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Burning With Potential: Understanding The Relationship Between Biochar And Agriculture Of The Northern Glaciated Plains Ecoregion, Kaitlyn Abrahamson Jan 2020

Burning With Potential: Understanding The Relationship Between Biochar And Agriculture Of The Northern Glaciated Plains Ecoregion, Kaitlyn Abrahamson

Electronic Theses and Dissertations

Achieving global sustainable agriculture is one of the most incredible challenges of this century, yet many continue to try to solve this problem through the development of precision technologies. Biotechnologies, such as biochar, can perform like a precision technology while protecting agricultural land from soil erosion and fertility loss. The Northern Glaciated Plains ecoregion of the United States is little researched in the benefits from the use of biochar through improved soil nutrient capture and water retention, crop health improvements, and yield increases. The study plot has four sections of corn stover biochar and eight sections of control sections. This ...


Phytoremediation Of Saline-Sodic Soils In East Central South Dakota Utilizing Perennial Grass Mixtures, Douglas J. Fiedler Jan 2020

Phytoremediation Of Saline-Sodic Soils In East Central South Dakota Utilizing Perennial Grass Mixtures, Douglas J. Fiedler

Electronic Theses and Dissertations

Several decades of above average precipitation in South Dakota has increased the area of saline and sodic soils, which reduce crop yields and inhibit sensitive plant growth. Saline and sodic soils are difficult to remediate using traditional agricultural crops. Establishing salt tolerant perennial species may restore productivity to salt affected areas. Two perennial grass mixtures (mix 1: slender wheatgrass, beardless wildrye; mix 2: slender wheatgrass, western wheatgrass, green wheatgrass, creeping meadow foxtail) were dormant frost seeded along a topographic gradient in Clark Co., SD. Soils were Forman-Cresbard loam and a Cresbard-Cavour loam with surface electrical conductivity (EC1:1) that ...


United States Midwest Soil And Weather Conditions Influence Anaerobic Potentially Mineralizable Nitrogen, Jason D. Clark, Kristen S. Veum, Fabian G. Fernandez, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, Carrie A.M. Laboski, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan Sep 2019

United States Midwest Soil And Weather Conditions Influence Anaerobic Potentially Mineralizable Nitrogen, Jason D. Clark, Kristen S. Veum, Fabian G. Fernandez, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Daniel E. Kaiser, Newell R. Kitchen, Carrie A.M. Laboski, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Agronomy, Horticulture and Plant Science Faculty Publications

Nitrogen provided to crops through mineralization is an important factor in N management guidelines. Understanding of the interactive effects of soil and weather conditions on N mineralization needs to be improved. Relationships between anaerobic potentially mineralizable N (PMNan) and soil and weather conditions were evaluated under the contrasting climates of eight US Midwestern states. Soil was sampled (0–30 cm) for PMNan analysis before pre-plant N application (PP0N) and at the V5 development stage from the pre-plant 0 (V50N) and 180 kg N ha−1 (V5180N) rates and incubated for 7, 14, and 28 d ...


Chemical Amendments Of Dryland Saline–Sodic Soils Did Not Enhance Productivity And Soil Health In Fields Without Effective Drainage, Girma A. Birru, David E. Clay, Thomas M. Desutter, Cheryl L. Reese, Ann C. Kennedy, Sharon A. Clay, Stephanie A. Bruggeman, Rachel K. Owen, Douglas D. Malo Apr 2019

Chemical Amendments Of Dryland Saline–Sodic Soils Did Not Enhance Productivity And Soil Health In Fields Without Effective Drainage, Girma A. Birru, David E. Clay, Thomas M. Desutter, Cheryl L. Reese, Ann C. Kennedy, Sharon A. Clay, Stephanie A. Bruggeman, Rachel K. Owen, Douglas D. Malo

Agronomy, Horticulture and Plant Science Faculty Publications

A common restoration treatment for saline–sodic soils involves improving soil drainage, applying soil amendments (e.g., CaSO4, CaCl2, or elemental S), and leaching with water that has a relatively low electrical conductivity. However, due to high subsoil bulk densities and low drainable porosities, these treatments many not be effective in glaciated dryland systems. A 3-yr field study conducted in three model systems determined the impact of chemical amendments (none, CaCl2, CaSO4, and elemental S) on plant growth, microbial composition, temporal changes in electrical conductivity (ECe ), and the relative sodium content (%Na). Chemical amendments (i ...


