Agricultural Science Commons^™

The Original Usda-Ars Experimental Watersheds In Texas And Ohio: Contributions From The Past And Visions For The Future, R. D. Harmel, J. V. Bonta, C. W. Richardson

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The USDA Soil Conservation Service (USDA‐SCS) realized the importance of understanding hydrologic processes on agricultural fields and watersheds in the mid‐1930s. Based on this realization, the research program of the Hydrologic Division of SCS established three experimental watersheds across the U.S. to analyze the impact of landuse practices on soil erosion, flood events, water resources, and the agricultural economy. Two of the original watersheds remain in operation today within the USDA Agricultural Research Service (USDA‐ARS): the Blacklands Experimental Watershed (now the Grassland, Soil and Water Research Laboratory) near Riesel, Texas, and the North Appalachian Experimental Watershed near Coshocton, Ohio. These …

Dry Weight And Nitrogen Content Of Chickpea And Winter Wheat Grown In Pots For Three Rotations, James E. Bidlack, Charles T. Mackown, Srinivas C. Rao

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Chickpea [Cicer arietinum (L.)] cultivars ‘ICCV-2’ and ‘Sarah’ were studied along with a control, multistrain, TAL 1148, and TAL 480 Bradyrhizobium strains to determine the effect(s) of cultivar and inoculum on dry weight (DW) and nitrogen (N) content of the legume, as well as soil mineral N, DW, and N content of wheat [Triticum aestivum (L.) emend. Thell.] in a continuous wheat-legume rotation. Chickpeas were planted during the summer and harvested in the fall of 1992, 1993, and 1994. Vegetative growth from chickpeas was incorporated into the soil prior to wheat planting, and soil cores were taken at …

Comparison Of Ground-Based Remote Sensors For Evaluation Of Corn Biomass Affected By Nitrogen Stress, Soon-Dal Hong, James Schepers, Dennis D. Francis, Michael R. Schlemmer

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The nondestructive determination of plant biomass is not possible; however, crop-canopy sensors that determine the normalized difference vegetation index have the potential to estimate living biomass, which is indicative of plant vigor and stress. Pot experiments using sand culture were conducted in 2002 and 2003 under greenhouse conditions to evaluate the effect of nitrogen (N) deficiency on corn biomass and reflectance. Stress was imposed by implementing six to eight levels of N in Hoagland’s nutrient solution. Canopy reflectance measurements made at three growth stages with a variety of handheld spectral sensors (active and passive) were closely correlated with dry weight …

Design And Testing Of A Closed, Stirring Respirometer For Measuring Oxygen Consumption Of Channel Catfish Eggs, Eugene L. Torrans

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A closed, stirring respirometer was designed to agitate small egg mass samples of channel catfish Ictalurus punctatus while measuring oxygen consumption by the eggs. Egg mass samples ranging in size from 15 to 46 g were placed on a screen platform above a magnetic stir bar in the respirometer; the degree of agitation was controlled with a magnetic stir plate. Dissolved oxygen (DO) concentration and temperature were measured with a luminescent DO sensor and meter. The respirometer was used to determine routine metabolic rate and limiting oxygen concentration (the presumed hypometabolic transition zone) on egg mass samples from 10 different …

Evidence Of Varietal Adaptation To Organic Farming Systems, Kevin M. Murphy, Kimberly A. Garland-Campbell, Steven R. Lyon, Stephen S. Jones

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Consumer demand regarding the impacts of conventional agriculture on the environment and human health have spurred the growth of organic farming systems; however, organic agriculture is often criticized as low-yielding and unable to produce enough food to supply the world’s population. Using wheat as a model crop species, we show that poorly adapted cultivars are partially responsible for the lower yields often found in organic farming systems when compared with conventional farming systems. Our results demonstrate that the highest yielding soft white winter wheat genotypes in conventional systems are not the highest yielding genotypes in organic systems. An analysis of …

Fertility Restoration Of The Sorghum A3 Male-Sterile Cytoplasm Through A Sporophytic Mechanism Derived From Sudangrass, Hoang V. Tang, Jeffrey F. Pedersen, Christine D. Chase, Daryl R. Pring

