Partitioning of eddy covariance derived pasture N2O emissions for different sources and respective emission factors

2020 ◽  
Author(s):  
Christof Ammann ◽  
Karl Voglmeier
Keyword(s):  
Eddy Covariance ◽  
Time Window ◽  
Organic Fertilizer ◽  
Mineral Fertilizer ◽  
Emission Factors ◽  
N2o Emissions ◽  
Field Scale ◽  
Grazed Pastures ◽  
N Input ◽  
Different Sources

<p>Nitrous oxide (N<sub>2</sub>O) is a very potent greenhouse gas, and the majority of the emissions are associated with intensive livestock production. The magnitude of the emissions depends on the nitrogen (N) input to the soil, and on grazed pastures the largest share of the emissions is typically originating from the N applied via fertilization and excreta of the grazing animals. The uneven spatial distribution of the excretion leads to emission hot spots on grazing systems and makes the quantification of the gaseous emissions difficult. Micrometeorological methods like the eddy covariance (EC) that integrate emissions over a larger area method are well suited to quantify total field-scale N<sub>2</sub>O emissions of grazed pastures. But the partioning of emissions for different sources and the determination of source-specific emission factors is still a challenge.</p><p>We present results of a 5-year field experiment carried out in western Switzerland. The investigated pasture was grazed by dairy cows in an intensive rotational management. The field was additionally fertilized with organic and mineral fertilizer each year, according to the N requirement of the grassland. The field-scale N<sub>2</sub>O fluxes were quantified with the EC technique using a fast response Quantum cascade laser spectrometer for N<sub>2</sub>O concentration measurements. The experimental setup and the environmental conditions resulted in high temporal and spatial dynamics of the N<sub>2</sub>O fluxes with highest values typically occurring after mineral fertilization events in the summer month. Using N<sub>2</sub>O background parametrizations retrieved from chamber measurements in one year and subtracting the background emission from the measured N<sub>2</sub>O fluxes allowed us to calculate excreta-related emission factors (EFs) according to the IPCC guidelines. EFs for fertilizer N input were calculated using a pre-defined time window after the fertilizer was applied. The subtracted background emissions during the fertilization events were calculated from the EC measurements outside this time window. We attribute the observed emissions to the different N inputs and discuss potential reasons for the supposedly higher emissions after mineral fertilizer applications in comparison to organic fertilizer emissions.</p>

Flux measurements of NHx and NOy with a dual-channel converter above an intensively managed grassland on peat

2021 ◽  
Author(s):  
Pascal Wintjen ◽  
Jeremy Rüffer ◽  
Liv Sokolowsky ◽  
Christof Ammann ◽  
Christian Brümmer
Keyword(s):  
Eddy Covariance ◽  
Nitrogen Saturation ◽  
Organic Fertilizer ◽  
Mineral Fertilizer ◽  
Fast Response ◽  
Reactive Nitrogen ◽  
Nitrogen Compounds ◽  
Northwest Germany ◽  
Flux Measurements ◽  
Intensively Managed

<p>We designed a fast-response two-channel converter called NO<sub>y</sub>-TRANC for eddy covariance measurements of reduced and oxidized reactive nitrogen compounds (N<sub>r</sub>). It is a combination of the Total Reactive Atmospheric Nitrogen Converter (TRANC), which converts all reactive forms of nitrogen (ΣN<sub>r</sub>), except for nitrous oxide (N<sub>2</sub>O) and molecular nitrogen (N<sub>2</sub>), to nitrogen monoxide (NO), and a heated gold catalyst, which converts NO<sub>y</sub> to NO. NO<sub>x</sub>, which is the sum of NO and nitrogen dioxide (NO<sub>2</sub>), and higher oxidized nitrogen compounds are described by the term NO<sub>y</sub>. The NO<sub>y</sub>-TRANC is coupled to a two-channel chemiluminescence detector (CLD) for measuring NO. Due to a high sampling frequency and a fast response time, the system meets the requirements for flux calculation based on the eddy-covariance method. With this setup, a separation of ΣN<sub>r</sub> fluxes in reduced and oxidized nitrogen can be done.</p><p>We conducted flux measurements at a typically deeply drained, intensively managed grassland site on peat in an intensive dairy region in Northwest Germany for one year. ΣN<sub>r</sub> concentration was 12.4 ppb and NO<sub>y</sub> concentration was 6.3 ppb on average. We observed mostly emission fluxes at the site after the first fertilization in early spring. The winter month were characterized by slight nitrogen dry deposition. Monthly median of ΣN<sub>r</sub> fluxes ranged from -8 to 57 ng N m<sup>-2</sup>s<sup>-1</sup> with the exchange being enhanced during summer. We found that ΣN<sub>r</sub> and NO<sub>y</sub> dry emission were comparatively higher under dry conditions, i.e., low air humidity and soil moisture. The emission factors of applied nitrogen after the respective fertilization released as NH<sub>x</sub> can reach up to 2.0%.</p><p>Site management included five fertilization events and five grass cuts. The first fertilization event was at the end of March starting with mineral fertilizer followed by organic fertilizer a week later.  The fertilization scheme was the same for second and third event, but approximately two days were between the application of the fertilizer types. The second fertilization was at the end of May, subsequent fertilizations were done in intervals of 4-5 weeks. Only for the fourth and fifth event, organic fertilizer was used. Organic fertilizer was injected in slits made by v-shaped discs, mineral fertilizer was spread on the soil surface. The emission factor was lower after the first fertilization event compared to events in summer probably indicating a beginning nitrogen saturation after the first fertilization.</p><p>Our study demonstrates the application of a novel measurement technique for the determination reactive nitrogen compounds and gives insight into the exchange characteristics of reactive nitrogen under a common agricultural management.</p>