Using A Case Study Approach To Teach Invasive Species And Climate Change, Amanda Hoover, Bradley Blaha, Jacob Englin, Madhav P. Nepal, Larry B. Browning, Matt L. Miller, P. Troy White Jan 2019

Using A Case Study Approach To Teach Invasive Species And Climate Change, Amanda Hoover, Bradley Blaha, Jacob Englin, Madhav P. Nepal, Larry B. Browning, Matt L. Miller, P. Troy White

iLEARN Teaching Resources

In this teaching module, students will explore emerald ash borer (EAB), its impacts on the ash trees, and how warming temperatures could affect EAB populations. The emerald ash borer is a green buprestid or jewel beetle native to north-eastern Asia that causes devastating disease in ash trees.


Long-Term Impacts Of Manure And Inorganic Fertilization On Soil Physical, Chemical And Biological Properties, Asmita Gautam Jan 2019

Long-Term Impacts Of Manure And Inorganic Fertilization On Soil Physical, Chemical And Biological Properties, Asmita Gautam

Electronic Theses and Dissertations

The intensive use of mineral fertilizers to achieve high crop yield has led to soil degradation and poor soil health. Thus, manure application as an alternative to mineral fertilizers can be an effective fertilization strategy to improve soil health and biodiversity. This study aims to assess the impacts of long-term manure and mineral fertilizers on soil physical, chemical and biological properties. The experimental site was initiated in 2003 near Beresford, South Dakota on Egan soil under a randomized complete block design with four replications and six treatments. The study treatments included: three manure rates [low manure (LM), manure application based ...


Estimating Soil Organic Carbon In Cultivated Soils Using Soil Test Data, Remote Sensing Imagery From Satellites (Landsat 8 And Plantscope), And Web Soil Survey Data, Muhammed Halil Koparan Jan 2019

Estimating Soil Organic Carbon In Cultivated Soils Using Soil Test Data, Remote Sensing Imagery From Satellites (Landsat 8 And Plantscope), And Web Soil Survey Data, Muhammed Halil Koparan

Electronic Theses and Dissertations

Soil organic carbon (SOC) is an important soil parameter of cultivated soils that needs to be monitored and mapped regularly to enhance soil health and productivity. SOC levels in cultivated areas is difficult to monitor for farmers and is costly to analyze using traditional methods. The objective of this study was to estimate surface SOC distribution in selected soils of Major Land Resource Areas (MLRA) 102A (Rolling Till Plain, Brookings County, SD) and 103 (Central Iowa and Minnesota Till Prairies, Lac qui Parle County, MN) using soil sample data, Web Soil Survey (WSS) data, and satellite imagery (Landsat 8 and ...


Brassica Carinata Growth And Yield Response To Nitrogen And Sulfur Fertilizers And Impacts On Selected Soil Parameters And Ghg Fluxes, Dwarika Bhattarai Jan 2019

Brassica Carinata Growth And Yield Response To Nitrogen And Sulfur Fertilizers And Impacts On Selected Soil Parameters And Ghg Fluxes, Dwarika Bhattarai

Electronic Theses and Dissertations

Carinata (Brassica carinata A. Braun), a non-food oilseed crop and an alternative bio-jet fuel feedstock, has received attention for its potential as a low-input option for production in the semi-arid regions of the Northern Great Plains of USA. The crop has a lower N fertilizer requirement as compared to the other oilseeds, suggesting less negative impact on soils and GHGs emissions. Carinata is a new crop to South Dakota (SD), thus, the best management practices have yet to be developed. In addition, no sufficient research to address the impact of growing carinata on soils and GHG emissions has been reported ...


