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Full-Text Articles in Agriculture

Substantial Contribution Of Genetic Variation In The Expression Of Transcription Factors To Phenotypic Variation Revealed By Erd-Gwas, Hung-Ying Lin, Qiang Liu, Xiao Li, Jinliang Yang, Sanzhen Liu, Yinlian Huang, Michael J. Scanlon, Dan Nettleton, Patrick S. Schnable Oct 2017

Substantial Contribution Of Genetic Variation In The Expression Of Transcription Factors To Phenotypic Variation Revealed By Erd-Gwas, Hung-Ying Lin, Qiang Liu, Xiao Li, Jinliang Yang, Sanzhen Liu, Yinlian Huang, Michael J. Scanlon, Dan Nettleton, Patrick S. Schnable

Department of Agronomy and Horticulture: Faculty Publications

Background: There are significant limitations in existing methods for the genome-wide identification of genes whose expression patterns affect traits.

Results: The transcriptomes of five tissues from 27 genetically diverse maize inbred lines were deeply sequenced to identify genes exhibiting high and low levels of expression variation across tissues or genotypes. Transcription factors are enriched among genes with the most variation in expression across tissues, as well as among genes with higher-than-median levels of variation in expression across genotypes. In contrast, transcription factors are depleted among genes whose expression is either highly stable or highly variable across genotypes. We developed a …


Estimation Of Irrigation Requirements For Drip-Irrigated Maize In A Sub-Humid Climate, Liu Yang, Hai-Shun Yang, Jiu-Sheng Li, Yan-Feng Li, Hai-Jun Yan Oct 2017

Estimation Of Irrigation Requirements For Drip-Irrigated Maize In A Sub-Humid Climate, Liu Yang, Hai-Shun Yang, Jiu-Sheng Li, Yan-Feng Li, Hai-Jun Yan

Department of Agronomy and Horticulture: Faculty Publications

Drip-irrigation is increasingly applied in maize (Zea mays L.) production in sub-humid region. It is critical to quantify irrigation requirements during different growth stages under diverse climatic conditions. In this study, the Hybrid-Maize model was calibrated and applied in a sub-humid Heilongjiang Province in Northeast China to estimate irrigation requirements for drip irrigated maize during different crop physiological development stages and under diverse agro-climatic conditions. Using dimensionless scales, the whole growing season of maize was divided into diverse development stages from planting to maturity. Drip-irrigation dates and irrigation amounts in each irrigation event were simulated and summarized in 30-year simulation …


Identifying Ecologically Relevant Scales Of Habitat Selection: Diel Habitat Selection In Elk, Caleb P. Roberts, James W. Cain Iii, Robert D. Cox Oct 2017

Identifying Ecologically Relevant Scales Of Habitat Selection: Diel Habitat Selection In Elk, Caleb P. Roberts, James W. Cain Iii, Robert D. Cox

Department of Agronomy and Horticulture: Faculty Publications

Although organisms make resource selection decisions at multiple spatiotemporal scales, not all scales are ecologically relevant to any given organism. Ecological patterns and rhythms such as behavioral and climatic patterns may provide a consistent method for identifying ecologically relevant scales of habitat selection. Using elk (Cervus canadensis) as an example species, we sought to test the ability of behavioral patterns to empirically partition diel scales for modeling habitat selection. We used model selection to partition diel scales by shifts in dominant behavior and then used resource selection probability functions to model elk habitat selection hierarchically at diel scales within seasons. …


Effects Of Nitrogen And Phosphorus Fertilizer And Topsoil Amendment On Native Plant Cover In Roadside Revegetation Projects, Heidi L. Hillhouse, Walter H. Schacht, Jonathan M. Soper, Carol E. Wienhold Oct 2017

Effects Of Nitrogen And Phosphorus Fertilizer And Topsoil Amendment On Native Plant Cover In Roadside Revegetation Projects, Heidi L. Hillhouse, Walter H. Schacht, Jonathan M. Soper, Carol E. Wienhold

Department of Agronomy and Horticulture: Faculty Publications

Establishing vegetation on roadsides following construction can be challenging, especially for relatively slow growing native species. Topsoil is generally removed during construction, and the surface soil following construction (“cut-slope soils”) is often compacted and low in nutrients, providing poor growing conditions for vegetation. Nebraska Department of Transportation (NDOT) protocols have historically called for nitrogen (N) and phosphorus (P) fertilization when planting roadside vegetation following construction, but these recommendations were developed for cool-season grass plantings and most current plantings use slower-establishing, native warmseason grasses that may benefit less than expected from current planting protocols. We evaluated the effects of nitrogen and …


