Nitrous Oxide Emissions from Agricultural Soil Receiving Manure in a Changing Climate

Nitrous Oxide Emissions from Agricultural Soil Receiving Manure in a Changing Climate PDF Author: Chih-Yu Hung
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
"Soil nitrous oxide (N2O) emission varies in magnitude and occurs sporadically during the spring freeze-thaw period in cold humid temperate regions. Fluctuations in soil N2O emissions are related to soil biophysical properties, which are influenced by agricultural practices like fall application of manure and fall-sown cover crops, as well as rainfall and other weather events. The objectives of this thesis were to (1) quantify N2O emissions in the spring period from agricultural soils that received manure and were planted with a cover crop in the previous fall, (2) estimate the influence of fall-applied manure and cover crops on the spring soil N2O emissions in changing climate, (3) determine the biophysical factors that control soil N¬2O emissions after a rain-induced thawing event, and (4) propose a monitoring method to estimate N2O emissions in agricultural soils. First, I quantified the soil N2O emissions with a two-year field experiment. Soil N2O emission in the spring freeze-thaw period (c.a. 30 d) was -2.35 to 13.57 g N ha-1 and not affected by dairy manure application (solid or liquid) or cover crops (ryegrass and ryegrass/hairy vetch), possibly due to the low manure N application rate and N loss over winter. Second, I evaluated soil N2O emissions in the spring freeze-thaw period under three climate scenarios (baseline, from 1981–2010; Representative Concentration Pathway 4.5 and 8.5 from 2071–2100) with the Decomposition-Denitrification model. The model predicted that more reactive N will be retained by cover crops under future climate scenarios, but the soil N2O emissions will not increase. However, applying solid manure without a cover crop led to more soil N2O emissions than other treatments tested under three climate scenarios (9.90 to 61.50 g N ha-1, P

Nitrous Oxide Emissions from Agricultural Soil Receiving Manure in a Changing Climate

Nitrous Oxide Emissions from Agricultural Soil Receiving Manure in a Changing Climate PDF Author: Chih-Yu Hung
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
"Soil nitrous oxide (N2O) emission varies in magnitude and occurs sporadically during the spring freeze-thaw period in cold humid temperate regions. Fluctuations in soil N2O emissions are related to soil biophysical properties, which are influenced by agricultural practices like fall application of manure and fall-sown cover crops, as well as rainfall and other weather events. The objectives of this thesis were to (1) quantify N2O emissions in the spring period from agricultural soils that received manure and were planted with a cover crop in the previous fall, (2) estimate the influence of fall-applied manure and cover crops on the spring soil N2O emissions in changing climate, (3) determine the biophysical factors that control soil N¬2O emissions after a rain-induced thawing event, and (4) propose a monitoring method to estimate N2O emissions in agricultural soils. First, I quantified the soil N2O emissions with a two-year field experiment. Soil N2O emission in the spring freeze-thaw period (c.a. 30 d) was -2.35 to 13.57 g N ha-1 and not affected by dairy manure application (solid or liquid) or cover crops (ryegrass and ryegrass/hairy vetch), possibly due to the low manure N application rate and N loss over winter. Second, I evaluated soil N2O emissions in the spring freeze-thaw period under three climate scenarios (baseline, from 1981–2010; Representative Concentration Pathway 4.5 and 8.5 from 2071–2100) with the Decomposition-Denitrification model. The model predicted that more reactive N will be retained by cover crops under future climate scenarios, but the soil N2O emissions will not increase. However, applying solid manure without a cover crop led to more soil N2O emissions than other treatments tested under three climate scenarios (9.90 to 61.50 g N ha-1, P

Soil Emission of Nitrous Oxide and its Mitigation

Soil Emission of Nitrous Oxide and its Mitigation PDF Author: David Ussiri
Publisher: Springer Science & Business Media
ISBN: 9400753640
Category : Science
Languages : en
Pages : 391

