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Effect Of Tannin In Animal Diet On Nitrification Rate Of Pasture Soil Under Dung Patches, J R. Crush Apr 2024

Effect Of Tannin In Animal Diet On Nitrification Rate Of Pasture Soil Under Dung Patches, J R. Crush

IGC Proceedings (1997-2023)

The rate of formation of nitrate and ammonium in the soil under dung patches was compared for dung from animals fed either ryegrass (Lolium perenne)/white clover (Trifolium repens) or ryegrass/Lotus pedunculatus forage. Tannin derived from the Lotus did not inhibit ammonification in the soil under dung but nitrate formation was strongly inhibited. The results support the theory that polyphenolics may bind to nitrite in acid soils and cause immobilisation of mineral nitrogen. Apart from their effect of reducing the proportion of dietary nitrogen excreted in urine, tannins in animal diets may make a further contribution to …


A Comparison Of Production And Soils In Modified Mixed Prairie Community, S W. Porter, W D. Willms, J F. Dormaar, B H. Ellert, H H. Janzen Apr 2024

A Comparison Of Production And Soils In Modified Mixed Prairie Community, S W. Porter, W D. Willms, J F. Dormaar, B H. Ellert, H H. Janzen

IGC Proceedings (1997-2023)

This study examined the effects of reseeding a Stipa-Agropyron- Bouteloua community to monocultures of crested wheatgrass (Agropyron cristatum (L.) Geartn.), Russian wild rye grass (Elymus junceus Fisch.), and wheat (Triticum aestivum L.) on above and below ground biomass and indicators of soil quality. Summer fallowed wheat produced 10817 kg ha-1 and 4090 kg ha-1 of above ground below ground biomass respectively whereas the native community produced 3191 kg ha-1 above ground and 13013 kg ha-1 of below ground biomass. However wheat, crested wheatgrass and Russian wildrye grass generally showed a lower biological index, phosphatase and dehydrogenase activity.


Can You Have Your Cake And Eat It Too? Impact Of Grazing Cover Crops On Soil Properties, M. E. Drewnoski Feb 2024

Can You Have Your Cake And Eat It Too? Impact Of Grazing Cover Crops On Soil Properties, M. E. Drewnoski

IGC Proceedings (1997-2023)

Does grazing of cover crops negate the soil health benefits of cover crops (CC)? A review of the literature was conducted to understand the soil impacts of grazing CC compared to a non-grazed CC control. Grazing CC did increase soil compaction in 50% of cases, but this increase was below the threshold that would be expected to impact root growth in most cases. It does appear that grazing under wet soils or high stocking rates can compact soil. Grazing did not affect wet aggregate stability in 83% of the studies. Soil carbon concentration was unaffected in 70% of the studies …


The Influence Of High Density Grazing And Conventional, Rotational Grazing On Soil And Vegetation Parameters In The Semi-Arid And Mesic Grasslands Of South Africa, Jamie Paulse, C. Visser, P. J. Malan, G. N. Smit, F. H. De Witt Jan 2024

The Influence Of High Density Grazing And Conventional, Rotational Grazing On Soil And Vegetation Parameters In The Semi-Arid And Mesic Grasslands Of South Africa, Jamie Paulse, C. Visser, P. J. Malan, G. N. Smit, F. H. De Witt

IGC Proceedings (1997-2023)

In South Africa, multi-camp rotational grazing using ‘conservative stocking rates’ have been the conventional approach to livestock grazing management systems. However, as of late, the high-desnity approach (used interchangeably – depending on the situation – with regenerative grazing, mob grazing, short duration, high pressure grazing, rapid rotation, time controlled, ultra-high density, holistic grazing and holistic resource management) has been adopted by numerous farmers. This approach is considered to be an adaptable one, incorporating the ‘herd effect’ concept, whereby large numbers of animals occupy an area for short periods of time, and allowed an extended rest period. It claims to improve …


