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Articles 10621 - 10650 of 14771

Full-Text Articles in Agricultural Science

Soil Carbon Increased By Twice The Amount Of Biochar Carbon Applied After 6 Years: Field Evidence Of Negative Priming, Humberto Blanco-Canqui, David A. Laird, Emily A. Heaton, Samuel Rathke, Bharat Sharma Acharya Jan 2020

Soil Carbon Increased By Twice The Amount Of Biochar Carbon Applied After 6 Years: Field Evidence Of Negative Priming, Humberto Blanco-Canqui, David A. Laird, Emily A. Heaton, Samuel Rathke, Bharat Sharma Acharya

Department of Agronomy and Horticulture: Faculty Publications

Applying biochar to agricultural soils has been proposed as a means of sequester-ing carbon (C) while simultaneously enhancing soil health and agricultural sustain-ability. However, our understanding of the long-term effects of biochar and annual versus perennial cropping systems and their interactions on soil properties under field conditions is limited. We quantified changes in soil C concentration and stocks, and other soil properties 6 years after biochar applications to corn (Zea mays L.) and dedicated bioenergy crops on a Midwestern US soil. Treatments were as fol-lows: no-till continuous corn, Liberty switchgrass (Panicum virgatum L.), and low-diversity prairie grasses, 45% big bluestem …


Transforming Unmanned Aerial Vehicle (Uav) And Multispectral Sensor Into A Practical Decision Support System For Precision Nitrogen Management In Corn, Laura J. Thompson, Laila A. Puntel Jan 2020

Transforming Unmanned Aerial Vehicle (Uav) And Multispectral Sensor Into A Practical Decision Support System For Precision Nitrogen Management In Corn, Laura J. Thompson, Laila A. Puntel

Department of Agronomy and Horticulture: Faculty Publications

Determining the optimal nitrogen (N) rate in corn remains a critical issue, mainly due to unaccounted spatial (e.g., soil properties) and temporal (e.g., weather) variability. Unmanned aerial vehicles (UAVs) equipped with multispectral sensors may provide opportunities to improve N management by the timely informing of spatially variable, in-season N applications. Here, we developed a practical decision support system (DSS) to translate spatial field characteristics and normalized difference red edge (NDRE) values into an in-season N application recommendation. On-farm strip-trials were established at three sites over two years to compare farmer’s traditional N management to a split-application N management guided by …


Benchmarking Impact Of Nitrogen Inputs On Grain Yield And Environmental Performance Of Producer Fields In The Western Us Corn Belt, Fatima A.M. Tenorio, Eileen L. Mclellan, Alison J. Eagle, Kenneth G. Cassman, Daryl Andersen, Marie Krausnick, Russell Oaklund, John Thorburn, Patricio Grassini Jan 2020

Benchmarking Impact Of Nitrogen Inputs On Grain Yield And Environmental Performance Of Producer Fields In The Western Us Corn Belt, Fatima A.M. Tenorio, Eileen L. Mclellan, Alison J. Eagle, Kenneth G. Cassman, Daryl Andersen, Marie Krausnick, Russell Oaklund, John Thorburn, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Benchmarking crop yields against nitrogen (N) input levels can help provide opportunities to improve N ferti-lizer efficiency and reduce N losses on maize in the US Corn Belt by identifying fields most likely to benefit from improved N management practices. Here, we evaluated a large producer database that includes field-level data on yield and applied N inputs from 9280 irrigated and rainfed fields over a 7-year period (2009–2015) in Nebraska (USA). A spatial framework, based on technology extrapolation domains, was used to cluster each field into spatial units with similar climate and soil type that represent 1.3 million ha of …


Prediction Strategies For Leveraging Information Of Associated Traits Under Single- And Multi-Trait Approaches In Soybeans, Reyna Persa, Arthur Bernardeli, Diego Jarquin Jan 2020

Prediction Strategies For Leveraging Information Of Associated Traits Under Single- And Multi-Trait Approaches In Soybeans, Reyna Persa, Arthur Bernardeli, Diego Jarquin

Department of Agronomy and Horticulture: Faculty Publications

The availability of molecular markers has revolutionized conventional ways to improve genotypes in plant and animal breeding through genome-based predictions. Several models and methods have been developed to leverage the genomic information in the prediction context to allow more efficient ways to screen and select superior genotypes. In plant breeding, usually, grain yield (yield) is the main trait to drive the selection of superior genotypes; however, in many cases, the information of associated traits is also routinely collected and it can potentially be used to enhance the selection. In this research, we considered different prediction strategies to leverage the information …