Control Of Glyphosate-Resistant Common Ragweed (Ambrosia Artemisiifolia L.) In Glufosinate-Resistant Soybean [Glycine Max (L.) Merr], Ethann R. Barnes, Stevan Z. Knezevic, Peter H. Sikkema, John L. Lindquist, Amit J. Jhala Aug 2017

Control Of Glyphosate-Resistant Common Ragweed (Ambrosia Artemisiifolia L.) In Glufosinate-Resistant Soybean [Glycine Max (L.) Merr], Ethann R. Barnes, Stevan Z. Knezevic, Peter H. Sikkema, John L. Lindquist, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Common ragweed emerges early in the season in Nebraska, USA and is competitive with soybean; therefore, preplant herbicides are important for effective control. Glyphosate has been used as a preplant control option; however, confirmation of glyphosate-resistant (GR) common ragweed in Nebraska necessitates evaluating other herbicide options. The objectives of this study were to (1) evaluate the efficacy of preplant (PP) herbicides followed by (fb) glufosinate alone or in tank-mixture with imazethapyr, acetochlor, or S-metolachlor applied post-emergence (POST) for control of GR common ragweed in glufosinate-resistant soybean; (2) their effect on common ragweed density, biomass, and soybean yield; and (3) the …


Impact Of Seed Protein Alleles From Three Soybean Sources On Seed Composition And Agronomic Traits, Lillian F. Brzostowski, Timothy I. Pruski, James Specht, Brian W. Diers Aug 2017

Impact Of Seed Protein Alleles From Three Soybean Sources On Seed Composition And Agronomic Traits, Lillian F. Brzostowski, Timothy I. Pruski, James Specht, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Evaluation of seed protein alleles in soybean populations showed that an increase in protein concentration is generally associated with a decrease in oil concentration and yield.

Soybean [Glycine max (L.) Merrill] meal is one of the most important plant-based protein sources in the world. Developing cultivars high in seed protein concentration and seed yield is a difficult task because the traits have an inverse relationship. Over two decades ago, a protein quantitative trait loci (QTL) was mapped on chromosome (chr) 20, and this QTL has been mapped to the same position in several studies and given the confirmed QTL …


Protocol For Enrichment Of The Membrane Proteome Of Mature Tomato Pollen, Puneet Paul, Palak Chaturvedi, Anida Mesihovic, Arindam Ghatak, Wolfram Weckwerth, Enrico Schleiff Jun 2017

Protocol For Enrichment Of The Membrane Proteome Of Mature Tomato Pollen, Puneet Paul, Palak Chaturvedi, Anida Mesihovic, Arindam Ghatak, Wolfram Weckwerth, Enrico Schleiff

Department of Agronomy and Horticulture: Faculty Publications

We established and elaborated on a method to enrich the membrane proteome of mature pollen from economically relevant crop using the example of Solanum lycopersicum (tomato). To isolate the pollen protein fraction enriched in membrane proteins, a high salt concentration (750 mM of sodium chloride) was used. The membrane protein-enriched fraction was then subjected to shotgun proteomics for identification of proteins, followed by in silico analysis to annotate and classify the detected proteins.


Transcriptomic Resources For The Medicinal Legume Mucuna Pruriens: De Novo Transcriptome Assembly, Annotation, Identification And Validation Of Est-Ssr Markers, N. Sathyanarayana, Ranjith Kumar Pittala, Pankaj Kumar Tripathi, Ratan Chopra, Heikham Russiachand Singh, Vikas Belamkar, Pardeep Kumar Bhardwaj, Jeff J. Doyle, Ashley N. Egan May 2017

Transcriptomic Resources For The Medicinal Legume Mucuna Pruriens: De Novo Transcriptome Assembly, Annotation, Identification And Validation Of Est-Ssr Markers, N. Sathyanarayana, Ranjith Kumar Pittala, Pankaj Kumar Tripathi, Ratan Chopra, Heikham Russiachand Singh, Vikas Belamkar, Pardeep Kumar Bhardwaj, Jeff J. Doyle, Ashley N. Egan

Department of Agronomy and Horticulture: Faculty Publications

Background:

The medicinal legume Mucuna pruriens (L.) DC. has attracted attention worldwide as a source of the anti-Parkinson’s drug L-Dopa. It is also a popular green manure cover crop that offers many agronomic benefits including high protein content, nitrogen fixation and soil nutrients. The plant currently lacks genomic resources and there is limited knowledge on gene expression, metabolic pathways, and genetics of secondary metabolite production. Here, we present transcriptomic resources for M. pruriens, including a de novo transcriptome assembly and annotation, as well as differential transcript expression analyses between root, leaf, and pod tissues. We also develop microsatellite markers …


A Comprehensive Analysis Of Alternative Splicing In Paleopolyploid Maize, Wenbin Mei, Sanzhen Liu, James C. Schnable, Cheng-Ting Yeh, Nathan M. Springer, Patrick S. Schnable, William Brad Barbazuk May 2017

A Comprehensive Analysis Of Alternative Splicing In Paleopolyploid Maize, Wenbin Mei, Sanzhen Liu, James C. Schnable, Cheng-Ting Yeh, Nathan M. Springer, Patrick S. Schnable, William Brad Barbazuk

Department of Agronomy and Horticulture: Faculty Publications

Identifying and characterizing alternative splicing (AS) enables our understanding of the biological role of transcript isoform diversity. This study describes the use of publicly available RNA-Seq data to identify and characterize the global diversity of AS isoforms in maize using the inbred lines B73 and Mo17, and a related species, sorghum. Identification and characterization of AS within maize tissues revealed that genes expressed in seed exhibit the largest differential AS relative to other tissues examined. Additionally, differences in AS between the two genotypes B73 and Mo17 are greatest within genes expressed in seed. We demonstrate that changes in the level …


Corn Residue Use By Livestock In The United States, Marty R. Schmer, Rachael M. Brown, Virginia L. Jin, Robert B. Mitchell, Daren D. Redfearn Jan 2017

Corn Residue Use By Livestock In The United States, Marty R. Schmer, Rachael M. Brown, Virginia L. Jin, Robert B. Mitchell, Daren D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Corn (Zea mays L.) residue grazing or harvest provides a simple and economical practice to integrate crops and livestock, but limited information is available on how widespread corn residue utilization is practiced by US producers. In 2010, the USDA Economic Research Service surveyed producers from 19 states on corn grain and residue management practices. Total corn residue grazed or harvested was 4.87 million ha. Approximately 4.06 million ha was grazed by 11.7 million livestock (primarily cattle) in 2010. The majority of grazed corn residue occurred in Nebraska (1.91 million ha), Iowa (385,000 ha), South Dakota (361,000 ha), and Kansas …


Influence Of Olfactory And Visual Cover On Nest Site Selection And Nest Success For Grassland-Nesting Birds, Dillon T. Fogarty, Dwayne Elmore, Samuel D. Fuhlendorf, Scott R. Loss Jan 2017

Influence Of Olfactory And Visual Cover On Nest Site Selection And Nest Success For Grassland-Nesting Birds, Dillon T. Fogarty, Dwayne Elmore, Samuel D. Fuhlendorf, Scott R. Loss

Department of Agronomy and Horticulture: Faculty Publications

Habitat selection by animals is influenced by and mitigates the effects of predation and environmental extremes. For birds, nest site selection is crucial to offspring production because nests are exposed to extreme weather and predation pressure. Predators that forage using olfaction often dominate nest predator communities; therefore, factors that influence olfactory detection (e.g., airflow and weather variables, including turbulence and moisture) should influence nest site selection and survival. However, few studies have assessed the importance of olfactory cover for habitat selection and survival. We assessed whether ground-nesting birds select nest sites based on visual and/or olfactory cover. Additionally, we assessed …


Long-Term Tillage Impact On Soil Hydraulic Properties, Humberto Blanco-Canqui, Brian J. Weinhold, Virginia L. Jin, Marty R. Schmer, Leonard C. Kibet Jan 2017

Long-Term Tillage Impact On Soil Hydraulic Properties, Humberto Blanco-Canqui, Brian J. Weinhold, Virginia L. Jin, Marty R. Schmer, Leonard C. Kibet

Department of Agronomy and Horticulture: Faculty Publications

An improved understanding of the impact of tillage systems on soil hydraulic properties is necessary to conserve and manage soil water under a changing climate. The objective of this study was to specifically measure soil hydraulic properties (total porosity, water infiltration, saturated hydraulic conductivity, and water retention characteristics) in no-till, chisel plow, disk, and moldboard plow systems under rainfed continuous corn (Zea mays L.) after 35 yr on silty clay loam soils in eastern Nebraska. We measured ponded water infiltration (positive soil water pressure) and tension (-1 kPa matric potential) infiltration to exclude macropore (>125 mm diameter) flow. …


