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Retrospective Theses and Dissertations

Environmental Sciences

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Reconstructing Quaternary Landscapes And Hydrology From Soil Survey Maps, Bradley A. Miller Jan 2006

Reconstructing Quaternary Landscapes And Hydrology From Soil Survey Maps, Bradley A. Miller

Retrospective Theses and Dissertations

This study was done to investigate the pre-settlement condition of the southern Des Moines Lobe landscape, with particular interest in the hydrological function of depressional wetlands. Soil survey maps were used to identify the soil formation environment from soil properties observed today. Understanding the factors of soil formation and geomorphology allows historical reconstructions of the landscape, hydrology, wildlife habitat, and potentially other areas of interest. This study interpreted and managed soil survey data to efficiently create a Quaternary geologic map, identify the extents of historical depressional wetlands, deduce information about the water budget of these wetlands, and estimate the region ...


Use Of Precision Agriculture Technologies In Studying The Relationships Among Soil Ph, Calcium Carbonate Equivalent, Soybean Cyst Nematode Population Density, And Soybean Yield , Natalia Rogovska Jan 2006

Use Of Precision Agriculture Technologies In Studying The Relationships Among Soil Ph, Calcium Carbonate Equivalent, Soybean Cyst Nematode Population Density, And Soybean Yield , Natalia Rogovska

Retrospective Theses and Dissertations

Iron deficiency chlorosis (IDC) and soybean cyst nematode (SCN; Heterodera glycines) infestation are major factors that contribute to soybean (Glycine max Merr.) yield reduction in the Midwest. The IDC is often associated with soybean grown on high pH, calcareous soils. In addition, it was documented that SCN population density is higher in high pH soils. The objectives of this paper were to assess the proportion of within-field soybean yield and SCN variability that could be explained by soil pH, calcium carbonate equivalent (CCE), and a previously defined alkalinity stress index (ASI). Aerial images from 21 fields planted to SCN-resistant or ...


Diversity And Efficacy Of Arbuscular Mycorrhizal (Am) Fungi Isolated From Soils Of Soybean Fields , Zahra Ifnou Troeh Jan 2006

Diversity And Efficacy Of Arbuscular Mycorrhizal (Am) Fungi Isolated From Soils Of Soybean Fields , Zahra Ifnou Troeh

Retrospective Theses and Dissertations

A field survey evaluated the population composition of AM fungal species in Clarion (a well drained fine-loamy, mixed, mesic Typic Hapludoll) and Webster (a poorly drained fine-loamy, mixed, mesic Typic Endoaquoll) soils of four Iowa soybean (Glycine max, L.) fields. Spores from six species of Glomus and from the genera Acaulospora, Gigaspora , and Paragomus were found in the original field soils. G. claroideum, G. etunicatum, G. mosseae, G. viscosum, and Paraglomus occultum-like spores were prevalent in both Clarion and Webster soils of all four fields. Minor species included G. geosporum and G. intraradices. Trap cultures led to detection of several ...


Cell Envelope Constituents Of Pseudomonas Putida Contributing To Growth And Survival In Low-Water-Content Habitats , Martinus Franciscus Maria Van De Mortel Jan 2005

Cell Envelope Constituents Of Pseudomonas Putida Contributing To Growth And Survival In Low-Water-Content Habitats , Martinus Franciscus Maria Van De Mortel

Retrospective Theses and Dissertations

The ability of bacteria to respond to the ever changing environmental conditions they encounter requires the utilization of a broad range of colonization and survival strategies. One of the most important and probably least understood factors determining bacterial activity in terrestrial habitats is water availability. The goal of this dissertation research was to identify traits that contribute to maintaining a functional cell envelope when cells are dehydrated, which will help us to assess the scope of physiological changes necessary for growth in low-water-content habitats. The primary objective was to identify genes that are specifically regulated by dehydration (matric stress), and ...


