1102 ◽  
Author(s):  
Mei Bai ◽  
Helen Suter ◽  
Shu Kee Lam ◽  
Thomas K. Flesch ◽  
Deli Chen
Keyword(s):  
Measurement Techniques ◽  
Chicken Manure ◽  
High Temporal Resolution ◽  
N2o Emissions ◽  
Emission Rates ◽  
Closed Chamber ◽  
Flux Gradient ◽  
Open Path ◽  
Slant Path ◽  
Vegetable Farm

Abstract. Improving direct field measurement techniques to quantify gas emissions from cropped agricultural fields is challenging. We compared nitrous oxide (N2O) emissions measured with static closed chambers to those from a newly developed aerodynamic flux gradient (FG) approach. Measurements were made at a vegetable farm following chicken manure application. The FG calculations were made with a single open-path Fourier transform infrared (OP-FTIR) spectrometer (height of 1.45 m) deployed in a slant-path configuration, sequentially aimed at retro reflectors at heights of 0.8 and 1.8 m above ground. Hourly emissions were measured with the FG technique, but once a day between 10:00 and 13:00 with chambers. We compared the concurrent emission ratios (FG∕chamber) of these two techniques and found N2O emission rates from a celery crop farm measured at midday by FG were statistically higher (1.22–1.40 times) than those from the chambers measured at the same time. Our results suggest the OP-FTIR slant-path FG configuration worked well in this study: it was sufficiently sensitive to detect the N2O gradients over our site, giving high temporal resolution N2O emissions corresponding to a large measurement footprint.

scholarly journals Comparison of flux gradient and chamber techniques to measure soil N<sub>2</sub>O emissions

2018 ◽  
Author(s):  
Mei Bai ◽  
Helen Suter ◽  
Shu Kee Lam ◽  
Thomas K. Flesch ◽  
Deli Chen
Keyword(s):  
Measurement Techniques ◽  
N2o Emission ◽  
Chicken Manure ◽  
High Temporal Resolution ◽  
N2o Emissions ◽  
Emission Rates ◽  
Flux Gradient ◽  
Large Measurement ◽  
Slant Path ◽  
Vegetable Farm

Abstract. Improving the direct field measurement techniques to quantify gases emissions from the large agriculture farm is challenging. We compared nitrous oxide (N2O) emissions measured with static chambers to those from a newly developed micrometeorological flux gradient (FG) approach. Measurements were made at a vegetable farm following chicken manure application. The FG calculations were made with a single open-path Fourier transform infrared (OP-FTIR) spectrometer (height of 1.45 m) deployed in a slant-path configuration: sequentially aimed at retro reflectors at heights of 0.8 and 1.8 m above ground. Hourly emissions were measured with the FG technique, but once a day between 10:00 and 13:00 with chambers. We compared the concurrent emission ratios (FG/Chambers) between these two techniques, and found N2O emission rates from celery crop farm measured at mid-day by FG were statistically higher (1.4 times) than those from the chambers measured at the same time. Our results suggest the OP-FTIR slant-path FG configuration worked well in this study: it was sufficiently sensitive to detect the N2O gradients over our site, giving high temporal resolution N2O emissions corresponding to a large measurement footprint.

scholarly journals Nitrous Oxide Emission from Organic Fertilizer and Controlled Release Fertilizer in Tea Fields

2017 ◽  
Author(s):  
Meihua Deng ◽  
Mudan Hou ◽  
Naoko Ohkama-Ohtsu ◽  
Tadashi Yokoyama ◽  
Haruo Tanaka ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Controlled Release ◽  
Green Tea ◽  
Organic Fertilizer ◽  
Organic Fertilizers ◽  
Chicken Manure ◽  
Fertilizer Treatment ◽  
N2o Emissions ◽  
Closed Chamber ◽  
Controlled Release Fertilizers

A field experiment was conducted for 2 years in Green Tea Laboratory of Saitama Prefectural Agriculture and Forestry Research Center, Iruma, Saitama, Japan from March 2014 to December 2015. Controlled release fertilizers (CRF) or organic fertilizers (ORG) which is the mixture of chicken manure and oil cakewere applied with the amount of 450 kg N ha-1 yr-1 in 2014 and 397 kg N ha-1 yr-1 in 2015. Nitrous oxide (N2O) emissionsfrom soil in green tea fields were measured by closed chamber method. The results showed that CRF has significantly lower N2O compared to ORG. The cumulative N2O emissions from CRF accounted for 51% of N2O emissions from ORG fields and 138% of control with no fertilizer treatment. The N2O flux from the row was higher than that of under the canopy, since fertilizer were applied on the row. However the total emission from the area between the rows was lower than that under the canopy because of the area ratio of row and canopy was 1:5.