Do Precision Chemical Amendment Applications Impact Sodium Movement In Dryland Semiarid Saline Sodic Soils?, Tulsi P. Kharel, David E. Clay, Cheryl Reese, Thomas Desutter, Doug D. Malo, Sharon Clay Mar 2018

Do Precision Chemical Amendment Applications Impact Sodium Movement In Dryland Semiarid Saline Sodic Soils?, Tulsi P. Kharel, David E. Clay, Cheryl Reese, Thomas Desutter, Doug D. Malo, Sharon Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Expanding sodicity and salinity problems have placed many northern Great Plains (NGP) soils at the sustainability tipping point. This study assessed the impact of chemical restoration on water and salt transport in undisturbed soil columns collected from three hillslope model landscape positions. The backslope (Redfield), footslope (White Lake), and toeslope (Pierpont) soils had moderate (3.27 ± 0.59), high (7.3 ± 3.34), and very high (13.29 ± 3.2) sodium adsorption ratio (SARe) values, respectively. The soils were treated with KBr and one of four soil amendments (none, H2SO4, CaSO4, and CaCl2). The ...


Isolation Of Potential Photosynthetic N2-Fixing Microbes From Topsoil Of Native Grasslands In South Dakota, Nanfang Wang, Shengni Tian, Liping Gu, Lan Xu, Yeyan Qiu, Trevor Van Den Top, Jose L. Gonzalez-Hernandez, Michael B. Hildreth, Shaoshan Li, Runbao Zhou Jan 2018

Isolation Of Potential Photosynthetic N2-Fixing Microbes From Topsoil Of Native Grasslands In South Dakota, Nanfang Wang, Shengni Tian, Liping Gu, Lan Xu, Yeyan Qiu, Trevor Van Den Top, Jose L. Gonzalez-Hernandez, Michael B. Hildreth, Shaoshan Li, Runbao Zhou

Natural Resource Management Faculty Publications

Nitrogen fertilizer is one of the most limiting factors and costly inputs in agriculture production. Current fossil fuel-dependent ammonia production is both energy intensive and environmentally damaging. An economically practical and environmentally friendly solution for the production of ammonia is urgently needed. Solar-powered N2-fixing cyanobacteria provide a unique opportunity and promise for applications in agriculture compared to all other N2-fixing bacteria that cannot use solar energy. Isolation of nitrogen-fixing microbes from the topsoil of native grasslands may have the potential to use them in crop fields as living ammonia factories. This may be a mechanism to free farmers from heavy ...


Identifying And Characterizing Salt-Tolerant Alfalfa (Medicago Sativa Subsp Falcata Germplasm, Katelin E. Frerichs, Lan Xu Jan 2018

Identifying And Characterizing Salt-Tolerant Alfalfa (Medicago Sativa Subsp Falcata Germplasm, Katelin E. Frerichs, Lan Xu

Natural Resource Management Faculty Publications

Soil salinity limits plant growth and crop production. More than 20% of cultivated land worldwide is affected by salinity. The situation is becoming more severe due to shifts in precipitation and evaporation patterns and improper irrigation. There is an urgent need to develop salt-tolerant, economically valuable plants to minimize the loss of and to sustain agricultural production. Alfalfa is one of the most extensively cultivated forage crops. Some yellow-flowered alfalfa (Medicago sativa subsp. falcata) have exhibited morphological and physiological drought tolerance. Since soil salinity is associated with physiological drought, it is reasonable to expect that these drought tolerant falcata populations ...


Impacts Of Diverse Crop Rotations And Integrated Crop-Livestock System On Soil Quality In South Dakota, Atilla Polat Jan 2018

Impacts Of Diverse Crop Rotations And Integrated Crop-Livestock System On Soil Quality In South Dakota, Atilla Polat

Electronic Theses and Dissertations

Crop diversification can be beneficial in improving soil quality parameters. Diverse crop rotations and integrated crop-livestock systems (ICLS), are two examples of crop diversification used in this study to assess soil quality. The objectives of this study were to: (i) assess the impacts of diverse rotations on soil quality parameters, and (ii) assess the impacts of low and high stocking density on soil quality parameters. Both of the studies were conducted separately and are presented as two different chapters. To accomplish objective (i), a long-term experiment was selected which was established near Brookings, South Dakota, USA at USDA-ARS lab in ...


