Download or read book Biofuel Cropping System Impacts on Soil C Microbial Communities and N2O Emissions written by Andrew R. McGowan and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Substitution of cellulosic biofuel in place of gasoline or diesel could reduce greenhouse gas (GHG) emissions from transportation. However, emissions of nitrous oxide (N2O) and changes in soil organic carbon (SOC) could have a large impact on the GHG balance of cellulosic biofuel, thus there is a need to quantify these responses in cellulosic biofuel crops. The objectives of this study were to: (i) measure changes in yield, SOC and microbial communities in potential cellulosic biofuel cropping systems (ii) measure and characterize the temporal variation in N2O emissions from these systems (iii) characterize the yield and N2O response of switchgrass to N fertilizer and to estimate the costs of production. Sweet sorghum, photoperiod-sensitive sorghum, and miscanthus yielded the highest aboveground biomass (20-32 Mg ha−1). The perennial grasses sequestered SOC over 4 yrs, while SOC stocks did not change in the annual crops. Root stocks were 4-8 times higher in the perennial crops, suggesting greater belowground C inputs. Arbuscular mycorrhizal fungi (AMF) abundance and aggregate mean weight diameter were higher in the perennials. No consistent significant differences were found in N2O emissions between crops, though miscanthus tended to have the lowest emissions. Most N2O was emitted during large events of short duration (1-3 days) that occurred after high rainfall events with high soil NO3. There was a weak relationship between IPCC Tier 1 N2O estimates and measured emissions, and the IPCC method tended to underestimate emissions. The response of N2O to N rate was nonlinear in 2 of 3 years. Fertilizer induced emission factor (EF) increased from 0.7% at 50 kg N ha−1 to 2.6% at 150 kg N ha−1. Switchgrass yields increased with N inputs up to 100-150 kg N ha−1, but the critical N level for maximum yields decreased each year, suggesting N was being applied in excess at higher N rates. Yield-scaled costs of production were minimized at 100 kg N ha-1 ($70.91 Mg−1). Together, these results show that crop selection and fertilizer management can have large impacts on the productivity and soil GHG emissions biofuel cropping systems.

Download or read book Linking Soil Microbiology and Environmental Conditions to Variability in Nitrous Oxide Production in Bioenergy Cropping Systems written by and published by . This book was released on 2016 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agroecosystems may differ in multiple ecosystem properties, among them nitrous oxide (N2O) production and soil microbial community composition. We hypothesized that perenniality, plant species richness, and exogenous nitrogen inputs all influence N2O production directly through regulation of substrate concentrations and other environmental conditions and indirectly through changes to soil microbial functional characteristics. We studied the interplay among cropping systems, microbial communities, and N2O production in the context of an agronomic trial of potential bioenergy feedstock cropping systems. We measured N2O production from 2009-2014 and collected accompanying data on soil temperature, water-filled pore space, and inorganic nitrogen concentrations. Individual N2O fluxes and aggregate annual N2O emissions were lower in perennial systems relative to annual ones, but were not consistently influenced by plant species richness in perennial systems. Environmental variables defined upper limits for N2O fluxes, but did little to explain cropping system effects or their lack. We explored microbial community differences between continuous corn and prairie systems using membrane lipid profiling, amplicon sequencing, and functional gene annotations from shotgun metagenomic sequencing. The strength of cropping system effects differed among methods, with the strongest effects observed in lipid profiles. We used elastic net modeling to correlate community profiles to aggregate N2O emissions. Only the corn system could be effectively modeled, with the best models created from 16S rRNA amplicons and functional gene abundances. We used bacterial functional gene abundance profiles to characterize microbial communities across a broader range of cropping systems. The strength of cropping system effects varied among site years. Ecological factors such as perenniality and species diversity did not determine abundance patterns for either the full set of genes explored or for groups of genes with similar functions. Similarly, individual denitrification pathway genes did not systematically differ among cropping systems. Cropping system effects on N2O production and functional gene abundances were weaker than anticipated. Despite this, elastic net modeling linked gene abundance patterns to variation in N2O emissions with considerable accuracy. This indicates that within-cropping system variability in N2O production and functional genes are in some way connected.