scholarly journals Pineapple Residue Ash Reduces Carbon Dioxide and Nitrous Oxide Emissions in Pineapple Cultivation on Tropical Peat Soils at Saratok, Malaysia

2021 ◽  
Vol 13 (3) ◽  
pp. 1014
Author(s):  
Liza Nuriati Lim Kim Choo ◽  
Osumanu Haruna Ahmed ◽  
Nik Muhamad Nik Majid ◽  
Zakry Fitri Abd Aziz
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Peat Soil ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Peat Soils ◽  
Closed Chamber ◽  
Npk Fertilizers ◽  
Npk Fertilizer ◽  
Carbon Dioxide Co2

Burning pineapple residues on peat soils before pineapple replanting raises concerns on hazards of peat fires. A study was conducted to determine whether ash produced from pineapple residues could be used to minimize carbon dioxide (CO2) and nitrous oxide (N2O) emissions in cultivated tropical peatlands. The effects of pineapple residue ash fertilization on CO2 and N2O emissions from a peat soil grown with pineapple were determined using closed chamber method with the following treatments: (i) 25, 50, 70, and 100% of the suggested rate of pineapple residue ash + NPK fertilizer, (ii) NPK fertilizer, and (iii) peat soil only. Soils treated with pineapple residue ash (25%) decreased CO2 and N2O emissions relative to soils without ash due to adsorption of organic compounds, ammonium, and nitrate ions onto the charged surface of ash through hydrogen bonding. The ability of the ash to maintain higher soil pH during pineapple growth primarily contributed to low CO2 and N2O emissions. Co-application of pineapple residue ash and compound NPK fertilizer also improves soil ammonium and nitrate availability, and fruit quality of pineapples. Compound NPK fertilizers can be amended with pineapple residue ash to minimize CO2 and N2O emissions without reducing peat soil and pineapple productivity.

scholarly journals Open-path, quantum cascade-laser-based sensor for high-resolution atmospheric ammonia measurements

2014 ◽  
Vol 7 (1) ◽  
pp. 81-93 ◽  
Author(s):  
D. J. Miller ◽  
K. Sun ◽  
L. Tao ◽  
M. A. Khan ◽  
M. A. Zondlo
Keyword(s):  
Gas Phase ◽  
Quantum Cascade Laser ◽  
High Temporal Resolution ◽  
Reduced Pressure ◽  
Total Uncertainty ◽  
Atmospheric Ammonia ◽  
Quantum Cascade ◽  
Open Path ◽  
Time Calibration

Abstract. We demonstrate a compact, open-path, quantum cascade-laser-based atmospheric ammonia sensor operating at 9.06 μm for high-sensitivity, high temporal resolution, ground-based measurements. Atmospheric ammonia (NH3) is a gas-phase precursor to fine particulate matter, with implications for air quality and climate change. Currently, NH3 sensing challenges have led to a lack of widespread in situ measurements. Our open-path sensor configuration minimizes sampling artifacts associated with NH3 surface adsorption onto inlet tubing and reduced pressure sampling cells, as well as condensed-phase partitioning ambiguities. Multi-harmonic wavelength modulation spectroscopy allows for selective and sensitive detection of atmospheric pressure-broadened absorption features. An in-line ethylene reference cell provides real-time calibration (±20% accuracy) and normalization for instrument drift under rapidly changing field conditions. The sensor has a sensitivity and noise-equivalent limit (1σ) of 0.15 ppbv NH3 at 10 Hz, a mass of ~ 5 kg and consumes ~ 50 W of electrical power. The total uncertainty in NH3 measurements is 0.20 ppbv NH3 ± 10%, based on a spectroscopic calibration method. Field performance of this open-path NH3 sensor is demonstrated, with 10 Hz time resolution and a large dynamic response for in situ NH3 measurements. This sensor provides the capabilities for improved in situ gas-phase NH3 sensing relevant for emission source characterization and flux measurements.

scholarly journals Short-term effects of biogas digestate and cattle slurry application on greenhouse gas emissions from high organic carbon grasslands