Effect Of Litter Addition On Amino Acid Content And Composition In Alpine Meadow Soil, Yanli L. Feng, X. Y. Li, W. Z. Zong, J. Wang Nov 2023

Effect Of Litter Addition On Amino Acid Content And Composition In Alpine Meadow Soil, Yanli L. Feng, X. Y. Li, W. Z. Zong, J. Wang

IGC Proceedings (1997-2023)

Litter plays an important role in plant-soil nutrient cycling. However, the response of soil amino acid pools to litter input is unclear. Therefore, the aim of this study was to explore the effects of litter addition on the content and composition of soil amino acids in an alpine meadow soil. Soil was amended with litter of its dominant species, Kobresia graminifolia, and incubated for four weeks. Our results show that litter addition significantly increased the exchangeable amino acid content and protease activity in the soil. These results are crucial for understanding the amino acid cycling in soil.


Spatial Distribution Of Soil Macroinvertebrates In A Dry Steppe (South-Eastern Siberia, Russia), K. B. Gongalsky Aug 2023

Spatial Distribution Of Soil Macroinvertebrates In A Dry Steppe (South-Eastern Siberia, Russia), K. B. Gongalsky

IGC Proceedings (1997-2023)

Soil macroinvertebrates are important components of ecosystems. They play a key role in decomposition processes and turnover of the most of elements. Adequate estimation of abundance and biomass of these animals is fundamental for understanding their input in steppe ecosystems. Asian steppes of Russia are poorly studied. Therefore, baseline soil invertebrate composition, abundance and rules of distribution were estimated.


Grazing Effects On Spatial Microdistribution Of Soil Macroinvertebrates In A Steppe Of European Russia, F. A. Savin, K. B. Gongalsky, A. D. Pokarzhevskii Aug 2023

Grazing Effects On Spatial Microdistribution Of Soil Macroinvertebrates In A Steppe Of European Russia, F. A. Savin, K. B. Gongalsky, A. D. Pokarzhevskii

IGC Proceedings (1997-2023)

Measures of ecosystems and their populations include biomass, production and trophic composition and animal spatial distribution. Grazing of grasslands influences spatial distribution of vegetation seriously. The same effects on soil macroinvertebrates are less well studied. Spatial distribution is usually studied at a coenosis level, and not at a studied point level, although the scale of sampling has a giant importance in estimation of organism's distribution. The aim of our study was to estimate grazing impact on large soil invertebrates in steppe ecosystems in Chernozem Nature Reserve in Russia.


Soil Enzyme Activities As Bio Indicators Of Soil Ph And Fertility In Temperate Grassland, Iker Mijangos, A. Ibarra, Isabel Albizu, Sorkunde Mendarte, Carlos Garbisu Aug 2023

Soil Enzyme Activities As Bio Indicators Of Soil Ph And Fertility In Temperate Grassland, Iker Mijangos, A. Ibarra, Isabel Albizu, Sorkunde Mendarte, Carlos Garbisu

IGC Proceedings (1997-2023)

In recent years, biological indicators are being used to estimate the continued capacity of a given soil to function (i.e., soil health). After all, biological processes are intimately linked with the maintenance of soil structure and fertility, being more sensitive to changes in the soil than conventional physicochemical parameters. Soil enzymes, as mediators and catalysts of vital soil functions, offer great potential as integrative indicators of soil health (Dick et al., 1996). The main aim of the current work was to study the potential of soil enzyme activities as biological (more precisely, biochemical) indicators of soil physicochemical …


Cattle Overwintering Areas In Middle-European Conditions - Important “Point” Sources Of Nitrous Oxide Emissions, M. Šimek, J. Hynšt, P. Brůček, J. Čuhel, D. Elhottová, H. Šantrůčková, V. Kamír Jun 2023

Cattle Overwintering Areas In Middle-European Conditions - Important “Point” Sources Of Nitrous Oxide Emissions, M. Šimek, J. Hynšt, P. Brůček, J. Čuhel, D. Elhottová, H. Šantrůčková, V. Kamír