Department of Agronomy and Horticulture: Faculty Publications

Fertility restoration of sorghum [Sorghum bicolor (L.) Moench] lines carrying the IS1112C (A3 group) male-sterile cytoplasm has been documented as a two-gene gametophytic mechanism involving complementary action of restoring alleles designated Rf3 and Rf4, as derived from IS1112C. Fertility restoration capability has also been reported from sudangrass (S. bicolor subsp. drummondii) populations. We describe characteristics of a fertility restoration system derived from sudangrass, in which male-sterile individuals were observed at high frequency in backcross and F₂-F₃ segregating populations. Segregation analyses were consistent with a sporophytic restoration system involving two complementary genes. Pollen iodine …

C3–C4 Composition And Prior Carbon Dioxide Treatment Regulate The Response Of Grassland Carbon And Water Fluxes To Carbon Dioxide, H. W. Polley, W. A. Dugas, P. C. Mielnick, H. B. Johnson

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

During May, July and October 2000, we measured the effects of temporarily increasing or decreasing CO₂ concentration by 150–200 μmol mol⁻¹ on daytime net ecosystem CO₂ exchange (NEE) and water flux (evapotranspiration, ET) of C₃–C₄ grassland in central Texas, USA that had been exposed for three growing seasons to a CO₂ gradient from 200 to 560 μmol mol⁻¹. Grassland grown at subambient CO₂ (< 365 μmol mol⁻¹) was exposed for 2 days to an elevated CO₂ gradient (> 365 μmol mol⁻¹). Grassland grown at elevated CO₂ was …

Publishing Ltd Whole-Plant Mineral Partitioning Throughout The Life Cycle In Arabidopsis Thaliana Ecotypes Columbia, Landsberg Erecta, Cape Verde Islands, And The Mutant Line Ysl1ysl3, Brian M. Waters, Michael A. Grusak

Department of Agronomy and Horticulture: Faculty Publications

• Minimal information exists on whole-plant dynamics of mineral flow through Arabidopsis thaliana or on the source tissues responsible for mineral export to developing seeds. Understanding these phenomena in a model plant could help in the development of nutritionally enhanced crop cultivars. • A whole-plant partitioning study, using sequential harvests, was conducted to characterize growth and mineral concentrations and contents of rosettes, cauline leaves, stems, immature fruit, mature fruit hulls, and seeds of three WT lines (Col-0, Ler, and Cvi) and one mutant line (Col-0::ysl1ysl3). • Shoot mineral content increased throughout the life cycle for all minerals, although tissue-specific mineral …

A Soybean Transcript Map: Gene Distribution, Haplotype And Single-Nucleotide Polymorphism Analysis, Ik-Young Choi, D. L. Hyten, Lakshmi K. Matukumalli, Qijian Song, Julian M. Chaky, Charles V. Quigley, Kevin Chase, K. Gordon Lark, Robert S. Reiter, Mun-Sup Yoon, Eun-Young Hwang, Seung-In Yi, Nevin D. Young, Randy C. Shoemaker, Curtis P. Van Tassell, James E. Specht, P. B. Cregan

Department of Agronomy and Horticulture: Faculty Publications

The first genetic transcript map of the soybean genome was created by mapping one SNP in each of 1141 genes in one or more of three recombinant inbred line mapping populations, thus providing a picture of the distribution of genic sequences across the mapped portion of the genome. Singlenucleotide polymorphisms (SNPs) were discovered via the resequencing of sequence-tagged sites (STSs) developed from expressed sequence tag (EST) sequence. From an initial set of 9459 polymerase chain reaction primer sets designed to a diverse set of genes, 4240 STSs were amplified and sequenced in each of six diverse soybean genotypes. In the …

Mycotoxin Occurrence And Aspergillus Flavus Soil Propagules In A Corn And Cotton Glyphosate-Resistant Cropping Systems, K. N. Reddy, H. K. Abbas, R. M. Zablotowicz, C. A. Abel, C. H. Koger

