Nitrous Oxide Soil Emissions From An Organic And Conventionally Managed Cropping System In Manitoba

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Nitrous Oxide Soil Emissions from an Organic and Conventionally Managed Cropping System in Manitoba

Author : Megan Westphal
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (135 download)

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Book Synopsis Nitrous Oxide Soil Emissions from an Organic and Conventionally Managed Cropping System in Manitoba by : Megan Westphal

Download or read book Nitrous Oxide Soil Emissions from an Organic and Conventionally Managed Cropping System in Manitoba written by Megan Westphal and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades the knowledge of nitrous oxide (N2O) emissions after the application of nitrogen (N) fertilizers in agriculture soil has improved. However the understanding of emissions of N2O from Canadian organic agricultural systems has not been developed. The Glenlea Long Term Crop Rotation is the longest running organic conventional comparison study in western Canada and was used here to compare N2O emissions between the systems. In organic cropping systems forage legumes such as alfalfa are incorporated into the soil as an N source. The amount of N2O that is emitted after the incorporation and during the subsequent crop is not well known. The wheat and legume phases (alfalfa (Medicago sativa) in organic system and soybean (Glycine max L.) in the conventional) of the rotation were monitored for N2O. In 2014, 2015, and spring 2016 (data still being analysed) emissions of N2O were monitored using the vented static chambers method as well, soil conditions (temperature, moisture, inorganic N and extractable carbon) and yields were measured. Typical N2O emissions from spring applied urea were observed after application in the conventional system however no emission episode was seen after the fall alfalfa plough down or during spring thaw in the organic system. Greater NO3- accumulation was observed in the organic treatments however low emissions were observed. The organic system resulted in lower yields for both years, but still resulted in lower emissions per amount of grain produced (yield-scaled emissions) than the conventional system. This study adds to the knowledge that N2O emissions from organic systems do differ from conventional however yields need to be improve to fully exploit the benefits.

Nitrous Oxide Emissions from California Tomato Cropping Systems Under Conventional and Alternative Management

Author : Taryn Lee Kennedy
Publisher :
ISBN 13 : 9781267238979
Total Pages : pages
Book Rating : 4.2/5 (389 download)

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Book Synopsis Nitrous Oxide Emissions from California Tomato Cropping Systems Under Conventional and Alternative Management by : Taryn Lee Kennedy

Download or read book Nitrous Oxide Emissions from California Tomato Cropping Systems Under Conventional and Alternative Management written by Taryn Lee Kennedy and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Primarily associated with soil fertility management practices, nitrous oxide (N2O) is a potent greenhouse gas (GHG) whose emission from farmland is a concern for environmental quality and agricultural productivity. In California, agriculture and forestry account for 8% of the total GHG emissions, of which 50% is accounted for by N2O (CEC, 2005). Furrow irrigation and high temperatures in the Central Valley, together with conventional fertilization, are ideal for the production of food, but also N2O production. These conditions can promote N2O emissions, but also suggest great potential to reduce N2O emissions by optimizing fertilizer and irrigation management. Smaller, more frequent fertilizer applications increase the synchrony between available soil nitrogen (N) and crop N uptake and may result in less N loss to the atmosphere. Given that the ecosystem processes regulating the production of N2O respond to and interact with multiple factors influenced by environmental and managerial conditions, it is not always feasible to approach the study of integrated agricultural systems and their affect on GHG emissions by use of a factorial experiment alone. On-farm studies are therefore an important precursor to research station trials to determine which management practices and components of a complete management system should be targeted and isolated for future study. Farm-based trials also provide a realistic evaluation of current management practices subject to practical and economic constraints. The following study took place on existing farms in order to assess the effect of active, operational farm field conditions and current managements on GHG emissions and to thoroughly characterize two typical management systems. In this study, I determined how management practices, such as fertilization, irrigation, tillage, and harvest, affect direct N2O emissions in tomato cropping systems under two contrasting irrigation managements and their associated fertilizer application method, i.e. furrow irrigation and knife injection (conventional system) versus drip irrigation, reduced tillage, and fertigation (integrated system). Field sites were located on two farms in close proximity, on the same soil type, and were planted with the same crop cultivar. This project demonstrated that shifts in fertilizer and irrigation water management directly affect GHG emissions. More fertilizer was applied in the conventional system (237 kg N ha−1 growing season−1) than the integrated system (205 kg N ha−1 growing season−1). The amount of irrigated water was comparable between the two systems; 64 to 70 cm was applied in the conventional system and 64 cm in the integrated system. Total weighted growing season emissions were 3.4 times greater in the conventional system (2.39 ± 0.17 kg N2O-N ha−1) than the integrated system (0.58 ± 0.06 kg N2O-N ha−1), with a higher tomato yield in the integrated system (131 vs. 86 Mg ha−1). The highest conventional N2O emissions resulted from fertilization plus irrigation events and the first fall precipitation. In the integrated system, the highest N2O fluxes occurred following harvest and the first fall precipitation. Environmental parameters of soil moisture, soil mineral N, and dissolved organic carbon (DOC) were higher and more spatially variable in the conventional system. Reduced N2O emissions in the integrated system, resulting from low soil moisture, mineral N concentrations, and DOC levels, imply that improved fertilizer and water management strategies can be effective in mitigating greenhouse gas emissions from agriculture.