IGC Proceedings (1997-2023)

Nitrous oxide (N2O) emissions in grazed grasslands are strongly influenced by animal excreta (Fowler et al., 1997). In addition, soil compaction caused by animal traffic significantly influences soil physical conditions and thus directly or indirectly impacts on the microbial processes producing N2O. In the Czech Republic pastures are mostly located in hilly and mountain areas. During the growing season, cattle are typically grazing, while during the winter the animals are concentrated near the animal house on a relatively small plot called an "overwintering area". The objective of this study was to estimate the fluxes of …


Nitrogen Transfer From Cover Crops To The Subsequent Grain Crop And The Influence Of Variability In Winter Conditions, Spencer Heuchan Dec 2022

Nitrogen Transfer From Cover Crops To The Subsequent Grain Crop And The Influence Of Variability In Winter Conditions, Spencer Heuchan

Electronic Thesis and Dissertation Repository

Cover crops, which are used to provide ground cover after the harvest of the grain crop, can potentially improve the sustainability of agroecosystems by reducing nutrient losses. However, few data are available to document the extent to which cover crops improve both the retention of soil nitrogen (N) and the transfer of this N to the grain crop. The efficiency of this N transfer may be further influenced by variation in winter soil temperature; for example, reduced snow cover can increase the frequency and intensity of soil freezing, which can affect the survival of cover crops and the timing of …


Diagnosing Excess Nitrogen In Rice Using Post-Season Tissue Samples, Kyle Hoegenauer Dec 2022

Diagnosing Excess Nitrogen In Rice Using Post-Season Tissue Samples, Kyle Hoegenauer

Graduate Theses and Dissertations

Proper nitrogen (N) management in rice production can be difficult to achieve without the aid of tools such as soil and tissue tests. There are no tests currently available to rice producers that determine whether N has been managed properly throughout the season or that detect instances of over fertilization. Rice stalk samples were collected from N response trials within 3 days of harvest from the primary Arkansas rice growing region in 2016-2018. Stalk samples were analyzed for N concentration through a KCl extraction and spectrofluorometric quantification. Samples analyzed with leaf material intact contained statistically different N concentrations than samples …


Biochar: Properties And Potential Benefits For Agricultural Soil In Rwanda, Andromede Uwase Jan 2022

Biochar: Properties And Potential Benefits For Agricultural Soil In Rwanda, Andromede Uwase

Honors Theses

Physical and chemical soil degradation is becoming a major challenge for agricultural productivity in Rwanda, which is the most important part of the country’s economy. The wide spreading soil degradation in Rwanda is mainly a result of naturally poor soils coupled with unsustainable soil management leading to, for example, accelerated soil erosion, acidification, nutrient loss, compaction, and to decreasing yields. Biochar, as an end product of pyrolysis of biomass in the absence of oxygen, has been proposed as a soil amendment in remediation strategies because of its positive effects on soil productivity relevant parameters such as soil pH, structure, nutrient …


Soybean Seed Yield Productivity And Biological Nitrogen Fixation In Kansas, L. F. A. Almeida, A. A. Correndo, E. Adee, S. Dooley, I. A. Ciampitti Jan 2022

Soybean Seed Yield Productivity And Biological Nitrogen Fixation In Kansas, L. F. A. Almeida, A. A. Correndo, E. Adee, S. Dooley, I. A. Ciampitti

Kansas Agricultural Experiment Station Research Reports

Soybean [Glycine max(L.) Merr.] productivity (seed yield) and biological nitrogen fixation (BNF) were evaluated in response to different fertilization strategies. The study comprised four different locations in Kansas during the 2021 growing season, two irrigated (Topeka and Scandia) and two dryland (Kiro and Ashland Bottoms) sites. Greater seed yields were recorded in Topeka and Kiro (80 bu/a) relative to Scandia (55 bu/a) and Ashland Bottoms (51 bu/a), without observing fertilizer effects on yields. Overall, the relative abundance of ureides (% RAU), an indicator of the level of BNF, increased as the crop matured and showed a negative association …