2014 ◽  
Vol 11 (4) ◽  
pp. 5765-5809 ◽  
Author(s):  
T. Eickenscheidt ◽  
A. Freibauer ◽  
J. Heinichen ◽  
J. Augustin ◽  
M. Drösler
Keyword(s):  
Organic Carbon ◽  
Application Rate ◽  
Organic Fertilizers ◽  
Organic Soils ◽  
N2o Emissions ◽  
Cattle Slurry ◽  
Closed Chamber ◽  
Chamber Method ◽  
Biogas Digestate ◽  
N2o Fluxes

Abstract. The change in the German energy policy resulted in a strong development of biogas plants in Germany. As a consequence, huge amounts of nutrient rich residues remain from the fermentative process, which are used as organic fertilizers. Drained peatlands are increasingly used to satisfy the huge demand for fermentative substrates and the digestate is returned to the peatlands. However, drained organic soils are considered as hot spots for nitrous oxide (N2O) emissions and organic fertilization is additionally known to increase N2O emissions from managed grasslands. Our study addressed the questions (a) to what extent biogas digestate and cattle slurry application increase N2O, methane (CH4) and ammonia (NH3) fluxes as well as the mineral nitrogen use efficiency (NUEmin), and (b) how different soil organic matter contents (SOM) promote the production of N2O. The study was conducted at two areas within a grassland parcel, which differed in their soil organic carbon (SOC) contents. At each area (named Corg-medium and Corg-high) two sites were established, one was fertilized five times with biogas digestate and one with cattle slurry. For each treatment, fluxes of N2O and CH4 were measured over two years using the closed chamber method. For NH3 measurements we used the calibrated dynamic chamber method. On an annual basis the application of biogas digestate significantly enhanced the N2O fluxes compared to the application of cattle slurry and additionally increased the NUEmin. Furthermore, N2O fluxes from the Corg-high site significantly exceeded N2O fluxes from the Corg-medium sites. Annual cumulative emissions ranged from 0.91 ± 0.49 kg N ha−1 yr−1 to 3.14 ± 0.91 kg N ha−1 yr−1. Significantly different CH4 fluxes between the investigated treatments or the different soil types were not observed. Cumulative annual CH4 exchange rates varied between −0.21 ± 0.19 kg C ha−1 yr−1 and −1.06 ± 0.46 kg C ha−1 yr−1. Significantly higher NH3 losses from treatments fertilized with biogas digestate compared to those fertilized with cattle slurry were observed. The total NH3 losses following splash plate application were 18.17 kg N ha−1 for the digestate treatments and 3.48 kg N ha−1 for the slurry treatments (36% and 15% of applied NH4&amp;plus;-N). The observed linear increase of 16 days cumulative N2O-N exchange or rather annual N2O emissions, due to a higher mean groundwater level and a higher application rate of NH4+-N, reveal the importance of site adapted N fertilization and the avoidance of N surpluses in Corg rich grasslands.

scholarly journals Reviews and syntheses: Soil N<sub>2</sub>O and NO emissions from land use and land-use change in the tropics and subtropics: a meta-analysis

2015 ◽  
Vol 12 (23) ◽  
pp. 7299-7313 ◽  
Author(s):  
J. van Lent ◽  
K. Hergoualc'h ◽  
L. V. Verchot
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Nitrogen Availability ◽  
Meta Analysis ◽  
Forest Conversion ◽  
N2o Emissions ◽  
Emission Rates ◽  
Soil N ◽  
The Tropics ◽  
No Emissions