Measured and Daycent- Simulated Nitrous Oxide Emissions from Soil Planted to Corn in Dairy Cropping Systems

Author : Maria Ponce De Leon Jara
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (1 download)

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Book Synopsis Measured and Daycent- Simulated Nitrous Oxide Emissions from Soil Planted to Corn in Dairy Cropping Systems by : Maria Ponce De Leon Jara

Download or read book Measured and Daycent- Simulated Nitrous Oxide Emissions from Soil Planted to Corn in Dairy Cropping Systems written by Maria Ponce De Leon Jara and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Crop rotations, organic nutrient amendments, reduced tillage practices, and integration of cover crops are practices that have the potential to increase the sustainability of crop production, yet they also impact nitrous oxide (N2O) emissions. Agricultural soil management has been estimated to contribute 79% of the total N2O emissions in the U.S., and inorganic nitrogen (N) fertilization is one of the main contributors. Nitrous oxide is a potent greenhouse gas that has a global warming potential which is approximately 298 times that of carbon dioxide (CO2) over a 100-year period and is currently the dominant ozone-depleting substance. Few studies have assessed the effects of organic N amendments on direct N2O within the context of a typical dairy forage cropping system. Most research has been limited to studying the effects of one or two sources of N inputs on N2O emissions; however, dairy forage cropping systems often apply manure and have more than two N sources that likely both contribute to N2O emissions. This study investigated how different dairy cropping practices that include differences in crop residues, N inputs (dairy manure and inorganic fertilizer), timing of N amendment applications and environmental conditions influenced N2O emissions from no-till soil planted to corn (Zea mays L.). A two-year field study was carried out as part of the Pennsylvania State Sustainable Dairy Cropping Systems Experiment, where corn was planted following annual grain crops, perennial forages, and a green manure legume crop; all were amended with dairy manure. In the corn-soybean (Glycine max (L.) Merr.) rotation, N sources (dairy manure and inorganic fertilizer) and two methods of manure application (broadcasted and injected) were also compared.Chapter 1 reviews the scientific literature; describing the biotic and abiotic processes of N2O production in soils, summarizing current research on N2O emissions in agricultural systems, and emphasizing the main management and environmental drivers contributing to the emissions. This chapter reviews methods for matching N supply with crop demand, coupling N flow cycles, using advanced fertilizer techniques, and optimizing tillage management. Also, the applicability and limitations of current research to effectively reduce N2O emissions in a variety of regions are discussed.Chapter 2 analyzes the effect of corn production management practices and environmental conditions contributing to N2O in the Pennsylvania State Sustainable Dairy Cropping Systems Experiment. Significantly higher N2O emissions were observed 15-42 days after manure injection and 1-4 days after mid-season UAN application. Manure injection had 2-3 times greater potential for N2O emissions compared to broadcast manure during this time period. Integration of legumes and grasses in the cropping system reduced inorganic fertilizer use compared to soybean with manure or UAN, however, direct N2O emissions were not reduced. The Random Forest method was used to identify and rank the predictor variables for N2O emissions. The most important variables driving N2O emissions were: time after manure application, time after previous crop termination, soil nitrate, and moisture. These field research results support earlier recommendations for reducing N losses including timing N inputs close to crop uptake, and avoiding N applications when there is a high chance of precipitation to reduce nitrate accumulation in the soil and potential N losses from denitrification.Chapter 3 reports the comparison of N2O fluxes predicted with the biogeochemical model DAYCENT compared to measured data from the two-year dairy cropping systems study. Daily N2O emissions simulated by DAYCENT had between 41% and 76% agreement with measured daily N2O emissions in 2015 and 2016. DAYCENT overestimated the residual inorganic N fertilizer impact on N2O emissions in the corn following soybean with inorganic fertilizer and broadcast manure. Comparisons between DAYCENT simulated and measured N2O fluxes indicate that DAYCENT did not represent well organic N amendments from crop residues of perennials and legume cover crops, or manure application in no-till dairy systems. DAYCENT was generally able to reproduce temporal patterns of soil temperature, but volumetric soil water contents (VSWC) predicted by DAYCENT were generally lower than measured values. After precipitation events, DAYCENT predicted that VSWC tended to rapidly decrease and drain to deeper layers. Both the simulated and measured soil inorganic N increased with N fertilizer addition; however, the model tended to underestimate soil inorganic N concentration in the 0-5 cm layer. Our results suggest that DAYCENT overestimated the residual N impact of inorganic fertilizer on N2O emissions and mineralization of organic residues and nitrification happened faster than DAYCENT predicted. Chapter 4 highlights the impact of manure injection and the importance of timing organic N amendments from manures and/or crop residue with crop N uptake to mitigate N2O emissions. More research is needed to better understand the tradeoffs of these strategies in no till dairy cropping systems to help farmers in their operational management decisions. Improving the parametrization of DAYCENT for dairy cropping systems in no-till systems with high surface legume crop residues from perennials and cover crops, will make the model a more useful tool for testing different mitigation scenarios for farmers and policy-designer decision making.