Overexpression Of Ferulate 5‑Hydroxylase Increases Syringyl Units In Sorghum Bicolor, Hannah M. Tetreault, Tammy Gries, Nathan Palmer, Deanna L. Funnell-Harris, Shirley Sato, Zhengxiang Ge, Gautam Sarath, Scott Sattler Jan 2020

Overexpression Of Ferulate 5‑Hydroxylase Increases Syringyl Units In Sorghum Bicolor, Hannah M. Tetreault, Tammy Gries, Nathan Palmer, Deanna L. Funnell-Harris, Shirley Sato, Zhengxiang Ge, Gautam Sarath, Scott Sattler

Department of Agronomy and Horticulture: Faculty Publications

Ferulate 5-hydroxylase (F5H) of the monolignol pathway catalyzes the hydroxylation of coniferyl alcohol, coniferaldehyde and ferulic acid to produce 5-hydroxyconiferyl moieties, which lead to the formation of sinapic acid and syringyl (S) lignin monomers. In contrast, guaiacyl (G) lignin, the other major type of lignin monomer, is derived from polymerization of coniferyl alcohol. In this study, the effects of manipulating S-lignin biosynthesis in sorghum (Sorghum bicolor) were evaluated. Overexpression of sorghum F5H (SbF5H), under the control of the CaMV 35S promoter, increased both S-lignin levels and the ratio of S/G lignin, while plant growth and development …


Biological And Cellular Functions Of The Microdomain-Associated Fwl/Cnr Protein Family In Plants, Sandra Thibivilliers, Andrew Farmer, Marc Libault Jan 2020

Biological And Cellular Functions Of The Microdomain-Associated Fwl/Cnr Protein Family In Plants, Sandra Thibivilliers, Andrew Farmer, Marc Libault

Department of Agronomy and Horticulture: Faculty Publications

Membrane microdomains/nanodomains are sub-compartments of the plasma membrane enriched in sphingolipids and characterized by their unique protein composition. They play important roles in regulating plant development and plant-microbe interactions including mutualistic symbiotic interactions. Several protein families are associated with the microdomain fraction of biological membranes such as flotillins, prohibitins, and remorins. More recently, GmFWL1, a FWL/CNR protein exclusively expressed in the soybean nodule, was functionally characterized as a new microdomain-associated protein. Interestingly, GmFWL1 is homologous to the tomato FW2-2 protein, a major regulator of tomato fruit development. In this review, we summarize the knowledge gained about the biological, cellular, and …


Investigation Of Heat-Induced Changes In The Grain Yield And Grains Metabolites, With Molecular Insights On The Candidate Genes In Barley, Mona F.A. Dawood, Yasser S. Moursi, Ahmed Amro, P. Stephen Baenziger, Ahmed Sallam Jan 2020

Investigation Of Heat-Induced Changes In The Grain Yield And Grains Metabolites, With Molecular Insights On The Candidate Genes In Barley, Mona F.A. Dawood, Yasser S. Moursi, Ahmed Amro, P. Stephen Baenziger, Ahmed Sallam

Department of Agronomy and Horticulture: Faculty Publications

Heat stress is one of the abiotic stresses that cause a significant reduction in barley yield. Climate change will increase the number of heatwaves, which will result in more deterioration in the agricultural sector. Therefore, understanding the physiological changes that occur in the plant to tolerate heat stress is very important. A collection of 60 Egyptian spring barley genotypes has been tested for heat stress under field conditions. To quantify the changes in yield-related traits and the grain-reserve parameters as indicators for heat tolerance, several traits were scored. The causative genes that regulate the variation of all traits of interest …


Soil Sample Timing, Nitrogen Fertilization, And Incubation Length Influence Anaerobic Potentially Mineralizable Nitrogen, Jason Clark, Kristen S. Veum, Fabián G. Fernández, Newell R. Kitchen, James J. Camberato, Paul Carter, Richard Ferguson, David W. Franzen, Daniel E. Kaiser, Carrie A. M. Laboski, Emerson Nafziger, Carl J. Rosen, John E. Sawyer, John F. Shanahan Jan 2020