Confounding Factors And Tertiary-Phase Control By A Surfactive Agent On Smectite Sorption Of Atrazine , Mark Albert Chappell Jan 2004

Confounding Factors And Tertiary-Phase Control By A Surfactive Agent On Smectite Sorption Of Atrazine , Mark Albert Chappell

Retrospective Theses and Dissertations

Atrazine is a widely used commercial pesticide applied to soil for the control broadleaf weeds in agriculture. Frequent detection of atrazine in surface and subsurface waters and the potential for adverse effects on toxicity to aquatic and terrestrial life have generated numerous investigations into the mechanisms governing atrazine sorption by soils. This dissertation seeks to add to that body of knowledge by elucidating basic mechanisms and processes that influence sorption of atrazine on clays in the presence and absence of surfactants commonly used in commercial formulations. Sorption studies showed that air-dried (AD), resuspended K+-saturated PC (KPC) exhibited a significantly ...


Soil And Runoff Phosphorus As Affected By Fertilizer And Manure Application , Brett Lee Allen Jan 2004

Soil And Runoff Phosphorus As Affected By Fertilizer And Manure Application , Brett Lee Allen

Retrospective Theses and Dissertations

Fertilizer or manure applications are increasing soil P in agricultural fields. This study assessed the impact of P application on soil P fractions and P loss with surface runoff based on P rate field trials and both indoor and field rainfall simulations. Bray P, Mehlich-3 (M3) P, Olsen P, total P (TPS) and soil P saturation (Psat) estimated by M3 or oxalate extractable P, Fe, and Al molar ratios increased with cumulative P application (0 to 1098 kg P ha-1 after 4 to 23 yr) at plots from 11 trials. Soil test P, TPS, and Psat were linearly correlated. Routine ...


The Fate Of Phosphorus And Molybdenum After Biosolids, Swine Manure And Triple Superphosphate Were Applied To A Soil , Jorge David Hernandez Jan 2003

The Fate Of Phosphorus And Molybdenum After Biosolids, Swine Manure And Triple Superphosphate Were Applied To A Soil , Jorge David Hernandez

Retrospective Theses and Dissertations

The possible effects of the application of swine manure and biosolids to high phosphorus (P) test soils has been widely debated due to the potential increase in P pollution. The application of these materials to soils might result in changes in water, soil, and crop quality. Increasing P in an already high soil P test (STP) soil may result in changing P dynamics in agro-ecosystems and enhancing P movement away from sorption sites. The purpose of this study was to determine the effect of swine manure (SM), biosolid (BS) and triple superphosphate (TSP) applications on the soil P content in ...


Evaluation Of Selected Factors That May Influence The Application Of Electromagnetic Induction Technology To Soil Science Investigations In Iowa , Eric Charles Brevik Jan 2001

Evaluation Of Selected Factors That May Influence The Application Of Electromagnetic Induction Technology To Soil Science Investigations In Iowa , Eric Charles Brevik

Retrospective Theses and Dissertations

Many who engage in soil survey have long desired discovery of a remote sensing technique that differentiates individual soil series. As research in precision agriculture has begun, many other agricultural scientists have also begun evaluating remote sensing tools for soil mapping purposes. Soil electrical conductivity (EC), as measured by instruments including the Geonics RTM EM-38, has shown promise as a soil survey tool. Most of the work done along these fines to date has involved comparing soil EC patterns to Order 1 or 2 soil surveys. It is important that we understand how certain field conditions that might be encountered ...


Evaluation Of A Collaborative Approach To Mediate Conflict Between Parties With Interests In Wildlife And Livestock In Colorado , Gina Marie Mcandrews Jan 2001

Evaluation Of A Collaborative Approach To Mediate Conflict Between Parties With Interests In Wildlife And Livestock In Colorado , Gina Marie Mcandrews

Retrospective Theses and Dissertations

The Habitat Partnership Program (HPP) is a collaborative initiative of the Colorado Division of Wildlife and the Colorado Cattleman's Association. The program consists of 15 committees, distributed over western Colorado, representing the interests of public resource managers, livestock growers and hunters. Through partnerships and projects, each committee strives to reduce fence damage and forage loss from big game activity. Information gathered from interviews, documents, projects and observation was used to assess the effectiveness of HPP in meeting its stated goals: resolve conflicts, improve ecosystem health, raise local knowledge about resource management and improve communication and understanding. Over seven years ...