Quantifying The Short-Term Impacts Of Cover Crops And Grazing On Soil Health Under An Integrated Crop-Livestock System In South Dakota, Vishal Seth Jan 2018

Quantifying The Short-Term Impacts Of Cover Crops And Grazing On Soil Health Under An Integrated Crop-Livestock System In South Dakota, Vishal Seth

Electronic Theses and Dissertations

Cover crops and grazing under Integrated Crop-Livestock System (ICLS) can impact the rhizosphere nutrient cycling and may have potential to increase the long-term sustainability and economic profitability of agricultural production system. In South Dakota, crop production practices and livestock husbandry are both common which provide the opportunity for ICLS to be successful in this region. However, little is known about the impacts of the cover crops and grazing under ICLS on soil properties in this region. The present study was conducted at South Dakota State University Research Farm (44°20'34.8"N, 96°48'14.8"W), Brookings, SD ...


Land Use Change Sustainability And Carbon Turnover Rate In The Northern Great Plains Soil, Deepak Raj Joshi Jan 2018

Land Use Change Sustainability And Carbon Turnover Rate In The Northern Great Plains Soil, Deepak Raj Joshi

Electronic Theses and Dissertations

Sustainable land management involves the management of land, water, biodiversity and other resources that meet human requirements while maintaining ecosystem services. In the northern Great Plains (NGP), the combined impacts of landuse and climate variability have placed many soils at the tipping point of sustainability. The objectives of this study were to: 1) calculate land-use changes from 2006 to 2012 and from 2012 to 2014 in South Dakota and Nebraska; 2) assess if land use changes had impacted on soil sustainability; 3) calculate variation in total carbon budget and turnover due to seasonal climate variability, biomass quality and soil properties ...


Modeling Soil Organic Carbon In Select Soils Of Southeastern South Dakota, Shaina Westhoff Jan 2018

Modeling Soil Organic Carbon In Select Soils Of Southeastern South Dakota, Shaina Westhoff

Electronic Theses and Dissertations

Soil organic matter (SOM) is composed of living biomass, dead plant and animal residues, and humus. Humus is a class of complex, organic molecules that are largely responsible for improving soil water holding capacity, nutrient mineralization, nutrient storage, and other critical soil functions. Soil organic carbon (SOC) accounts for approximately 60 percent of SOM and thus SOC is recognized as a strong indicator of soil health. Land use changes and intense cultivation of arable soils in the United States over the past century have led to large decreases in SOM. The objective of this research was to develop a multiple ...


Greenhouse Gas Emissions From Soil Applied Nitrogen Fertilizers, Samuel Thies Jan 2018

Greenhouse Gas Emissions From Soil Applied Nitrogen Fertilizers, Samuel Thies

Electronic Theses and Dissertations

Greenhouse gases (GHG) absorb and emit radiant energy in the thermal range. Their concentrations in the atmosphere are increasing and becoming an ever increasing issue as the Earth’s average temperature continues to rise. Agricultural practices, such as applying nitrogen fertilizer to increase crop yield can be a major source of GHG emissions and methods are needed to decrease these emissions. The measurements of GHG emissions have been difficult, expensive, and erratic. However, advancing technologies have increased the accuracy and confidence in measuring GHG emissions. The objectives of this study were to determine the 1) effects of different nitrogen fertilizer ...


Soil Response To Cropping Sequences And Grazing Under Integrated Crop-Livestock System, Hanxiao Feng Jan 2017

Soil Response To Cropping Sequences And Grazing Under Integrated Crop-Livestock System, Hanxiao Feng

Electronic Theses and Dissertations

Integrated crop-livestock system (ICLS) is helpful in diversifying a farm for improving its long-term sustainability and economic benefits. In the United States, the ICLS has been increasing in recent years because of its economic and environmental benefits. However, the impacts of ICLS on soil quality is not well documented in North Dakota. The objective of our study is to assess the impacts of cropping sequences and cattle grazing on the selected soil properties in the crop diversity and livestock integration practice. This study site was established in 2010 at the Dickinson Research Extension Center, Dickinson, North Dakota. The study design ...