Soil Sample Timing, Nitrogen Fertilization, And Incubation Length Influence Anaerobic Potentially Mineralizable Nitrogen, Jason Clark, Kristen S. Veum, Fabián G. Fernández, Newell R. Kitchen, James J. Camberato, Paul Carter, Richard Ferguson, David W. Franzen, Daniel E. Kaiser, Carrie A. M. Laboski, Emerson Nafziger, Carl J. Rosen, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Understanding the variables that affect the anaerobic potentially mineralizable N (PMNan) test should lead to a standard procedure of sample collection and incubation length, improving PMNan as a tool in corn (Zea mays L.) N management. We evaluated the effect of soil sample timing (preplant and V5 corn development stage [V5]), N fertilization (0 and 180 kg ha−1) and incubation length (7, 14, and 28 d) on PMNan (0–30 cm) across a range of soil properties and weather conditions. Soil sample timing, N fertilization, and incubation length affected PMNan differently based on soil and weather conditions. Preplant vs. V5 PMNan …


Weather And Soil In The Us Midwest Influence The Effectiveness Of Single- And Split-Nitrogen Applications In Corn Production, Jason D. Clark, Fabián G. Fernández, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Newell R. Kitchen, Carrie A. M. Laboski, Emerson Nafziger, John E. Sawyer, John F. Shanahan Jan 2020

Weather And Soil In The Us Midwest Influence The Effectiveness Of Single- And Split-Nitrogen Applications In Corn Production, Jason D. Clark, Fabián G. Fernández, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Newell R. Kitchen, Carrie A. M. Laboski, Emerson Nafziger, John E. Sawyer, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Splitting the N application into two or more timings may improve corn (Zea mays L.) grain yield and N recovery relative to a single-N application. A 49 site-year study across eight U.S. Midwestern states compared the effect of an at-planting (single-N application) and two split-N applications [45 (45+SD) or 90 kg N ha−1 (90+SD) at planting with the remainder of the total rate (180 or 270 kg N ha−1) applied at V9]. For split-N applications, soil and plant responses were similar between 45+SD and 90+SD 93–98% of the time, indicating the at-planting N rate of 45 kg N ha−1 may …


Organic Fertilizer Abrasive Grits Increase Soil Available Nitrogen, Plant Height, And Biomass, Michael Carlson, Frank Forcella, Samuel E. Wortman, David Clay, Sharon A. Clay Jan 2020

Organic Fertilizer Abrasive Grits Increase Soil Available Nitrogen, Plant Height, And Biomass, Michael Carlson, Frank Forcella, Samuel E. Wortman, David Clay, Sharon A. Clay

Department of Agronomy and Horticulture: Faculty Publications

In organic cropping systems, air-propelled abrasive grits can be used to control in-row weeds. If the applied abrasive grit is an approved organic fertilizer, these applications may serve a dual purpose of weed control and crop fertility. Laboratory soil incubations examined the N mineralization rates of several grit types with differing C/N ratios (Agra Grit [crushed walnut shells, 170:1], corncob grit [91:1], Sustane [composted turkey litter, 5.0:1], Phytaboost Plant Food [crushed and pelletized soybean meal, 5.0:1]). A greenhouse study determined plant wheat (Triticum aestivum L.), kale (Brassica napus pabluaria DC), and velvetleaf (Abu- tilon theophrasti Medik.) growth response in soils …


Does Cover Crop Grazing Damage Soils And Reduce Crop Yields?, Humberto Blanco-Canqui, Mary E. Drewnoski, Jim C. Macdonald, Daren Redfearn, Jay Parsons, Gary W. Lesoing, Tyler Williams Jan 2020

Does Cover Crop Grazing Damage Soils And Reduce Crop Yields?, Humberto Blanco-Canqui, Mary E. Drewnoski, Jim C. Macdonald, Daren Redfearn, Jay Parsons, Gary W. Lesoing, Tyler Williams

Department of Agronomy and Horticulture: Faculty Publications

Cover crop (CC) grazing can be a potential strategy to support livestock and crop production while enhancing soil ecosystem services, but research on this potential multi-functionality of CCs is limited. We assessed 3-yr cereal rye (Secale cereale L.) CC grazing impacts on soil compaction, structure, water infiltration, fertility, and crop yields on an on-farm irrigated strip-till continuous corn (Zea mays L.) silage experiment on a sandy loam with <1% slope in west-central Nebraska. Treatments were: (a) non-grazed CC, (b) grazed CC, and (c) no CC. Across the 3 yr, cattle grazed CCs at 5.9 AUM ha−1 with grazing occurring over a 4-mo period during winter and/or spring, depending on the year. We measured soil properties within 5 d after grazing ended in spring before tilling and plant- ing corn. Cattle grazing resulted in a 92% decrease of CC biomass, compared with non-grazed CCs. Grazing did not affect soil penetration resistance (com- paction parameter), bulk density, aggregate stability, pH, and concentration of organic matter and nutrients except in the 2nd yr where it reduced cumulative infiltration by 80% and increased penetration resistance from 1.23 to 1.72 MPa but such increase was below root growth thresholds (<2 MPa). Cover crop grazing had no negative effect on corn silage yields although data were variable. Overall, CC grazing for 3 yr had small and variable effects on soils and crop yields, indi- cating that it can be a management option to support livestock production but more long-term data from different tillage and cropping systems, and climates are needed to further understand CC grazing implications.


