Life Sciences Commons^™

Soil Quality Indices As Affected By Long-Term Burning, Irrigation, Tillage, And Fertility Management, Helen C.S. Amorim, Amanda J. Ashworth, Kristofor R. Brye, Brian J. Wienhold, Mary C. Savin, Phillip R. Owens, Sergio H.G. Silva

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

Understanding the impacts of long-term agricultural practices on soil quality (SQ) is key for sustaining agroecosystem productivity. This study investigated conventional and no-tillage (NT), residue burning and no burning, residue level (high and low), and irrigation (irrigated and dryland) effects on soil properties, SQ, and crop yields following 16 yr of a wheat (Triticum aestivum L.)–soybean [Glycine max (L.) Merr.] double-crop system via the Soil Management Assessment Framework (SMAF). A field experiment was conducted in the Lower Mississippi River Delta region on a silt-loam soil. Bulk density, soil organic C (SOC), total N (TN), pH, electrical conductivity (EC), and soil …

Evaluation Of Lotions Of Botanical-Based Repellents Against Aedes Aegypti (Diptera: Culicidae), Whitney A. Qualls, Rui De Xue, Muhammad Farooq, Steven T. Peper, Vindhya Aryaprema, Kai Blore, Richard Weaver, Dena Autry, Asghar Talbalaghi, James Kenar, Steven C. Cermak, Junwei J. Zhu

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

Thirteen botanical product repellent compounds such as 2-undecanone, capric, lauric, coconut fatty acids (and their methyl ester derivatives), and catnip oil were formulated in either Coppertone or Aroma Land lotions and evaluated against laboratory-reared Aedes aegypti L. (Diptera: Culicidae) mosquitoes. These formulations contained 7-15 wt/wt of the botanical repellent as the major active ingredient either pure or as mixtures. USDA standard repellent test cages were used to determine the complete protection time (CPT) of the different formulated repellents. Two of the evaluated formulations, a 7% capric acid in Coppertone (CPT 2.7 ± 0.6 h) and 7% coconut fatty acids containing …

Ecosystem-Scale Biogeochemical Fluxes From Three Bioenergy Crop Candidates: How Energy Sorghum Compares To Maize And Miscanthus, Caitlin E. Moore, Adam C. Von Haden, Mark B. Burnham, Ilsa B. Kantola, Christy D. Gibson, Bethany J. Blakely, Evan C. Dracup, Michael D. Masters, Wendy H. Yang, Evan H. Delucia, Carl J. Bernacchi

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

Perennial crops have been the focus of bioenergy research and development for their sustainability benefits associated with high soil carbon (C) and reduced nitrogen (N) requirements. However, perennial crops mature over several years and their sustainability benefits can be negated through land reversion. A photoperiod-sensitive energy sorghum (Sorghum bicolor) may provide an annual crop alternative more ecologically sustainable than maize (Zea mays) that can more easily integrate into crop rotations than perennials, such as miscanthus (Miscanthus × giganteus). This study presents an ecosystem-scale comparison of C, N, water and energy fluxes from energy sorghum, maize and miscanthus during a typical …

A Reporting Format For Leaf-Level Gas Exchange Data And Metadata, Kim S. Ely, Alistair Rogers, Deborah A. Agarwal, Elizabeth A. Ainsworth, Loren P. Albert, Ashehad Ali, Jeremiah Anderson, Michael J. Aspinwall, Chandra Bellasio, Carl Bernacchi, Steve Bonnage, Thomas N. Buckley, James Bunce, Angela C. Burnett, Florian A. Busch, Amanda Cavanagh, Lucas A. Cernusak, Robert Crystal-Ornelas, Joan Damerow, Kenneth J. Davidson, Martin G. De Kauwe, Michael C. Dietze, Tomas F. Domingues, Mirindi Eric Dusenge, David S. Ellsworth, John R. Evans, Paul P.G. Gauthier, Bruno O. Gimenez, Elizabeth P. Gordon, Christopher M. Gough, Aud H. Halbritter, David T. Hanson, Mary Heskel, J. Aaron Hogan, Jason R. Hupp, Kolby Jardine, Jens Kattge, Trevor Keenan, Johannes Kromdijk, Dushan P. Kumarathunge

