Download or read book Microbial Communities and Nitrogen Dynamics in Prairie and Cropland Soils written by Bikram Kumar Das and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Carbon and Nitrogen Dynamics and Microbial Community Structure of a Tall Grass Prairie Soil Subjected to Simulated Global Warming and Clipping written by Asfaw Belay Tedla and published by . This book was released on 2004 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Microbial Dynamics and Associative Nitrogen Fixation in Kansan Tallgrass Prairies written by Steven William Culman and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil ecosystem properties and processes which simultaneously maintain native fertility and sustain plant yields are of principal interest in sustainable agriculture. Native prairies in Kansas are relevant in this context, as they have been annually hayed with no fertilization or detectable decline in yield or soil fertility. In contrast, intensive wheat production has resulted in significant reductions in soil fertility and now requires intensive inputs to maintain yield. This study aimed to shed light on the soil microbiological differences between these two contrasting agricultural systems in an attempt to gain insight into possible mechanisms driving nutrient and energy efficiencies in these hayed prairie ecosystems. The objectives of this study were: i) to identify major differences in soil bacterial and nitrogen fixing communities between prairies and adjacent annual wheat fields, ii) to determine if dramatic losses of soil organic carbon (SOC) are a result of obsolete farming practices, or from plant community composition, and iii) to document the relative contribution of associative N-fixation to total plant N in three C4 prairie grasses. Soil analyses, microbial biomass, and terminal restriction fragment length polymorphism analyses (T-RFLP) revealed that bacterial and nitrogen fixing communities that were correlated with soil chemical, physical, and biological properties indicative of higher soil quality in prairie sites. In addition, SOC loss was documented in annual agriculture fields, even in the absence of tillage, demonstrating the large role that prairie plant communities play in maintaining soil fertility. Finally, evidence of associative N fixation was found in prairie grasses which may help alleviate N limitations and sustain long-term exports of N. Two additional studies were conducted to advance T-RFLP methodology. The first study was an evaluation of statistical multivariate analyses for T-RFLP data and yielded insight into which analyses were most appropriate given research objectives and dataset complexity. The second study yielded T-REX, a free, online software for rapid and less-biased analyses of T-RFLP data. Collectively, the results of this work suggest a greater synchrony of plant nutrient demand in prairies, which may help to explain the greater nutrient use efficiencies seen in these systems relative to wheat.

Download or read book Soil Microbial Dynamics and Associative Nitrogen Fixation in Kansas Tallgrass Prairies written by Steven William Culman and published by . This book was released on 2008 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soil ecosystem properties and processes which simultaneously maintain native fertility and sustain plant yields are of principal interest in sustainable agriculture. Native prairies in Kansas are relevant in this context, as they have been annually hayed with no fertilization or detectable decline in yield or soil fertility. In contrast, intensive wheat production has resulted in significant reductions in soil fertility and now requires intensive inputs to maintain yield. This study aimed to shed light on the soil microbiological differences between these two contrasting agricultural systems in an attempt to gain insight into possible mechanisms driving nutrient and energy efficiencies in these hayed prairie ecosystems. The objectives of this study were: (i) to identify major differences in soil bacterial and nitrogen fixing communities between prairies and adjacent annual wheat fields, (ii) to determine if dramatic losses of soil organic carbon (SOC) are a result of obsolete farming practices, or from plant community composition, and (iii) to document the relative contribution of associative N-fixation to total plant N in three C4 prairie grasses. Soil analyses, microbial biomass, and terminal restriction fragment length polymorphism analyses (T-RFLP) revealed that bacterial and nitrogen fixing communities that were correlated with soil chemical, physical, and biological properties indicative of higher soil quality in prairie sites. In addition, SOC loss was documented in annual agriculture fields, even in the absence of tillage, demonstrating the large role that prairie plant communities play in maintaining soil fertility. Finally, evidence of associative N fixation was found in prairie grasses which may help alleviate N limitations and sustain long-term exports of N. Two additional studies were conducted to advance T-RFLP methodology. The first study was an evaluation of statistical multivariate analyses for T-RFLP data and yielded insight into which analyses were most appropriate given research objectives and dataset complexity. The second study yielded T-REX, a free, online software for rapid and less-biased analyses of T-RFLP data. Collectively, the results of this work suggest a greater synchrony of plant nutrient demand in prairies, which may help to explain the greater nutrient use efficiencies seen in these systems relative to wheat.