The Impact Of Continuous Living Cover On Soil Hydrologic Properties: A Meta-Analysis, Andrea D. Basche, Marcia Delonge Jan 2017

The Impact Of Continuous Living Cover On Soil Hydrologic Properties: A Meta-Analysis, Andrea D. Basche, Marcia Delonge

Department of Agronomy and Horticulture: Faculty Publications

Increased rainfall variability due to climate change threatens the efficacy of critical soil ecosystem services. One strategy to negate effects of too much or not enough rainfall is to improve soil water properties. Practices that offer “continuous living cover” can enhance soil water storage and other soil hydrologic properties relative to annual crop systems, but to what extent such benefits can accrue, under different conditions, remains under-quantified. To address these uncertainties, we conducted a meta-analysis that included 27 studies representing 93 paired observations measuring two soil hydrologic properties: porosity and the water retained at field capacity. All experiments compared the …


Mapping And Characterization Of The Fefe Gene That Controls Iron Uptake In Melon (Cucumis Melo L.), Raghuprakash Kastoori Ramamurthy, Brian M. Waters Jan 2017

Mapping And Characterization Of The Fefe Gene That Controls Iron Uptake In Melon (Cucumis Melo L.), Raghuprakash Kastoori Ramamurthy, Brian M. Waters

Department of Agronomy and Horticulture: Faculty Publications

Iron (Fe) deficiency in plants limits crop growth and productivity. Molecular mechanisms that plants use to sense and respond to Fe deficiency by coordinated expression of Feuptake genes are not fully understood. The C940-fe chlorotic melon (Cucumis melo) mutant known as fefe is unable to upregulate Fe-uptake genes, however, the FeFe gene had not been identified. In this study, we used two F2 mapping populations to map and identify the FeFe gene as bHLH38, a homolog of subgroup Ib bHLH genes from Arabidopsis thaliana that are involved in transcriptional regulation of Feuptake genes in partnership with the …


Patterns Of Gene Expression In Western Corn Rootworm (Diabrotica Virgifera Virgifera) Neonates, Challenged With Cry34ab1, Cry35ab1 And Cry34/35ab1, Based On Next-Generation Sequencing, Haichuan Wang, Seong-Il Eyun, Kanika Arora, Sek Yee Tan, Premchand Gandra, Etsuko N. Moriyama, Chitvan Khajuria, Jessica D. Jurzenski, Huarong Li, Maia Donahue, Kenneth E. Narva, Blair Siegfried Jan 2017

Patterns Of Gene Expression In Western Corn Rootworm (Diabrotica Virgifera Virgifera) Neonates, Challenged With Cry34ab1, Cry35ab1 And Cry34/35ab1, Based On Next-Generation Sequencing, Haichuan Wang, Seong-Il Eyun, Kanika Arora, Sek Yee Tan, Premchand Gandra, Etsuko N. Moriyama, Chitvan Khajuria, Jessica D. Jurzenski, Huarong Li, Maia Donahue, Kenneth E. Narva, Blair Siegfried

Department of Agronomy and Horticulture: Faculty Publications

With Next Generation Sequencing technologies, high-throughput RNA sequencing (RNAseq) was conducted to examine gene expression in neonates of Diabrotica virgifera virgifera (LeConte) (Western Corn Rootworm, WCR) challenged with individual proteins of the binary Bacillus thuringiensis insecticidal proteins, Cry34Ab1 and Cry35Ab1, and the combination of Cry34/Cry35Ab1, which together are active against rootworm larvae. Integrated results of three different statistical comparisons identified 114 and 1300 differentially expressed transcripts (DETs) in the Cry34Ab1 and Cry34/35Ab1 treatment, respectively, as compared to the control. No DETs were identified in the Cry35Ab1 treatment. Putative Bt binding receptors previously identified in other insect species were not identified …


Jasmonoyl-L-Tryptophan Disrupts Iaa Activity Through The Aux1 Auxin Permease, Paul E. Staswick, Martha Rowe, Edgar P. Spalding, Bessie L. Splitt Jan 2017

Jasmonoyl-L-Tryptophan Disrupts Iaa Activity Through The Aux1 Auxin Permease, Paul E. Staswick, Martha Rowe, Edgar P. Spalding, Bessie L. Splitt