Download or read book Linking Soil Microbiology and Environmental Conditions to Variability in Nitrous Oxide Production in Bioenergy Cropping Systems written by David Sean Duncan and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Agroecosystems may differ in multiple ecosystem properties, among them nitrous oxide (N2O) production and soil microbial community composition. We hypothesized that perenniality, plant species richness, and exogenous nitrogen inputs all influence N2O production directly through regulation of substrate concentrations and other environmental conditions and indirectly through changes to soil microbial functional characteristics. We studied the interplay among cropping systems, microbial communities, and N2O production in the context of an agronomic trial of potential bioenergy feedstock cropping systems. We measured N2O production from 2009-2014 and collected accompanying data on soil temperature, water-filled pore space, and inorganic nitrogen concentrations. Individual N2O fluxes and aggregate annual N2O emissions were lower in perennial systems relative to annual ones, but were not consistently influenced by plant species richness in perennial systems. Environmental variables defined upper limits for N2O fluxes, but did little to explain cropping system effects or their lack. We explored microbial community differences between continuous corn and prairie systems using membrane lipid profiling, amplicon sequencing, and functional gene annotations from shotgun metagenomic sequencing. The strength of cropping system effects differed among methods, with the strongest effects observed in lipid profiles. We used elastic net modeling to correlate community profiles to aggregate N2O emissions. Only the corn system could be effectively modeled, with the best models created from 16S rRNA amplicons and functional gene abundances. We used bacterial functional gene abundance profiles to characterize microbial communities across a broader range of cropping systems. The strength of cropping system effects varied among site years. Ecological factors such as perenniality and species diversity did not determine abundance patterns for either the full set of genes explored or for groups of genes with similar functions. Similarly, individual denitrification pathway genes did not systematically differ among cropping systems. Cropping system effects on N2O production and functional gene abundances were weaker than anticipated. Despite this, elastic net modeling linked gene abundance patterns to variation in N2O emissions with considerable accuracy. This indicates that within-cropping system variability in N2O production and functional genes are in some way connected.

Download or read book Biofuel Cropping Systems written by Hans Langeveld and published by Routledge. This book was released on 2014-01-21 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: Choosing appropriate practices and policies for biofuel production requires an understanding of how soils, climate, farm types, infrastructure, markets and social organisation affect the establishment and performance of these crops. The book highlights land use dynamics, cultivation practices related to conversion and wider impacts. It explores how biofuel production chain development is steered by emerging technologies and management practices and how both can be influenced by effective policies designed to encourage sustainable biofuel production. The book highlights major biofuel production chains including: cane cultivation in Brazil corn ethanol in the USA wheat and rapeseed in Europe oil palm in the Far East cane in Asia and Africa SRC and other lignocellulosic crops. In each case the development, cropping systems and impacts are discussed, system dynamics are shown and lessons drawn for the way things could or should change. Biofuel Cropping Systems is a vital resource for all those who want to understand the way biofuels are produced and how they impact other elements of society and especially how improvements can be made. It is a handbook for students, biofuel producers, researchers and policymakers in energy and agriculture.