Response Of Soil Properties To 23-25 Years Of Diverse Crop Rotations And Tillage Systems In South Dakota, Usa, Abdullah H. Alhameid Jan 2017

Response Of Soil Properties To 23-25 Years Of Diverse Crop Rotations And Tillage Systems In South Dakota, Usa, Abdullah H. Alhameid

Electronic Theses and Dissertations

No abstract provided.


Impacts Of Landscape Position And Nitrogen Fertilizer On Soils, Carbon And Nitrogen Leaching, And Greenhouse Gas Fluxes From Switchgrass Production In South Dakota, Liming Lai Jan 2017

Impacts Of Landscape Position And Nitrogen Fertilizer On Soils, Carbon And Nitrogen Leaching, And Greenhouse Gas Fluxes From Switchgrass Production In South Dakota, Liming Lai

Electronic Theses and Dissertations

Switchgrass (Panicum virgatum L.) production for biofuels has potential economic values. It can also improve soil properties and perform better under marginal lands than the other major biomass crops. However, little is known about its potential ecological impacts assessed in terms of soils, water, and air quality in the northern Great Plains region of United States of America. The objectives of this study were to (i) evaluate the impacts of nitrogen fertilization rate (N rate) and landscape position on soil pH, soil organic carbon (SOC), total nitrogen (TN), bulk density (ρb), and phosphorus (P) in switchgrass field; (ii) assess the ...


Impacts Of Integrated Crop-Livestock System On Soil Surface Greenhouse Gas Fluxes At A Farm Scale In South Dakota, Brant Douville Jan 2017

Impacts Of Integrated Crop-Livestock System On Soil Surface Greenhouse Gas Fluxes At A Farm Scale In South Dakota, Brant Douville

Electronic Theses and Dissertations

Grazing and cover crops (CC) can impact soil nutrient cycling but may increase the greenhouse gas (GHG) emissions from soils. However, little is known about their impacts on soil properties and soil surface GHG emissions in an integrated crop-livestock system (ICLS) in South Dakota, USA. The present study was conducted at a farm scale at the Research Farm of South Dakota State University, Brookings, South Dakota, to assess the impact of cover crops and grazing on soil pH, electrical conductivity (EC), and bulk density (BD), and soil surface carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2 ...


Impacts Of Crop Residue And Cover Crops On Soil Hydrological Properties, Soil Water Storage And Water Use Efficiency Of Soybean Crop, Kopila Subedi-Chalise Jan 2017

Impacts Of Crop Residue And Cover Crops On Soil Hydrological Properties, Soil Water Storage And Water Use Efficiency Of Soybean Crop, Kopila Subedi-Chalise

Electronic Theses and Dissertations

Cover crops and crop residue play a multifunctional role in improving soil hydrological properties, soil water storage and water use efficiency (WUE). This study was conducted to better understand the role of crop residue and cover crop on soil properties and soil water dynamics. The study was conducted at the USDA-ARS North Central Agricultural Research Laboratory, located in Brookings, South Dakota. Two residue removal treatments that include low residue removal (LRR) and high residue removal (HRR) were established in 2000 with randomized complete block design under no-till corn (Zea mays L.) and soybean (Glycine max L.) rotation. In 2005, cover ...


Interactive Effects Of Cover Crops, Invertebrate Communities And Soil Health In Corn Production Systems, Claire Lacanne Jan 2017

Interactive Effects Of Cover Crops, Invertebrate Communities And Soil Health In Corn Production Systems, Claire Lacanne

Electronic Theses and Dissertations

The adoption of regenerative farming practices is gaining traction, but the costs and benefits are not often considered on a systems level. Encouraging biodiversity and soil health is the goal of many agricultural practices used in regenerative farming; regenerative systems employ practices which abide by the two main principles of increasing biodiversity and decreasing disturbance, with the goal of encouraging ecosystem functioning to minimize inputs and maximize the productivity of a farm. I examined the management of corn (Zea mays) fields across four states in the Upper Midwest region of the United States. Regenerative systems in this study used practices ...