Temporal Changes In The Nutrient Content Of Cattle Dung In The Nebraska Sandhills Ecosystem, Amanda Shine, Martha Mamo, Gandura O. Abagandura, Walter Schacht, Jerry Volesky Jan 2022

Temporal Changes In The Nutrient Content Of Cattle Dung In The Nebraska Sandhills Ecosystem, Amanda Shine, Martha Mamo, Gandura O. Abagandura, Walter Schacht, Jerry Volesky

Department of Agronomy and Horticulture: Faculty Publications

Dung excreted by cattle composes a significant portion of the nutrient inputs in a grazed ecosystem and can have wide-ranging effects on soil properties and vegetation. However, little research has been conducted on the nutrient dynamics of excreted dung in situ that has not been disturbed prior to field sampling. In this study, we analyzed 294 dung pats (1–24 days old) collected from a Nebraska Sandhills meadow to determine water-extractable organic carbon (WEOC), water-extractable nitrogen (WEN), water-extractable phosphorus (WEP), and percent dry matter (DM) changes over time. In addition, we investigated if sample handling - frozen storage – and the …


Cover Crop Effects On Near-Surface Soil Aggregate Stability In The Southern Mississippi Valley Loess (Mlra 134), Chandler M. Arel Dec 2021

Cover Crop Effects On Near-Surface Soil Aggregate Stability In The Southern Mississippi Valley Loess (Mlra 134), Chandler M. Arel

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Intensive agricultural cultivation within major land resource area (MLRA) 134, the Southern Mississippi Valley Loess, has led to soil erosion, soil compaction, and the overall destabilization of near-surface soil aggregates. The use of cover crops during the agricultural offseason has been shown to help alleviate soil compaction and provide stabilizing effects against soil erosion, which are particularly important as the silty soils of MLRA 134 have a large erosion potential. This study evaluated the effects of cover crop and no-cover crop treatment on silt-loam soils within MLRA 134. Treatments were implemented during Fall 2018 and Fall 2019 and consisted of …


A Method For Visualizing Water Flow Through Modified Root Zones, Dallas M. Williams Dec 2021

A Method For Visualizing Water Flow Through Modified Root Zones, Dallas M. Williams

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

As the number of impervious surfaces in urban environments increases, the ability of modified root zones to infiltrate water is becoming more important. Current methods of tracing water flow through soil profiles include excavating large pits in situ or analyzing soil cores in the laboratory with computed tomography or magnetic resonance imaging. While useful, these methods may not be suitable for urban settings or practical in every laboratory. We propose a new method that is less invasive, does not require extensive technical equipment and can reliably trace water movement through the soil profile in order to calculate flow rate based …


Does Integrating Crops With Livestock Production Impact Soil Properties And Crop Production?, Lindsey Anderson May 2021

Does Integrating Crops With Livestock Production Impact Soil Properties And Crop Production?, Lindsey Anderson

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Re-integrating crop and livestock production through cover crop (CC) and corn residue grazing could efficiently utilize resources and ensure profitability while improving environmental quality, but how this integration affects soils and crops is not well understood. We conducted two studies to address this. In the first study, we evaluated the impact of cattle (1.3-3.7 head ha-1) grazing an oat (Avena sativa L.) CC on soil and crop yields in two adjacent irrigated no-till corn (Zea mays L.)-soybean (Glycine max L.) fields on silt loam soils in eastern Nebraska. Field I was grazed twice, while Field …


Wayne E. Sabbe Arkansas Soil Fertility Studies 2020, Nathan A. Slaton Mar 2021

Wayne E. Sabbe Arkansas Soil Fertility Studies 2020, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.