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The effects of cotton–corn rotation and glyphosate use on levels of soil-borne Aspergillus flavus, aflatoxin and fumonisin contamination in corn and cotton seed were determined during 2002–2005 in Stoneville, Mississippi (USA). There were four rotation systems (continuous cotton, continuous corn, cotton–corn and corn–cotton) for both glyphosate-resistant (GR) and non-GR cultivars–herbicide system arranged in a randomized complete block design with four replications. Aspergillus flavus populations in surface (5-cm depth) soil, sampled before planting (March/April), mid-season (June) and after harvest (September), ranged from 1.47 to 2.99 log (10) cfu g^-1 soil in the four rotation systems. Propagules of A. flavus …

First Report Of Yersinia Ruckeri Biotype 2 In The Usa, Cova R. Arias, Oscar Olivares-Fuster, Karl Hayden, Craig A. Shoemaker, John M. Grizzle, Phillip H. Klesius

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A polyphasic characterization of atypical isolates of Yersinia ruckeri (causative agent of enteric redmouth disease in trout) obtained from hatchery-reared brown trout Salmo trutta in South Carolina was performed. The Y. ruckeri isolates were biochemically and genetically distinct from reference cultures, including the type strain, but were unequivocally ascribed to the species Y. ruckeri, based on API 20E, VITEK, fatty acid methyl ester profiles, and 16S rRNA gene sequencing analysis. These isolates were nonmotile and unable to hydrolyze Tween 20/80 and were therefore classified as Y. ruckeri biotype 2. Genetic fingerprint typing of the isolates via enterobacterial repetitive intergenic …

Mineralization Of Nitrogen In Soils Amended With Dairy Manure As Affected By Wetting/Drying Cycles, D. B. Watts, H. A. Torbert, S. A. Prior

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Interest in manure management and its effects on nitrogen (N) mineralization has increased in recent years. The focus of this research was to investigate the N-mineralization rates of different soil types in Coastal Plain soils and compare them to a soil from Illinois. Soils with and without dairy composted manure addition were subjected to different wetting/drying cycles [constant moisture at 60% waterfilled pore space (WFPS) and cycling moisture from 60 to 30% WFPS] under laboratory conditions at three different temperatures (11 °C, 18 °C, and 25 °C). Samples were collected from three different soil types: Catlin (Mollisols), Bama (Ultisols), and …

Non-Composted Municipal Solid Waste Processing Byproduct Effect On Soil Reclamation, H. Allen Torbert, Dick L. Gebhart, Ryan R. Busby, Kenneth N. Potter, Deborah R. Curtain

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

A new garbage processing technology has been developed that sterilizes and separates inorganic and organic components of municipal solid waste. The non-composted byproduct of this process, Fluff ®, has the potential to be utilized as a soil amendment to improve soil conditions in highly degraded soils. A study was initiated to evaluate Fluff as a soil amendment for establishing native grasses on disturbed US Army training lands. The Fluff was incorporated into a sandy loam soil at Fort Benning Military Reservation, GA on two sites: a moderately degraded and a highly degraded soil. The Fluff was incorporated at rates of …

Alkaline Phosphatase Reactivity In The Vagina And Uterovaginal Junctionsperm-Storage Tubules Of Turkeys In Egg Production: Implications Forsperm Storage, M. R. Bakst, V. Akuffo

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

1. Currently there remains contradictory intortliation on the localisation and possible roleof alkaline phosphatase (AP) in the chicken and Japanese quail oviducts.

2.Using turkeys with a hard-shelled egg in their uteri, vaginal and uterovaginal junction mucosae werestretched and fixed as whole mounts prior to the Imistochemical localisation of All activity.

3.Scattered All reactive cells were observed in the vaginal and uteiovaginal junction surface epitheliaand intense All reactivity of the sperm-storage tubule (SST) epithelium, localised to its apical border.