Microbial Sources of Nitrous Oxide Emissions from Diverse Cropping Systems

Author : Di Liang
Publisher :
ISBN 13 : 9781392872741
Total Pages : 143 pages
Book Rating : 4.8/5 (727 download)

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Book Synopsis Microbial Sources of Nitrous Oxide Emissions from Diverse Cropping Systems by : Di Liang

Download or read book Microbial Sources of Nitrous Oxide Emissions from Diverse Cropping Systems written by Di Liang and published by . This book was released on 2019 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrous oxide (N2O) is a potent greenhouse gas with a global warming potential ~300 times higher than CO2. As the primary source of reactive nitrogen oxides (NOx) in the stratosphere, N2O also depletes stratospheric ozone. N2O concentrations in the atmosphere are increasing rapidly, primarily due to agricultural activity. Nitrification, an autotrophic process that converts ammonia (NH3) into nitrite (NO2−) and nitrate (NO3−), and denitrification, a heterotrophic process that reduces NO3− into NO, N2O and N2, are the two major processes leading to N2O emissions. Nitrification has been reported to dominate N2O emissions from agricultural soils under aerobic conditions.Ammonia oxidizing bacteria (AOB) and ammonia oxidizing archaea (AOA) are the two main taxa involved in nitrification. Both AOA and AOB are capable of producing N2O, but their relative importance in nitrification is still largely unknown. In this dissertation I address three nitrification knowledge gaps: 1) Importance: what is the contribution of nitrification versus other microbial processes for producing N2O in systems under different management intensities (Chapter 2)? 2) Ecology: can high NH4+ inputs induce niche differentiation between AOA and AOB (Chapter 3)? 3) Complexity: how do plants mediate N2O emissions from AOA and AOB in situ in annual and perennial bioenergy cropping systems (Chapter 4)?In Chapters 2 and 3, I sampled soils from ecosystems under a management intensity gradient ranging from heavily-managed row crop agriculture to unmanaged deciduous forest. Results in chapter 2 show that soil nitrification is unlikely to be the dominant source of N2O in annual row crop systems, as the 25th-75th percentile of the maximum potential contribution ranged only between 13-42% of total N2O. In contrast, a maximum potential contribution of 52-63% of total N2O emissions could be attributed to nitrification in perennial or successional systems. In Chapter 3, I found high NH4+ inputs could inhibit nitrification of AOB but not AOA, especially in perennial and successional systems. Moreover, long-term N fertilization significantly promoted nitrification potentials of both AOA and AOB in the early succession but not in the deciduous forest systems. In summary, results from these two chapters suggest 1) nitrification is a minor source of N2O, especially in row crop systems, and 2) NH4+ inhibition of AOB could be another mechanism leading to niche differentiation between AOA and AOB in terrestrial environments.In Chapter 4, I examined nitrifier N2O emissions from annual (corn) and perennial (switchgrass) bioenergy cropping systems during different seasons that differ in plant nutrient demands. Both AOA and AOB responded to N fertilizer applications in situ but N fertilizer-induced N2O emissions were mainly observed in corn but not in switchgrass system. Because plants can compete with soil nitrifiers for NH4+ during the growing season, competition for NH4+ appeared to reduce N2O emissions from nitrification. Thus, synchronizing fertilizer application with plant nutrient uptake can be an important strategy for mitigating nitrification-derived N2O. Overall, results from this dissertation suggest that nitrifier-derived N2O in terrestrial ecosystems is significant but not a dominant source of N2O, and although AOB are more responsive to added N than are AOA, AOB can also be inhibited by high NH4+ concentrations in soil.

