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 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 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.

scholarly journals Seasonal changes in the abundance and activity of bacterial and fungal denitrifying communities associated with different compost amendments

2021 ◽  
Author(s):  
Amy Novinscak ◽  
Claudia Goyer ◽  
Carolyn Wilson ◽  
Bernie J. Zebarth ◽  
David L. Burton ◽  
...  
Keyword(s):  
Poultry Manure ◽  
Organic Amendments ◽  
N2o Emission ◽  
Nitrous Oxide Emissions ◽  
N2o Emissions ◽  
Activity Levels ◽  
Emission Rates ◽  
Agricultural Field ◽  
Compost Amendments ◽  
Amended Soil

Composts can be efficient organic amendments in potato culture as they can supply carbon and nutrients to the soil. However, more information is required to the effects of composts on denitrification and nitrous oxide emissions (N2O) and the emission-producing denitrifying communities. The effect of three compost amendments (municipal source separated organic waste compost (SSOC), forestry waste mixed with poultry manure compost (FPMC), and forestry residues compost (FRC)) on fungal and bacterial denitrifying communities and activity was examined in an agricultural field cropped to potatoes in during the fall, spring and summer seasons. The denitrification enzyme activity (DEA), N2O emissions and respiration were measured in parallel. N2O emission rates were greater in FRC-amended soils in the fall and summer, while soil respiration was highest in SSOC-amended soil in the fall. A large number of <i>nirK</i> denitrifying fungal transcripts was detected in the fall, coinciding with compost application while the greatest <i>nirK</i> bacterial transcripts were measured in the summer when plants were actively growing. Denitrifying community and transcript levels were poor predictors of DEA, N2O emissions or respiration rates in compost-amended soil. Overall, the sampling date was driving the population and activity levels of the three denitrifying communities under study.

scholarly journals N2O emissions from a cultivated mollisol: optimal time of day for sampling and the role of soil temperature

2012 ◽  
Vol 36 (6) ◽  
pp. 1814-1819 ◽  
Author(s):  
Vanina Rosa Noemi Cosentino ◽  
Patricia Lilia Fernandez ◽  
Santiago Andrés Figueiro Aureggi ◽  
Miguel Angel Taboada
Keyword(s):  
N2o Emission ◽  
Time Of Day ◽  
Optimal Time ◽  
N2o Emissions ◽  
Closed Field ◽  
Emission Rates ◽  
N2o Flux ◽  
Study Region ◽  
Term Field

The correct use of closed field chambers to determine N2O emissions requires defining the time of day that best represents the daily mean N2O flux. A short-term field experiment was carried out on a Mollisol soil, on which annual crops were grown under no-till management in the Pampa Ondulada of Argentina. The N2O emission rates were measured every 3 h for three consecutive days. Fluxes ranged from 62.58 to 145.99 ∝g N-N2O m-2 h-1 (average of five field chambers) and were negatively related (R² = 0.34, p < 0.01) to topsoil temperature (14 - 20 ºC). N2O emission rates measured between 9:00 and 12:00 am presented a high relationship to daily mean N2O flux (R² = 0.87, p < 0.01), showing that, in the study region, sampling in the mornings is preferable for GHG.

scholarly journals Nitrous Oxide Emissions in Pineapple Cultivation on a Tropical Peat Soil

2021 ◽  
Vol 13 (9) ◽  
pp. 4928
Author(s):  
Alicia Vanessa Jeffary ◽  
Osumanu Haruna Ahmed ◽  
Roland Kueh Jui Heng ◽  
Liza Nuriati Lim Kim Choo ◽  
Latifah Omar ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Soil Temperature ◽  
Peat Soil ◽  
Farming Systems ◽  
N2o Emission ◽  
Nitrous Oxide Emissions ◽  
Natural State ◽  
N2o Emissions ◽  
Wet Season ◽  
Peat Soils