Rapid Surface Water Volume Estimations In Beaver Ponds, Daniel J. Karran, Cherie J. Westbrook, Joseph M. Wheaton, Carol A. Johnston, Angela Bedard-Haughn Aug 2016

Rapid Surface Water Volume Estimations In Beaver Ponds, Daniel J. Karran, Cherie J. Westbrook, Joseph M. Wheaton, Carol A. Johnston, Angela Bedard-Haughn

Natural Resource Management Faculty Publications

Beaver ponds are surface water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface water storage are difficult to acquire without time and labour intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface water ...


Wetland Issues Affecting Waterfowl Conservation In North America, Heath M. Hagy, Scott C. Yaich, John W. Simpson, Eduardo Carrera, David A. Haukos, W.Carter Johnson, Charles R. Loesch, Fritz A. Reid, Scott E. Stephens, Ralph W. Tiner, Brett A. Werner, Greg S. Yarris Jan 2014

Wetland Issues Affecting Waterfowl Conservation In North America, Heath M. Hagy, Scott C. Yaich, John W. Simpson, Eduardo Carrera, David A. Haukos, W.Carter Johnson, Charles R. Loesch, Fritz A. Reid, Scott E. Stephens, Ralph W. Tiner, Brett A. Werner, Greg S. Yarris

Natural Resource Management Faculty Publications

This paper summarises discussions by invited speakers during a special session at the 6th North American Duck Symposium on wetland issues that affect waterfowl, highlighting current ecosystem challenges and opportunities for the conservation of waterfowl in North America. Climate change, invasive species, U.S. agricultural policy (which can encourage wetland drainage and the expansion of row-crop agriculture into grasslands), cost and competition for water rights, and wetland management for non-waterfowl species were all considered to pose significant threats to waterfowl populations in the near future. Waterfowl populations were found to be faced with significant threats in several regions, including: the ...


Great Plains Soils May Be C Sinks, David E. Clay, Gregg C. Carlson, Sharon A. Clay, James Stone, Kurtis Reitsma, Ronald Gelderman Jan 2012

Great Plains Soils May Be C Sinks, David E. Clay, Gregg C. Carlson, Sharon A. Clay, James Stone, Kurtis Reitsma, Ronald Gelderman

Agronomy, Horticulture and Plant Science Faculty Publications

Numerous studies with wide-ranging results have been conducted to resolve if Great Plains soils are a C source or sink. The authors addressed the source/sink question by examining the results from producer soil samples and production surveys that were analyzed and archived by the South Dakota Soil Testing Laboratory. Results showed that between 1985 and 2010, soil organic C content increased at a rate of 326 lb C/A/year, for a total increase of 24%. The increase was attributed to planting better adapted varieties and using better management practices that on average increased corn grain yields 2.29 ...


Soil Organic Carbon Maintenance Requirements And Mineralizatyion Rate Constants: Site Specific Calculations, David Clay, Gregg Carlson, Sharon Clay Oct 2011

Soil Organic Carbon Maintenance Requirements And Mineralizatyion Rate Constants: Site Specific Calculations, David Clay, Gregg Carlson, Sharon Clay

Agronomy, Horticulture and Plant Science Faculty Publications

Over the past 100 years numerous studies have been conducted with the goal of quantifying the impact of management on carbon turnover. It is difficult to conduct a mechanistic evaluation of these studies because each study was conducted under unique soil, climatic, and management conditions. Techniques for directly comparing data from unique studies are needed. This paper: 1) demonstrates an approach for calculating SOC maintenance requirements and mineralization rate constants at different landscape positions; and 2) discusses techniques for conducting site- specific experiments and determining site-specific C sequestration potentials.


Radiative Forcing Over The Conterminous United States Due To Contemporary Land Cover Use Change And Sensitivity To Snow And Interannual Albedo Variability, Christoper A. Barnes, David P. Roy Dec 2010

Radiative Forcing Over The Conterminous United States Due To Contemporary Land Cover Use Change And Sensitivity To Snow And Interannual Albedo Variability, Christoper A. Barnes, David P. Roy

GSCE Faculty Publications

Satellite‐derived land cover land use (LCLU), snow and albedo data, and incoming surface solar radiation reanalysis data were used to study the impact of LCLU change from 1973 to 2000 on surface albedo and radiative forcing for 58 ecoregions covering 69% of the conterminous United States. A net positive surface radiative forcing (i.e., warming) of 0.029 Wm−2 due to LCLU albedo change from 1973 to 2000 was estimated. The forcings for individual ecoregions were similar in magnitude to current global forcing estimates, with the most negative forcing (as low as −0.367 Wm−2) due to ...