Field And Laboratory Investigations Of Solute Transport Through Soil , Francis Xavier Mckeon Casey Jan 2000

Field And Laboratory Investigations Of Solute Transport Through Soil , Francis Xavier Mckeon Casey

Retrospective Theses and Dissertations

Two single tracer methods (basic and variance) and one multiple tracer method were developed to simultaneously estimate soil hydraulic properties and mobile/immobile solute transport parameters in situ. In this study, immobile water contents (thetaim) and mass exchange coefficients (alpha) were estimated with the multiple tracer method and the single tracer methods on the same five field sites. The theta im values estimated by the basic single tracer method were consistently lower than the multiple tracer method values. This was attributed to the assumption that alpha = 0 for the basic single tracer method. Furthermore, alpha values estimated by multiple tracer ...


Interactions And Transformations Of Chlorpyrifos In Aqueous And Colloidal Systems , Jigang Wu Jan 2000

Interactions And Transformations Of Chlorpyrifos In Aqueous And Colloidal Systems , Jigang Wu

Retrospective Theses and Dissertations

Chlorpyrifos [o,o-diethyl o-(3,5,6-trichloro-2-pyridyl) phosphorothioate] is a broad-spectrum organophosphorus insecticide widely used in agricultural, industrial, and residential environments. Understanding interaction of chlorpyrifos with colloidal materials is fundamental for assessing fate and toxicity of chlorpyrifos in soil and aquatic environments. The objectives of this study were: (1) to quantify sorption and desorption of chlorpyrifos on colloidal materials in aqueous systems; (2) to investigate hydrolysis of chlorpyrifos in aqueous systems; (3) to evaluate the effects of colloidal materials on the fate of the sorbed chlorpyrifos in aqueous systems; and (4) to study abiotic transformation of chlorpyrifos in water;Six ...


Mobility And Bioavailability Of Heavy Metals In Selected Soils Of Iowa And Nigeria , Monday Ochu Mbila Jan 2000

Mobility And Bioavailability Of Heavy Metals In Selected Soils Of Iowa And Nigeria , Monday Ochu Mbila

Retrospective Theses and Dissertations

Environmental pollution due to release of heavy metals from various sources is a widespread problem throughout the world. This research was conducted to investigate the behavior of heavy metals released to soils from sewage-sludge application and ore mining. The distribution, chemical forms, bioavailability and microenvironment of Zn, Cu, Pb, and Ni in sewage-sludge-amended Ultisols from southeastern Nigeria, and Pb and Zn in Alfisols of an abandoned mine in northeast Iowa, were investigated using field studies and microanalytical techniques to complement standard bulk analytical methods. After 37 years of sludge amendment, the soil chemical properties had changed enough to wan-ant a ...


Human Impacts On Soils And Geomorphic Processes On The Des Moines Lobe, Iowa , Michael E. Konen Jan 1999

Human Impacts On Soils And Geomorphic Processes On The Des Moines Lobe, Iowa , Michael E. Konen

Retrospective Theses and Dissertations

A watershed scale approach to examining post-European settlement erosion-sedimentation was undertaken on the Des Moines Lobe in northcentral Iowa. Two closed basins comprised of glacigenic diamicton were selected for detailed field examination. The objectives of the study were to quantify post-settlement erosion-sedimentation rates and to characterize post-settlement hillslope sediments (PSHS) and the underlying buried soils. Soil morphology, particle-size distribution, mass magnetic susceptibility measurements, organic carbon depth distributions, quantitative soil color measurements, and cesium-137 depth distributions were utilized to identify PSHS and quantify erosion-sedimentation rates. Maximum thicknesses of 100 and 93 cm of PSHS were described in the two basins. Average ...