Download or read book Soil Microbial Dynamics and Nitrogen Availability in Organic Low Input and Conventional Cropping Systems written by Nirmala Gunapala and published by . This book was released on 1994 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Microbiology and Sustainable Crop Production written by Geoffrey R. Dixon and published by Springer Science & Business Media. This book was released on 2010-09-08 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soils into which crop plants root and from which they obtain essential minerals and water contain huge arrays of microbes. Many have highly beneficial effects on crop growth and productivity, others are pathogens causing diseases and losses to yield and quality, a few microbes offer protection from these pathogenic forms and others have little or no effect. These intimate and often complex inter-relationships are being explored with increasing success providing exciting opportunities for increasing crop yields and quality in sustainable harmony with the populations of beneficial soil microbes and to the detriment of pathogens. This book explores current knowledge for each of these aspects of soil microbiology and indicates where future progress is most likely to aid in increasing crop productivity by means which are environmentally benign and beneficial.

Download or read book Links Between Soil Microbial Communities and Transformations of Soil Carbon and Nitrogen Along a Gradient in Land use History and Soil Disturbance written by Kerri Loraine Steenwerth and published by . This book was released on 2003 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microbial Community Dynamics in Tallgrass Prairie Soil Affected by Native Grazer Feces Bison Bison written by Karley Chantos and published by . This book was released on 2017 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tallgrass prairies have been reduced in area by over 90% and are therefore one of the most threatened ecosystems in the world. Efforts to restore these native lands from agriculture are ongoing throughout the North American Midwest. Changes in the microbial community and ecosystem properties that follow conversion of agriculture to restored tallgrass prairies are poorly understood. In this work we sought to characterize how nutrient influx and microbial communities from reintroduced native grazer feces affected the microbial community of prairie soil during restoration. Nachusa Grasslands, located in Franklin Grove, IL, USA, is a successful long-term effort of restoring agricultural land to a mosaic of tallgrass prairies. More than 30 bison (species Bison bison) were reintroduced into 500 acres of enclosed prairie in November 2014 to reinstate integral grazing regimes to the landscape. Newly-reintroduced bison had access to restored prairies that were re-planted at nine different time-points over the previous 16 years, as well as remnant prairies that were never used for agriculture. Manipulative field experiments were used to explore the direct interactions between bison dung and prairie soil that differed in restoration age, with bulk soil from both bison-exposed and bison-free treatments sampled biweekly from spring to fall 2015. In addition, we sampled soil below and along a transect away from transplanted fecal patties during a three-week period to examine the direct impact of dung on soil geochemistry and microbial diversity. The mass quantification carbon and nitrogen and 16S rDNA amplicon sequencing were used to quantify nutrient influx and changes in microbial communities upon fecal introduction. Initial community analyses in 2015 suggested that feces inputs drove an increase in easily cultivable, acidophilic Acidobacteria Groups 1 and 3 in old and remnant prairies, but decreased these groups in a newly-planted prairie. Conversely, primarily uncultured, neutrophilic Acidobacteria Groups 6 and 16 show the opposite trend, suggesting that pH and nutrient concentration may have drastically different effects on different-aged prairies. Surprisingly, repeated experiments in 2016 found soils that appeared to have converged on a seemingly novel, homogenized microbial community structure. Further analyses of soil geochemistry and the reconstruction of microbial metabolism will determine if bison-mediated increases in nitrogen and carbon are directly responsible for these community shifts or whether bison transport, either through feces or physical disruption, is seeding a new prairie microbiota. Continuing studies at Nachusa Grasslands will establish whether changes in geological, ecological and microbial structure due to fecal deposits are temporary or have long-term impacts on both the prairie soil and higher trophic levels. Ecosystem restoration is a critical component of managing sustainable biogeochemical cycles in the Anthropocene, and characterizing the microbial contributions, in concert with plants, animals, insects, and fungi, will be critical to improving success rates for future restoration efforts.

Download or read book Paired Prairie and Cultivated Soils written by Thomas Henry DeLuca and published by . This book was released on 1993 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: The internal nitrogen (N) cycle in soils of native and established prairies is highly conservative of N, whereas that of cultivated soils has a geater potential for loss of N to denitrification and leaching. In addition to rapid plant uptake of inorganic N, the efficiency of the N cycle in prairie soils has been partly attributed to the quality and quantity of available carbon (C) substrate to allow for microbial immobilization of N. In this study we investigate soluble or "free" anthrone-reactive carbon (ARC), as a measure of hexoses sugars, soluble organic C, and soluble amino-N status of prairie and cultivated soils as possible measures of instantaneously available C and N. Soils were collected from 11 adjacent prairie and cultivated sites in July 1991. Field moist soil samples were analyzed for biomass C, KC1 extractable NH4+, NO3-, and amino-N, and K2SO4-soluble organic C and ARC. Soil samples were also air-dried and analyzed for total C and N. Prairie soils were generally higher in total C, total N, biomass C, soluble amino-N, and soluble ARC than their cultivated counterparts. Total soluble organic C was not consistent among sites, but ratios of soluble C to inorganic N gave a better indication of the status of the internal N cycle than did the total C:N ratios. The prairie soils were lower in NO3 and total inorganic N than cultivated soils and had higher NH4:NO3 ratios. This may reflect the tight internal N cycle in prairie soils. Net production of NO3 in systems where an available C source is limiting results in the accumulation of NO3. Conditions of high NO3 and low levels of soluble ARC may be representative of a perturbed internal N cycle.