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

Leaf-level gas exchange data support the mechanistic understanding of plant fluxes of carbon and water. These fluxes inform our understanding of ecosystem function, are an important constraint on parameterization of terrestrial biosphere models, are necessary to understand the response of plants to global environmental change, and are integral to efforts to improve crop production. Collection of these data using gas analyzers can be both technically challenging and time consuming, and individual studies generally focus on a small range of species, restricted time periods, or limited geographic regions. The high value of these data is exemplified by the many publications that …

The Inverse Relationship Between Solar-Induced Fluorescence Yield And Photosynthetic Capacity: Benefits For Field Phenotyping, Peng Fu, Katherine Meacham-Hensold, Matthew H. Siebers, Carl J. Bernacchi

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

Improving photosynthesis is considered a promising way to increase crop yield to feed a growing population. Realizing this goal requires non-destructive techniques to quantify photosynthetic variation among crop cultivars. Despite existing remote sensing-based approaches, it remains a question whether solar-induced fluorescence (SIF) can facilitate screening crop cultivars of improved photosynthetic capacity in plant breeding trials. Here we tested a hypothesis that SIF yield rather than SIF had a better relationship with the maximum electron transport rate (Jmax). Time-synchronized hyperspectral images and irradiance spectra of sunlight under clear-sky conditions were combined to estimate SIF and SIF yield, which were then correlated …

Cropping System Partially Offsets Tillage-Related Degradation Of Soil Organic Carbon And Aggregate Properties In A 30-Yr Rainfed Agroecosystem, Virginia L. Jin, Brian J. Wienhold, Maysoon M. Mikha, Marty Schmer

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

Soil tillage increases the susceptibility of agricultural soils to erosion and organic carbon losses, but tillage effects could be mitigated through other management practices such as crop rotation. Here, we evaluated the 30-year impacts of tillage intensity and cropping system on surface soil bulk density, nutrient availability, dry aggregate size distribution, and water-stable aggregation. This study was established in 1980 in eastern Nebraska USA, and included six tillage treatments of varying intensity (no-till, ridge till, disk till, subsoil rip, chisel plow, moldboard plow) and four crop rotation treatments (continuous soybean [Glycine max (L.) Merr.]; soybean-corn [Zea mays L.]; corn-soybean, continuous …

Report From The Conference, ‘Identifying Obstacles To Applying Big Data In Agriculture’, Emma L. White, J. Alex Thomasson, Brent Auvermann, Newell R. Kitchen, Leland Sandy Pierson, Dana Porter, Craig Baillie, Hendrik Hamann, Gerrit Hoogenboom, Todd Janzen, Rajiv Khosla, James Lowenberg-Deboer, Matt Mcintosh, Seth Murray, Dave Osborn, Ashoo Shetty, Craig Stevenson, Joe Tevis, Fletcher Werner

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

Data-centric technology has not undergone widespread adoption in production agriculture but could address global needs for food security and farm profitability. Participants in the U.S. Department of Agriculture (USDA) National Institute for Food and Agriculture (NIFA) funded conference, “Identifying Obstacles to Applying Big Data in Agriculture,” held in Houston, TX, in August 2018, defined detailed scenarios in which on-farm decisions could benefit from the application of Big Data. The participants came from multiple academic fields, agricultural industries and government organizations and, in addition to defining the scenarios, they identified obstacles to implementing Big Data in these scenarios as well as …

Soil Health Management Enhances Microbial Nitrogen Cycling Capacity And Activity, Jianlin Hu, Virginia L. Jin, Julie Y.M. Konkel, Sean M. Schaeffer, Liesel G. Schneider, Jennifer M. Debruyn

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

Soil microbial transformations of nitrogen (N) can be affected by soil health management practices. Here, we report in situ seasonal dynamics of the population size (gene copy abundances) and functional activity (transcript copy abundances) of five bacterial genes involved in soil N cycling (ammonia-oxidizing bacteria [AOB] amoA, nifH, nirK, nirS, and nosZ) in a long-term continuous cotton production system under different management practices (cover crops, tillage, and inorganic N fertilization). Hairy vetch (Vicia villosa Roth), a leguminous cover crop, most effectively promoted the expression of N cycle genes, which persisted after cover crop termination throughout the growing season. Moreover, we …