A Systematic Review Of Durum Wheat: Enhancing Production Systems By Exploring Genotype, Environment, And Management (G × E × M) Synergies, Brian L. Beres, Elham Rahmani, John M. Clarke, Patricio Grassini, Curtis J. Pozniak, Cameron Guy Robinson Geddes, Kenton D. Porker, William E. May, Joel Ransom Jan 2020

A Systematic Review Of Durum Wheat: Enhancing Production Systems By Exploring Genotype, Environment, And Management (G × E × M) Synergies, Brian L. Beres, Elham Rahmani, John M. Clarke, Patricio Grassini, Curtis J. Pozniak, Cameron Guy Robinson Geddes, Kenton D. Porker, William E. May, Joel Ransom

Department of Agronomy and Horticulture: Faculty Publications

According to the UN-FAO, agricultural production must increase by 50% by 2050 to meet global demand for food. This goal can be accomplished, in part, by the development of improved cultivars coupled with modern best management practices. Overall, wheat production on farms will have to increase significantly to meet future demand, and in the face of a changing climate that poses risk to even current rates of production. Durum wheat [Triticum turgidum L. ssp. durum (Desf.)] is used largely for pasta, couscous and bulgur production. Durum producers face a range of factors spanning abiotic (frost damage, drought, and sprouting) and …


Transformative Education In Agroecology: Student, Teacher, And Client Involvement In Co-Learning, Charles A. Francis, Anna Marie Nicolaysen, Geir Lieblein, Tor Arvid Breland Jan 2020

Transformative Education In Agroecology: Student, Teacher, And Client Involvement In Co-Learning, Charles A. Francis, Anna Marie Nicolaysen, Geir Lieblein, Tor Arvid Breland

Department of Agronomy and Horticulture: Faculty Publications

Educational methods have evolved rapidly in agroecology, which is a complex and holistic field without a long history or the formal tradition of any single academic discipline. Definitions of agroecology have evolved from its initial conception as a marriage of agriculture with ecology, to an aggregation of different paths including science, practices, and movements, and recently as a broad appreciation of the ecology of food systems. In contrast with traditional courses that begin with a history of the discipline and review the contributions of early leaders, we have embraced phenomenology to firmly establish roots in students’ learning through their experiences …


Urban Food Sovereignty: Urgent Need For Agroecology And Systems Thinking In A Post-Covid-19 Future, Ali Loker, Charles A. Francis Jan 2020

Urban Food Sovereignty: Urgent Need For Agroecology And Systems Thinking In A Post-Covid-19 Future, Ali Loker, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

The current COVID-19 pandemic has brought attention to challenges associated with our dominant industrial food system in the U.S. The general public now has more appreciation for farm workers and meatpacking employees, as well as those in grocery stores and in food transportation who are suddenly recognized as essential frontline workers. It apparently takes a crisis for us to focus clearly on the fragility of this system and the lives of people on whom we depend. In this commentary we discuss the definition of food sovereignty, how it manifests in urban areas, and how the COVID-19 pandemic can trigger viable …


Training For Specialists Vs. Education For Agroecologists, Charles A. Francis Jan 2020

Training For Specialists Vs. Education For Agroecologists, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

I admit to being a slow learner. Graduate school training in agronomy at the University of California, Davis and in plant breeding at Cornell University provided me with top-quality opportunities to acquire the tools for crop improvement, plus the contacts to join professionals at the International Center for Tropical Agriculture in Colombia. As a young scientist dedicated to building on successes of the Green Revolution, I was convinced that genetic changes would solve global hunger. This had been amply demonstrated with the yield increases of wheat in Mexico and India, and with rice in Southeast Asia. Should this success not …


Validation Of Predictive Empirical Weed Emergence Models Of Abutilon Theophrasti Medik Based On Intercontinental Data, Valle Egea-Cobrero, Kevin Bradley, Isabel M. Calha, Adam S. Davis, Jose Dorado, Frank Forcella, John L. Lindquist, Christy L. Sprague, Jose L. Gonzalez-Andujar Jan 2020