Effect Of Soil Ph On Phytoavailability Of Nitrogen In Biotechnology By-Products And Animal Manures , Fahad Mohamad Alromian Jan 1999

Effect Of Soil Ph On Phytoavailability Of Nitrogen In Biotechnology By-Products And Animal Manures , Fahad Mohamad Alromian

Retrospective Theses and Dissertations

Biotechnology by-products and animal manures have received considerable attention in recent years because of the problems associated with their disposal and because of their potential use as soil amendments and as sources of nutrients for crops. A laboratory experiment was conducted to assess the potential N mineralization in five biotechnology by-products and three animal manures added to an agricultural soil with pH values of 5, 6, and 7 and incubated at 20°C or 30°C. Two greenhouse experiments were conducted by using the same soils to evaluate those materials as sources of N for plants; corn (Zea mays L ...


Characterization Of Preferential Solute Transport In Soil , Jaehoon Lee Jan 1999

Characterization Of Preferential Solute Transport In Soil , Jaehoon Lee

Retrospective Theses and Dissertations

The occurrence of preferential flow for rapid movement of solute through soil has been reported. However, there are not many practical methods to detect, quantify, and identify preferential flow. The characterization of preferential flow would improve our understanding of field water and solute behavior. A concept that separates water content into "mobile" and "immobile" domain has been successful in describing some forms of preferential solute transport. The mobile-immobile model (MIM) has three significant parameters- immobile water content (thetaim), mass exchange coefficient (alpha), and dispersion coefficient (D m). Although one can determine these parameters by applying inverse methods to effluent breakthrough ...


Weeds/Weed Seedbank And Soil Fungi Responses To Tillage And Cropping Systems , Joel Felix Jan 1999

Weeds/Weed Seedbank And Soil Fungi Responses To Tillage And Cropping Systems , Joel Felix

Retrospective Theses and Dissertations

A four year field experiment was conducted from 1994 through 1997 to elucidate the effects of tillage, cropping systems, and weed management regimes on land previously under the conservation reserve program (CRP). A total of 13 weed species comprised the weed seedbank which was dominated by broadleaf weeds. The seedbank for common lambsquarters and Amaranthus species were 10,365 and 31,925 seeds M-2 in the first year out of CRP, respectively. The Amaranthus species seedbank continued to increase and climaxed at 51,670 seeds M-2 in 1996. The seedbank for Setaria species increased 19 fold between 1994 and 1997 ...


Dynamics Of Biosolids-Derived Phosphorus In A Mollisol , Yaobing Sui Jan 1999

Dynamics Of Biosolids-Derived Phosphorus In A Mollisol , Yaobing Sui

Retrospective Theses and Dissertations

Land application of biosolids (treated municipal sewage sludge) is becoming more popular because it is an agronomically, environmentally, and economically acceptable means for biosolids disposal. When the amount of biosolids is applied to agricultural land according to N-based on agronomic rate, however, the amount of P applied is generally more than plants need. The subsequent accumulation of P is of environmental concern, because it could lead to eutrophication of water bodies if P is carried off-site in runoff water and eroded soils. Thus, a completely randomized block experiment with three biosolids treatments (control, low, and high biosolids application rates) and ...


Effects Of Variable Rates, Times And Methods Of Application Of Swine Manure On Nitrate-Nitrogen In Subsoil Water, Crop Yields, N Uptake And Recovery And Soil Residual Nitrate-Nitrogen: A Three Year Study , Sara Dominga Smith Jan 1999

Effects Of Variable Rates, Times And Methods Of Application Of Swine Manure On Nitrate-Nitrogen In Subsoil Water, Crop Yields, N Uptake And Recovery And Soil Residual Nitrate-Nitrogen: A Three Year Study , Sara Dominga Smith

Retrospective Theses and Dissertations

Land application of swine manure offers the alternative use of its nutrients for crop production but growing concerns exist when not properly managed because of potential water quality problems;The field experiment consisted of 48 plots (15.24 x 3.04 m), located in a Clarion-Nicollet-Webster soil association. Corn (Zea mays L.) was rotated with soybean (Glycine max L.). Treatments applied were a factorial combination of Nitrogen (N) rates (0, 84, 168 and 252 kg-N/ha) of liquid swine manure and Urea-Ammonium-Nitrate (UAN) with methods of application (manure in spring, fall and side-dress; manure with nitrapyrin in fall and UAN ...


