Other Plant Sciences Commons^™

Two Magnaporthe Appressoria-Specific (Mas) Proteins, Momas3 And Momas5, Are Required For Suppressing Host Innate Immunity And Promoting Biotrophic Growth In Rice Cells, Ziwen Gong, Na Ning, Zhiqiang Li, Xin Xie, Richard Wilson, Wende Liu

Department of Plant Pathology: Faculty Publications

In the devastating rice blast fungus Magnaporthe oryzae, six Magnaporthe appressoria-specific (MAS) proteins are encoded by MoGAS1, MoGAS2 and MoMAS3–MoMAS6. MoGAS1 and MoGAS2 were previously characterized as M. oryzae virulence factors; however, the roles of the other four genes are unknown. Here, we found that, although the loss of any MAS gene did not affect appressorial formation or vegetative growth, ΔMomas3 and ΔMomas5 mutant strains (but not the others) were reduced in virulence on susceptible CO-39 rice seedlings. Focusing on ΔMomas3 and ΔMomas5 mutant strains, we found that they could penetrate …

Variation In Bacterial Community Structure Under Long-Term Fertilization, Tillage, And Cover Cropping In Continuous Cotton Production, Ning Duan, Lidong Li, Xiaolong Liang, Aubrey Fine, Jie Zhuang, Mark Radosevich, Sean M. Schaeffer

Department of Agronomy and Horticulture: Faculty Publications

Agricultural practices alter the structure and functions of soil microbial community. However, few studies have documented the alterations of bacterial communities in soils under long-term conservation management practices for continuous crop production. In this study, we evaluated soil bacterial diversity using 16S rRNA gene sequencing and soil physical and chemical properties within 12 combinations of inorganic N fertilization, cover cropping, and tillage throughout a cotton production cycle. Soil was collected from field plots of the West Tennessee Agriculture Research and Education Center in Jackson, TN, United States. The site has been under continuous cotton production for 38 years. A total …

Fine Mapping And Cloning Of The Major Seed Protein Quantitative Trait Loci On Soybean Chromosome 20, Christina E. Fliege, Russell A. Ward, Pamela Vogel, Hanh Nguyen, Truyen Quach, Ming Guo, João Paulo Gomes Viana, Lucas Borges Dos Santos, James Specht, Thomas Clemente, Matthew E. Hudson, Brian W. Diers

Department of Agronomy and Horticulture: Faculty Publications

Soybean [Glycine max (L.) Merr.] is a unique crop species because it has high levels of both protein and oil in its seed. Of the many quantitative trait loci (QTL) controlling soybean seed protein content, alleles of the cqSeed protein-003 QTL on chromosome 20 exert the greatest additive effect. The high-protein allele exists in both cultivated and wild soybean (Glycine soja Siebold & Zucc.) germplasm. Our objective was to fine map this QTL to enable positional-based cloning of its underlying causative gene(s). Fine mapping was achieved by developing and testing a series of populations in which the chromosomal region surrounding …

Microbiome Variation Across Populations Of Desert Halophyte Zygophyllum Qatarensis, Abdul Latif Khan, Lucas Dantas Lopes, Saqib Bilal, Sajjad Asaf, Kerri M. Crawford, Venkatesh Balan, Ahmed Al-Rawahi, Ahmed Al-Harrasi, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Microbial symbionts play a significant role in plant health and stress tolerance. However, few studies exist that address rare species of core-microbiome function during abiotic stress. In the current study, we compared the microbiome composition of succulent dwarf shrub halophyte Zygophyllum qatarensis Hadidi across desert populations. The results showed that rhizospheric and endosphere microbiome greatly varied due to soil texture (sandy and gravel). No specific bacterial amplicon sequence variants were observed in the core-microbiome of bulk soil and rhizosphere, however, bacterial genus Alcaligenes and fungal genus Acidea were abundantly distributed across root and shoot endospheres. We also analyzed major nutrients …

Microbiome Variation Across Populations Of Desert Halophyte Zygophyllum Qatarensis, Abdul Latif Khan, Lucas Dantas Lopes, Saqib Bilal, Sajjad Asaf, Kerri M. Crawford, Venkatesh Balan, Ahmed Al-Rawahi, Ahmed Al-Harrasi, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Microbial symbionts play a significant role in plant health and stress tolerance. However, few studies exist that address rare species of core-microbiome function during abiotic stress. In the current study, we compared the microbiome composition of succulent dwarf shrub halophyte Zygophyllum qatarensis Hadidi across desert populations. The results showed that rhizospheric and endosphere microbiome greatly varied due to soil texture (sandy and gravel). No specific bacterial amplicon sequence variants were observed in the core-microbiome of bulk soil and rhizosphere, however, bacterial genus Alcaligenes and fungal genus Acidea were abundantly distributed across root and shoot endospheres. We also analyzed major nutrients …