Abstract. Deforestation and forest degradation in the tropics may substantially alter soil N-oxide emissions. It is particularly relevant to accurately quantify those changes to properly account for them in a REDD+ climate change mitigation scheme that provides financial incentives to reduce the emissions. With this study we provide updated land use (LU)-based emission rates (104 studies, 392 N2O and 111 NO case studies), we determine the trend and magnitude of flux changes with land-use change (LUC) using a meta-analysis approach (44 studies, 135 N2O and 37 NO cases) and evaluate biophysical drivers of N2O and NO emissions and emission changes for the tropics. The average N2O and NO emissions in intact upland tropical forest amounted to 2.0 ± 0.2 (n = 90) and 1.7 ± 0.5 (n = 36) kg N ha−1 yr−1, respectively. In agricultural soils annual N2O emissions were exponentially related to N fertilization rates and average water-filled pore space (WFPS) whereas in non-agricultural sites a Gaussian response to WFPS fit better with the observed NO and N2O emissions. The sum of soil N2O and NO fluxes and the ratio of N2O to NO increased exponentially and significantly with increasing nitrogen availability (expressed as NO3− / [NO3−+NH4+]) and WFPS, respectively; following the conceptual Hole-In-the-Pipe model. Nitrous and nitric oxide fluxes did not increase significantly overall as a result of LUC (Hedges's d of 0.11 ± 0.11 and 0.16 ± 0.19, respectively), however individual LUC trajectories or practices did. Nitrous oxide fluxes increased significantly after intact upland forest conversion to croplands (Hedges's d = 0.78 ± 0.24) and NO increased significantly following the conversion of low forest cover (secondary forest younger than 30 years, woodlands, shrublands) (Hedges's d of 0.44 ± 0.13). Forest conversion to fertilized systems significantly and highly raised both N2O and NO emission rates (Hedges's d of 1.03 ± 0.23 and 0.52 ± 0.09, respectively). Changes in nitrogen availability and WFPS were the main factors explaining changes in N2O emissions following LUC, therefore it is important that experimental designs monitor their spatio-temporal variation. Gaps in the literature on N oxide fluxes included geographical gaps (Africa, Oceania) and LU gaps (degraded forest, wetland (notably peat) forest, oil palm plantation and soy cultivation).

scholarly journals Measuring N2O Emissions from Multiple Sources Using a Backward Lagrangian Stochastic Model

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1277
Author(s):  
Cheng-Hsien Lin ◽  
Richard H. Grant ◽  
Cliff T. Johnston
Keyword(s):  
Management Practices ◽  
Cropping System ◽  
Fertilizer Application ◽  
N2o Emission ◽  
N2o Emissions ◽  
Emission Rates ◽  
Multiple Sources ◽  
Maize Production ◽  
Emissions Modeling ◽  
Short Period

Nitrous oxide (N2O) emissions from agricultural soil are substantially influenced by nitrogen (N) and field management practices. While routinely soil chambers have been used to measure emissions from small plots, measuring field-scale emissions with micrometeorological methods has been limited. This study implemented a backward Lagrangian stochastic (bLS) technique to simultaneously and near-continuously measure N2O emissions from four adjacent fields of approximately 1 ha each. A scanning open-path Fourier-transform infrared spectrometer (OP-FTIR), edge-of-field gas sampling and measurement, locally measured turbulence, and bLS emissions modeling were integrated to measure N2O emissions from four adjacent fields of maize production using different management in 2015. The maize N management treatments consisted of 220 kg NH3-N ha−1 applied either as one application in the fall after harvest or spring before planting or split between fall after harvest and spring before planting. The field preparation treatments evaluated were no-till (NT) and chisel plow (ChP). This study showed that the OP-FTIR plus bLS method had a minimum detection limit (MDL) of ±1.2 µg m−2 s−1 (3σ) for multi-source flux measurements. The average N2O emission of the four treatments ranged from 0.1 to 2.3 µg m−2 s−1 over the study period of 01 May to 11 June after the spring fertilizer application. The management of the full-N rate applied in the fall led to higher N2O emissions than the split-N rates applied in the fall and spring. Based on the same N application, the ChP practice tended to increase N2O emissions compared with NT. Advection of N2O from adjacent fields influenced the estimated emissions; uncertainty (1σ) in emissions was 0.5 ± 0.3 µg m−2 s−1 if the field of interest received a clean measured upwind background air, but increased to 1.1 ± 0.5 µg m−2 s−1 if all upwind sources were advecting N2O over the field of interest. Moreover, higher short-period emission rates (e.g., half-hour) were observed in this study by a factor of 1.5~7 than other micrometeorological studies measuring N2O-N loss from the N-fertilized cereal cropping system. This increment was attributed to the increase in N fertilizer input and soil temperature during the measurement. We concluded that this method could make near-continuous “simultaneous” flux comparisons between treatments, but further studies are needed to address the discrepancies in the presented values with other comparable N2O flux studies.