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Book Description
Nitrous oxide gas is a long-lived relatively active greenhouse gas (GHG) with an atmospheric lifetime of approximately 120 years, and heat trapping effects about 310 times more powerful than carbon dioxide per molecule basis. It contributes about 6% of observed global warming. Nitrous oxide is not only a potent GHG, but it also plays a significant role in the depletion of stratospheric ozone. This book describes the anthropogenic sources of N2O with major emphasis on agricultural activities. It summarizes an overview of global cycling of N and the role of nitrous oxide on global warming and ozone depletion, and then focus on major source, soil borne nitrous oxide emissions. The spatial-temporal variation of soil nitrous oxide fluxes and underlying biogeochemical processes are described, as well as approaches to quantify fluxes of N2O from soils. Mitigation strategies to reduce the emissions, especially from agricultural soils, and fertilizer nitrogen sources are described in detail in the latter part of the book.

Nitrous Oxide and Climate Change

Nitrous Oxide and Climate Change PDF Author: Keith Smith
Publisher: Earthscan
ISBN: 1849775117
Category : Political Science
Languages : en
Pages : 247

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Book Description
"Nitrous oxide, N2O, is the third most important (in global warming terms) of the greenhouse gases, after carbon dioxide and methane. As this book describes, although it only comprises 320 parts per billion of the earth's atmosphere, it has a so-called Global Warming Potential nearly 300 times greater than that of carbon dioxide. N2O emissions are difficult to estimate, because they are predominantly biogenic in origin. The N2O is formed in soils and oceans throughout the world, by the microbial processes of nitrification and denitrification, that utilise the reactive N compounds ammonium and nitrate, respectively. These forms of nitrogen are released during the natural biogeochemical nitrogen cycle, but are also released by human activity. In fact, the quantity of these compounds entering the biosphere has virtually doubled since the beginning of the industrial age, and this increase has been matched by a corresponding increase in N2O emissions. The largest source is now agriculture, driven mainly by the use of synthetic nitrogen fertilisers. The other major diffuse source derives from release of NOx into the atmosphere from fossil fuel combustion and biomass burning, as well as ammonia from livestock manure. Some N2O also comes directly from combustion, and from two processes in the chemical industry: the production of nitric acid, and the production of adipic acid, used in nylon manufacture. Action is being taken to curb the industrial point-source emissions of N2O, but measures to limit or reduce agricultural emissions are inherently more difficult to devise. As we enter an era in which measures are being explored to reduce fossil fuel use and/or capture or sequester the CO2 emissions from the fuel, it is likely that the relative importance of N2O in the 'Kyoto basket' of greenhouse gases will increase, because comparable mitigation measures for N2O are inherently more difficult, and because expansion of the land area devoted to crops, to feed the increasing global population and to accommodate the current development of biofuels, is likely to lead to an increase in N fertiliser use, and thus N2O emission, worldwide. The aim of this book is to provide a synthesis of scientific information on the primary sources and sinks of nitrous oxide and an assessment of likely trends in atmospheric concentrations over the next century and the potential for mitigation measures"--Publisher's description.

Mitigating Gaseous Nitrogen and Carbon Losses From Northeastern Agricultural Soils Via Alternative Soil Management Practices

Mitigating Gaseous Nitrogen and Carbon Losses From Northeastern Agricultural Soils Via Alternative Soil Management Practices PDF Author: Kyle Michael Dittmer
Publisher:
ISBN:
Category : Climatic changes
Languages : en
Pages : 282