Farming systems on peat soils are novel, considering the complexities of these organic soil. Since peat soils effectively capture greenhouse gases in their natural state, cultivating peat soils with annual or perennial crops such as pineapples necessitates the monitoring of nitrous oxide (N2O) emissions, especially from cultivated peat lands, due to a lack of data on N2O emissions. An on-farm experiment was carried out to determine the movement of N2O in pineapple production on peat soil. Additionally, the experiment was carried out to determine if the peat soil temperature and the N2O emissions were related. The chamber method was used to capture the N2O fluxes daily (for dry and wet seasons) after which gas chromatography was used to determine N2O followed by expressing the emission of this gas in t ha−1 yr−1. The movement of N2O horizontally (832 t N2O ha−1 yr−1) during the dry period was higher than in the wet period (599 t N2O ha−1 yr−1) because of C and N substrate in the peat soil, in addition to the fertilizer used in fertilizing the pineapple plants. The vertical movement of N2O (44 t N2O ha−1 yr−1) was higher in the dry season relative to N2O emission (38 t N2O ha−1 yr−1) during the wet season because of nitrification and denitrification of N fertilizer. The peat soil temperature did not affect the direction (horizontal and vertical) of the N2O emission, suggesting that these factors are not related. Therefore, it can be concluded that N2O movement in peat soils under pineapple cultivation on peat lands occurs horizontally and vertically, regardless of season, and there is a need to ensure minimum tilling of the cultivated peat soils to prevent them from being an N2O source instead of an N2O sink.

scholarly journals The interaction of seasonal rainfall and nitrogen fertiliser rate on soil N2O emission, total N loss and crop yield of dryland sorghum and sunflower grown on sub-tropical Vertosols

Soil Research ◽  
2016 ◽  
Vol 54 (5) ◽  
pp. 604 ◽  
Author(s):  
G. D. Schwenke ◽  
B. M. Haigh
Keyword(s):  
Crop Yield ◽  
Crop Production ◽  
Field Experiments ◽  
N2o Emission ◽  
N2o Emissions ◽  
N Loss ◽  
N Losses ◽  
Total N ◽  
Tropical Regions ◽  
The Impact

Summer crop production on slow-draining Vertosols in a sub-tropical climate has the potential for large emissions of soil nitrous oxide (N2O) from denitrification of applied nitrogen (N) fertiliser. While it is well established that applying N fertiliser will increase N2O emissions above background levels, previous research in temperate climates has shown that increasing N fertiliser rates can increase N2O emissions linearly, exponentially or not at all. Little such data exists for summer cropping in sub-tropical regions. In four field experiments at two locations across two summers, we assessed the impact of increasing N fertiliser rate on both soil N2O emissions and crop yield of grain sorghum (Sorghum bicolor L.) or sunflower (Helianthus annuus L.) in Vertosols of sub-tropical Australia. Rates of N fertiliser, applied as urea at sowing, included a nil application, an optimum N rate and a double-optimum rate. Daily N2O fluxes ranged from –3.8 to 2734g N2O-Nha–1day–1 and cumulative N2O emissions ranged from 96 to 6659g N2O-Nha–1 during crop growth. Emissions of N2O increased with increased N fertiliser rates at all experimental sites, but the rate of N loss was five times greater in wetter-than-average seasons than in drier conditions. For two of the four experiments, periods of intense rainfall resulted in N2O emission factors (EF, percent of applied N emitted) in the range of 1.2–3.2%. In contrast, the EFs for the two drier experiments were 0.41–0.56% with no effect of N fertiliser rate. Additional 15N mini-plots aimed to determine whether N fertiliser rate affected total N lost from the soil–plant system between sowing and harvest. Total 15N unaccounted was in the range of 28–45% of applied N and was presumed to be emitted as N2O+N2. At the drier site, the ratio of N2 (estimated by difference)to N2O (measured) lost was a constant 43%, whereas the ratio declined from 29% to 12% with increased N fertiliser rate for the wetter experiment. Choosing an N fertiliser rate aimed at optimum crop production mitigates potentially high environmental (N2O) and agronomic (N2+N2O) gaseous N losses from over-application, particularly in seasons with high intensity rainfall occurring soon after fertiliser application.

NO x and N2O Emissions During Fluidized Bed Combustion of Leather Wastes

2005 ◽  
Vol 128 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Alberto Bahillo ◽  
Lourdes Armesto ◽  
Andrés Cabanillas ◽  
Juan Otero
Keyword(s):  
Nitrogen Content ◽  
Fluidized Bed ◽  
Oxygen Content ◽  
N2o Emission ◽  
N2o Emissions ◽  
Fluidized Bed Combustion ◽  
High Nitrogen Content ◽  
High Nitrogen ◽  
Leather Wastes ◽  
Leather Waste