Global warming as affected by incorporation of variably aged biomass of hairy vetch for rice cultivation

Soil Research ◽  
2016 ◽  
Vol 54 (3) ◽  
pp. 346 ◽  
Author(s):  
Md Mozammel Haque ◽  
Jatish Chandra Biswas ◽  
Tatoba R. Waghmode ◽  
Pil Joo Kim
Keyword(s):  
Global Warming ◽  
Biomass Production ◽  
Animal Feed ◽  
Ghg Emissions ◽  
Rice Cultivation ◽  
Emission Rates ◽  
Hairy Vetch ◽  
Closed Chamber ◽  
Vicia Villosa ◽  
Carbon Dioxide Co2

Hairy vetch (Vicia villosa Roth) is cultivated during the cold fallow season in paddy soils of temperate countries such as South Korea and Japan, mostly as animal feed and green manure. Information on the effect of ageing of hairy vetch incorporation in relation to greenhouse gas (GHG) emissions and global warming potential (GWP) is not available. Therefore, hairy vetch biomass of ages 183, 190, 197, and 204 days was incorporated in paddy soil to estimate GWP during rice cultivation. The emission rates of methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) gases were monitored once a week by using the closed-chamber method. The net ecosystem carbon budget was used to estimate pure CO2 emission fluxes. Biomass production of hairy vetch was 6.5 Mg ha–1 at 204 days, which was similar to other treatments. The GWP was lower with the 204-day-old vetch biomass incorporation than with other treatments. High content of cellulose and lignin in 204-day-old hairy vetch might have affected decomposition rate and subsequently reduced GHGs emissions during rice cultivation. Our results suggest that hairy vetch can be allowed to grow for 204 days before incorporation at 3 Mg ha–1 without sacrificing rice yield, while maximising biomass production and minimising GWP during rice cultivation.

scholarly journals Compact Open-Path Sensor for Fast Measurements of CO2 and H2O using Scanned-Wavelength Modulation Spectroscopy with 1f-Phase Method

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1910
Author(s):  
Xiang Li ◽  
Feng Yuan ◽  
Mai Hu ◽  
Bin Chen ◽  
Yabai He ◽  
...  
Keyword(s):  
High Sensitivity ◽  
Fast Response ◽  
Wavelength Modulation Spectroscopy ◽  
Phase Method ◽  
High Temporal Resolution ◽  
Wavelength Modulation ◽  
Modulation Spectroscopy ◽  
Open Path ◽  
Averaging Time ◽  
Term Performance

We report here the development of a compact, open-path CO2 and H2O sensor based on the newly introduced scanned-wavelength modulation spectroscopy with the first harmonic phase angle (scanned-WMS-θ1f) method for high-sensitivity, high temporal resolution, ground-based measurements. The considerable advantage of the sensor, compared with existing commercial ones, lies in its fast response of 500 Hz that makes this instrument ideal for resolving details of high-frequency turbulent motion in exceptionally dynamic coastal regions. The good agreement with a commercial nondispersive infrared analyzer supports the utility and accuracy of the sensor. Allan variance analysis shows that the concentration measurement sensitivities can reach 62 ppb CO2 in 0.06 s and 0.89 ppm H2O vapor in 0.26 s averaging time. Autonomous field operation for 15-day continuous measurements of greenhouse gases (CO2/H2O) was performed on a shore-based monitoring tower in Daya Bay, demonstrating the sensor’s long-term performance. The capability for high-quality fast turbulent atmospheric gas observations allow the potential for better characterization of oceanographic processes.

scholarly journals Electrochemical Detection of Neurotransmitters

Biosensors ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 101 ◽  
Author(s):  
Saikat Banerjee ◽  
Stephanie McCracken ◽  
Md Faruk Hossain ◽  
Gymama Slaughter
Keyword(s):  
Nervous System ◽  
Measurement Techniques ◽  
Electrochemical Measurement ◽  
High Temporal Resolution ◽  
Sensing Platforms ◽  
Target Analytes ◽  
Assessment Techniques ◽  
The Brain ◽  
Significant Attention ◽  
Chemical Messengers

Neurotransmitters are important chemical messengers in the nervous system that play a crucial role in physiological and physical health. Abnormal levels of neurotransmitters have been correlated with physical, psychotic, and neurodegenerative diseases such as Alzheimer’s, Parkinson’s, dementia, addiction, depression, and schizophrenia. Although multiple neurotechnological approaches have been reported in the literature, the detection and monitoring of neurotransmitters in the brain remains a challenge and continues to garner significant attention. Neurotechnology that provides high-throughput, as well as fast and specific quantification of target analytes in the brain, without negatively impacting the implanted region is highly desired for the monitoring of the complex intercommunication of neurotransmitters. Therefore, it is crucial to develop clinical assessment techniques that are sensitive and reliable to monitor and modulate these chemical messengers and screen diseases. This review focuses on summarizing the current electrochemical measurement techniques that are capable of sensing neurotransmitters with high temporal resolution in real time. Advanced neurotransmitter sensing platforms that integrate nanomaterials and biorecognition elements are explored.

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