Localized Soil Compaction And Soil Doming Of The Fertilizer Injection Zone To Control Nitrate Leaching , Daniel Eric Ressler Jan 1998

Localized Soil Compaction And Soil Doming Of The Fertilizer Injection Zone To Control Nitrate Leaching , Daniel Eric Ressler

Retrospective Theses and Dissertations

Chemical movement is fundamental to production agriculture. Crop roots and nutrients must be in contact for optimum crop growth. In the pursuit of this goal, nitrogen that is applied in fertilizers is often leached prior to crop uptake. Means to limit fertilizer leaching to conserve resources are needed;Application method plays a role in the way chemicals move through soil. Structured soil column effluent studies suggest that leaching could be reduced if chemicals are allowed to penetrate soil aggregates prior to saturation by an infiltrating solution. In well structured soil, mixing chemicals with a limited volume of soil and destroying ...


Composition And Transport Of Sludge-Derived Organic Carbon In Soil And Aquifer Material , Nizhou Han Jan 1996

Composition And Transport Of Sludge-Derived Organic Carbon In Soil And Aquifer Material , Nizhou Han

Retrospective Theses and Dissertations

Land application of sewage sludge may introduce handful trace metals into soils and cause surface and ground water contamination. The mobilities of the metals are affected by dissolved organic carbon (DOC) in sludge or in soils. The major objective of the present study was to characterize the DOC in a digested sewage sludge and a sludge-amended soil and to examine the influence of DOC subcomponents on Cu mobility in an aquifer material collected near sludge application field;DOC from digested sewage sludge was fractionated according to its molecular weight (MW) and polarity. Investigations were performed on the mobilities and Cu-binding ...


Corn Yield Response To Rotation Effect, N Fertilizer Application And Row Position In A Strip Intercropping System, Urszula Choromanska Jan 1995

Corn Yield Response To Rotation Effect, N Fertilizer Application And Row Position In A Strip Intercropping System, Urszula Choromanska

Retrospective Theses and Dissertations

No abstract provided.


Amino Acid Composition Of Soil Organic Matter And Nitrogen Transformations In Soils Under Different Management Systems , Zachary Ngewoh Senwo Jan 1995

Amino Acid Composition Of Soil Organic Matter And Nitrogen Transformations In Soils Under Different Management Systems , Zachary Ngewoh Senwo

Retrospective Theses and Dissertations

Studies of amino acid composition of soil organic matter extracted from 10 Iowa surface soils and from surface soils of two long-term rotation experiments showed that, with the exception of asparagine plus aspartic acid and glutamine plus glutamic acid, the other 13 amino acids, expressed as percentages of total amino acid extracted, were very uniform among the soils. The total amino acid extracted was significantly correlated with organic C (r = 0.79[superscript]\*\*) and clay content (r = 0.76[superscript]\*\*), but not with total N. Expressed as percentages of organic C and N in soils, the amounts extracted ranged from ...


Paired Prairie And Cultivated Soils: Soluble Organics And Nitrogen Dynamics , Thomas Henry Deluca Jan 1993

Paired Prairie And Cultivated Soils: Soluble Organics And Nitrogen Dynamics , Thomas Henry Deluca

Retrospective Theses and Dissertations

Nitrate contamination of water resources in the Midwestern U.S. is largely a result of conventional agricultural practices. In contrast, soils of prairie ecosystems do not accumulate NO[subscript]3 because of rapid NO[subscript]3 assimilation by plants and microbes. Microbial NO[subscript]3 assimilation requires a readily available C source; however, there is little known regarding available C in soils. The ability of prairie soils to recycle NO[subscript]3 makes the prairie ecosystem a useful model in N cycle studies designed to develop agricultural systems that minimize N loss;I performed field and laboratory studies on paired ...