Department of Agronomy and Horticulture: Faculty Publications

Amide-linked conjugates between tryptophan (Trp) and jasmonic (JA) or indole-3- acetic (IAA) acids interfered with gravitropism and other auxin-dependent activities in Arabidopsis, but the mechanism was unclear. To identify structural features necessary for activity several additional Trp conjugates were synthesized. The phenylacetic acid (PAA) conjugate was active, while several others were not. Common features of active conjugates is that they have ring structures that are linked to Trp through an acetic acid side chain, while longer or shorter linkages are inactive or less active. A dominant mutant, called tryptophan conjugate response1-D that is insensitive to JA-Trp, but still sensitive …


Interaction Of 2,4-D Or Dicamba With Glufosinate For Control Of Glyphosate-Resistant Giant Ragweed (Ambrosia Trifida L.) In Glufosinate-Resistant Maize (Zea Mays L.), Zahoor A. Ganie, Amit J. Jhala Jan 2017

Interaction Of 2,4-D Or Dicamba With Glufosinate For Control Of Glyphosate-Resistant Giant Ragweed (Ambrosia Trifida L.) In Glufosinate-Resistant Maize (Zea Mays L.), Zahoor A. Ganie, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Glyphosate-resistant (GR) giant ragweed is a problematic broadleaf weed in crops including maize and soybean in the Midwestern United States. Commercialization of crops with 2,4-D or dicamba and glufosinate resistance will allow post-emergence (POST) applications of these herbicides. Therefore, information is needed on how 2,4-D/dicamba will interact with glufosinate in various rate combinations. The objectives of this study were to evaluate the interaction of glufosinate plus 2,4-D and/or dicamba for control of GR giant ragweed, and to determine their effect on GR giant ragweed density, biomass, maize injury, and yield. Field experiments were conducted in 2013 and 2014 in a …


Estimating Yield Gaps At The Cropping System Level, Nicolas Guilpart, Patricio Grassini, Victor O. Sadras, Jagadish Timsina, Kenneth Cassman Jan 2017

Estimating Yield Gaps At The Cropping System Level, Nicolas Guilpart, Patricio Grassini, Victor O. Sadras, Jagadish Timsina, Kenneth Cassman

Department of Agronomy and Horticulture: Faculty Publications

Yield gap analyses of individual crops have been used to estimate opportunities for increasing crop production at local to global scales, thus providing information crucial to food security. However, increases in crop production can also be achieved by improving cropping system yield through modification of spatial and temporal arrangement of individual crops. In this paper we define the cropping system yield potential as the output from the combination of crops that gives the highest energy yield per unit of land and time, and the cropping system yield gap as the difference between actual energy yield of an existing cropping system …


Molecular And Phenotypic Characterization Of Transgenic Wheat And Sorghum Events Expressing The Barley Alanine Aminotransferase, Pamela A. Peña, Truyen Quach, Shirley Sato, Zhengxiang Ge, Natalya Nersesian, Ismail M. Dweikat, Madhavan Soundararajan, Tom Clemente Jan 2017

Molecular And Phenotypic Characterization Of Transgenic Wheat And Sorghum Events Expressing The Barley Alanine Aminotransferase, Pamela A. Peña, Truyen Quach, Shirley Sato, Zhengxiang Ge, Natalya Nersesian, Ismail M. Dweikat, Madhavan Soundararajan, Tom Clemente

Department of Agronomy and Horticulture: Faculty Publications

Main conclusion — The expression of a barley alanine aminotransferase gene impacts agronomic outcomes in a C3 crop, wheat.

The use of nitrogen-based fertilizers has become one of the major agronomic inputs in crop production systems. Strategies to enhance nitrogen assimilation and flux in planta are being pursued through the introduction of novel genetic alleles. Here an Agrobacterium-mediated approach was employed to introduce the alanine aminotransferase from barley (Hordeum vulgare), HvAlaAT, into wheat (Triticum aestivum) and sorghum (Sorghum bicolor), regulated by either constitutive or root preferred promoter elements. Plants harboring the transgenic …


Plantcv V2: Image Analysis Software For High-Throughput Plant Phenotyping, Malia A. Gehan, Noah Fahlgren, Arash Abbasi, Jeffrey C. Berry, Steven T. Callen, Leonardo Chavez, Andrew N. Doust, Max J. Feldman, Kerrigan B. Gilbert, John G. Hodge, J. Steen Hoyer, Andy Lin, Suxing Liu, César Lizárraga, Argelia Lorence, Michael Miller, Eric Platon, Monica Tessman, Tony Sax Jan 2017