Download or read book Plant Diversity and Nitrogen Addition on Belowground Biodiversity and Soil Organic Carbon Storage in Biofuel Cropping Systems written by Jennifer Butt and published by . This book was released on 2020 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Bioenergy production may reduce the emission of CO2 which contributes to climate change, particularly when management strategies are adopted that promote soil carbon (C) sequestration in bioenergy cropping systems. Planting perennial native grasses, such as switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerardii Vitman) may be used as a strategy to enhance soil C accumulation owing to their extensive root systems. Fertilizer use may further promote soil C sequestration, because of its positive impacts on plant production and soil C input. However, the influence of fertilizer addition on soil C accumulation is variable across bioenergy cropping systems, and fertilizer can negatively impact the environment. Increasing plant diversity may be used as a strategy to enhance soil C accumulation while augmenting other ecosystem properties such as soil biodiversity. The present study evaluates how inter- and intra- specific plant community diversity and N addition influence soil C storage and soil biodiversity. Soil was collected from a long-term (9 growing seasons) field experiment located at the Fermilab National Environmental Research Park in Illinois, USA. Treatments included [1] three cultivars of big bluestem and three cultivars of switchgrass cultivars grown in monoculture, [2] plant community diversity manipulated at both the species- and cultivar level, and [3] nitrogen (N) applied annually at two levels (0 and 67 kg ha-1). The soil at the site was dominated by C3 grasses for 30 years before replacement with C4 bioenergy grasses, which enabled quantification of plant-derived C accumulation owing to the natural difference in isotopic signature between C3 and C4 grasses. Soil samples were analyzed for [1] soil C and its delta13C isotopic signature, and [2] nematode and soil bacterial diversity. Our results indicate that both plant diversity and N addition influence soil community structure but not soil C storage or soil nematode biodiversity. However, the addition of big bluestem to the plant species mixes enhanced plant-derived C storage. In summary, our findings suggest that plant species identity can control soil C accumulation in the years following land conversion, and that manipulating plant community structure in bioenergy cropping systems may have a greater positive impact on soil C accumulation than N fertilization."--Boise State University ScholarWorks.

Download or read book Impacts of Biofuel Crops on Greenhouse Gas Emissions from Agricultural Ecosystems written by Leilei Ruan and published by . This book was released on 2014 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Corn based and Perennial Bioenergy Cropping Systems written by Laura A. Lipps and published by . This book was released on 2010 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Biofuel Feedstocks written by El Hadji Habib Sy Diop and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Biofuel feedstocks such as grains and cellulose are gaining increased attention as part of the U.S. portfolio of solutions to address climate change and improve energy security. As the future of biofuels unfolds, major concerns are emerging, including the sustainability of the soil resource in bioenergy cropping system. With a clear understanding of the sustainability risks that exist within the agricultural soil resources, it is now essential to develop metrics that document the soil health as well as the total biomass production of different cropping system. We tested the effectiveness of eight bioenergy plant species grouped between annual and perennial crops. Our main objective was to determine the sustainability of bioenergy cropping systems. There was significantly greater soil structural stability plus greater root biomass under the perennial crops but greater aboveground biomass in the annual crop. Differences in soil carbon measured to 1.2 m were not significant between energy crops after five years. A transparent, unbiased method to identify possible change in soil characteristics under bioenergy cropping practice was offered. Our next metrics were soil aggregate stability and microbial community structure as indicators of soil ecosystem health and environmental stability. The effects 24 years of differing levels of residue and fertilizer inputs on soil aggregate stability, aggregate C and microbial community structure were evaluated. A native, undisturbed prairie site, located nearby was used as a reference in this study. The results showed that greater inputs of inorganic N and increased returns of crop residues did not cause a proportionately greater increase in SOC. The abundance of microbial parameters generally followed their potential carbon pool in cultivated soils but a strong mismatch was observed in the native prairie site. Our results showed for the first time a clear disconnect between decomposers and macroaggregates; highlighting the role of soil structure in protecting organic matter. Soil carbon sequestration is one of the mechanisms that have been proposed as temporary measure to mitigate global climate change. However, there was a particularly large risk of negative effects of mitigation measures related to the increased removal of crop residues from cropping systems for use in bioenergy, if this means that soil carbon is reduced. Effective measurement of soil C at the field scale requires an understanding of the spatial variability of soil C on a landscape scale. Recent technological advances in soil C measurement offer new opportunities in this area. Our surface measurements of soil C by near infrared spectroscopy (NIRS) provided a quick assessment of soil C and, soil C predicted by NIRS and measured by dry combustion laboratory measurements was correlated with and R-squared of 0.84.