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Book Description
Traditional agricultural practices often result in gaseous losses of nitrous oxide (N2O), ammonia (NH3), and carbon dioxide (CO2), representing a net loss of nutrients from agricultural soils, which negatively impacts crop yield and requires farmers to increase nutrient inputs. By adopting best management practices (BMPs; i.e., no-tillage, cover crops, sub-surface manure application, and proper manure application timing), there is great potential to reduce these losses. Because N2O and CO2 are also greenhouse gases (GHGs), climate change mitigation via BMP adoption and emissions reductions would be an important co-benefit. However, adopting a no-tillage and cover cropping system has had setbacks within the Northeast, primarily due to concerns regarding manure nitrogen (N) losses in no-tillage systems as well as uncertainty surrounding the benefits of cover crops. This thesis used two field-trials located in Alburgh, Vermont to assess differences in (i) GHG emissions from agricultural soils, (ii) nitrate and ammonium retention, (iii) corn yield and protein content, and (iv) N uptake and retention via cover crop scavenging under a combination of different BMPs. Chapter 1 evaluates the effects of different reduced-tillage practices and manure application methods (i.e., vertical-tillage, no-tillage, manure injection, and broadcast manure application) on reducing N2O and CO2 emissions, retaining inorganic N, and improving crop yields. Greenhouse gas measurements were collected every other week for the growing season of 2015-2017 via static chamber method using a photoacoustic gas analyzer. Results from this study showed that tillage regimes and manure application method did not interact to affect any of the three research objectives, although differences between individual BMPs were observed. Notably, vertical tillage enhanced CO2 emissions relative to no-tillage, demonstrating the role of soil disturbance and aeration on aerobic microbial C transformations. Manure injection was found to significantly enhance both N2O and CO2 emission relative to broadcast application, likely due to the formation of anerobic micro-zones created from liquid manure injection. However, plots that received manure injection retained greater concentrations of soil nitrate, a vital nutrient for quality crop production, thereby highlighting a major tradeoff between gaseous N losses and N retention with manure injection. Chapter 2 evaluates the effects of tillage practices and timing of manure application to increase N retention with the use of cover crops in order to mitigate GHG emissions, enhance soil nitrate and ammonium retention, and improve cropping system N uptake. Treatments at this field trial consisted of a combination of the presence or absence of cover crops, no-tillage or conventional-tillage, and spring or fall manure application. Greenhouse gas emissions were measured every other week via static chamber method using a gas chromatograph for the growing season of 2018. Results from this study showed that the presence of cover crops enhanced both N2O and CO2 emissions relative to fallow land, irrespective of tillage regime and manure application season, likely as a result of greater N and carbon substrates entering the soil upon cover crop decomposition. Due to enhanced N2O emissions with cover crops, cover crops did not retain significantly greater inorganic N in the system upon termination.

Soil Nitrous Oxide Emissions from Agriculture in a Changing Global Environment

Soil Nitrous Oxide Emissions from Agriculture in a Changing Global Environment PDF Author: Charlotte Decock
Publisher:
ISBN: 9781267398338
Category :
Languages : en
Pages :

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Book Description
Agricultural soils encompass one of the major sources of anthropogenic nitrous oxide (N2O), a potent greenhouse gas and stratospheric ozone depleting substance. Therefore, accurate prediction of N2O emissions from soils and development of effective mitigation strategies are pertinent. However, the scientific understanding of mechanisms underlying N2O emissions is limited, in part, by the lack of suitable methods to assess sources of N2O, especially under field conditions and in undisturbed soil cores. In this dissertation, two ecological applications of source-partitioning N2O were considered: (1) the feedback of N2O emissions to elevated atmospheric CO2 and tropospheric O3 and (2) mechanisms underlying N2O emissions during a simulated rainfall event in a tomato cropping system in California. Furthermore, four methods were evaluated for their utility in source-partitioning N2O with minimal disturbance of the system: (1) tracing of added 15N enriched NH4 and/or NO3− to N2O, (2) use of natural abundance 15N of N2O and its precursors, (3) measuring the intramolecular distribution of 15N in N2O, expressed as site preference (SP), and (4) determining relationships between natural abundance 18O and 15N. Method comparisons elucidated that the use of isotope models that include all natural abundance isotopes of N2O and its precursors and uncertainty deductions for isotope fractionation factors to estimate N transformation rates and sources of N2O during peak N2O emissions is the most promising approach to improve our understanding of mechanisms underlying N2O emissions with minimal sampling-associated disturbance of the system. Various approaches to study sources of N2O and N-cycling suggested that elevated CO2 and O3 will unlikely cause a feedback on global climate change through altered N2O emissions in soybean agroecosystems in the Midwestern USA. Furthermore, elevated CO2 decelerated, whereas elevated O3 accelerated N-cycling if integrated over longer time scales. In a California tomato cropping system, N2O reduction to N2 decreased progressively as soil dried out following wetting up. Overall, this dissertation illustrates the added benefit of studying mechanisms underlying N2O emissions in addition to field N2O fluxes per se and encourages further research to source-partition N2O emissions and its needed methodology to understand N2O responses of agroecosystems in a changing global environment.