Download or read book Carbon and Nitrogen Dynamics and Microbial Ecology in Tallgrass Prairie written by Fernando Oscar Garcia and published by . This book was released on 1992 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Responses to Long term Fertilization and Burning written by Michael A. Carson and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic activities impact ecosystems in numerous direct and indirect ways, affecting the cycling of carbon (C) and nitrogen (N) on local, regional and global scales. North America tallgrass prairie is an ecosystem profoundly altered by anthropogenic activities, with most native prairie converted to alternate land uses or heavily impacted by other environmental changes. While aboveground responses to anthropogenic drivers have received much attention, the responses of belowground biota, ecological processes, and nutrient allocation to land management and environmental change are poorly documented, especially over long timeframes. This research builds upon a long-term experiment (the Belowground Plot Experiment) initiated in 1986 at Konza Prairie Biological Station (Manhattan, KS). I utilized a subset of treatments to address the effects of annual burning vs. fire suppression and/or chronic N additions on soil C and N dynamics and microbial communities in tallgrass prairie. I measured a suite of soil variables related to C and N cycling during the 2012 growing season, including total soil C and N, microbial biomass C and N, in situ net N mineralization, potential N mineralization, in situ CO2 efflux, and potentially mineralizable soil C.I also assessed changes in microbial community composition using microbial phospholipid fatty acids (PLFA) profiles. Annual burning significantly (p[less then or equal to]0.05) increased the soil C:N ratio and in situ CO2 efflux, while decreasing potential ammonification and nitrification rates. Annual burning also increased total PLFA mass and relative abundance of fungi. Chronic N addition (100 kg N ha−1 year−1) significantly reduced the soil C:N ratio, while increasing total soil N and potential nitrification and ammonification rates. Chronic N addition reduced potential C mineralization, microbial biomass C and N, and altered microbial community composition by increasing abundance of bacterial PLFAs and reducing fungal PLFAs. Sampling date also significantly affected many variables. These results indicate that different fire regimes and chronic N enrichment over decades affects soil C and N pools and transformations, as well as microbial biomass and composition. In total, this study highlights the importance of long-term ecological research and identifies likely changes in tallgrass prairie nutrient dynamics and soil microbial communities under increased N and frequent burning.

Download or read book Grassland Soil Microbial Responses to Long term Management of N Availability written by Christine Michelle Carson and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Anthropogenic actions have significantly increased biological nitrogen (N) availability on a global scale. In tallgrass prairies, this phenomenon is exacerbated by land management changes, such as fire suppression. Historically, tallgrass prairie fire removed N through volatilization, but fire suppression has contributed to increased soil N availability as well as woody encroachment. Because soil microbes respond to N availability and plant growth, these changes may alter microbial composition and important microbially-mediated functions. Grassland management affects the soil environment on multiple time scales including short (fertilization or fire event), seasonal (growing vs. non-growing season), and long-term (decadal plant turnover and nutrient accumulation), therefore my goal was to understand community variability at different time scales affecting the population and community dynamics of soil microbes. I predicted soil microbes would be sensitive to environmental changes at all time scales, seasonal variation would reflect increased plant rhizodeposit-supported populations during summer and decomposers during winter, and long-term fire suppression and chronic fertilization would drive soil microbial community turnover associated with accumulation of plant litter and N. To address these predictions, soils were collected from the Belowground Plot Experiment (BGPE) at Konza Prairie Biological Station: a 30-y factorial field manipulation of N fertilization and burning. Surface soils (0-15 cm) were sampled monthly between Nov 2014 - Dec 2015, including one week post-fire (April) and post-fertilization (June). Genomic DNA was extracted from each sample for qPCR and PCR for Illumina MiSeq library sequencing of the prokaryotic 16S rRNA gene and fungal ITS, to estimate population and community dynamics of soil microbes. Soil environmental characteristics and plant communities were measured in July 2015 to evaluate correlations between plant and microbial communities, and environmental variability. Soil microbial responses to short-term fire/fertilization events were minimal, while microbial population sizes fluctuate seasonally and synchronously, and microbial community composition varied more with management history than at shorter time scales. Bacterial populations increased 10x during growing-season plant rhizodeposition, while fungal populations were less dynamic, but decreased in fall, possibly reflecting a shift to subsistence on soil organic matter. In contrast, microbial community composition was seasonally stable, but distinct between long-term management treatments, which may indicate accumulation of niche-defining plant or soil properties over decades. Prokaryotic communities responded to altered N availability via both fertilization and loss due to fire, with the highest abundance of "copiotrophic" (r-selected) taxa in unburned, fertilized soils. Fungal communities responded to N fertilization with higher abundance of arbuscular mycorrhizal fungi, pathogens, and saprotrophs, possibly due to changes in nutrient stoichiometry and litter availability in fertilized plots. However, fungal response to fire was largely independent of N availability, and plant community differences were correlated with fungal, but not bacterial, community composition, highlighting the likely nutritional codependence of fungi and plants, and fungal competitive advantages for plant litter substrates. The timing of changes in soil microbial communities is critical for plant nutrition and nutrient cycling in prairies, and this novel dataset on the temporal resolution of microbial responses to environmental variability contributes to the broader understanding of ecosystem responses to global change.