4.We suggest that such All in hens in egg production may reflect cell dif.ftreiitiation andproliferation in the vagina and SST and possibly …

Adrenomedullin (Am) And Adrenomedullin Binding Protein (Am-Bp) In The Bovine Mammary Gland And Milk: Effects Of Stage Of Lactation And Experimental Intramammary E. Coli Infection, Ted H. Elsasser, Anthony V. Capuco, Thomas J. Caperna, Alfredo Martínez, Frank Cuttitta, Stanislaw Kahl

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Adrenomedullin (AM) has been characterized as an endogenous tissue survival factor and modulator of many inflammatory processes. Because of the increased susceptibility of the mammary gland to infection during the time surrounding parturition in the cow, we investigated how milk and tissue content of AM and its binding protein (AM-BP) might be affected by the stage of lactation and the udder health status. Milk and mammary biopsy samples were obtained from Holstein cows 21 days prior to and at various times after calving to represent the dry period and early and midstages of lactation. Additional cows received an intramammary challenge …

Identification And Characterization Of Aquaporin-9 (Aqp9) In Porcine Hepatic Tissue And Hepatocytes In Monolayer Culture, Thomas J. Caperna, Amy E. Shannon, Mark P. Richards, Wesley M. Garrett, Neil C. Talbot

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Aquaporins (AQPs) are members of a large family of integral membrane proteins involved in the rapid movement of water and neutral solutes across cell membranes. In this study, we have prepared an affinity-purified porcine-specific polyclonal antiserum to AQP9 and have investigated the distribution and expression of AQP9 in pig liver tissue and in hepatocytes in primary culture. Immunocytochemical analysis showed that AQP9 was primarily localized in the membrane structures of hepatocytes and was not associated with intrahepatic bile ducts or blood vessels. Western blot analysis indicated that AQP9 ranged in apparent molecular mass between 27 and 38 kD in whole …

Isolation And Characterization Of Porcine Visceral Endoderm Cell Lines Derived From In Vivo 11-Day Blastocysts, Neil C. Talbot, Le Ann Blomberg, Ayesha Mahmood, Thomas J. Caperna, Wesley M. Garrett

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Two porcine cell lines of yolk-sac visceral endoderm, designated as PE-1 and PE-2, were derived from in vivo 11-d porcine blastocysts that were either ovoid (PE-1) or at the early tubular stage of elongation (PE-2). Primary and secondary culture of the cell lines was done on STO feeder cells. The PE-1 and PE-2 cells morphologically resembled visceral endoderm previously cultured from in vivo-derived ovine and equine blastocysts and from in vitro-derived bovine blastocysts. Analysis of the PE-1- and PE-2-conditioned medium by 2D-gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flightmass spectrometry demonstrated that they produced serum proteins. Reverse transcriptase polymerase chain …

Proteomic And Genetic Analysis Of Glycinin Subunits Of Sixteen Soybean Genotypes, Savithiry Natarajan, Chenping Xu, Hanhong Bae, Bryan A. Bailey, Perry Cregan, Thomas J. Caperna, Wesley M. Garrett, Devanand Luthria

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

We investigated proteomic and genomic profiles of glycinin, a family of major storage proteins in 16 different soybean genotypes consisting of four groups including wild soybean (Glycine soja), unimproved cultivated soybean landraces from Asia (G. max), ancestors of N. American soybean (G. max), and modern soybean (G. max) genotypes. We observed considerable variation in all five glycinin subunits, G1, G2 G3, G4 and G5 using proteomics and genetic analysis. Two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS) analysis showed that the wild genotypes had a range of 25-29 glycinin protein spots that included …

Characterization Of Biological Types Of Cattle (Cycle Vii): Influence Of Postpartum Interval And Estrous Cycle Length On Fertility, R. A. Cushman, M. F. Allan, R. M. Thallman, L. V. Cundiff

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Genetic improvement in reproductive efficiency through selection is difficult because many reproductive traits are binomial and have low heritabilities. Before genetic markers can be generated for fertility in cows, greater characterization of reproductive phenotypes is needed to understand the components of the trait. The current study tested the hypotheses that: 1) breeds vary in postpartum interval to estrus (PPIE) and estrous cycle length, 2) a longer estrous cycle immediately before breeding increased pregnancy rates, and 3) a greater number of cycles before breeding increased conception rates. The postpartum interval to estrus, estrous cycle length, and number of cycles before breeding …