A Global Soil Spectral Calibration Library And Estimation Service, Keith D. Sheperd, Rich Ferguson, David Hoover, Fenny Van Egmond, Jonathan Sanderman, Yufeng Ge

Department of Agronomy and Horticulture: Faculty Publications

There is growing global interest in the potential for soil reflectance spectroscopy to fill an urgent need for more data on soil properties for improved decision-making on soil security at local to global scales. This is driven by the capability of soil spectroscopy to estimate a wide range of soil properties from a rapid, inexpensive, and highly reproducible measurement using only light. However, several obstacles are preventing wider adoption of soil spectroscopy. The biggest obstacles are the large variation in the soil analytical methods and operating procedures used in different laboratories, poor reproducibility of analyses within and amongst laboratories and …

Southeast Asia Must Narrow Down The Yield Gap To Continue To Be A Major Rice Bowl, Shen Yuan, Alexander M. Stuart, Alice G. Laborte, Juan I. Rattalino Edreira, Achim Dobermann, Le Vu Ngoc Kien, Lưu Thị Thúy, Kritkamol Paothong, Prachya Traesang, Khin Myo Tint, Su Su San, Marcelino Q. Villafuerte Ii, Emma D. Quicho, Anny Ruth P. Pame, Rathmuny Then, Rica Joy Flor, Neak Thon, Fahmuddin Agus, Nurwulan Agustiani, Nanyan Deng, Tao Li, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Southeast Asia is a major rice-producing region with a high level of internal consumption and accounting for 40% of global rice exports. Limited land resources, climate change and yield stagnation during recent years have once again raised concerns about the capacity of the region to remain as a large net exporter. Here we use a modelling approach to map rice yield gaps and assess production potential and net exports by 2040. We find that the average yield gap represents 48% of the yield potential estimate for the region, but there are substantial differences among countries. Exploitable yield gaps are relatively …

Editorial: Genomics-Enabled Triticeae Improvement, Xue-Feng Ma, Xianchun Xia, Shuyu Liu, P. Stephen Baenziger, Hakan Özkan

Department of Agronomy and Horticulture: Faculty Publications

No abstract provided.

Quantifying And Manipulating The Angles Of Light In Experimental Measurements Of Plant Gas Exchange, Z. Carter Berry, Jerry Larue, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Diffuse light has been shown to alter plant leaf photosynthesis, transpiration and water-use efficiency. Despite this, the angular distribution of light for the artificial light sources used with common gas exchange systems is unknown. Here, we quantify the angular distribution of light from common gas exchange systems and demonstrate the use of an integrating sphere for manipulating those light distributions. Among three different systems, light from a 90° angle perpendicular to the leaf surface (±5.75°) was <25% of the total light reaching the leaf surface. The integrating sphere resulted in a greater range of possible distributions from predominantly direct light (i.e., >40% of light from a 90 ± 5.75° angle perpendicular to the leaf surface) to almost entirely diffuse (i.e., light from an even distribution …

No-Till Farming And Greenhouse Gas Fluxes: Insights From Literature And Experimental Data, S. J. Ruis, H. Blanco-Canqui, P. J. Jasa, V. L. Jin

Department of Agronomy and Horticulture: Faculty Publications

Tillage intensity may differently impact gaseous losses of C and N to the atmosphere, but data from long-term experiments are relatively few. Yet, this information is needed to better understand C and N losses and gains in agricultural systems. The objective of this study was to determine how tillage intensity affects soil greenhouse gas (GHG) fluxes (CO₂, N₂O, and CH₄) by comparing experimental data from moldboard plow (MP), chisel plow (CP), double disk (DD), and no-till (NT) soils after 38–40 yr of management in a rainfed corn (Zea mays L.)- soybean (Glycine …

Ecology And Diversity Of Culturable Fungal Species Associated With Soybean Seedling Diseases In The Midwestern United States, Mirian F. Pimentel, Ali Y. Srour, Amanda J. Warner, Jason P. Bond, Carl A. Bradley, John Rupe, Martin I. Chilvers, J. Alejandro Rojas, Janette L. Jacobs, Christopher R. Little, Alison E. Robertson, Loren J. Giesler, Dean Malvick, Kiersten Wise, Albert Tenuta, Ahmad M. Fakhoury

Department of Plant Pathology: Faculty Publications

Aims: To isolate and characterize fungi associated with diseased soybean seedlings in Midwestern soybean production fields and to determine the influence of environmental and edaphic factors on their incidence.