Effects of Management on Selected Soil Properties and Nitrous Oxide Fluxes in Dairy Cropping Systems

Author : Emily Paige Ball
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (11 download)

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Book Synopsis Effects of Management on Selected Soil Properties and Nitrous Oxide Fluxes in Dairy Cropping Systems by : Emily Paige Ball

Download or read book Effects of Management on Selected Soil Properties and Nitrous Oxide Fluxes in Dairy Cropping Systems written by Emily Paige Ball and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates selected soil properties and management decisions and their effect on nitrous oxide (N2O) emissions from agricultural soils. Nitrate, an inorganic form of N, is extremely mobile in soils, making it susceptible to loss through processes like denitrification. Denitrification is an anaerobic microbial process that reduces nitrate to N2 or incompletely to N2O, a potent greenhouse gas. The experimental site for this research was the Sustainable Dairy Cropping System (SDCS) located at Penn States Agronomy Farm. Chapter one is a review of the literature on nitrogen (N) cycling in agriculture, N loss pathways and the management and environmental factors affecting denitrification. This process is driven by soil properties, nitrate availability, and other factors. A prior study in this experiment in 2015 and 2016 found that the driving factors for N2O emissions in some of the same treatments were explained by days after manure application, growing degree days (GDD), and manure rate.Research on the effects of prior crop and management on N2O emissions in a typical PA dairy cropping system is described in chapter two. Labile carbon, total carbon, inorganic N species, and other environmental data were measured to determine their impact on measured N2O fluxes in 2017 and 2018. However, the measured soil and environmental properties in this experiment were not able to explain the observed patterns in N2O emissions through a regression analysis. The highest N2O fluxes were measured in 2018 in Corn after two years of Alfalfa (Medicago sativa) + Orchardgrass (Dactylis glomerata). Cumulative emissions were more than six times higher than those measured in treatments without a winter cover in the same year.Based on findings in 2017, chapter three investigates the impact of termination timing of Alfalfa+Orchardgrass on spring N2O fluxes and soil properties in 2018. This management decision is becoming more popular in the Northeast as spring conditions become wetter, making the proper timing of spring management events difficult. The findings from this experiment are promising for farmers interested in adopting this management practice as yields did not significantly differ from the subsequent corn crop and although they did not significantly differ, spring cumulative emissions from the spring terminated treatment were more than three times those from the fall terminated treatment. Because N2O emissions were not measured in the fall, however, the comparison of the two treatments in this study was not comprehensive.Chapter four described an investigative study on redox potentials in unsaturated agricultural soils. Equipment constraints and spatial variability made understanding and interpreting these results difficult. There were diurnal trends exhibited in some treatments, reflecting diurnal changes in soil moisture but not others. There also seemed to be stratification in depth, although this trend also differed across treatments. Overall, there is evidence that different crops can facilitate different redox environments and in turn, different microbial processes. However, more research and equipment advances need to take place before redox potential could be considered a useful indicator of microbial processes in unsaturated soils.Finally, the conclusions summarized the major findings of each of these experiments and discussed the impact of sustainable management practices on improving soil resiliency. Implementing sustainable practices like cover cropping and no-till can improve soil, although trade-offs of higher N2O emissions may result. Further research on these practices and their impact on soil properties is necessary as the effects of climate change are becoming more apparent.