Transformation of hide (animal skins) into leather is a complicated process during which significant amounts of wastes are generated. Fluidized bed combustion has been extended to burn different wastes that have problems with their disposal showing its technical feasibility. Considering the characteristics of the leather waste, especially the heating value (12.5-21MJ∕kg), it is a fairly good fuel. Moreover, leather waste has a high volatile matter, 65%, similar to other biomasses and unusual high nitrogen content, 14%. The aim of this work was to study leather wastes combustion in fluidized bed presenting experimental results regarding NOx and N2O emissions. A series of experiments were carried out in a fluidized bed pilot plant to understand the importance of operating parameters such as furnace temperature, oxygen content in gases, staged combustion and residence time on the NOx and N2O emission level. Despite having high nitrogen content, low conversion of N-fuel to NOx and N2O was measured during the combustion of leather waste in BFB. Bed temperature and oxygen content were found as the most important single parameters on N2O emission and only oxygen content has a significant influence on NOx emission. Leather waste exhibits a great NOx∕O2 trend; NOx emission decreases as the oxygen concentration decreases while the effect of combustion temperature on NOx is insignificant. Staged combustion does not give a reduction in NOx.

scholarly journals Water Salinity Should Be Reduced for Irrigation to Minimize Its Risk of Increased Soil N2O Emissions

2018 ◽  
Vol 15 (10) ◽  
pp. 2114 ◽  
Author(s):  
Qi Wei ◽  
Junzeng Xu ◽  
Linxian Liao ◽  
Yawei Li ◽  
Haiyu Wang ◽  
...  
Keyword(s):  
Saline Water ◽  
N2o Emission ◽  
Salinity Level ◽  
N2o Emissions ◽  
Low Salinity ◽  
Nitrogen Inputs ◽  
Salinity Levels ◽  
N2o Fluxes ◽  
Moisture Dynamics ◽  
Irrigated Soils

To reveal the effect of irrigation salinity on soil nitrous oxide (N2O) emission, pot experiments were designed with three irrigation salinity levels (NaCl and CaCl2 of 1, 2.5 and 4 g/L equivalence, Ec = 3.6, 8.1 and 12.7 ds/m), either for 0 kg N/ha (N0) or 120 kg N/ha (N120) nitrogen inputs. N2O emissions from soils irrigated at different salinity levels varied in a similar pattern which was triggered by soil moisture dynamics. Yet, the magnitudes of pulse N2O fluxes were significantly varied, with the peak flux at 5 g/L irrigation salinity level being much higher than at 2 and 8 g/L. Compared to fresh water irrigated soils, cumulative N2O fluxes were reduced by 22.7% and 39.6% (N0), 29.1% and 39.2% (N120) for soils irrigated with 2 and 8 g/L saline water, while they were increased by 87.7% (N0) and 58.3% (N120) for soils irrigated with 5 g/L saline water. These results suggested that the effect degree of salinity on consumption and production of N2O might vary among irrigation salinity ranges. As such, desalinating brackish water to a low salinity level (such as 2 g/L) before it is used for irrigation might be helpful for solving water resources crises and mitigating soil N2O emissions.

scholarly journals Environmental change impacts on the C- and N-cycle of European forests: a model comparison study

2013 ◽  
Vol 10 (3) ◽  
pp. 1751-1773 ◽  
Author(s):  
D. R. Cameron ◽  
M. Van Oijen ◽  
C. Werner ◽  
K. Butterbach-Bahl ◽  
R. Grote ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Central Europe ◽  
Tree Species ◽  
Carbon Sink ◽  
N2o Emission ◽  
Forest Growth ◽  
N2o Emissions ◽  
European Forests ◽  
Considerable Uncertainty ◽  
Carbon And Nitrogen