Nitrous Oxide Emissions

Nitrous Oxide Emissions PDF Author: Miguel Andres Arango Argoti
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Nitrogen is critical for plant growth and is a major cost of inputs in production agriculture. Too much nitrogen (N) is also an environmental concern. Agricultural soils account for 85% of anthropogenic N2O which is a major greenhouse gas. Management strategies for N fertilization and tillage are necessary for enhancing N use efficiency and reducing negative impacts of N to the environment. The different management practices induce changes in substrate availability for microbial activity that may result in increasing or reducing net N2O emitted from soils. The objectives of this research were to (1) integrate results from field studies to evaluate the effect of different management strategies on N2O emissions using a meta-analysis, (2) quantify N2O-N emissions under no-tillage (NT) and tilled (T) agricultural systems and the effect of different N source and placements, (3) perform sensitivity analysis, calibration and validation of the Denitrification Decomposition (DNDC) model for N2O emissions, and (4) analyze future scenarios of precipitation and temperature to evaluate the potential effects of climate change on N2O emissions from agro-ecosystems in Kansas. Based on the meta-analysis there was no significant effect of broadcast and banded N placement. Synthetic N fertilizer usually had higher N2O emission than organic N fertilizer. Crops with high N inputs as well as clay soils had higher N2O fluxes. No-till and conventional till did not have significant differences regarding N2O emissions. In the field study, N2O-N emissions were not significantly different between tillage systems and N source. The banded N application generally had higher emissions than broadcasted N. Slow release N fertilizer as well as split N applications reduced N2O flux without affecting yield. Simulations of N2O emissions were more sensitive to changes in soil parameters such as pH, soil organic carbon (SOC), field capacity (FIELD) and bulk density (BD), with pH and SOC as the most sensitive parameters. The N2O simulations performed using Denitrification Decomposition model on till (Urea) had higher model efficiency followed by no-till (compost), no-till (urea) and till (compost). At the regional level, changes in climate (precipitation and temperature) increased N2O emission from agricultural soils in Kansas. The conversion from T to NT reduced N2O emissions in crops under present conditions as well as under future climatic conditions.

Nitrogen in Agriculture

Nitrogen in Agriculture PDF Author: Takuji Ohyama
Publisher: BoD – Books on Demand
ISBN: 1839684887
Category : Technology & Engineering
Languages : en
Pages : 218

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Book Description
Nitrogen is the most important nutrient in agricultural practice because the availability of nitrogen from the soil is generally not enough to support crop yields. To maintain soil fertility, the application of organic matters and crop rotation have been practiced. Farmers can use convenient chemical nitrogen fertilizers to obtain high crop yields. However, the inappropriate use of nitrogen fertilizers causes environmental problems such as nitrate leaching, contamination in groundwater, and the emission of N2O gas. This book is divided into the following four sections: “Ecology and Environmental Aspects of Nitrogen in Agriculture”, “Nitrogen Fertilizers and Nitrogen Management in Agriculture”, “N Utilization and Metabolism in Crops”, “Plant-Microbe Interactions”.