Effects Of Graded Levels Of Sorghum Wet Distiller’S Grains And Degraded Intake Protein Supply On Performance And Carcass Characteristics Of Feedlot Cattle Fed Steam-Flaked Corn-Based Diets, J. T. Vasconcelos, L. M. Shaw, K. A. Lemon, N. A. Cole, M. L. Galyean

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Two experiments evaluated different levels of sorghum wet distiller’s grains plus solubles (SWDG) and effects of increasing the degraded intake protein (DIP) concentration in diets containing SWDG on performance and carcass characteristics of feedlot cattle. In Exp. 1, 200 beef steers (average BW = 404 kg) were fed increasing levels of SWDG (0, 5, 10, and 15% of DM) and one level of corn wet distiller’s grains plus solubles (10% of DM), which replaced steamflaked corn in a high-concentrate diet. Final BW (P = 0.04) and overall ADG (P = 0.01) decreased linearly with increasing levels of SWDG. Increasing SWDG …

Livestock Management During Drought In The Northern Great Plains. I. A Practical Predictor Of Annual Forage Production, R. E. Kruse, M. W. Tess, R. K. Heitschmidt

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This research addressed the hypothesis that spring precipitation data can be used to detect agricultural drought early in the growing season. The Rangetek range model was used to simulate yearly forage data based on historical precipitation and temperature records from the USDA-ARS Fort Keogh Livestock and Range Research Laboratory (Miles City, MT) and the Agriculture and Agri-Food Canada Manyberries Substation (Lethbridge, AB, Canada). Monthly total precipitation and monthly average maximum and minimum temperatures were used to develop regression equations predicting growing season forage production at the Fort Keogh Laboratory and Manyberries Substation. At Fort Keogh Laboratory, a combination of fall …

Identification Of Compounds From Etonia Rosemary (Conradina Etonia), Brian P. Quinn, Ulrich R. Bernier, Matthew M. Booth

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Mosquitoes transmit pathogens that result in diseases harmful to human, livestock, and wildlife hosts. Numerous measures can be used to reduce insect-borne disease risk to humans, and one approach is the use of topical repellents to prevent host-seeking arthropods from taking a blood meal. A current emphasis in the development of new repellents is that they be safe. Therefore, natural products sources are increasingly being explored. Compounds from plants of the mint family (Lamiaceae) have been demonstrated to be insect repellents. This study examines compounds from Etonia rosemary (Conradina etonia) to identify compounds for examination as insect repellents. …

Using Comparative Genomics To Reorder The Human Genome Sequence Into A Virtual Sheep Genome, Brian Dalrymple, Ewen Kirkness, Mikhail Nefedov, Sean Mcwilliam, Abhirami Ratnakumar, Wes Barris, Shaying Zhao, Jyoti Shetty, Jillian Maddox, Margaret O'Grady, Frank Nicholas, Allan Crawford, Tim Smith, Pieter De Jong, John Mcewan, V. Hutton Oddy, Noelle Cockett

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Background: Is it possible to construct an accurate and detailed subgene-level map of a genome using bacterial artificial chromosome (BAC) end sequences, a sparse marker map, and the sequences of other genomes?
Results: A sheep BAC library, CHORI-243, was constructed and the BAC end sequences were determined and mapped with high sensitivity and low specificity onto the frameworks of the human, dog, and cow genomes. To maximize genome coverage, the coordinates of all BAC end sequence hits to the cow and dog genomes were also converted to the equivalent human genome coordinates. The 84,624 sheep BACs (about 5.4-fold genome coverage) …

Construction And Characterization Of A Full-Length Cdna Library For The Wheat Stripe Rust Pathogen, Peng Ling, Meinan Wang, Xianming Chen, Kimberly A. Garland-Campbell

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Puccinia striiformis is a plant pathogenic fungus causing stripe rust, one of the most important diseases on cereal crops and grasses worldwide. However, little is know about its genome and genes involved in the biology and pathogenicity of the pathogen. We initiated the functional genomic research of the fungus by constructing a full-length cDNA and determined functions of the first group of genes by sequence comparison of cDNA clones to genes reported in other fungi.