Theoretical Derivation Of Stable And Nonisotopic Approaches For Assessing Soil Organic Carbon Turnover, D. E. Clay, C. G. Carlson, S. A. Clay, C. Reese, Z. Liu, J. Chang, M. M. Ellsbury Jan 2006

Theoretical Derivation Of Stable And Nonisotopic Approaches For Assessing Soil Organic Carbon Turnover, D. E. Clay, C. G. Carlson, S. A. Clay, C. Reese, Z. Liu, J. Chang, M. M. Ellsbury

Agronomy, Horticulture and Plant Science Faculty Publications

Techniques for measuring soil organic C (SOC) turnover in production fields are needed. The objectives of this study were to propose and test nonisotopic and 13 C stable isotopic techniques for assessing SOC turnover. Based on SOC equilibrium and mass balance relationships, an equation was derived: NHC/SOC initial=[1/(SOC× k NHC)](dSOC/dt)+ k SOC/k NHC, where dSOC/dt is the annual change in SOC, NHC is nonharvested C returned to soil, k SOC is the annual mineralization rate of SOC, and k NHC is the annual mineralization rate of NHC. This equation was used to calculate ...


Sorption-Desorption Of Imidacloprid And Its Metabolites In Soil And Vadose Zone Materials, Sharon V. Papiernik, William C. Koskinen, Lucia Cox, Pamela J. Rice, Sharon A. Clay, Nancy R. Werdin-Pfisterer, Kristen A. Norberg Jan 2006

Sorption-Desorption Of Imidacloprid And Its Metabolites In Soil And Vadose Zone Materials, Sharon V. Papiernik, William C. Koskinen, Lucia Cox, Pamela J. Rice, Sharon A. Clay, Nancy R. Werdin-Pfisterer, Kristen A. Norberg

Agronomy, Horticulture and Plant Science Faculty Publications

Sorption-desorption is one of the most important processes affecting the leaching of pesticides through soil because it controls the amount of pesticide available for transport. Subsurface soil properties can significantly affect pesticide transport and the potential for groundwater contamination. This research characterized the sorption-desorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-Nnitro-2-imidazolidinimine) and three of its metabolites, 1-[(6-chloro-3-pyridinyl)methyl]-2-imidazolidinone (imidacloprid-urea), 1-[(6-chloro-3-pyridinyl)methyl]-4,5-dihydro-1H-imidazol-2-amine (imidaclopridguanidine), and 1-[(6-chloro-3-pyridinyl)methyl]-1H-imidazol-2-amine (imidacloprid-guanidine-olefin), as a function of changing soil properties with depth in two profiles extending from the surface to a depth of 1.8 or 8 m. Sorption of each ...


Factors Influencing Spatial Variability Of Soil Apparent Electrical Conductivity, D. E. Clay, J. Chang, D. D. Malo, C. G. Carlson, C. Reese, S. A. Clay, M. Ellsbury, B. Berg Jan 2001

Factors Influencing Spatial Variability Of Soil Apparent Electrical Conductivity, D. E. Clay, J. Chang, D. D. Malo, C. G. Carlson, C. Reese, S. A. Clay, M. Ellsbury, B. Berg

Agronomy, Horticulture and Plant Science Faculty Publications

Soil apparent electrical conductivity (ECa) can be used as a precision farming diagnostic tool more efficiently if the factors influencing ECa spatial variability are understood. The objective of this study was to ascertain the causes of ECa spatial variability in soils developed in an environment with between 50 and 65 cm of annual rainfall. Soils at the research sites were formed on calcareous glacial till parent materials deposited approximately 10,000 years ago. Soil samples (0–15 cm) collected from at least a 60 by 60 m grid in four fields were analyzed for Olsen phosphorus (P ...