The Emissions of Nitrous Oxide from Agricultural Fields in New York State

The Emissions of Nitrous Oxide from Agricultural Fields in New York State PDF Author: Marina Molodovskaya
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The atmospheric nitrous oxide (N2O) is of special interest, due to its persistent effect as a potent greenhouse gas and stratospheric ozone destructor. Animal manure fertilization is one of the key factors contributing to N2O formation. In the Northeastern US, dairy industry is the largest agricultural activity, and the manure cropland fertilization is a common practice. Continuous monitoring of N2O emissions from croplands in New York State was conducted by eddy covariance method from 2006 to 2009. The research was aimed at quantification of N2O emissions from manure-fertilized corn (Zea mays) and alfalfa (Medicago sativa) fields, estimating strength and spatial variability of soil N2O sources by conducting simultaneous static chamber campaign, and analysis of temporal distribution of N2O fluxes as affected by seasonality of climate variations and manure practices. The analysis of cumulative N2O emissions and source contributions into the integrated flux showed that manure nitrogen (N) was the most important factor controlling the extent of N2O formation: areas which received more manure N were stronger N2O emitters. Whereas N availability determined a magnitude of N2O emissions, the environmental changes altering soil moisture and temperature status were major N2O event triggers. The temporal flux distribution demonstrated episodic event-induced nature of N2O peak fluxes, which were primarily driven by strong rainfall and warm temperatures in growing season and soil thaw in winter and early spring. The greatest N2O emissions were observed when flux-triggering weather events coincided with or followed manure application. The most intense single N2O peak event was produced from combination of summer manure spreading and strong rainfall; however spring thaw-induced N2O fluxes showed more consistent seasonal year-to-year trend. The daily average fluxes measured by the EC and chamber techniques were in good agreement. The spatial variability of chamber measurements was mainly caused by high heterogeneity of soil N2O formation, which resulted both in net N2O production and consumption. The EC integrated flux was strongly dependent on wind direction and contributing footprint. The combination of the two different scale methods may help in reducing temporal and spatial variability of N2O estimates and improving N2O emission data quality. .

Direct and Indirect Nitrous Oxide Emissions from Agricultural Soils, 1990-2003. Background Document on the Calculation Method for the Dutch National Inventory Repor

Direct and Indirect Nitrous Oxide Emissions from Agricultural Soils, 1990-2003. Background Document on the Calculation Method for the Dutch National Inventory Repor PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Since 2005 the Dutch method to calculate the nitrous oxide emissions from agricultural soils has fully complied with the Intergovernmental Panel on Climate Change (IPCC) Good Practice Guidelines. In order to meet the commitments of the Convention on Climate Change and the Kyoto Protocol, nitrous oxide emissions have to be reported annually in the Dutch National Inventory Report (NIR). Countries are encouraged to use country-specific data rather than the default values provided by the IPCC. This report describes the calculation schemes and data sources used for nitrous oxide emissions from agricultural soils in the Netherlands. The nitrous oxide emissions, which contribute to the greenhouse effect, occur due to nitrification and denitrification processes. They include direct emissions from agricultural soils due to the application of animal manure and fertilizer nitrogen and the manure production in the meadow. Also included are indirect emissions resulting from the subsequent leaching of nitrate to ground water and surface waters, and from deposition of ammonia that had volatilized as a result of agricultural activities. Before 2005 indirect emissions in the Netherlands were calculated using a method that did not compare well with IPCC definitions and categories. The elaborate explanation here should facilitate reviewing by experts. Finally, the report also presents an overview of the nitrous oxide emissions from agricultural soils and the underlying data used in the 1990 - 2003 period.

Methods of Introducing System Models into Agricultural Research

Methods of Introducing System Models into Agricultural Research PDF Author: Lajpat R. Ahuja
Publisher: John Wiley & Sons
ISBN: 0891181806
Category : Technology & Engineering
Languages : en
Pages : 480

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Book Description
Why model? Agricultural system models enhance and extend field research...to synthesize and examine experiment data and advance our knowledge faster, to extend current research in time to predict best management systems, and to prepare for climate-change effects on agriculture. The relevance of such models depends on their implementation. Methods of Introducing System Models into Agricultural Research is the ultimate handbook for field scientists and other model users in the proper methods of model use. Readers will learn parameter estimation, calibration, validation, and extension of experimental results to other weather conditions, soils, and climates. The proper methods are the key to realizing the great potential benefits of modeling an agricultural system. Experts cover the major models, with the synthesis of knowledge that is the hallmark of the Advances in Agricultural Systems Modeling series.