Growth And Carcass Characteristics In Goat Kids Fed Grass- And Alfalfa-Hay-Based Diets With Limited Concentrate Supplementation, S. Wildeus, J.-M. Luginbuhl, K. E. Turner, Y. L. Nutall, J. R. Collins

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Two experiments were conducted to evaluate the effect of feeding legume hay (alfalfa; Medicago sativa L.) or mixed-grass hay on ADG and carcass characteristics of growing goats.

Dominant Species Constrain Effects Of Species Diversity On Temporal Variability In Biomass Production Of Tallgrass Prairie, H. Wayne Polley, Brian J. Wilsey, Justin D. Derner

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Species diversity is thought to stabilize functioning of plant communities. An alternative view is that stability depends more on dynamics of dominant species than on diversity. We compared inter-annual variability (inverse of stability) of aboveground biomass in paired restored and remnant tallgrass prairies at two locations in central Texas, USA. Data from these two locations were used to test the hypothesis that greater richness and evenness in remnant than restored prairies would reduce variability in aboveground biomass in response to natural variation in rainfall. Restored prairies were chosen to be similar to paired remnant prairies in characteristics other than species …

Storm Event And Continuous Hydrologic Modeling For Comprehensive And Efficient Watershed Simulations, Deva K. Borah, Jeffrey G. Arnold, Maitreyee Bara, Edward C. Krug, Xin-Zhong Liang

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Based on recent reviews of 11 physically based watershed models, the long-term continuous model soil and water assessment tool (SWAT) and the storm event dynamic watershed simulation model (DWSM) were selected to examine their hydrologic formulations, calibrate, and validate them on the 620 km² watershed of the upper Little Wabash River at Effingham, Ill., and examine their compatibility and benefits of combining them into a more comprehensive and efficient model. Calibration and validation of the SWAT by comparing monthly simulated and observed flows and adjusting the model-assigned resulted in coefficients of determination and Nash–Sutcliffe coefficients for individual years and …

High Water Regime Can Reduce Ammonia Volatilization From Soils Under Potato Production, Guodong Liu, Yuncong Li, A. K. Alva

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

This research was conducted with Biscayne marl soil and Krome gravelly loam from Florida and Quincy fine sand and Warden silt loam from Washington to determine ammonia (NH₃) volatilization at various temperature and soil water regimes. Potassium nitrate (KNO₃), ammonium nitrate (NH₄NO₃), ammonium sulfate [(NH₄)₂SO₄], or urea were applied to the soil at a rate of 75 kg N ha^-1. Soil water regime was maintained at either 20% or 80% of field capacity (FC) and incubated at 11, 20, or 29 °C, which represented …

Nitrogen Contribution Of Peanut Residue To Cotton In A Conservation Tillage System, B. Meso, K. S. Balkcom, C. W. Wood, J. F. Adams

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Leguminous crops, particularly winter annuals, have been utilized in conservation systems to partially meet nitrogen (N) requirements of succeeding summer cash crops. Previous research also highlights the benefits of utilizing summer annual legumes in rotation with non-leguminous crops. This study assessed the N contribution of peanut (Arachis hypogaea L.) residues to a subsequent cotton (Gossypium hirsitum L.) crop in a conservation system on a Dothan sandy loam (fine-loamy, kaolinitic, thermic Plinthic Kandiudults) at Headland, AL during the 2003–2005 growing seasons. Treatments were arranged in a split plot design, with main plots of peanut residue retained or removed from …

Influence Of Soil Moisture On Root Colonization Of Glyphosate-Treated Soybean By Fusarium Species, Nathan E. Means, Robert J. Kremer

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The widespread use of glyphosate-resistant (GR) cropping systems may impact rhizosphere microbial associations and crop productivity. It was previously reported that glyphosate accumulation in the rhizosphere may stimulate colonization of soybean [Glycine max (L.) Merr.] roots by soilborne Fusarium. Field studies often reveal inconsistent root colonization by Fusarium, especially during growing seasons characterized by contrasting rainfall patterns. Therefore, this study was conducted to determine the impact of different soil moisture contents on root colonization of glyphosate-treated soybean by Fusarium species. Glyphosate (0.84 kg ae ha^-1) was applied to greenhouse-grown glyphosate-resistant (GR) soybean at the two to …