Plantcv V2: Image Analysis Software For High-Throughput Plant Phenotyping, Malia A. Gehan, Noah Fahlgren, Arash Abbasi, Jeffrey C. Berry, Steven T. Callen, Leonardo Chavez, Andrew N. Doust, Max J. Feldman, Kerrigan B. Gilbert, John G. Hodge, J. Steen Hoyer, Andy Lin, Suxing Liu, César Lizárraga, Argelia Lorence, Michael Miller, Eric Platon, Monica Tessman, Tony Sax

Department of Agronomy and Horticulture: Faculty Publications

Systems for collecting image data in conjunction with computer vision techniques are a powerful tool for increasing the temporal resolution at which plant phenotypes can be measured non-destructively. Computational tools that are flexible and extendable are needed to address the diversity of plant phenotyping problems. We previously described the Plant Computer Vision (PlantCV) software package, which is an image processing toolkit for plant phenotyping analysis. The goal of the PlantCV project is to develop a set of modular, reusable, and repurposable tools for plant image analysis that are open-source and community-developed. Here we present the details and rationale for major …


Comparison Of Organic And Integrated Nutrient Management Strategies For Reducing Soil N2O Emissions, Rebecca F. Graham, Samuel E. Wortman, Cameron M. Pittelkow Jan 2017

Comparison Of Organic And Integrated Nutrient Management Strategies For Reducing Soil N2O Emissions, Rebecca F. Graham, Samuel E. Wortman, Cameron M. Pittelkow

Department of Agronomy and Horticulture: Faculty Publications

To prevent nutrient limitations to crop growth, nitrogen is often applied in agricultural systems in the form of organic inputs (e.g., crop residues, manure, compost, etc.) or inorganic fertilizer. Inorganic nitrogen fertilizer has large environmental and economic costs, particularly for low-input smallholder farming systems. The concept of combining organic, inorganic, and biological nutrient sources through Integrated Nutrient Management (INM) is increasingly promoted as a means of improving nutrient use efficiency by matching soil nutrient availability with crop demand. While the majority of previous research on INM has focused on soil quality and yield, potential climate change impacts have rarely been …


Supplemental Material For: Multi-Site Evaluation Of Apex For Water Quality: Ii. Regional Parameterization, Nathan O. Nelson, Claire Baffaut, John A. Lory, G.M.M.M. Anomaa Senaviratne, Ammar B. Bhandari, Ranjith P. Udawatta, Daniel W. Sweeney, Matt J. Helmers, Mike W. Van Liew, Antonio P. Mallarino, Charles S. Wortmann Jan 2017

Supplemental Material For: Multi-Site Evaluation Of Apex For Water Quality: Ii. Regional Parameterization, Nathan O. Nelson, Claire Baffaut, John A. Lory, G.M.M.M. Anomaa Senaviratne, Ammar B. Bhandari, Ranjith P. Udawatta, Daniel W. Sweeney, Matt J. Helmers, Mike W. Van Liew, Antonio P. Mallarino, Charles S. Wortmann

Department of Agronomy and Horticulture: Faculty Publications

Model performance was assessed using Nash-Sutcliffe model efficiency (NSE), coefficient of determination (r2), and percent bias (PBIAS) as defined by Moriasi et al. (2007 and 2015). Threshold values indicating acceptable model performance based on these statistics are dependent on the spatial and temporal scales of the data, water quality constituents of interest, and the modeling objectives (Moriasi et al., 2015). Although some standard values have been suggested (Moriasi et al., 2007 and 2015), considerable variability exist in the published literature. For instance Ramanarayan et al. (1997) considered r2 >0.5 and NSE >0.40 as satisfactory for simulation of …


Rooting For Food Security In Sub-Saharan Africa, Nicolas Guilpart, Patricio Grassini, Justin Van Wart, Haishun Yang, Martin K. Van Ittersum, Lenny G.J. Van Bussel, Joost Wolf, Lieven Claessens, Johan G.B. Leenaars, Kenneth G. Cassman Jan 2017

Rooting For Food Security In Sub-Saharan Africa, Nicolas Guilpart, Patricio Grassini, Justin Van Wart, Haishun Yang, Martin K. Van Ittersum, Lenny G.J. Van Bussel, Joost Wolf, Lieven Claessens, Johan G.B. Leenaars, Kenneth G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