scholarly journals Environmental Impact of Rotationally Grazed Pastures at Different Management Intensities in South Africa

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1214
Author(s):  
Hendrik P. J. Smit ◽  
Thorsten Reinsch ◽  
Pieter A. Swanepoel ◽  
Ralf Loges ◽  
Christof Kluß ◽  
...  
Keyword(s):  
South Africa ◽  
N Fertilization ◽  
Yield Response ◽  
N2o Emissions ◽  
Pasture Management ◽  
N Losses ◽  
Enteric Fermentation ◽  
Soil C ◽  
Grazed Pastures ◽  
Soil C And N

Nitrogen fertilization, irrigation and concentrate feeding are important factors in rotational pasture management for dairy farms in South Africa. The extent to which these factors affect environmental efficiency is subject to current and intense debate among scientists. A three-year field study was conducted to investigate the yield response of different N-fertilizer treatments (0 (N0), 220 (N20), 440 (N40), 660 (N60) and 880 (N80) kg N ha−1 year−1) on grazed pastures and to calculate the carbon footprint (CF) of milk produced. Excessive N-fertilization (N60 and N80) did not increase herbage dry matter and energy yields from pastures. However, N80 indicated the highest N-yield but at the same time also the highest N surpluses at field level. A maximum fertilizer rate of 220 kg ha−1 year−1 (in addition to excreted N from grazing animals) appears sufficient to ensure adequate herbage yields (~20 t DM ha−1 year−1) with a slightly positive field-N-balance. This amount will prevent the depletion of soil C and N, with low N losses to the environment, where adequate milk yields of ~17 t ECM ha−1 with a low CF (~1.3 kg CO2 kg ECM−1) are reached. Methane from enteric fermentation (~49% ± 3.3) and N2O (~16% ± 3.2) emissions from irrigated pastures were the main contributors to the CF. A further CF reduction can be achieved by improved N-fertilization planning, low emission irrigation techniques and strategies to limit N2O emissions from pasture soils in South Africa.

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).

Perspectives on greenhouse gas emission estimates based on Australian wastewater treatment plant operating data

2013 ◽  
Vol 69 (3) ◽  
pp. 451-463 ◽  
Author(s):  
D. W. de Haas ◽  
C. Pepperell ◽  
J. Foley
Keyword(s):  
Wastewater Treatment ◽  
Steady State ◽  
Greenhouse Gas ◽  
Greenhouse Gas Emission ◽  
Electrical Power ◽  
Research Work ◽  
Treatment Plant ◽  
Emission Factors ◽  
N2o Emissions ◽  
Operating Data

Primary operating data were collected from forty-six wastewater treatment plants (WWTPs) located across three states within Australia. The size range of plants was indicatively from 500 to 900,000 person equivalents. Direct and indirect greenhouse gas emissions were calculated using a mass balance approach and default emission factors, based on Australia's National Greenhouse Energy Reporting (NGER) scheme and IPCC guidelines. A Monte Carlo-type combined uncertainty analysis was applied to the some of the key emission factors in order to study sensitivity. The results suggest that Scope 2 (indirect emissions due to electrical power purchased from the grid) dominate the emissions profile for most of the plants (indicatively half to three quarters of the average estimated total emissions). This is only offset for the relatively small number of plants (in this study) that have significant on-site power generation from biogas, or where the water utility purchases grid electricity generated from renewable sources. For plants with anaerobic digestion, inventory data issues around theoretical biogas generation, capture and measurement were sometimes encountered that can skew reportable emissions using the NGER methodology. Typically, nitrous oxide (N2O) emissions dominated the Scope 1 (direct) emissions. However, N2O still only accounted for approximately 10 to 37% of total emissions. This conservative estimate is based on the ‘default’ NGER steady-state emission factor, which amounts to 1% of nitrogen removed through biological nitrification-denitrification processing in the plant (or indicatively 0.7 to 0.8% of plant influent total nitrogen). Current research suggests that true N2O emissions may be much lower and certainly not steady-state. The results of this study help to place in context research work that is focused on direct emissions from WWTPs (including N2O, methane and carbon dioxide of non-biogenic origin). For example, whereas non-biogenic CO2 contributions are relatively minor, it appears that opportunities to reduce indirect emissions as a result of modest savings in power consumption are at least in the same order as those from reducing N2O emissions. To avoid potentially high reportable emissions under NGER guidelines, particularly for methane, the onus is placed on WWTP managers to ensure that accurate plant monitoring operating records are kept.