Evaluating Mitigation Options of Nitrous Oxide Emissions in California Cropping Systems

Author : Martin Burger
Publisher :
ISBN 13 :
Total Pages : 104 pages
Book Rating : 4.:/5 (318 download)

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Book Synopsis Evaluating Mitigation Options of Nitrous Oxide Emissions in California Cropping Systems by : Martin Burger

Download or read book Evaluating Mitigation Options of Nitrous Oxide Emissions in California Cropping Systems written by Martin Burger and published by . This book was released on 2016 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

The Alliance of Bioenergy Production and Organic Farming

Author : Torsten Siegmeier
Publisher : kassel university press GmbH
ISBN 13 : 3737600724
Total Pages : 138 pages
Book Rating : 4.7/5 (376 download)

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Book Synopsis The Alliance of Bioenergy Production and Organic Farming by : Torsten Siegmeier

Download or read book The Alliance of Bioenergy Production and Organic Farming written by Torsten Siegmeier and published by kassel university press GmbH. This book was released on 2016-01-01 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current global energy needs and the effort to substitute fossil fuels have led to extensive production of biomass in agricultural systems for purposes of renewable energy generation. At the same time, energy cropping poses new threats to the sustainability of land use systems. Large-scale industrialized farming in general and intensive energy crop production in particular are increasingly drawing criticism from various stakeholders for their negative external effects. Organic farming systems alleviate the environmental burden of agricultural production by minimizing negative this food-energy-climate nexus a large-scale conversion of agricultural area to organic management seems infeasible. Against this backdrop, this dissertation examined interrelations and connections of organic agriculture and biomass energy systems in regard to three dimensions: (i) Scientific interest and publication structure, (ii) research topics and contents, and (iii) systemic implications of integrated bioenergy and organic farming systems in the case of farm biogas production in Germany.

Short-term Carbon Dioxide and Nitrous Oxide Flux Following Tillage of the Clay Soil in the Red River Valley in Southern Manitoba

Author : Alexander J. Koiter
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (855 download)

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Book Synopsis Short-term Carbon Dioxide and Nitrous Oxide Flux Following Tillage of the Clay Soil in the Red River Valley in Southern Manitoba by : Alexander J. Koiter

Download or read book Short-term Carbon Dioxide and Nitrous Oxide Flux Following Tillage of the Clay Soil in the Red River Valley in Southern Manitoba written by Alexander J. Koiter and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been resurgence in the interest of conservation tillage as a way to sequester carbon from the atmosphere, to help improve soil quality, and as a means to mitigate the increasing concentration of greenhouse gases (GHGs) in the atmosphere. However, the term conservation tillage is qualitative and quite ambiguous, and refers to a wide range of tillage practices. This makes the interpretation of information gathered from different tillage systems difficult. There currently exists a need for the quantification of soil surface properties following different tillage methods because surface properties are closely linked to soil surface processes. Previous research has focused on the long-term impacts of tillage systems and their effects on soil biological processes and properties, such as soil microbial populations and activity, soil organic matter fractions and their role in the production and emission of greenhouse gases. However, the more immediate impacts of tillage on soil physical processes and properties and their role in the production and emission of GHGs are not well understood and are often overlooked. The first objective of this research addressed the need for better quantification of soil physical properties after tillage practices. This research demonstrated the use of a laser profiling system and digital imagery and image analysis software in measuring soil micro-relief and crop residue cover. Furthermore, comparisons of geostatisitical and univariate procedures of quantifying surface roughness were also investigated. There was a definite advantage in using a geostatistical approach to characterize soil topography as the indices they provide give insight into the characterisitcs of the surface roughness. Soil disturbance and the addition of corn residue were both found to be significant factors affecting the surface roughness, crop residue cover, exposed surface area, and near-surface porosity. The second objective of this research focused on the quantification and characterization of the short-term effects of soil disturbance as a result of tillage on the carbon dioxide (CO2) and nitrous oxide (N2O) flux from the clay soils of the Red River Valley, Manitoba. The short-term CO2 flux (up to 5 days) following a soil disturbance event was characterized by an immediate increase in the CO2 flux following the soil disturbance event that quickly dissipated within the first 24 hours. Both the addition of residue and soil disturbance were found to be significant factors in the cumulative CO2 loss over the 5-day observation period. However, the incorporation of the residue through the action of soil disturbance was found to be a more important factor than soil disturbance or the addition of residue alone. The effects of residue and soil disturbance on the N2O flux were highly variable. However, there was some indication that the N2O flux under soil conditions may have a response to soil disturbance similar to that of CO2. The third objective is a combination in the previous two objectives and deals with the need to better understand the underlying physical mechanisms that control the CO2 and N2O flux. This was accomplished by combining the detailed information on the changes in surface properties and the CO2 and N2O fluxes that occur due to soil disturbance. Generally, the soil disturbance treatments that resulted in a rougher surface ...

