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 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 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 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 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 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 Soil Organic Carbon Dynamics and Tallgrass Prairie Land Management written by Joshua W. Beniston and published by . This book was released on 2009 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This study was composed of two research components that examined the effects of tallgrass prairie land use changes on soil organic C (SOC). The central objective of the first study was to examine changes in SOC and a suite of soil quality parameters in former agricultural soils now under restored tallgrass prairie. This research was conducted at the Prairie Nature Center, on the OSU Marion campus in northwest Ohio. Soils from 31 year, 13 year, and 8 year- old prairies, and adjacent agricultural and lawn soils were analyzed. These soils demonstrated significant increases in SOC concentration, particulate organic matter (POM), water stable aggregation (%WSA), aggregate mean weight diameter (MWD), total porosity (ft), and available water capacity (AWC), and significant decreases in soil bulk density ([rho]b) associated with time under tallgrass prairie. The second research component observed long and short-term effects of the conversion of remnant tallgrass prairies to wheat production, in north central Kansas. Total C, microbial biomass C (MBC), and a particle size fractionation of SOC were used as indices of change. Long-term sites showed changes in all fractions analyzed, while only MBC showed significant change in the short-term study. This study provides further evidence that perennial plant communities store and cycle C, and maintain ecosystem processes at far greater levels than annual plant communities.
Download or read book CSSA Special Publication written by and published by . This book was released on 1998 with total page 1074 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Dynamics of Microbial Community Structure and Function in a Tallgrass Prairie Ecosystem written by Allison Michelle Veach and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to agricultural practices and urbanization, tallgrass prairie ecosystems have become threatened as
Download or read book Native Warm season Grasses written by Kenneth J. Moore and published by . This book was released on 2000 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt: Including native warm-season grasses in pasture systems makes good ecological sense, and this publication explores the benefits and challenges associated with their use. The uneven seasonal distribution of forage production from introduced cool-season species is a primary factor complicating pasture management, while native plant communities are more efficient at capturing solar radiation.
Download or read book Rhizosphere interactions Root exudates and the rhizosphere microbiome written by Linkun Wu and published by Frontiers Media SA. This book was released on 2023-10-05 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plant induced soil changes Processes and feedbacks written by N. van Breemen and published by Springer Science & Business Media. This book was released on 1998-08-31 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book by soil scientists and ecologists reviews how and why plants influence soils. Topics include effects on mineral weathering, soil structure, and soil organic matter and nutrient dynamics, case studies of soil-plant interactions in specific biomes and of secondary chemicals influencing nutrient cycling, the rhizosphere, and potential evolutionary consequences of plant-induced soil changes. This is the first volume that specifically highlights the effects of plants on soils and their feedbacks to plants. By contrast, other texts on soil-plant relationships emphasize effects of soil fertility on plants, following the strongly agronomic character of most research in this area. The aspects discussed in this volume are crucial for understanding terrestrial ecosystems, biogeochemistry and soil genesis. The book is directed to terrestrial ecologists, foresters, soil scientists, environmental scientists and biogeochemists, and to students following specialist courses in these fields.
Download or read book Importance of Root Symbiomes for Plant Nutrition New Insights Perspectives and Future Challenges written by Kevin Garcia and published by Frontiers Media SA. This book was released on 2020-07-01 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Agronomy Abstracts written by and published by . This book was released on 1995 with total page 1348 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes abstracts of the annual meetings of the American Society of Agronomy; Soil Science Society of America; Crop Science Society of America ( - of its Agronomic Education Division).
Download or read book Agrindex written by and published by . This book was released on 1995 with total page 822 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecological Society of America Annual Meeting Abstracts written by Ecological Society of America. Meeting and published by . This book was released on 2000 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:
