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Full-Text Articles in Life Sciences

Assessment Of Concentrated Flow Through Riparian Buffers, Michael G. Dosskey, Matthew J. Helmers, Dean E. Eisenhauer, Thomas G. Franti, Kyle D. Hoagland Nov 2002

Assessment Of Concentrated Flow Through Riparian Buffers, Michael G. Dosskey, Matthew J. Helmers, Dean E. Eisenhauer, Thomas G. Franti, Kyle D. Hoagland

Matthew J. Helmers

Concentrated flow of surface runoff from agricultural fields may limit the capability of riparian buffers to remove pollutants. This study was conducted on four farms in southeastern Nebraska to develop a method for assessing the extent of concentrated flow in riparian buffers and for evaluating the impact that it has on sediment-trapping efficiency. Field methods consisted of mapping field runoff areas and their pathways to and through riparian buffers to streams. Mathematical relationships were developed from a model (VFSMOD) that estimates sediment-trapping efficiency from the ratio of buffer area to field runoff area. Among the farms surveyed, riparian buffers averaged ...


Hyperspectral Imagery For Various Crop Growth Information Extraction, Haibo Yao, Lei Tian, Marvin Paulsen, Amy L. Kaleita, Mukti Singh Jul 2002

Hyperspectral Imagery For Various Crop Growth Information Extraction, Haibo Yao, Lei Tian, Marvin Paulsen, Amy L. Kaleita, Mukti Singh

Amy L. Kaleita

Aerial hyperspectral imagery has potential for agriculture applications. The objective of this study is to identify significant wavelength ranges (image bands or band combinations) from hyperspectral imagery for different field information extraction. The field information include corn nitrogen content, plant population, yield, and grain quality such as oil, protein, and extractable starch. All the images were processed using the GA-SPCA (Genetic Algorithm based Selective Principal Component Analysis) method . T he GA-SPCA method can filter out significant image bands and reduce the image data dimension to only one principle component image through a cascade two-step dimension reduction process. It was found ...


Noninvasive Sampling And Analysis Of Bovine Breath Using Solid-Phase Microextraction And Gas Chromatography-Mass Spectrometry: A Feasibility Study, Jacek A. Koziel, Jarett P. Spinhirne, Norbert K. Chirase Jul 2002

Noninvasive Sampling And Analysis Of Bovine Breath Using Solid-Phase Microextraction And Gas Chromatography-Mass Spectrometry: A Feasibility Study, Jacek A. Koziel, Jarett P. Spinhirne, Norbert K. Chirase

Jacek A. Koziel

An experiment was conducted to examine the feasibility of detecting unique volatile organic biomarkers exhaled by healthy and morbid heifer calves on-site using noninvasive sampling with solid phase microextraction (SPME) and analysis with gas chromatography-mass spectrometry (GC-MS). Two heifers were selected on the bases of health status and were sampled from 5 to 15 min with a special facemask sampling system using DVB/Carboxen/PDMS 50/30 µ m and PDMS 100 µ m SPME fibers. The samples were sealed and transported to the laboratory and analyzed with ion trap GC-MS. Acetone, methyl ethyl ketone, toluene, pentadecane, and nonanal were ...


An Overland Flow Sampler For Use In Vegetative Filters, D. Eisenhauer, Matthew J. Helmers, J. Brothers, M. Dosskey, T. Franti, A. Boldt, B. Strahm Jul 2002

An Overland Flow Sampler For Use In Vegetative Filters, D. Eisenhauer, Matthew J. Helmers, J. Brothers, M. Dosskey, T. Franti, A. Boldt, B. Strahm

Matthew J. Helmers

Vegetative filters (VF) are used to remove contaminants from agricultural runoff and improve surface water quality. State and federal cost-share funds are available to encourage landowners to install VF. The USDA-National Conservation Buffer Initiative calls for 3.2 million km of buffers to be installed by the year 2002. Numerous experimental plot and modeling studies have quantified the removal of sediments and other non-point source (NPS) contaminants from agricultural runoff by VF. Almost all of these studies have been conducted under controlled settings, including artificial sheet flow conditions, and using expensive, labor-intensive measurement systems. There is a critical need for ...


Screening For Volatile Fatty Acids In Agricultural Air Using Solid Phase Microextraction And Gas Chromatography – Mass Spectrometry, Jarett P. Spinhirne, Jacek A. Koziel, David B. Parker, Darren L. Williams, N. Andy Cole, John M. Sweeten Jul 2002

Screening For Volatile Fatty Acids In Agricultural Air Using Solid Phase Microextraction And Gas Chromatography – Mass Spectrometry, Jarett P. Spinhirne, Jacek A. Koziel, David B. Parker, Darren L. Williams, N. Andy Cole, John M. Sweeten

Jacek A. Koziel

Volatile fatty acids (VFAs) are a major component of odorous gases associated with agricultural sources. Because of typically low VFA air concentrations, conventional air sampling methods including sorbent tubes and vacuum canisters are often not sensitive enough to detect them. Solid phase microextraction (SPME) was used in this research because it is very sensitive, reusable, fast, and combines sampling and sample preparation, allowing for rapid detection of low concentrations of organics in air. This research focused on 7 VFAs: acetic, propionic, isobutyric, butyric, isovaleric, valeric, and hexanoic acids. Field experiments were conducted to test this method for air sampling of ...