Validation Of Predictive Empirical Weed Emergence Models Of Abutilon Theophrasti Medik Based On Intercontinental Data, Valle Egea-Cobrero, Kevin Bradley, Isabel M. Calha, Adam S. Davis, Jose Dorado, Frank Forcella, John L. Lindquist, Christy L. Sprague, Jose L. Gonzalez-Andujar

Department of Agronomy and Horticulture: Faculty Publications

Good weed management relies on the proper timing of weed control practices in relation to weed emergence dynamics. Therefore, the development of models that predict the timing of emergence may help provide growers with tools to make better weed management decisions. The aim of this study was to validate and compare two previously published predictive empirical thermal time models of the emergence of Abutilon theophrasti growing in maize with data sets from the USA and Europe, and test the hypothesis that a robust and general weed emergence model can be developed for this species. Previously developed Weibull and Logistic models …


Quantifying On‐Farm Nitrous Oxide Emission Reductions In Food Supply Chains, A.J. Eagle, E. Mclellan, E.M. Brawner, M.H. Chantigny, Eric A. Davidson, J.B. Dickey, Bruce A. Linquist, T.M. Maaz, D.E. Pelster, Cameron M. Pittelkow, C. Van Kessel, T.J. Vyn, K. G. Cassman Jan 2020

Quantifying On‐Farm Nitrous Oxide Emission Reductions In Food Supply Chains, A.J. Eagle, E. Mclellan, E.M. Brawner, M.H. Chantigny, Eric A. Davidson, J.B. Dickey, Bruce A. Linquist, T.M. Maaz, D.E. Pelster, Cameron M. Pittelkow, C. Van Kessel, T.J. Vyn, K. G. Cassman

Department of Agronomy and Horticulture: Faculty Publications

Reducing nitrous oxide (N2O) emissions from agriculture is critical to limiting future global warming. In response, a growing number of food retailers and manufacturers have committed to reducing N2O emissions from their vast networks of farmer suppliers by providing technical assistance and financial incentives. A key challenge for such companies is demonstrating that their efforts are leading to meaningful progress toward their climate mitigation commitments. We show that a simplified version of soil surface nitrogen (N) balance—or partial N balance—the difference between N inputs to and outputs

from a farm field (fertilizer N minus crop N), is a robust indicator …


Cover Crops And Weed Suppression In The U.S. Midwest: A Meta-Analysis And Modeling Study, Virginia Nicholas, Rafael Martinez-Feria, David Weisberger, Sarah Carlson, B. Basso, Andrea Basche Jan 2020

Cover Crops And Weed Suppression In The U.S. Midwest: A Meta-Analysis And Modeling Study, Virginia Nicholas, Rafael Martinez-Feria, David Weisberger, Sarah Carlson, B. Basso, Andrea Basche

Department of Agronomy and Horticulture: Faculty Publications

In addition to soil health and conservation benefits, cover crops (CCs) may offer weed control in the midwestern United States, but individual studies report vary- ing effects. We conducted a meta-analysis of studies measuring weed biomass (WBIO) or density (WDEN) in paired CC and no-cover treatments in corn (Zea mays L.)–soybean [Glycine max (L.) Merr] rotations in the U.S. Midwest. Fifteen studies provided 123 paired comparisons of WBIO and 119 of WDEN. Only grass CCs significantly reduced WBIO, while no CC reduced WDEN. We found no evidence CC management factors (e.g., termination method) directly affected out- comes. Our dataset showed …


Solar Dimming Decreased Maize Yield Potential On The North China Plain, Qingfeng Meng, Baohua Liu, Haishun Yang, Xinping Chen Jan 2020

Solar Dimming Decreased Maize Yield Potential On The North China Plain, Qingfeng Meng, Baohua Liu, Haishun Yang, Xinping Chen

Department of Agronomy and Horticulture: Faculty Publications

Solar dimming has been increasing in rapidly developing regions (China and India) and threatening food security. Although previous studies have summarized the ef- fects of climate change-associated increases in temperature on agriculture, few have examined the effects due to solar dimming. Here, we analyzed the effects of solar dimming on maize on the North China Plain (NCP). It is reported that solar dimming intensified and maize yield potential decreased since the 1960s. The total decrease in solar radiation for the whole maize growing season of this period was 17%, and solar dimming explained 87% of the decrease in yield potential. …