Fungal Contributions To Soil Aggregation And Soil Quality , Neal Samuel Eash Jan 1993

Fungal Contributions To Soil Aggregation And Soil Quality , Neal Samuel Eash

Retrospective Theses and Dissertations

Conceptual models implicate the fungi as important mechanisms in soil aggregate formation but the lack of suitable assays for routine quantification of fungal biomass make validation of these models evasive. The objectives of these studies were threefold: (1) to evaluate the effectiveness of ergosterol as an indicator of fungal biomass; (2) to evaluate interrelationships between aggregate-forming processes induced by fungi and those caused by physical and chemical factors; (3) to evaluate potential soil quality indicators under different tillage and residue management systems. Objective 1 focused on determining the efficiency of recovering ergosterol from spiked soil samples and measuring ergosterol of ...


Herbicide And Tracer Movement In Soil , George Frank Czapar Jan 1990

Herbicide And Tracer Movement In Soil , George Frank Czapar

Retrospective Theses and Dissertations

Field movement of several herbicides, rhodamine WT, chloride, and bromide was measured by sampling field drainage tiles 1.2 m deep. Under natural rainfall conditions, alachlor (2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide) and metribuzin (4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one) were detected in tile effluent samples 12 to 18 hours after a 30.7 mm rainstorm. Rainfall occurring 1 to 2 days after chemical application was primarily responsible for the elevated concentrations found. In a second experiment, a rainfall simulator was used to apply 50 to 80 mm of water to 8 plots, 24 hours after ...


Determination Of Metals In Soils And Sewage Sludges By Ion Chromatography And The Effect Of Cropping Systems On Metal Adsorption By Soils , Nicholas Thomas Basta Jan 1989

Determination Of Metals In Soils And Sewage Sludges By Ion Chromatography And The Effect Of Cropping Systems On Metal Adsorption By Soils , Nicholas Thomas Basta

Retrospective Theses and Dissertations

An accurate and precise ion chromatographic (IC) method for determination of total Cu, Ni, and Zn in soils was developed. The metals in soil digests were extracted with dithizone in CHCl[subscript]3, and the metal-dithizonate complexes were digested with HNO[subscript]3 before injection into the IC system. After separation on HPIC-CS5 column, the metals were determined by measuring the absorbance of metal complexes formed by postcolumn reaction with 4-(2-pyridylazo) resorcinol (PAR) at 520 nm. The results by this IC method agreed closely with those obtained by atomic absorption spectrophotometry (AA). Comparison of results of total Cu, Mn ...


Response Of Soybeans And Wheat To Limestone Application On Acid Soils In Rio Grande Do Sul, Brazil , Otavio J. F. De Siqueira Jan 1980

Response Of Soybeans And Wheat To Limestone Application On Acid Soils In Rio Grande Do Sul, Brazil , Otavio J. F. De Siqueira

Retrospective Theses and Dissertations

Yield responses of soybeans (Glycine max, L) and wheat (Tritcum aestivum, L) to limestone applications were evaluated on several acid soils (Oxisols) of the Rio Grande do Sul plateau region, Brazil.;Seven field experiments were conducted during a five-year period to evaluate the efficiency of lime rate in relation to varying soil acidity conditions and time after lime applications.;Soil textural properties were related to the effect of lime treatments on the soil pH, on the exchangeable Ca + Mg content, and on CEC properties of the soils in this study. Maximum soil pH values occurred at higher values on the ...


Eroded Sediment Size Distributions As Affected By Corn-Soybean Rotations And Tillage Systems, Vicente De Paula Pereira Jan 1979

Eroded Sediment Size Distributions As Affected By Corn-Soybean Rotations And Tillage Systems, Vicente De Paula Pereira

Retrospective Theses and Dissertations

No abstract provided.


Saturated Flow Models Applicable To Hillside Surface Mine Reclamation , Lyle Prunty Jan 1978

Saturated Flow Models Applicable To Hillside Surface Mine Reclamation , Lyle Prunty

Retrospective Theses and Dissertations

No abstract provided.


Mathematical Models For Gully-Wall And Mineland-Soil Seep And Slip, Seyed Farhad Mousavi Jan 1978

Mathematical Models For Gully-Wall And Mineland-Soil Seep And Slip, Seyed Farhad Mousavi

Retrospective Theses and Dissertations

No abstract provided.