Download or read book Greenhouse Gas Footprint of Organic Amendments and Water Management in Rice Cropping Systems in Southeast Asia written by Baldur Janz and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Rice is the staple food for half the world's population. To keep up with global population growth and growing food demand, rice production will inevitably increase. Increasing water scarcity and South-east Asia's rapid economic and social development, specifically the growing demand for animal products and biofuels challenge the traditional lowland double-rice (rice-rice; [R-R]) cropping systems and has already resulted in a partial transformation to mixed lowland-upland systems. Owing to water scarcity, upland crops such as aerobic rice [R-A] or maize [R-M] are grown instead of paddy rice during the dry season (DS). Other water-saving strategies, which allow for intermitted irrigation or 'alternate-wetting and drying' (AWD) are also emerging. Such changes in water management affect C and N cycling in the soil-plant system. For instance, methane (CH4: global warming potential (GWP) of 28) emissions from paddy fields will be replaced by emissions of the more potent greenhouse gas (GHG) nitrous oxide (N2O: GWP of 265) since methane is only produced in large amounts under anaerobic conditions and N cycling and associated release of nitrous oxide is stimulated in unsaturated soil conditions. Moreover, soil organic carbon stocks will decrease due to amplified soil respiration in presence of oxygen, thereby jeopardizing soil fertility. To counteract declining soil fertility, catch crops can be used as green manure (GM) during fallow period and rice residues can be returned with both approaches supplying and recharging organic matter, improving N retention and avoiding unproductive water losses in intensified crop rotations. Due to a lack of incentives, expensive labor and rigid cropping schedules, large amounts of rice residues are traditionally burnt after harvest and thereby adversely affect local air quality. Many Asian governments have banned open-field burning and thus are putting pressure on rice farmers to seek other ways for sustainable straw disposal. While GM and residue returns have been shown to have a positive effect in upland soils, this approach may promote CH4 emissions from submerged, anoxic paddy soils as it provides additional substrate for methanogenesis. The management of earthworms, in turn, could restrain microbial crop residue decomposition in non-flooded rice soils and thus mitigate GHG emissions triggered by straw incorporation. Consequently, conservation practices including the management of organic amendments might be a promising approach to retain soil fertility, and sustain the productivity of emerging diversified rice rotations. However, little is known about the actual effects of such practices on soil C and N cycling and GHG balance under contrasting water management. Therefore, the major goal of my work was to i) quantify the effect of crop residue return, specifically rice straw application and legume cover crop cultivation on CH4 and N2O emissions of diversifying rice cropping systems and ii) provide a mid to long-term assessment of the annual GHG balance of diversified rice systems based on area and productivity. For this, I calculate annual GWPs and yield-scaled GWPs of three different rice systems (R-R: rice-rice, R-A: rice-aerobic rice, R-M: rice-maize) without (control) or with additions of straw (+ 6 Mg C ha-1 [S]) or + straw + mungbean as catch crop ([M+S]) on the basis of GHG (CH4 and N2O) flux measurements in high temporal resolution, and measurements of yield parameters. The field trials were carried out at the International Rice Research Institute (IRRI), Philippines, with year-round automated chamber measurements, covering the growing season as well as off-season emissions. My investigations further explored the potential of the AWD irrigation practice and earthworm management as GHG mitigation strategies. Results from five years of continuous measurements show that maize in rotation with paddy rice has a significantly lower GWP than aerobic rice or a traditional double paddy rotation. Although dry season N2O emissions increased two- to threefold in the diversified systems (R-A, R-M), the strong reduction of CH4 emissions during this period resulted in significantly lower annual GWP as compared to the traditional double rice system (R-R). Direct CH4 reductions during DS were complemented by overall lower CH4 emission during wet season paddy rice cultivation, which is explained by increased availability of oxidants and a delayed growth of soil methanogens. With an equivalent of 0.6 ± 0.1 Mg CO2 per ton of grain produced, the R-M system had a significantly lower annual GHG footprint than R-R with 1.4 ± 0.3 Mg CO2-eq. GY . From both a GHG perspective and productivity perspective, the performance of aerobic rice was not significantly better than paddy rice (1.2 ± 0.2 Mg CO2-eq. GY-1), mostly due to yield penalties from less intensive irrigation management during DS. This ranking persists even with the application and incorporation of rice straw and mungbean GM, however, the additional organic matter led to higher substrate availability for methanogens during the following season. Rice straw incorporation strongly stimulated CH4 emissions, but the magnitude of CH4 emissions was significantly lower under aerated soil conditions and negligible for the annual GHG balance. Likewise, the effect of GM application to CH4 emissions during wet season paddy rice cultivation was less pronounced with maize as a preceding upland crop. However, GM application to flooded rice paddies is disqualified as sustainable management practice with CH4 emission being approximately doubled. Contrary to expectations, N2O emissions were not reduced due to N immobilization after straw or GM incorporation. Reasons might be a higher O2 content in straw mulch top layer on upland soils which enhanced nitrification and inhibited the further reduction of N2O to N2, as well as excess N supply after not adjusting mineral fertilizer N rates to the N input from leguminous mungbean GM. Therefore, the annual GWP was 9-39% higher after straw incorporation during DS, as compared to straw removal. Additional incorporation of mungbean GM further increased the GWP, with the highest increment in R-R rotation (88%), followed by R-A (73%), and lowest in R-M rotation (55%), and annual GHG footprint of 11.8, 9.4, and 5.6 Mg CO2 eq. ha-1, respectively. My findings further demonstrate that the presence of earthworms in non-flooded rice soils can reduce adverse effects of straw incorporation on CH4 release, without boosting N2O emissions or impairing yields. Straw organic carbon might be preserved in earthworm cast aggregates and thereby limit C availability for methanogenic CH4 production while methanotrophic CH4 consumption is increase due to improved soil aeration. My work also calls for a refinement of IPCC Tier 1 and 2 emission factor approach as it does not accurately represent emerging upland crop - paddy rice rotations. IPCC guidelines also do not consider a short pre-season flooding period (i.e. land- preparation). As observed in this long-term study, this period is contributing up to 13% to seasonal CH4 budget. Addressing this with a daily flux rate of 0.38 kg CH4-C day-1 for the days of land-preparation, analogous to the IPCC baseline emission factor, would take this period into account. My field GHG measurements of AWD water regime were used to validate and subsequently apply the biogeochemical model LandscapeDNDC at national scale, similar to IPCC Tier 3 approach for the UNFCC GHG reporting. Replacing CF field management by the water-saving technique AWD, most likely can decrease GHG emissions from rice cultivation in the Philippines by one third. Compared to traditional double paddy system, rice - maize cropping has a significantly lower irrigation water demand and GHG footprint. Due to prolonged aerated soil conditions, upland - lowland rotation systems also allow for a more flexible residue management, a requirement for farmers as the ban of open-field burning is increasingly enforced. However, socio-economic concerns emerge when maize is cultivated to satisfy the growing demand for poultry feed and biofuel production and enters into direct competition to food security and the required land resources. Therefore, further research is needed to increase yields particularly of aerobic rice varieties and to further explore mitigation potentials e.g. of low-CH4 emitting rice cultivars. Further investigations should extend the process understanding of plant- and water-mediated CH4 release pathways with the help of stable isotope fractionation