Management Strategies For Early- And Late-Planted Soybean In The North-Central United States, Emma G. Matcham, Spyridon Mourtzinis, Shawn P. Colney, Juan I. Rattalino Edreira, Patricio Grassini, Adam C. Roth, Shaun N. Casteel, Igancio A. Ciampitti, Hans J. Kandel, Peter M. Kyveryga, Mark A. Licht, Daren S. Mueller, Emerson Nafziger, Seth Naeve, Jordan D. Stanley, Michael J. Staton, Laura E. Lindsey Jan 2020

Management Strategies For Early- And Late-Planted Soybean In The North-Central United States, Emma G. Matcham, Spyridon Mourtzinis, Shawn P. Colney, Juan I. Rattalino Edreira, Patricio Grassini, Adam C. Roth, Shaun N. Casteel, Igancio A. Ciampitti, Hans J. Kandel, Peter M. Kyveryga, Mark A. Licht, Daren S. Mueller, Emerson Nafziger, Seth Naeve, Jordan D. Stanley, Michael J. Staton, Laura E. Lindsey

Department of Agronomy and Horticulture: Faculty Publications

It is widely recognized that planting soybean [Glycine max (L.) Merr.] early is critical to maximizing yield, but the influence of changing management factors when soybean planting is delayed is not well understood. The objectives of this research were to (a) identify management decisions that increase seed yield in either early- or late-planted soybean scenarios, and (b) estimate the maximum break-even price of each management factor identified to influence soybean seed yield in early- or late-planted soybean. Producer data on seed yield and management decisions were collected from 5682 fields planted with soybean during 2014−2016 and grouped into 10 technology …


Calibrating Soybean Parameters In Jules 5.0 From The Us-Ne2/3 Fluxnet Sites And The Soyface-O3 Experiment, Felix Leung, Karina Williams, Stephen Sitch, Amos P.K. Tai, Andy Wiltshire, Jemma Gornall, Elizabeth A. Ainsworth, Timothy J. Arkebauer, David Scoby Jan 2020

Calibrating Soybean Parameters In Jules 5.0 From The Us-Ne2/3 Fluxnet Sites And The Soyface-O3 Experiment, Felix Leung, Karina Williams, Stephen Sitch, Amos P.K. Tai, Andy Wiltshire, Jemma Gornall, Elizabeth A. Ainsworth, Timothy J. Arkebauer, David Scoby

Department of Agronomy and Horticulture: Faculty Publications

Abstract. Tropospheric ozone (O3) is the third most important anthropogenic greenhouse gas. O3 is detrimental to plant productivity, and it has a significant impact on crop yield. Currently, the Joint UK Land Environment Simula- tor (JULES) land surface model includes a representation of global crops (JULES-crop) but does not have crop-specific O3 damage parameters and applies default C3 grass O3 pa- rameters for soybean that underestimate O3 damage. Physiological parameters for O3 damage in soybean in JULES- crop were calibrated against leaf gas-exchange measure- ments from the Soybean Free Air Concentration Enrichment (SoyFACE) with O3 experiment in Illinois, USA. Other …


Insufficient Nitrogen Supply From Symbiotic Fixation Reduces Seasonal Crop Growth And Nitrogen Mobilization To Seed In Highly Productive Soybean Crops, Nicolas Cafaro La Menza, Juan Pablo Monzon, John L. Lindquist, Timothy J. Arkebauer, Johannes M.H. Knops, Murray Unkovich, James E. Specht, Patricio Grassini Jan 2020

Insufficient Nitrogen Supply From Symbiotic Fixation Reduces Seasonal Crop Growth And Nitrogen Mobilization To Seed In Highly Productive Soybean Crops, Nicolas Cafaro La Menza, Juan Pablo Monzon, John L. Lindquist, Timothy J. Arkebauer, Johannes M.H. Knops, Murray Unkovich, James E. Specht, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Nitrogen (N) supply can limit the yields of soybean [Glycine max (L.) Merr.] in highly productive environments. To explore the physiological mechanisms underlying this limitation, seasonal changes in N dynamics, aboveground dry matter (ADM) accumula- tion, leaf area index (LAI) and fraction of absorbed radiation (fAPAR) were compared in crops relying only on biological N2 fixation and available soil N (zero-N treatment) versus crops receiving N fertilizer (full-N treatment). Experiments were conducted in seven high-yield environments without water limitation, where crops received optimal management. In the zero-N treatment, biological N2 fixation was not sufficient to meet the N demand of …


Seeding Rates And Productivity Of Broadcast Interseeded Cover Crops, Katja Koehler-Cole, Roger W. Elmore Jan 2020