Evaluation Of Nitrous Oxide Emissions From Furrow-Irrigated Rice On A Silt-Loam Soil In Arkansas, Jordan M. Slayden Jan 2021

Evaluation Of Nitrous Oxide Emissions From Furrow-Irrigated Rice On A Silt-Loam Soil In Arkansas, Jordan M. Slayden

Graduate Theses and Dissertations

As the number one rice (Oryza sativa)-producing state in the United States, Arkansas also ranks fourth as the largest user of groundwater. Recently, due to the development of drought- resistant hybrid cultivars, the furrow-irrigated rice production system has become an increasingly popular alternative to traditional flood-irrigated production with respect to conserving groundwater and maintaining yield. However, other environmental parameters, like greenhouse gas emissions, specifically nitrous oxide (N2O), have yet to be evaluated under furrow-irrigated rice. The objectives of this study were to i) evaluate the effects of site position (i.e., up-, mid-, and down-slope) and tillage treatment [i.e., conventional tillage …


Wayne E. Sabbe Arkansas Soil Fertility Studies 2019, Nathan A. Slaton May 2020

Wayne E. Sabbe Arkansas Soil Fertility Studies 2019, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.


Southeast Research And Extension Center Agricultural Research 2020 Jan 2020

Southeast Research And Extension Center Agricultural Research 2020

Kansas Agricultural Experiment Station Research Reports

Research report for the Southeast Research and Extension Center, Kansas State University, 2020


Decomposition In Pasture Soil Receiving Excreta From Ruminants Fed Alfalfa Forage Diet Supplemented With Increasing Proportions Of Sericea Lespedeza Legume, Yang Kai Tang, Mary C. Savin, Dirk Philipp, Ken Coffey, Jiangchao Zhao Jan 2020

Decomposition In Pasture Soil Receiving Excreta From Ruminants Fed Alfalfa Forage Diet Supplemented With Increasing Proportions Of Sericea Lespedeza Legume, Yang Kai Tang, Mary C. Savin, Dirk Philipp, Ken Coffey, Jiangchao Zhao

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Healthy soil is fundamental to a productive pasture system as it will decompose labile organic matter and promote retention of carbon to build a stable, resistant pool of organic matter. An easy, standardized approach to measure decomposition and litter stabilization that is gaining popularity in both citizen science and research studies is the use of the Tea Bag Index. The Tea Bag Index is a relatively new method evaluating the loss of organic material in two different kinds of commercial tea bags (green tea and Rooibos tea) after burial in the soil for 90 days. The objective of this experiment …


Remediating Soil For Successful Vegetation Establishment Along Nebraska Highways, Shad Mills, Martha Mamo, Walt Schacht, Humberto Blanco-Canqui Dec 2019

Remediating Soil For Successful Vegetation Establishment Along Nebraska Highways, Shad Mills, Martha Mamo, Walt Schacht, Humberto Blanco-Canqui

Nebraska Department of Transportation: Research Reports

Vegetation along roadsides is important to prevent soil erosion, provide habitat, and filter water running off the road. Vegetation close to the pavement along highways in Nebraska does not readily establish and persist. It is thought that the sodium and bulk density are the driving factors behind the lack of vegetation. After a construction project the shoulder is seeded into the compacted soil, and during winter salts can accumulate in the soil because of deicing agents being used. The purpose of our study was to determine if the sodium and bulk density are the driving factors of the vegetation cover. …


Nematode Populations As Affected By Residue And Water Management In A Long-Term Wheat-Soybean Double Crop In Eastern Arkansas, Lucia Emperatriz Escalante Ortiz Dec 2019

Nematode Populations As Affected By Residue And Water Management In A Long-Term Wheat-Soybean Double Crop In Eastern Arkansas, Lucia Emperatriz Escalante Ortiz

Graduate Theses and Dissertations

Soybeans (Glycine max) are one of the major row crops in the United States, particularly in Arkansas. Soybean cyst nematode (SCN, Heterodera glycines) and southern root-knot nematode (RKN, Meloidogyne incognita) are two of the most damaging pests that cause major economic losses in soybeans. Little is known concerning the effects of common and alternative agronomic practices on nematodes in fields with nematode population densities below threshold levels. Therefore, the objective of this study was to evaluate the effects of the combination of tillage (conventional tillage and no-tillage), irrigation (irrigated and non-irrigated), wheat (Triticum aestivum) residue burning (burned and no burned), …