Organic Farming for Sustainable Agriculture

Author : Dilip Nandwani
Publisher : Springer
ISBN 13 : 3319268031
Total Pages : 353 pages
Book Rating : 4.3/5 (192 download)

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Book Synopsis Organic Farming for Sustainable Agriculture by : Dilip Nandwani

Download or read book Organic Farming for Sustainable Agriculture written by Dilip Nandwani and published by Springer. This book was released on 2016-02-02 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focusing on organic farming, this book presents peer-reviewed contributions from leading international academics and researchers in the field of organic agriculture, plant ecosystems, sustainable horticulture and related areas of biodiversity science. It includes case studies and reviews on organic agriculture, horticulture and pest management, use of microorganisms, composting, crop rotation, organic milk and meat production, as well as ecological issues. This unique book addresses a wide array of topics from all continents, making it a valuable reference resource for students, researchers and agriculturists who are concerned with biodiversity, agroecology and sustainable development of agricultural resources.

Soil Nitrous Oxide Emissions from Agriculture in a Changing Global Environment

Author : Charlotte Decock
Publisher :
ISBN 13 : 9781267398338
Total Pages : pages
Book Rating : 4.3/5 (983 download)

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Book Synopsis Soil Nitrous Oxide Emissions from Agriculture in a Changing Global Environment by : Charlotte Decock

Download or read book Soil Nitrous Oxide Emissions from Agriculture in a Changing Global Environment written by Charlotte Decock and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Cropping System Affects Emissions of Nitrous Oxide But Not Methane from an Arable Wisconsin Soil

Author : William R. Osterholz
Publisher :
ISBN 13 :
Total Pages : 122 pages
Book Rating : 4.:/5 (814 download)

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Book Synopsis Cropping System Affects Emissions of Nitrous Oxide But Not Methane from an Arable Wisconsin Soil by : William R. Osterholz

Download or read book Cropping System Affects Emissions of Nitrous Oxide But Not Methane from an Arable Wisconsin Soil written by William R. Osterholz and published by . This book was released on 2012 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Chemical Properties of Organic Amendments Influence Nitrous Oxide Emissions from Agricultural Soils

Author : Anaïs Charles
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (953 download)

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Book Synopsis Chemical Properties of Organic Amendments Influence Nitrous Oxide Emissions from Agricultural Soils by : Anaïs Charles