There is a persistent narrative about the potential of Sub-Saharan Africa (SSA) to be a ‘grain breadbasket’ because of large gaps between current low yields and yield potential with good management, and vast land resources with adequate rainfall. However, rigorous evaluation of the extent to which soils can support high, stable yields has been limited by lack of data on rootable soil depth of sufficient quality and spatial resolution. Here we use location-specific climate data, a robust spatial upscaling approach, and crop simulation to assess sensitivity of rainfed maize yields to root-zone water holding capacity. We find that SSA could …


Genotype, Environment, Seeding Rate, And Top-Dressed Nitrogen Effects On End-Use Quality Of Modern Nebraska Winter Wheat, Madhav Bhatta, Teshome Regassa, Devin J. Rose, P. Stephen Baenziger, Kent M. Eskridge, Dipak K. Santra, Rachana Poudel Jan 2017

Genotype, Environment, Seeding Rate, And Top-Dressed Nitrogen Effects On End-Use Quality Of Modern Nebraska Winter Wheat, Madhav Bhatta, Teshome Regassa, Devin J. Rose, P. Stephen Baenziger, Kent M. Eskridge, Dipak K. Santra, Rachana Poudel

Department of Agronomy and Horticulture: Faculty Publications

Background: Fine-tuning production inputs such as seeding rate, nitrogen (N), and genotype may improve end-use quality of hard red winter wheat (Triticum aestivium L.) when growing conditions are unpredictable. Studies were conducted at the Agronomy Research Farm (ARF; Lincoln, NE, USA) and the High Plains Agricultural Laboratory (HPAL; Sidney, NE, USA) in 2014 and 2015 in Nebraska, USA, to determine the effects of genotype (6), environment (4), seeding rate (3), and flag leaf top-dressed N (0 and 34 kg N ha−1) on the end-use quality of winter wheat.

Results: End-use quality traits were influenced by environment, genotype, …


Leveraging Agroecology For Solutions In Food, Energy, And Water, Marcia Delonge, Andrea D. Basche Jan 2017

Leveraging Agroecology For Solutions In Food, Energy, And Water, Marcia Delonge, Andrea D. Basche

Department of Agronomy and Horticulture: Faculty Publications

Global agriculture is facing growing challenges at the nexus of interconnected food, energy and water systems, including but not limited to persistent food insecurity and diet-related diseases; growing demands for energy and consequences for climate change; and declining water resources, water pollution, floods and droughts. Further, soil degradation and biodiversity loss are both triggers for and consequences of these problems. In this commentary, we argue that expanding agroecological principles, tools, and technologies and enhancing biological diversity can address these challenges and achieve better socioeconomic outcomes. Agroecology is often described as multi- or transdiscplinary, and applies ecological principles to the design …


Research Topics To Scale Up Cover Crop Use: Reflections From Innovative Iowa Farmers, Andrea D. Basche, Gabrielle E. Roesch-Mcnally Jan 2017

Research Topics To Scale Up Cover Crop Use: Reflections From Innovative Iowa Farmers, Andrea D. Basche, Gabrielle E. Roesch-Mcnally

Department of Agronomy and Horticulture: Faculty Publications

Cover crops as a conservation practice continue to receive attention from farmers, researchers, media, and policy makers, given their ability to effectively reduce water pollution and improve soil quality. Recent estimates of cover crop use across the midwestern Corn Belt, as well as the United States, demonstrate large acreage increases over the last number of years. The annual Sustainable Agriculture Research and Education–Conservation Technology Information Center (SARE– CTIC) survey found that nationally cover crop acreage doubled from 2011 to 2016, based on farmers self-reporting cover crop planting (CTIC 2016). However, the total cover crop acreage based on 2012 Census of …


Shifts In Microbial Communities In Soil, Rhizosphere And Roots Of Two Major Crop Systems Under Elevated Co2 And O3, Peng Wang, Ellen L. Marsh, Elizabeth A. Ainsworth, Andrew D. B. Leakey, Amy M. Sheflin, Daniel P. Schachtman Jan 2017