Evaluation Of Soil Type And Seeding Rate On Winter Cover Crop Species In A Soybean Production System, Donna S. Morgan Nov 2019

Evaluation Of Soil Type And Seeding Rate On Winter Cover Crop Species In A Soybean Production System, Donna S. Morgan

LSU Doctoral Dissertations

The integration of winter annual cover crops into a cropping system can potentially improve soil health and crop production, however, the impact of variables such as seeding rates, across two very different soil types, has not been well documented. A two-year study was conducted at the Dean Lee Research Station and Extension Center in Alexandria, Louisiana to evaluate the effects of cover crop seeding rate and soil type on cover crop biomass, weed suppression, soil fertility, and soybean (Glycine max L) growth and yield. Analysis of potential economic impacts was also performed to estimate financial net returns for three …


Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan Aug 2019

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

John E. Sawyer

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset …


Soil And Water Conservation: An Annotated Bibliography, Colby J. Moorberg Jan 2019

Soil And Water Conservation: An Annotated Bibliography, Colby J. Moorberg

NPP eBooks

Soil and Water Conservation: An Annotated Bibliography highlights freely-available online resources covering various aspects of soil and water conservation, and is designed to be a resource for conservation students and practitioners. The thirteen chapters in the annotated bibliography are grouped into four sections, including History and Fundamentals, Conservation Practices, Conservation Implementation, and Careers. Types of cited resources include extension bulletins, USDA NRCS conservation practice standards, and other government reports and resources. Cited resources are generally concise, easily read, and meant for general audiences. Annotations and images are used to provide context for each resource. Many contributors made Soil and Water …


Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan Jan 2019

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabian G. Fernandez, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset …


Rethinking Invasion Impacts Across Multiple Field Sites Using European Swallowwort (Vincetoxicum Rossicum) As A Model Invader, Grant L. Thompson, Terrence H. Bell, Jenny Kao-Kniffin Aug 2018

Rethinking Invasion Impacts Across Multiple Field Sites Using European Swallowwort (Vincetoxicum Rossicum) As A Model Invader, Grant L. Thompson, Terrence H. Bell, Jenny Kao-Kniffin

Grant Thompson

European swallowwort [Vincetoxicum rossicum (Kleopow) Barbarich] is found in the northeastern United States and southeastern Canada. It forms dense growth patterns that reduce plant and insect biodiversity, and lab assays show that it produces allelopathic compounds that affect microbial activity. Consequently, we hypothesized that V. rossicum alters soil microbiome composition and activity in invaded habitats, which may impact
ecosystem properties and processes. We sampled soil from a similar time point within a growing season at each of five sites in New York State where V. rossicum was both present and absent. We measured bacterial and fungal microbiome composition, available soil …


Soil Properties That Influence The Occurrence Of Hydrogen Sulfide Toxicity In Rice Fields, Julia Marie Fryer May 2018

Soil Properties That Influence The Occurrence Of Hydrogen Sulfide Toxicity In Rice Fields, Julia Marie Fryer

Graduate Theses and Dissertations

Rice (Oryza sativa L.) producers face many challenges throughout each growing season. Hydrogen sulfide (H2S) toxicity is a physiological disorder where sulfate (SO42-) is excessively reduced to the toxic gas, H2S. This can reduce yield and, in severe cases, result in crop death. The main research objectives were to: i) understand chemical and physical characteristics in soils prone to H2S toxicity, ii) determine influential soil characteristics on the incidence of H2S toxicity, iii) determine ammonium sulfate ((NH4)2SO4) fertilizer additions influence on H2S toxicity, and iv) predict when and where H2S will occur. Three greenhouse experiments were conducted using Arkansas field …