Abstract. Forests are important components of the greenhouse gas balance of Europe. There is considerable uncertainty about how predicted changes to climate and nitrogen deposition will perturb the carbon and nitrogen cycles of European forests and thereby alter forest growth, carbon sequestration and N2O emission. The present study aimed to quantify the carbon and nitrogen balance, including the exchange of greenhouse gases, of European forests over the period 2010–2030, with a particular emphasis on the spatial variability of change. The analysis was carried out for two tree species: European beech and Scots pine. For this purpose, four different dynamic models were used: BASFOR, DailyDayCent, INTEGRATOR and Landscape-DNDC. These models span a range from semi-empirical to complex mechanistic. Comparison of these models allowed assessment of the extent to which model predictions depended on differences in model inputs and structure. We found a European average carbon sink of 0.160 ± 0.020 kgC m−2 yr−1 (pine) and 0.138 ± 0.062 kgC m−2 yr−1 (beech) and N2O source of 0.285 ± 0.125 kgN ha−1 yr−1 (pine) and 0.575 ± 0.105 kgN ha−1 yr−1 (beech). The European average greenhouse gas potential of the carbon sink was 18 (pine) and 8 (beech) times that of the N2O source. Carbon sequestration was larger in the trees than in the soil. Carbon sequestration and forest growth were largest in central Europe and lowest in northern Sweden and Finland, N. Poland and S. Spain. No single driver was found to dominate change across Europe. Forests were found to be most sensitive to change in environmental drivers where the drivers were limiting growth, where changes were particularly large or where changes acted in concert. The models disagreed as to which environmental changes were most significant for the geographical variation in forest growth and as to which tree species showed the largest rate of carbon sequestration. Pine and beech forests were found to have differing sensitivities to environmental change, in particular the response to changes in nitrogen and precipitation, with beech forest more vulnerable to drought. There was considerable uncertainty about the geographical location of N2O emissions. Two of the models BASFOR and LandscapeDNDC had largest emissions in central Europe where nitrogen deposition and soil nitrogen were largest, whereas the two other models identified different regions with large N2O emission. N2O emissions were found to be larger from beech than pine forests and were found to be particularly sensitive to forest growth.

scholarly journals Groundwater N<sub>2</sub>O emission factors of nitrate-contaminated aquifers as derived from denitrification progress and N<sub>2</sub>O accumulation

2008 ◽  
Vol 5 (5) ◽  
pp. 1215-1226 ◽  
Author(s):  
D. Weymann ◽  
R. Well ◽  
H. Flessa ◽  
C. von der Heide ◽  
M. Deurer ◽  
...  
Keyword(s):  
Emission Factor ◽  
Noble Gas ◽  
N2o Emission ◽  
Emission Factors ◽  
N2o Emissions ◽  
Northern Germany ◽  
Stable Component ◽  
Sand And Gravel ◽  
First Time ◽  
Ipcc Default

Abstract. We investigated the dynamics of denitrification and nitrous oxide (N2O) accumulation in 4 nitrate (NO−3) contaminated denitrifying sand and gravel aquifers of northern Germany (Fuhrberg, Sulingen, Thülsfelde and Göttingen) to quantify their potential N2O emission and to evaluate existing concepts of N2O emission factors. Excess N2 – N2 produced by denitrification – was determined by using the argon (Ar) concentration in groundwater as a natural inert tracer, assuming that this noble gas functions as a stable component and does not change during denitrification. Furthermore, initial NO−3 concentrations (NO−3 that enters the groundwater) were derived from excess N2 and actual NO−3 concentrations in groundwater in order to determine potential indirect N2O emissions as a function of the N input. Median concentrations of N2O and excess N2 ranged from 3 to 89 μg N L−1 and from 3 to 10 mg N L−1, respectively. Reaction progress (RP) of denitrification was determined as the ratio between products (N2O-N + excess N2) and starting material (initial NO−3 concentration) of the process, characterizing the different stages of denitrification. N2O concentrations were lowest at RP close to 0 and RP close to 1 but relatively high at a RP between 0.2 and 0.6. For the first time, we report groundwater N2O emission factors consisting of the ratio between N2O-N and initial NO−3-N concentrations (EF1). In addition, we determined a groundwater emission factor (EF2) using a previous concept consisting of the ratio between N2O-N and actual NO−3-N concentrations. Depending on RP, EF(1) resulted in smaller values compared to EF(2), demonstrating (i) the relevance of NO−3 consumption and consequently (ii) the need to take initial NO−3-N concentrations into account. In general, both evaluated emission factors were highly variable within and among the aquifers. The site medians ranged between 0.00043–0.00438 for EF(1) and 0.00092–0.01801 for EF(2), respectively. For the aquifers of Fuhrberg and Sulingen, we found EF(1) median values which are close to the 2006 IPCC default value of 0.0025. In contrast, we determined significant lower EF values for the aquifers of Thülsfelde and Göttingen. Summing the results up, our study supports the substantial downward revision of the IPCC default EF5-g from 0.015 (1997) to 0.0025 (2006).

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