Shifts In Microbial Communities In Soil, Rhizosphere And Roots Of Two Major Crop Systems Under Elevated Co2 And O3, Peng Wang, Ellen L. Marsh, Elizabeth A. Ainsworth, Andrew D. B. Leakey, Amy M. Sheflin, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Rising atmospheric concentrations of CO2 and O3 are key features of global environmental change. To investigate changes in the belowground bacterial community composition in response to elevated CO2 and O3 (eCO2 and eO3) the endosphere, rhizosphere and soil were sampled from soybeans under eCO2 and maize under eO3. The maize rhizosphere and endosphere α-diversity was higher than soybean, which may be due to a high relative abundance of Rhizobiales. Only the rhizosphere microbiome composition of the soybeans changed in response to eCO2, associated with an increased abundance of nitrogen …


Evaluation Of Jules-Crop Performance Against Site Observations Of Irrigated Maize From Mead, Nebraska, Karina Williams, Jemma Gornall, Anna Harper, Andy Wiltshire, Debbie Hemming, Tristan Quaife, Tim Arkebauer, David Scoby Jan 2017

Evaluation Of Jules-Crop Performance Against Site Observations Of Irrigated Maize From Mead, Nebraska, Karina Williams, Jemma Gornall, Anna Harper, Andy Wiltshire, Debbie Hemming, Tristan Quaife, Tim Arkebauer, David Scoby

Department of Agronomy and Horticulture: Faculty Publications

The JULES-crop model (Osborne et al., 2015) is a parametrisation of crops within the Joint UK Land Environment Simulator (JULES), which aims to simulate both the impact of weather and climate on crop productivity and the impact of croplands on weather and climate. In this evaluation paper, observations of maize at three FLUXNET sites in Nebraska (US-Ne1, US-Ne2 and US-Ne3) are used to test model assumptions and make appropriate input parameter choices. JULES runs are performed for the irrigated sites (US-Ne1 and US-Ne2) both with the crop model switched off (prescribing leaf area index (LAI) and canopy height) and with …


Science In The Supply Chain: Collaboration Opportunities For Advancing Sustainable Agriculture In The United States, Allison M. Thomson, Stewart Ramsey, Ed Barnes, Bruno Basso, Marlen Eve, Sasha Gennet, Patricio Grassini, Brandon Kliethermes, Marty Matlock, Eileen Mcclellen, Ed Spevak, Clifford S. Snyder, Mark D. Tomer, Chris Van Kessel, Tristram West, Grant Wick Jan 2017

Science In The Supply Chain: Collaboration Opportunities For Advancing Sustainable Agriculture In The United States, Allison M. Thomson, Stewart Ramsey, Ed Barnes, Bruno Basso, Marlen Eve, Sasha Gennet, Patricio Grassini, Brandon Kliethermes, Marty Matlock, Eileen Mcclellen, Ed Spevak, Clifford S. Snyder, Mark D. Tomer, Chris Van Kessel, Tristram West, Grant Wick

Department of Agronomy and Horticulture: Faculty Publications

Consumers and corporations are increasingly interested in understanding the sustainability of agricultural supply chains and reducing the environmental impacts of food, fiber, feed, and fuel production. This emerging need to quantify environmental impacts from agricultural production creates an opportunity for collaboration with the scientific community. Without such collaboration, sustainability efforts risk failure by adopting unrealistic goals or misguided approaches. This commentary explores the role of science in Field to Market, a nonprofit organization developing a sustainability program for US commodity crops, and highlights opportunities to address emerging science challenges. We evaluate changes over the past 35 years in key environmental …


Genomic Prediction With Pedigree And Genotype X Environment Interaction In Spring Wheat Grown In South And West Asia, North Africa, And Mexico, Sivakumar Sukumaran, José Crossa, Diego Jarquin, Marta Lopes, Matthew P. Reynolds Jan 2017

Genomic Prediction With Pedigree And Genotype X Environment Interaction In Spring Wheat Grown In South And West Asia, North Africa, And Mexico, Sivakumar Sukumaran, José Crossa, Diego Jarquin, Marta Lopes, Matthew P. Reynolds

Department of Agronomy and Horticulture: Faculty Publications

Developing genomic selection (GS) models is an important step in applying GS to accelerate the rate of genetic gain in grain yield in plant breeding. In this study, seven genomic prediction models under two cross-validation (CV) scenarios were tested on 287 advanced elite spring wheat lines phenotyped for grain yield (GY), thousand-grain weight (GW), grain number (GN), and thermal time for flowering (TTF) in 18 international environments (year-location combinations) in major wheat-producing countries in 2010 and 2011. Prediction models with genomic and pedigree information included main effects and interaction with environments. Two random CV schemes were applied to predict a …