Download or read book Ecological Stoichiometry written by Robert W. Sterner and published by Princeton University Press. This book was released on 2017-02-15 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: All life is chemical. That fact underpins the developing field of ecological stoichiometry, the study of the balance of chemical elements in ecological interactions. This long-awaited book brings this field into its own as a unifying force in ecology and evolution. Synthesizing a wide range of knowledge, Robert Sterner and Jim Elser show how an understanding of the biochemical deployment of elements in organisms from microbes to metazoa provides the key to making sense of both aquatic and terrestrial ecosystems. After summarizing the chemistry of elements and their relative abundance in Earth's environment, the authors proceed along a line of increasing complexity and scale from molecules to cells, individuals, populations, communities, and ecosystems. The book examines fundamental chemical constraints on ecological phenomena such as competition, herbivory, symbiosis, energy flow in food webs, and organic matter sequestration. In accessible prose and with clear mathematical models, the authors show how ecological stoichiometry can illuminate diverse fields of study, from metabolism to global change. Set to be a classic in the field, Ecological Stoichiometry is an indispensable resource for researchers, instructors, and students of ecology, evolution, physiology, and biogeochemistry. From the foreword by Peter Vitousek: ? "[T]his book represents a significant milestone in the history of ecology. . . . Love it or argue with it--and I do both--most ecologists will be influenced by the framework developed in this book. . . . There are points to question here, and many more to test . . . And if we are both lucky and good, this questioning and testing will advance our field beyond the level achieved in this book. I can't wait to get on with it."

Download or read book Seed and Soil Dynamics in Shrubland Ecosystems written by Ann L. Hild and published by . This book was released on 2004 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spatial and Temporal Fluctuations in Bacteria Microfauna and Mineral Nitrogen in Response to a Nutrient Impulse in Soil written by Vladimir V. Zelenev and published by . This book was released on 2004 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: .

Download or read book Nitrogen and Carbon Changes in Great Plains Soils as Influenced by Cropping and Soil Treatments written by Howard J. Haas and published by . This book was released on 1957 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modern Soil Microbiology Second Edition written by Jan Dirk van Elsas and published by CRC Press. This book was released on 2006-12-21 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the ten years since the publication of Modern Soil Microbiology, the study of soil microbiology has significantly changed, both in the understanding of the diversity and function of soil microbial communities and in research methods. Ideal for students in a variety of disciplines, this second edition provides a cutting-edge examination of a fascinating discipline that encompasses ecology, physiology, genetics, molecular biology, and biotechnology, and makes use of biochemical and biophysical approaches. The chapters cover topics ranging from the fundamental to the applied and describe the use of advanced methods that have provided a great thrust to the discipline of soil microbiology. Using the latest molecular analyses, they integrate principles of soil microbiology with novel insights into the physiology of soil microorganisms. The authors discuss the soil and rhizosphere as habitats for microorganisms, then go on to describe the different microbial groups, their adaptive responses, and their respective processes in interactive and functional terms. The book highlights a range of applied aspects of soil microbiology, including the nature of disease-suppressive soils, the use of biological control agents, biopesticides and bioremediation agents, and the need for correct statistics and experimentation in the analyses of the data obtained from soil systems.