Download or read book Chemical Properties of Organic Amendments Influence Nitrous Oxide Emissions from Agricultural Soils written by Anaïs Charles and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Prediction of organic amendment's (OA) potential to emit soil nitrous oxide (POA-N2O) is difficult because of the variable composition of OAs and of complex interactions with soil properties and environmental conditions. The objectives of this thesis were (1) to conduct a meta-analysis of in-field N2O emissions following OA application to agricultural soils to assess the global emission factor (EF) for all organic sources (EForg) and its modulation by environmental and management-related factors; (2) to determine how experimental conditions affect the POA-N2O and select optimal conditions for laboratory-based assessment; (3) to measure the immediate (P1), short- (P2) and medium-term (P3) POA-N2O with the selected laboratory-based incubation method and then, relate P1, P2, and P3 to the physico-chemical characteristics of more than 131 OAs. The meta-analysis conducted on 256 EFs from 43 sites in 12 countries yielded an EForg equal to 0.57 ± 0.30%, which is lower than the IPCC default EF of 1% for synthetic fertilizer (SF). Three groups of OAs with similar EFs were identified: the high-risk group including animal manures, waste waters and biosolids (1.09 ± 0.17%); the medium-risk group including composts with fertilizers and crop residues with fertilizers (0.46 ± 0.22%); and the low-risk group including composts, crop residues, paper mill sludge and pellets (0.25 ± 0.20%). The EF was modulated by the C/N ratio of the OA, soil properties and precipitation. The EFs were on average 2.8 times greater in fine-textured soils than coarse-textured soils. The comparative incubation study showed that O2-limited conditions in headspace of a sealed-jar system increased the magnitude of N2O fluxes by 1.1 to 2.3-fold compared to open-jar systems. Intermittent aerations of a sealed-jar system relying on repeated measurement periods was then selected to assess P1 (48h), P2 (2nd wk), and P3 (3rd wk). In O2-limited conditions created in a Kamouraska clay soil, maximum P1 was reached for crop residues (CR) with C/N ratio

Greenhouse Gas Emissions

Author : Narasinha Shurpali
Publisher : Springer
ISBN 13 : 981133272X
Total Pages : 188 pages
Book Rating : 4.8/5 (113 download)

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Book Synopsis Greenhouse Gas Emissions by : Narasinha Shurpali

Download or read book Greenhouse Gas Emissions written by Narasinha Shurpali and published by Springer. This book was released on 2018-10-31 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the exchange of greenhouse gases in various ecosystems, biomes and climatic zones, and discusses the measurement, modelling and processes involved in these exchange dynamics. It reflects the growing body of knowledge on the characterization, feedback processes and interaction of greenhouse gases with ecosystems and the impact of human activities. Offering a compilation of selected case studies prepared by international researchers working in the field, it represents a valuable resource for researchers and students alike.

Weed Ecology and New Approaches for Management

Author : Anna Kocira
Publisher : MDPI
ISBN 13 : 3036515127
Total Pages : 286 pages
Book Rating : 4.0/5 (365 download)

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Book Synopsis Weed Ecology and New Approaches for Management by : Anna Kocira

Download or read book Weed Ecology and New Approaches for Management written by Anna Kocira and published by MDPI. This book was released on 2021-09-08 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satisfying consumer needs through the production of healthy and nutritious agricultural products is a substantial challenge facing modern agriculture. However, agricultural production should be carried out with care for plant health, biological safety of products, and environmental safety while minimizing the risks to human health. Therefore, the implementation of agricultural practices while respecting these principles is very important for improving the quantity and quality of crops. Additionally, ecosystems have been altered as a result of human activities and climate change, resulting in the reduction of biodiversity and creation of new niches where pests can thrive. This is of particular importance in 2020, as the United Nations General Assembly declared this year as the International Year of Plant Health (IYPH), with “protecting plants, protecting life” as a leading subject. This Special Issue promotes the subject of plant health and emphasize the importance of preventing the spread of pests, including weeds, which cause substantial economic losses. Research articles cover topics related to the biology and harmfulness of weeds, particularly in connection with crop health, segetal weed communities and their biodiversity, and integrated methods of weed control. For this Special Issue, we welcome all types of articles, including original research, opinions, and reviews.

The Food Security, Biodiversity, and Climate Nexus

Author : Mohamed Behnassi
Publisher : Springer Nature
ISBN 13 : 303112586X
Total Pages : 516 pages
Book Rating : 4.0/5 (311 download)

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Book Synopsis The Food Security, Biodiversity, and Climate Nexus by : Mohamed Behnassi