Seeding Rates And Productivity Of Broadcast Interseeded Cover Crops, Katja Koehler-Cole, Roger W. Elmore

Department of Agronomy and Horticulture: Faculty Publications

Broadcast interseeding cover crops into corn (Zea mays L.) and soybean (Glycine max (L.) Merr.) instead of drill-planting after harvest extends the cover crop season and improves productivity, but establishment can be insufficient. Our objectives were to find broadcast seeding rates that result in maximum spring biomass and N uptake. We tested cereal rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) in south-central and eastern Nebraska in 2016–2017 and 2017–2018. Seeding rates for rye were 341, 512, and 682 seeds·m−2, and 119, 178, and 238 seeds·m−2 for vetch. We broadcast in late September and terminated by early May. …


Woody Plant Encroachment And The Sustainability Of Priority Conservation Areas, Dillon Fogarty, Caleb P. Roberts, Daniel R. Uden, Victoria M. Donovan, Craig R. Allen, David E. Naugle, Matthew O. Jones, Brady W. Allred, Dirac L. Twidwell Jr Jan 2020

Woody Plant Encroachment And The Sustainability Of Priority Conservation Areas, Dillon Fogarty, Caleb P. Roberts, Daniel R. Uden, Victoria M. Donovan, Craig R. Allen, David E. Naugle, Matthew O. Jones, Brady W. Allred, Dirac L. Twidwell Jr

Department of Agronomy and Horticulture: Faculty Publications

Woody encroachment is a global driver of grassland loss and management to counteract encroachment represents one of the most expensive conservation practices implemented in grasslands. Yet, outcomes of these practices are often unknown at large scales and this constrains practitioner’s ability to advance conservation. Here, we use new monitoring data to evaluate outcomes of grassland conservation on woody encroachment for Nebraska’s State Wildlife Action Plan, a statewide effort that targets management in Biologically Unique Landscapes (BULs) to conserve the state’s natural communities. We tracked woody cover trajectories for BULs and compared BUL trajectories with those in non-priority landscapes (non-BULs) to …


Is Allelopathy From Winter Cover Crops Affecting Row Crops?, Katja Koehler-Cole, Sydney Everhart, Yan Gu, Christopher A. Proctor, Margarita Marroquin-Guzman, Daren Redfearn, Roger W. Elmore Jan 2020

Is Allelopathy From Winter Cover Crops Affecting Row Crops?, Katja Koehler-Cole, Sydney Everhart, Yan Gu, Christopher A. Proctor, Margarita Marroquin-Guzman, Daren Redfearn, Roger W. Elmore

Department of Agronomy and Horticulture: Faculty Publications

Cover crops (CC) have been explored in corn (Zea mays L.), cotton (Gossypium hirsutum L.), soybean [Glycine max (L.) Merr.], and wheat (Triticum aestivum L.) systems for their allelopathic potential to control weeds. However, allelopathic compounds may negatively affect these row crops by reducing germination, emergence, and grain yields. We reviewed studies that document allelopathic effects of CC on subsequent row crops in field and laboratory settings. We summarize the influence of CC management, including biomass production, planting and termination timing on allelochemical quantity. Our review found few studies documenting allelopathic effects of CC on row …


Winter Wheat Residue Impact On Soil Water Storage And Subsequent Corn Yield, Luana Machado Simão, Amanda Easterly, Greg Kruger, Cody Creech Jan 2020

Winter Wheat Residue Impact On Soil Water Storage And Subsequent Corn Yield, Luana Machado Simão, Amanda Easterly, Greg Kruger, Cody Creech

Department of Agronomy and Horticulture: Faculty Publications

Standing winter wheat (Triticum aestivum L.) residue can capture snow, reduce soil erosion and water evaporation, and increase crop yields in semi-arid environments. Solid-stemmed winter wheat (SSWW) varieties may remain standing longer in the field; however, SSWW consistently yields less than conventional hollow-stemmed winter wheat (HSWW). This research investigates if the negative economic impact of yield loss of SSWW may be overcome by increasing the subsequent corn (Zea mays L.) yield due to increased snow capture and soil moisture. The experiment covered two cycles of a wheat–corn–fallow rotation in two separate fields between 2016 and 2019 near Sidney, NE. …


Improvement Of Smallholder Farming Systems In Africa, Charles S. Wortmann, Tilahun Amede, Mateete Bekunda, Keziah Ndung’U-Magiroi, Patricia Masikati, Sieglinde S. Snapp, Zachary P. Stewart, Mark Westgate, Zacarie Zida, Charles E. Kome Jan 2020