Multiple Constraints Cause Positive And Negative Feedbacks Limiting Grassland Soil Co2efflux Under Co2enrichment, Philip A. Fay, Dafeng Hui, Robert B. Jackson, Harold P. Collins, Lara G. Reichmann, Michael J. Aspinwall, Virginia L. Jin, Albina R. Khasanova, Robert W. Heckman, H. Wayne Polley

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

Terrestrial ecosystems are increasingly enriched with resources such as atmospheric CO2that limit ecosystem processes. The consequences for ecosystem carbon cycling depend on the feedbacks from other limiting resources and plant community change, which remain poorly understood for soil CO2efflux, JCO2, a primary carbon flux from the biosphere to the atmosphere. We applied a unique CO2enrichment gradient (250 to 500 μL L-1) for eight years to grassland plant communities on soils from different landscape positions. We identified the trajectory of JCO2responses and feedbacks from other resources, plant diversity [effective species richness, exp(H)], and community change (plant species turnover). We found linear …

Hermetic Storage Of Shelled Peanut Using The Purdue Improved Crop Storage Bags, Chris Butts, L. L. Dean, K. W. Hendrix, Renee Arias, Ronald B. Sorensen, Marshall Lamb

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

Low oxygen or hermetic storage has been successfully used to store several commodities such as corn (Zea mays L.), cowpea (Vigna Savi), cocoa (Theobroma cocao), coffee (Coffea L.), and rice (Oryza sativa L.). However, previous research using hermetic storage for peanut or groundnut (Arachis hypogaea L.) had mixed results. Research was conducted to determine the effect on aflatoxin contamination, seed germination, and oil chemistry of shelled peanut hermetically stored in the Purdue Improved Crop Storage (PICS) bags for up to 12 months. A 234 factorial study included 1) normal and high oleic peanut, 2) two initial moisture contents by four …

Planting Depth And Within-Field Soil Variability Impacts On Corn Stand Establishment And Yield, Stirling Stewart, Newell Kitchen, Matt Yost, Lance Stephen Conway, Paul Carter

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

Seedbed conditions during corn (Zea mays L.) planting can have substantial impact on corn stand establishment and final yield. Planting management decisions are complex due to spatial variability caused by changing soil characteristics such as soil texture or landscape position. Field experiments conducted in central Missouri from 2017 to 2019 assessed the effects of varying corn planting depths on stand establishment and yield. Sites included fine- and coarse-textured alluvial soils, and summit, back, and foot slope positions of Alfisol claypan soil landscapes. On alluvial soil, deep planting (7.6 cm) often had the most uniform and timely emergence. Shallow planting (3.8 …

Genotyping Tools And Resources To Assess Peanut Germplasm: Smut-Resistant Landraces As A Case Study, Alicia N. Massa, Marina Bressano, Juan A. Soave, Mario I. Buteler, Guillermo J. Seijo, Victor S. Sobolev, Valerie Orner, Claudio Oddino, Sara Soave, Paola C. Faustinelli, Francisco J. De Blas, M. C. Lamb, Renee Arias

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

Peanut smut caused by Thecaphora frezii is a severe fungal disease currently endemic to Argentina and Brazil. The identification of smut resistant germplasm is crucial in view of the potential risk of a global spread. In a recent study, we reported new sources of smut resistance and demonstrated its introgression into elite peanut cultivars. Here, we revisited one of these sources (line I0322) to verify its presence in the U.S. peanut germplasm collection and to identify single nucleotide polymorphisms (SNPs) potentially associated with resistance. Five accessions of Arachis hypogaea subsp. fastigiata from the U.S. peanut collection, along with the resistant …

Pheromone Antagonism In Plutella Xylostella (Linnaeus) By Sex Pheromones Of Two Sympatric Noctuid Moths, Fu Min Wang, Zhi Jie Shen, Coby Schal, Junwei J. Zhu, Guo Xin Zhou, Yu Lei Wang, Ji Rui Wang, Jian Yu Deng, Nian Feng Wan

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

BACKGROUND: Responses to sex pheromones are commonly antagonized by pheromone components of closely related species. Pheromone antagonism has not been widely explored for phylogenetically distant species that have completely different pheromone components. Yet, pheromone components of sympatrically occurring species may also interfere with each other even if these species are distantly related. Here, the effects of heterospecific pheromones on electrophysiology (electroantennogram, EAG) and behavioral responses were tested on the diamondback moth Plutella xyloslella (Plutellidae) and two sympatric noctuid moth species, Spodoptera litura and Spodoptera exigua, whose larvae also feed on Brassica crops.