Hyperspectral Imagery For Various Crop Growth Information Extraction, Haibo Yao, Lei Tian, Marvin Paulsen, Amy Kaleita, Mukti Singh Jul 2002

Hyperspectral Imagery For Various Crop Growth Information Extraction, Haibo Yao, Lei Tian, Marvin Paulsen, Amy Kaleita, Mukti Singh

Amy L. Kaleita

Aerial hyperspectral imagery has potential for agriculture applications. The objective of this study is to identify significant wavelength ranges (image bands or band combinations) from hyperspectral imagery for different field information extraction. The field information include corn nitrogen content, plant population, yield, and grain quality such as oil, protein, and extractable starch. All the images were processed using the GA-SPCA (Genetic Algorithm based Selective Principal Component Analysis) method . T he GA-SPCA method can filter out significant image bands and reduce the image data dimension to only one principle component image through a cascade two-step dimension reduction process. It was found ...


Remote Sensing Of Site-Specific Soil Characteristics For Precision Farming, Amy L. Kaleita, Lei Tian Jul 2002

Remote Sensing Of Site-Specific Soil Characteristics For Precision Farming, Amy L. Kaleita, Lei Tian

Amy L. Kaleita

A methodology for assessing distributed surface soil moisture content from optical remote sensing is developed. This study uses both ground-based and remotely sensed spectral measurements of soil reflectance in visible and near-infrared wavelengths and concurrent measurements of volumetric soil moisture within the top 6 cm to establish a relationship between spectral response and moisture. Various approaches, including principal component analyses and regression techniques are investigated to determine the potential for quantifying soil moisture from the spectral reflection data. Preliminary investigations have yielded R 2 values as high as 0.62 when comparing predictions to actual moisture values. Investigation of predicting ...


Remote Sensing Of Site-Specific Soil Characteristics For Precision Farming, Amy L. Kaleita, Lei F. Tian Jul 2002

Remote Sensing Of Site-Specific Soil Characteristics For Precision Farming, Amy L. Kaleita, Lei F. Tian

Amy L. Kaleita

A methodology for assessing distributed surface soil moisture content from optical remote sensing is developed. This study uses both ground-based and remotely sensed spectral measurements of soil reflectance in visible and near-infrared wavelengths and concurrent measurements of volumetric soil moisture within the top 6 cm to establish a relationship between spectral response and moisture. Various approaches, including principal component analyses and regression techniques are investigated to determine the potential for quantifying soil moisture from the spectral reflection data. Preliminary investigations have yielded R 2 values as high as 0.62 when comparing predictions to actual moisture values. Investigation of predicting ...


Modeling Vegetative Filter Performance With Vfsmod, Matthew J. Helmers, Dean E. Eisenhauer, Michael G. Dosskey, Thomas G. Franti Apr 2002

Modeling Vegetative Filter Performance With Vfsmod, Matthew J. Helmers, Dean E. Eisenhauer, Michael G. Dosskey, Thomas G. Franti

Matthew J. Helmers

The model VFSMOD was used to investigate the effect of varying watershed characteristics and buffer dimensions on the sediment trapping efficiency of vegetative filters. This investigation allows for a better understanding of how watershed characteristics, buffer dimensions, and storm characteristics impact the performance of vegetative filters. Using VFSMOD, relationships that estimate sediment trapping efficiency from the ratio of filter area and field area were developed for different sites. These relationships have been applied for field assessment of concentrated flow.


Estrogen Concentrations In Dairy And Swine Waste Storage And Treatment Structures In And Around Tennessee, D. Raj Raman, Elizabeth L. Williams, Robert T. Burns, Alice C. Layton, Adam S. Daugherty, Michael D. Mullen Jan 2002

Estrogen Concentrations In Dairy And Swine Waste Storage And Treatment Structures In And Around Tennessee, D. Raj Raman, Elizabeth L. Williams, Robert T. Burns, Alice C. Layton, Adam S. Daugherty, Michael D. Mullen

D. Raj Raman

Naturally occurring estrogens in animal wastes may cause negative environmental impacts in some watersheds. However, there is little published data regarding the concentrations of these estrogenic compounds in full-scale animal waste treatment and storage structures, thus making risk assessment difficult. To address this knowledge gap, the research described in this paper explores estrogen concentrations in 19 animal waste storage and treatment structures at dairy and swine production facilities in and around Tennessee.

Samples have been collected from eight dairy and eleven swine facilities, representing a range of waste storage and treatment structures typical of Tennessee, and much of the southeastern ...