scholarly journals Development and Use of a Planter for Simultaneous Application of Seed, Fertilizer and Compost in Pearl Millet Production in Niger—Effects on Labor Use, Yield and Economic Return

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1886
Author(s):  
Abdourahamane Issa M. Nourou ◽  
Addam Kiari Saidou ◽  
Jens B. Aune
Keyword(s):  
Pearl Millet ◽  
Organic Fertilizer ◽  
Cropping System ◽  
Mineral Fertilizer ◽  
Cereal Crops ◽  
Randomized Experiments ◽  
Economic Return ◽  
Simultaneous Application ◽  
Combined Application ◽  
Reduced Time

Sowing and application of mineral and organic fertilizer is generally done manually in the Sahel, resulting in low precision and delayed application. The objective of this paper is to present a new mechanical planter (Gangaria) for the combined application of seeds and soil amendments (mineral fertilizer, compost, etc.), and to assess the effects of using this planter in pearl millet on labor use, yield and economic return. The labor study showed that the mechanized application of seeds and compost reduced time use by a factor of more than six. The on-station experiments were completely randomized experiments with six replications and six treatments: T0 (control), T1 (0.3 g NPK hill−1), T2 (25 g compost hill−1), T3 (25 g compost + 0.3 g NPK hill−1), T4 (50 g compost hill−1) and T5 (50 g compost + 0.3 g NPK hill−1). Treatments T1 to T5 were sown by the planter with seeds that were primed in combination with coating of seeds with a fungicide/insecticide. The treatment T5 increased grain yield and economic return compared to the control by 113% and 106%, respectively. The advantages for farmers using this approach of agricultural intensification are timelier sowing of dryland cereal crops, easy application of organic fertilizer and more precise delivery of input, thereby making this cropping system more productive and less vulnerable to drought.

scholarly journals Effects of fertilizer and plant density on yield and quality of anise (Pimpinella anisum L.)

2013 ◽  
Vol 58 (3) ◽  
pp. 209-215
Author(s):  
Mahdi Faravani ◽  
Behjat Salari ◽  
Mostafa Heidari ◽  
Mohammad Kashki ◽  
Barat Gholami
Keyword(s):  
Essential Oil ◽  
Plant Density ◽  
Block Design ◽  
Organic Fertilizer ◽  
Canopy Cover ◽  
Mineral Fertilizer ◽  
Yield And Quality ◽  
Plant Densities ◽  
Biological Yield ◽  
Lateral Branches

In order to understand the effect of organic fertilizer on yield of anise, an experiment was conducted in the form of split-plot in randomized complete block design with three replications in Mashhad, Khorasan Agriculture and Natural Resource Research Center. Four treatments of fertilization: the control, vermicompost - 5 t/ha, cow manure - 25 t/ha, and mineral fertilizer (NPK) - 60 kg/ha (the same rate of each nutrient) were applied as the main factor. The second factor was plant density, applied at three levels: 17, 25, and 50 plants/m2. The results showed a significant effect of fertilizer on the number of umbels per plant, number of umbellets per umbel and canopy cover. Plant density had a significant effect on grain yield, biological yield, the number of lateral branches, essential oil percentage and yield of essential oil. Seed and essential oil yield were the highest in the case of the application of vermicompost and plant densities of 50 and 25 plants/m2 respectively.

scholarly journals Atributos químicos de Latossolo sob plantio direto adubado com esterco de bovinos e fertilizantes minerais

2015 ◽  
Vol 6 (3) ◽  
pp. 263 ◽  
Author(s):  
Milena Barcellos ◽  
Antonio Carlos Vargas Motta ◽  
Volnei Pauletti ◽  
José Carlos Peixoto Modesto Da Silva ◽  
Julierme Zimmer Barbosa
Keyword(s):  
Organic Fertilizer ◽  
Mineral Fertilizer ◽  
Mineral Fertilizers ◽  
Organic Fertilization ◽  
Organic C ◽  
Tillage System ◽  
High Production ◽  
Chemical Attributes ◽  
Four Levels ◽  
Total Organic C