RESULTS: The sex pheromone blend of P. xyloslella, …

Patterns Of Genetic Variation In A Prairie Wildflower, Silphium Integrifolium, Suggest A Non-Prairie Origin And Locally Adaptive Variation, Andrew R. Raduski, Adam Herman, Cloe Pogoda, Kevin M. Dorn, David L. Van Tassel, Nolan Kane, Yaniv Brandvain

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

PREMISE: Understanding the relationship between genetic structure and geography provides information about a species’ history and can be used for breeding and conservation goals. The North American prairie is interesting because of its recent origin and subsequent fragmentation. Silphium integrifolium, an iconic perennial American prairie wildflower, is targeted for domestication, having undergone a few generations of improvement. We present the first application of population genetic data in this species to address the following goals: (1) improve breeding by characterizing genetic structure and (2) identify the species geographic origin and potential targets and drivers of selection during range expansion. METHODS: We …

Antibacterial Activities Of Nepetalactones Against Public Health-Related Pathogens, Anuradha Ghosh, Enya V. Zhu, Haichuan Wang, Ludek Zurek, Junwei J. Zhu

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

The antimicrobial activities of (Z,E)- and (E,Z)-nepetalactones, 2 major compositional compounds from the essential oil of catnip (Nepeta cataria), were first discovered from fly larval development media studies with over 98% inhibition of bacterial growth. Further investigation demonstrated inhibition of the growth of various bacterial species of public health significance. Catnip oil showed antibacterial activity against 5 Gram-positive and 9 Gram-negative bacteria. The antimicrobial activity varied among the original essential oil from the plant and its major compositional compounds as a blended mixture or an individual compound. Growth inhibition was observed against 5 Neisseria species, with particularly strong inhibition against …

Forages For Conservation And Improved Soil Quality, John F. Obrycki, Douglas L. Karlen

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

Forages provide several soil benefits, including reduced soil erosion, reduced water runoff, improved soil physical properties, increased soil carbon, increased soil biologic activity, reduced soil salinity, and improved land stabilization and restoration when grown continuously or as part of a crop rotation. Ongoing research and synthesis of knowledge have improved our understanding of how forages alter and protect soil resources, thus providing producers, policymakers, and the general public information regarding which forage crops are best suited for a specific area or use (e.g. hay, grazing or bioenergy feedstock). Forages can be produced in forestland, range, pasture, and cropland settings. These …

Evaluation Of Leaf Spot Resistance In Wild Arachis Species Of Section Arachis, Alicia Massa, Renee Arias, Ronald B. Sorensen, Victor S. Sobolev, S. P. Tallury, H. T. Stalker, Marshall Lamb

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

Wild diploid Arachis species are potential sources of resistance to early (ELS) and late (LLS) leaf spot diseases caused by Passalora arachidicola (syn. Cercospora arachidicola Hori), and Nothopassalora personata (syn. Cercosporidium personatum (Berk. & Curt.) Deighton), respectively. Within section Arachis, limited information is available on the extent of genetic variation for resistance to these fungal pathogens. A collection of 78 accessions representing 15 wild species of Arachis section Arachis from the U.S peanut germplasm collection was evaluated for resistance to leaf spots. Screening was conducted under field (natural inoculum) conditions in Dawson, Georgia, during 2017 and 2018. Accessions differed …

Understanding Growth Dynamics And Yield Prediction Of Sorghum Using High Temporal Resolution Uav Imagery Time Series And Machine Learning, Sebastian Varela, Taylor Pederson, Carl J. Bernacchi, Andrew D.B. Leakey

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

Unmanned aerial vehicles (UAV) carrying multispectral cameras are increasingly being used for high-throughput phenotyping (HTP) of above-ground traits of crops to study genetic diversity, resource use efficiency and responses to abiotic or biotic stresses. There is significant unexplored potential for repeated data collection through a field season to reveal information on the rates of growth and provide predictions of the final yield. Generating such information early in the season would create opportunities for more efficient in-depth phenotyping and germplasm selection. This study tested the use of high-resolution time-series imagery (5 or 10 sampling dates) to understand the relationships between growth …