Improvement Of Smallholder Farming Systems In Africa, Charles S. Wortmann, Tilahun Amede, Mateete Bekunda, Keziah Ndung’U-Magiroi, Patricia Masikati, Sieglinde S. Snapp, Zachary P. Stewart, Mark Westgate, Zacarie Zida, Charles E. Kome

Department of Agronomy and Horticulture: Faculty Publications

This forum paper provides a synthesis and discussion of 14 categories of lessons learned from experiences for achieving farm-level impact with smallholder farm- ers in Africa. These lessons were reported in a symposium hosted by the Agron- omy in Africa community of the American Society of Agronomy. The lessons, listed in order of frequency of reporting, were the need to: have adequate infras- tructure and services; enable spontaneous adoption; have multi-disciplinary and institutional collaboration; build on previous adoption of good agronomic practices (GAP); have farmer participation in research; encourage and learn from smallholder adaptations; make GAP promotion demand-driven; allow GAP …


Soil Aggregation As Affected By Application Of Diverse Organic Materials, Maman Garba, Charles S. Wortmann, Humberto Blanco-Canqui Jan 2020

Soil Aggregation As Affected By Application Of Diverse Organic Materials, Maman Garba, Charles S. Wortmann, Humberto Blanco-Canqui

Department of Agronomy and Horticulture: Faculty Publications

Application of organic materials can amend soil for improved water infiltration and reduced erodibility with effects varying with soil properties and the organic amendment type and rate. The effects of four livestock manures, three municipal biosolids, and one industrial by-product on dry and wet soil aggregate stability were evaluated at six sites in Nebraska. The amendments had similar C/N ratios but the biosolids had relatively high concentrations of lignin and cellulose. Soil organic matter (SOM) ranged from 21 to 65 g kg−1 and soils were silty clay loam, silt loam, or loamy sand. Soil was sampled for the 0- to …


Strategic Switchgrass (Panicum Virgatum) Production Within Row Cropping Systems: Regional-Scale Assessment Of Soil Erosion Loss And Water Runoff Impacts, Enheng Wang, R. M. Cruse, Bharat Sharma-Acharya, Daryl E. Herzmann, Brian K. Gelder, David E. James, Dennis C. Flanagan, Humberto Blanco-Canqui, Robert B. Mitchell, David Laird Jan 2020

Strategic Switchgrass (Panicum Virgatum) Production Within Row Cropping Systems: Regional-Scale Assessment Of Soil Erosion Loss And Water Runoff Impacts, Enheng Wang, R. M. Cruse, Bharat Sharma-Acharya, Daryl E. Herzmann, Brian K. Gelder, David E. James, Dennis C. Flanagan, Humberto Blanco-Canqui, Robert B. Mitchell, David Laird

Department of Agronomy and Horticulture: Faculty Publications

A strong need exists for tools to assess the efficacy of conservation practices across large regions supporting informed policy decisions that may lead to better soil and water conservation while optimizing agricultural production options. Perennial warm-season grasses (WSGs) such as switchgrass (Panicum virgatum), can be grown on marginally productive and/or environmentally sensitive lands to meet growing bioenergy demands while reducing water runoff and soil erosion compared to current row crop systems. Quantifying the soil and water conservation effects of WSG when strategically placed on the landscape would help support decisions favoring both economic and environmental benefits. We used the Daily …


Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens And Induce Growth Promotion In Tomato, Serkan Tokgöz, Dilip K. Lakshman, Mahmoud H. Ghozlan, Hasan Pinar, Daniel P. Roberts, Amitava Mitra Jan 2020

Soybean Nodule-Associated Non-Rhizobial Bacteria Inhibit Plant Pathogens And Induce Growth Promotion In Tomato, Serkan Tokgöz, Dilip K. Lakshman, Mahmoud H. Ghozlan, Hasan Pinar, Daniel P. Roberts, Amitava Mitra

Department of Agronomy and Horticulture: Faculty Publications

The root nodules are a unique environment formed on legume roots through a highly specific symbiotic relationship between leguminous plants and nodule-inducing bacteria. Previously, Rhizobia were presumed to be the only group of bacteria residing within nodules. However, recent studies discovered diverse groups of bacteria within the legume nodules. In this report soybean nodule-associated bacteria were studied in an effort to identify beneficial bacteria for plant disease control and growth promotion. Analysis of surface-sterilized single nodules showed bacterial diversity of the nodule microbiome. Five hundred non-rhizobial colonies from 10 nodules, 50 colonies per nodule, were tested individually against the tomato …