Download or read book Soil Health and Intensification of Agroecosystems written by Mahdi M. Al-Kaisi and published by Academic Press. This book was released on 2017-03-15 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil Health and Intensification of Agroecosystems examines the climate, environmental, and human effects on agroecosystems and how the existing paradigms must be revised in order to establish sustainable production. The increased demand for food and fuel exerts tremendous stress on all aspects of natural resources and the environment to satisfy an ever increasing world population, which includes the use of agriculture products for energy and other uses in addition to human and animal food. The book presents options for ecological systems that mimic the natural diversity of the ecosystem and can have significant effect as the world faces a rapidly changing and volatile climate. The book explores the introduction of sustainable agroecosystems that promote biodiversity, sustain soil health, and enhance food production as ways to help mitigate some of these adverse effects. New agroecosystems will help define a resilient system that can potentially absorb some of the extreme shifts in climate. Changing the existing cropping system paradigm to utilize natural system attributes by promoting biodiversity within production agricultural systems, such as the integration of polycultures, will also enhance ecological resiliency and will likely increase carbon sequestration. Focuses on the intensification and integration of agroecosystem and soil resiliency by presenting suggested modifications of the current cropping system paradigm Examines climate, environment, and human effects on agroecosystems Explores in depth the wide range of intercalated soil and plant interactions as they influence soil sustainability and, in particular, soil quality Presents options for ecological systems that mimic the natural diversity of the ecosystem and can have significant effect as the world faces a rapidly changing and volatile climate

Download or read book Impacts of Organic Cropping Systems on Greenhouse Gas Emissions Soil Mineral Nitrogen and Crop Yields in Field Crop Production in Qu bec written by Joannie D'Amours and published by . This book was released on 2022 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: Organic farming aims to enhance the sustainability of cropping systems, but some soil conservation practices implemented may increase greenhouse gas (GHG) emissions. The main objective of this study was to determine the effects of various organic cropping systems on GHG emissions and crop yields, in Québec, Canada. A field experiment was conducted at the Institut national d'agriculture biologique, over two growing seasons (26 April to 31 October 2019 and 29 April to 12 November 2020), on a sandy loam soil. The randomized complete block design included two controls (perennial forage and bare fallow [BF]) and five organic cropping systems combining different: (i) crop sequences (barley [Hordeum vulgare L.]- grain corn [Zea mays L.], soybean [Glycine max (L.) Merr.]- spring wheat [Triticum aestivum L.], grain corn-soybean); (ii) sources of fertilizers (poultry manure [PM] and/or a fall-seeded green manure [GM] or no source); and (iii) primary tillage intensities (moldboard plough [MP] or chisel plough [CP]). Soil temperature, water content, and mineral N concentrations were evaluated periodically, as well as direct nitrous oxide (N2O) and methane (CH4) emissions, which were quantified using non-flow-through non-steady-state chambers and gas chromatography. The lowest cumulative N2O emissions were found in CP-GM (0.52 ± 0.11 and 3.55 ± 0.72 kg N ha−1 in 2019 and 0.47 ± 0.06 kg N ha−1 in 2020), whereas the highest emissions were found in MP-PM in 2019 (3.55 ± 0.72 kg N ha−1) and BF in 2020 (1.44 ± 0.20 kg N ha−1). During both years, CH4 emissions varied from -0.65 to +0.18 kg C ha−1 and were similar between cropping systems. Organic cropping system CP-GM minimized the area-scaled N2O emissions without increasing the yield-scaled N2O emissions. However, long-term assessment is necessary to determine the agronomic, economic, and environmental benefits of these cropping systems.

Download or read book Healthcare Simulation Research written by Debra Nestel and published by Springer Nature. This book was released on 2019-11-13 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides readers with a detailed orientation to healthcare simulation research, aiming to provide descriptive and illustrative accounts of healthcare simulation research (HSR). Written by leaders in the field, chapter discussions draw on the experiences of the editors and their international network of research colleagues. This seven-section practical guide begins with an introduction to the field by relaying the key components of HSR. Sections two, three, four, and five then cover various topics relating to research literature, methods for data integration, and qualitative and quantitative approaches. Finally, the book closes with discussions of professional practices in HSR, as well as helpful tips and case studies.Healthcare Simulation Research: A Practical Guide is an indispensable reference for scholars, medical professionals and anyone interested in undertaking HSR.