Organic fertilization in no-tillage system (NTS) has been used in regions milk production, in an order to provide nutrients for crops and provide a destination for high production of animal waste. The aim of this study was to evaluate the chemical attributes of an Oxisol, a function of organic fertilization with liquid manure from dairy cattle (LMDC) and mineral fertilizers. The experiment was conducted under NTS with crop rotation including legumes and grasses. The treatments were distributed in three randomized blocks with factorial arrangement, using three levels of mineral fertilizer (0, 50 and 100 % of the dose recommended for the crops) and four levels of organic fertilizer (0, 30, 60 and 90 m3 ha-1year-1). After six years of fertilizer management of crops, soil was collected from five depths (0-0.05, 0.05-0.10, 0.10-0.30, 0.30-0.50 e 0.50-0.80 m). The samples were determined the chemical pH, H++Al3+, Al3+, Ca2+, Mg2+, K+,electrical conductivity (EC), bases saturation (V), Ca2+/Mg2+ ratio, total organic C (TOC), B, Cl, Fe, Cu, Zn and Mn. The mineral fertilizers acidify the soil, raised the K+, P and EC and, changed the Zn and Cu contents. The organic fertilization with LMDC was a source of nutrients (Ca 2+, Mg2+, K+, P, Zn and Cu), raised the TOC and the EC, and kept the soil acidity attributes (pH, H++ Al3+ and V).

scholarly journals Effets d’engrais organique liquide (NPK 5-9-18) et minéral (NPK 12-11-18) sur la matière organique du sol et du rendement de la tomate au Sud et au Centre –Ouest de la Côte d’Ivoire

2019 ◽  
Vol 41.3 ◽  
pp. 7055-7067
Author(s):  
Acka Jacques Alain KOTAIX ◽  
Téhua Kouassi Pascal ANGUI ◽  
Sidiky BAKAYOKO ◽  
Koffi Emmanuel KASSIN ◽  
Kouadio Emmanuel N’GORAN ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Cote D'ivoire ◽  
Ivory Coast ◽  
Côte D’Ivoire ◽  
Organic Fertilizer ◽  
Mineral Fertilizer ◽  
Cote D’Ivoire ◽  
Tomato Yield ◽  
Split Plot

1 RESUME Une étude sur la fertilisation minérale et organique liquide a été conduite sur la tomate en petite saison de pluie au Sud et au Centre-Ouest de la Côte d’Ivoire sur deux années, afin d’améliorer la fertilité du sol et le rendement de la tomate. De manière spécifique, il s’agissait d’évaluer les effets des traitements de quatre doses d’engrais organique liquide associées ou non à l’engrais minéral sur la teneur du sol en matière organique, le rapport C/N et le rendement. Le dispositif expérimental était un split-plot avec quatre répétitions ayant pour facteur principal, l’engrais minéral et le facteur secondaire, l’engrais organique à quatre doses (Lha-1) : C0 = 0 (témoin), C1 = 2,5; C2 = 3,75 et C3 = 5. Les résultats ont montré que le traitement T10 (50 % engrais minéral + 3,75 Lha-1 engrais organique) a amélioré la teneur du sol en matière organique, et le rendement. Cependant, le traitement avec 3,75 Lha-1 d’engrais organique utilisée seule a amélioré le rapport C/N du sol. Effects of liquid organic (NPK 5-9-18) and mineral (NPK 12-11-18) fertilizers on soil organic matter of and tomato yield in the South and the Mid-west of Ivory Coast ABSTRACT A study on the mineral and liquid organics fertilizations was conducted on tomato during short rainy season in South and Central West regions of Ivory Coast over two years to improve soil fertility and tomato yield. Specifically, the treatment effects of four doses of organic fertilizer, associated or not with the mineral fertilizer on the content of the soil organic matter, the C/N ratio and the yield. The experimental design was split-plot, with four repetitions having as principal factor, the mineral fertilizer and the secondary factor, the organic fertilizer in four doses (L ha-1): C0 = 0 (control); C1 = 2.5; C2 = 3.75 and C3 = 5. The results showed that the treatment T10 (50 % mineral fertilizer + 3.75 Lha-1 of the organic fertilizer), better improved the content of the soil organic matter and the yield. However, the treatment with 3.75 L ha-1 of organic fertilizer used alone has increased advantage the report C/N of the ground.

Field Scale N2O Flux Measurements from Grassland Using Eddy Covariance

2004 ◽  
Vol 4 (6) ◽  
pp. 143-149 ◽  
Author(s):  
C. Di Marco ◽  
U. Skiba ◽  
K. Weston ◽  
K. Hargreaves ◽  
D. Fowler
Keyword(s):  
Eddy Covariance ◽  
Field Scale ◽  
N2o Flux ◽  
Flux Measurements
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