Download or read book The Food Security, Biodiversity, and Climate Nexus written by Mohamed Behnassi and published by Springer Nature. This book was released on 2022-10-20 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is the outcome of an international cooperation between 73 scientists, experts, and practitioners from many countries, disciplines, and professional areas. As a part of a series of CERES publications, the volume attempts to contribute to the scientific debate about the food–biodiversity–climate nexus by developing a comprehensive region-specific and broader global understanding of the linkages between these areas, especially in the context of Global South. Instead of providing only modern science-based solutions for the nexus related challenges, the volume covers case studies that present mixed solutions, offering the use of traditional ecological knowledge in combination with modern science for both resilience and sustainability. This is increasingly instrumental in shaping the needed response options regarding the economic, social, and environmental future of the world. Based on a multi-regional and cross-sectoral analysis, the approach consists of: assessing the different natural and anthropogenic factors currently affecting ecosystems and their services, especially the impacts of climate change; highlighting the different linkages between the state of biodiversity and food systems in many contexts and scales; and exploring the various response mechanisms to effectively manage the implications of such linkages. Most chapters provide inputs for future relevant research and policy agendas.

Agricultural Management Intensity's Influence on Nitrous Oxide Emissions and Arbuscular Mycorrhizal Fungi

Author : Jennifer Haskell
Publisher :
ISBN 13 : 9781658413688
Total Pages : pages
Book Rating : 4.4/5 (136 download)

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Book Synopsis Agricultural Management Intensity's Influence on Nitrous Oxide Emissions and Arbuscular Mycorrhizal Fungi by : Jennifer Haskell

Download or read book Agricultural Management Intensity's Influence on Nitrous Oxide Emissions and Arbuscular Mycorrhizal Fungi written by Jennifer Haskell and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nitrogen (N) fertilizer and management intensity have been shown to influence N2O emissions from agricultural systems, along with other intrinsic soil conditions. Nitrous oxide (N2O) is a potent greenhouse gas emitted by agricultural soils and represents about 37% of total anthropogenic N2O emissions. Few studies have examined the influence of management gradients to understand their contribution to N2O emissions. Additionally, the role of arbuscular mycorrhizal fungi (AMF), a key player in plant nutrient acquisition, were evaluated for their response to management intensity and for their potential role in affecting N2O emissions. Intact soil cores were collected from thirty field sites across Yolo County, California including grassland sites with little to zero management and tomato fields of differing management intensity. The soil cores (120) were planted with tomato variety (Solanum lycopersicum, "Micro Tom"). Over the course of a 12-week long greenhouse experiment the relationship between management intensity, AMF, and nitrous oxide was evaluated. Nitrous oxide emissions and colonization of tomato roots by AMF were measured and relationships between management systems, AMF, and nitrous oxide were analyzed. Extensive and Intensive systems' AMF colonization were not significantly different though Grasslands were slightly higher. Nitrous oxide emissions were not significantly different among systems but were highest on average in Extensive systems. Lastly, there was a positive correlation between Extensive system's nitrous oxide output and colonization by AMF.

Challenges and Strategies of Dryland Agriculture

Author : S.C. Rao
Publisher : Scientific Publishers
ISBN 13 : 9387991091
Total Pages : 458 pages
Book Rating : 4.3/5 (879 download)

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Book Synopsis Challenges and Strategies of Dryland Agriculture by : S.C. Rao

Download or read book Challenges and Strategies of Dryland Agriculture written by S.C. Rao and published by Scientific Publishers. This book was released on 2011-01-01 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: The world has made remarkable progress in maintaining adequate food supplies during the past quarter century by introducing yield-increasing technologies such as better genetics, crop protection products, and more efficient use of fertilizers and irrigations. Far more people depend on irrigation in the modern world than during the times of ancient Sumeria. The spread of irrigation has been the key factor in increasing global crop yields. But future scarcity present the single biggest threat to future food production. The shift of water from agriculture to the growing cities and industry almost certainly will impact global food production. This means that dryland agriculture will be increasingly important in meeting food requirement for the growing population. Advaces in plant genetics and agronomic conservation technologies, when considered in concert, continue to provide the greatest opportunities to achieve sustainability and profitability in dryland agriculture and will continue to be the focus of the ARS research program. The ARS is please to join the crop Science Society of America and international center for Agriculture Research in Dry Areas (ICARDA) in sponsoring a symposium “Challenges and strategies for Dryland Agriculture” at the Trisocieties Annual Meeting in November 2002 at Indianapolis, IN. This special publication contains an impressive series of paper by international group of experts on dryland agricultural production, conservation, and policy. The principles, philosophies, and technologies presented in this publication have the potential to contribute to improve food security and livelihoods for the people in dryland regions of the world.