Download or read book Biomass Biofuels Biochemicals written by Indu Shekhar Thakur and published by Elsevier. This book was released on 2021-12-01 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomass, Biochemicals, Biofuel: Climate Change Mitigation: Sequestration of Green House Gases is designed to not only give basic knowledge on the topics presented, but also to enlighten on conventional and advanced technologies, socioeconomic aspects, techno-economic feasibility, models and modeling tools, and detailed LCA approaches in the sequestration of GHGs for biofuel and biomaterials, including biopolymer production. These innovative technologies and novel prospective directly find applications in day-to-day practices. The book is a useful guide to politicians, researchers, teachers and waste management practitioners. It offers a treasure of knowledge to guide readers on the importance of GHGs sequestration in important areas. The issue of climate change is gaining much more attention by researchers, public, politicians and others. Climate change is one of the most complex issues the world is facing today. It has implications across society, including in science, technology, economics, society, politics, and moral and ethical dilemmas. Introduces appropriate technologies for GHG sequestration for biofuel and biomaterials production Presents the best available technologies for climate mitigation and examples from various geographical areas Evaluates technological systems to help users develop technically best and economically feasible projects Offers chemical looping mechanisms for the sequestration of green house gases for biofuel and biomaterials

Download or read book Effect of Cropping Systems on Microbial Biomass Carbon and Nitrogen Dehydrogenase Activity and Fixed Ammonium in Soils written by Jennifer Marie Moore and published by . This book was released on 1998 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainable agriculture, including cropping systems, has received considerable attention in recent years. Soil management practices may affect the physical, chemical, and biological properties of soils, including microbial biomass C (C[subscript mic]), microbial biomass N (N[subscript mic]), enzyme activities, especially dehydrogenase activity, and (possibly) fixed NH4+. In this work, soil samples were collected in 1996 and 1997 from two long-term cropping systems at the Northeast Research Center (NERC) in Nashua and the Clarion-Webster Research Center (CWRC) in Kanawha, Iowa.

Download or read book Carbon mediated Ecological and Physiological Controls on Nitrogen Cycling Across Agricultural Landscapes written by Andrew James Curtright and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sustainable intensification of agriculture relies on the efficient use of ecosystem services, particularly those provided by the microbial community. Managing for these ecosystem services can improve plant yields and reduce off-site impacts. For instance, increasing plant diversity is linked to positive effects on yield, and these beneficial effects are often mediated by the microbial community and the nutrient transformations it carries out. My dissertation has aimed to elucidate the mechanisms by which plant diversity improves agricultural production. In particular, I have focused on how changes to the amount and diversity of carbon (C) inputs affects soil microorganisms involved in the nitrogen (N) cycle. My work spans multiple scales of observation: from a global meta-analysis to mechanistic studies utilizing denitrification as a model system.In a global meta-analysis, I found that increasing plant diversity through intercropping yields a net increase in extracellular enzyme activity. This effect varied by plant species and soil type suggesting that increases in the quality of nutrient inputs mediates these positive effects on microbial activity. Then, I looked at how intercropping cover crops into corn affects soil nutrient pools and microbial activities in a field experiment. No effect of interseeding cover crops into corn was found on soil nutrient pools or microbial activities. However, by analyzing differences in relationships between nutrient pools and microbial activities at two locations throughout Michigan, I was able to describe how the availability of dissolved organic C (DOC) drives differences in microbial N-cycling processes. I then investigated how C availability drives activity in microbial hotspots within the soil by comparing differences in denitrification potential in bulk soil versus the rhizospheres of corn and interseeded cover crops. Here, I found that denitrification rates were increased in the rhizospheres of all plant types, and this effect varied depending on the species of plant. I was able to further differentiate the impact of DOC and microbial biomass C on the rhizosphere effect and found that C availability was the primary driver of differences in denitrification rates between rhizospheres. Since plants provide many different forms of C to soil microbes, it is important to understand how the chemistry of C inputs affects microbial activity. I used a series of C-substrate additions to determine how C chemistry affects denitrifiers. I found that amino acids and organic acids tended to stimulate the most nitrous oxide (N2O) production and reduction. Although management and site affected overall rates of denitrification, C-utilization patterns of microbes were mostly similar between locations. To identify the mechanisms responsible for these effects, I performed a final experiment to track how denitrifiers utilized different C compounds. The C substrates that stimulated the most complete reduce of N2O also were utilized with the lowest C-use efficiency (CUE). This suggests possible trade-offs between N2O reduction and CUE, with important implications for how to manage microbial communities.Overall, my work demonstrates that land management can impact microbial community activity by influencing the identity of soil C inputs. While the importance of increasing soil C inputs has been known, this dissertation supports the notion that the chemical identity of C inputs can exert significant controls on microbial activity. Moreover, by comparing microbial traits I highlight the importance of trade-offs in how microbially mediated C- and N cycling are coupled.

Download or read book Impacts of Cropping Systems on Soil Health and Microbial Ecology written by Korbla Edwin Akley and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Declining soil health is the underlying cause of decreasing agricultural productivity and environmental degradation. To address this challenge, research was conducted to determine how: (1) cover crops affect soil health in Kansas, USA and (2) direct seeding mulch-based cropping (DMC) systems affect soil health in Nyankpala, Ghana. Soil health indicators assessed include: biomass yield (kg ha−1), soil microbial respiration (SMR), soil microbial C and N (MBC & MBN), potentially mineralizable N (PMN), dissolved organic carbon (DOC), soil organic C (SOC), soil total nitrogen (TN), phospholipid fatty acid analysis (PLFA), water stable aggregate (WSA), bulk density, pH, N, P, K, Ca and Mg. DMC systems from Ghana yielded significantly greater biomass compared to the control. High biomass produced by DMC systems did not increase SOC and PMN relative to the control. Fertilizer application had a significant impact on biomass production, which resulted in a significant increase in SOC and PMN in the 0-5 cm soil layer. Soil pH was significantly reduced by cropping systems and fertilizer in the 0-5 cm soil layer. Microbial biomass N, TN, SMR, N, P, Ca and Mg were not affected by the DMC cropping systems. Application of mineral fertilizer increased SMR, MBN, TN, N, and P. Soil K was also significantly affected by cropping systems and mineral fertilizer. The combination of mineral fertilizer and plant residues would be needed to improve soil health and increase crop productivity in the Guinea Savanna Zone of Ghana. Liming would be required to address low soil pH. In the USA, of all the soil health indicators examined, actinomycetes, gram-positive bacteria, fungi-bacteria ratio (F:B), SMR, MBN and WSA, were those significantly influenced by cover crops. The interactive effect of cover cops and N fertilizer also affected gram-positive bacteria, total PLFA, MBN, F:B ratio and WSA. Cover crop residues contributed to the observed differences in these indicators. The low response of soil health indicators suggest further evaluations are needed to determine the effectiveness of the indicators.

Download or read book CO2 Sequestration and Valorization written by Claudia R. V. Morgado and published by BoD – Books on Demand. This book was released on 2014-03-12 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reconciliation of economic development, social justice and reduction of greenhouse gas emissions is one of the biggest political challenges of the moment. Strategies for mitigating CO2 emissions on a large scale using sequestration, storage and carbon technologies are priorities on the agendas of research centres and governments. Research on carbon sequestration is the path to solving major sustainability problems of this century a complex issue that requires a scientific approach and multidisciplinary and interdisciplinary technology, plus a collaborative policy among nations. Thus, this challenge makes this book an important source of information for researchers, policymakers and anyone with an inquiring mind on this subject.