Methods and Results: Seedlings were collected from fields with seedling disease history in 2012 and 2013 for fungal isolation. Environmental and edaphic data associated with each field was collected. 3036 fungal isolates were obtained and assigned to 76 species. The most abundant genera recovered were Fusarium (73%) and Trichoderma (11.2%). Other genera included Mortierella, Clonostachys, Rhizoctonia, Alternaria, Mucor, Phoma, Macrophomina and Phomopsis. …

Improving Taxonomic Delimitation Of Fungal Species In The Age Of Genomics And Phenomics, Asjley Stengel, Kimberly M. Stanke, Amanda C. Quattrone, Joshua Herr

Department of Plant Pathology: Faculty Publications

Species concepts have long provided a source of debate among biologists. These lively debates have been important for reaching consensus on how to communicate across scientific disciplines and for advancing innovative strategies to study evolution, population biology, ecology, natural history, and disease epidemiology. Species concepts are also important for evaluating variability and diversity among communities, understanding biogeographical distributions, and identifying causal agents of disease across animal and plant hosts. While there have been many attempts to address the concept of species in the fungi, there are several concepts that have made taxonomic delimitation especially challenging. In this review we discuss …

Hybrid Seed Set In Relation With Male Floral Traits, Estimation Of Heterosis And Combining Abilities For Yield And Its Components In Wheat (Triticum Aestivum L.), Samira El Hanafi, Souad Cherkaoui, Zakaria Kehel, Miguel Sanchez-Garcia, Jean-Benoit Sarazin, Stephen Baenziger, Wuletaw Tadesse

Department of Agronomy and Horticulture: Faculty Publications

Breeding hybrids with maximum heterosis requires efficient cross-pollination and an improved male sterility system. Renewed efforts have been made to dissect the phenotypic variation and genetic basis of hybrid floral traits, although the potential of tailoring the appropriate flower design on seed setting is less known. To this end, elite wheat genotypes were crossed using a chemical hybridizing agent at different doses. A total of 23 hybrids were developed from a partial diallel design; and planted in an alpha lattice design with their parents at two locations in Morocco, for two years, to evaluate for yield components, heterosis and combining …

The Astounding World Of Glycans From Giant Viruses, Anna Notaro, Chantal Abergel, Rosa Lanzetta, Todd L. Lowary, Antonio Molinaro, Michela Tonetti, James L. Van Etten, Cristina De Castro

Department of Plant Pathology: Faculty Publications

Viruses are a heterogeneous ensemble of entities, all sharing the need for a suitable host to replicate. They are extremely diverse, varying in morphology, size, nature, and complexity of their genomic content. Typically, viruses use host-encoded glycosyltransferases and glycosidases to add and remove sugar residues from their glycoproteins. Thus, the structure of the glycans on the viral proteins have, to date, typically been considered to mimick those of the host. However, the more recently discovered large and giant viruses differ from this paradigm. At least some of these viruses code for an (almost) autonomous glycosylation pathway. These viral genes include …

Post-Termination Effects Of Cover Crop Monocultures And Mixtures On Soil Inorganic Nitrogen And Microbial Communities On Two Organic Farms In Illinois, Eleanor E. Lucadamo, Ashley A. Holmes, Samuel E. Wortman, Anthony C. Yannarell

Department of Agronomy and Horticulture: Faculty Publications

Cover crops can continue to affect agricultural systems even after they have been terminated by influencing nitrogen dynamics and by altering soil microbial communities. These post-termination effects can influence soil fertility, weed pressure, and the dynamics of potential plant pathogens in the narrow window of time between cover crop termination and cash crop emergence. We evaluated the post-termination effects of 12 different spring-sown cover crop mixtures and monocultures on soil nitrogen and microbial communities on two different organic farms in Central Illinois (on Lawson silt loam soil) and Northern Illinois (on Virgil silt loam soil). In comparison to control plots …

Post-Termination Effects Of Cover Crop Monocultures And Mixtures On Soil Inorganic Nitrogen And Microbial Communities On Two Organic Farms In Illinois, Eleanor E. Lucadamo, Ashley A. Holmes, Samuel E. Wortman, Anthony C. Yannarell

Department of Agronomy and Horticulture: Faculty Publications

Cover crops can continue to affect agricultural systems even after they have been terminated by influencing nitrogen dynamics and by altering soil microbial communities. These post-termination effects can influence soil fertility, weed pressure, and the dynamics of potential plant pathogens in the narrow window of time between cover crop termination and cash crop emergence. We evaluated the post-termination effects of 12 different spring-sown cover crop mixtures and monocultures on soil nitrogen and microbial communities on two different organic farms in Central Illinois (on Lawson silt loam soil) and Northern Illinois (on Virgil silt loam soil). In comparison to control plots …

Practice Cost And Size Differences In Invasive Plant Management Strategies: An Empirical Analysis Of Us Great Plains States, Mazbahul G. Ahamad

Department of Agronomy and Horticulture: Faculty Publications

Grassland conservation of the Conservation Stewardship Program in the United States (US) is one of the largest cost-sharing initiatives for protecting grazing land from invasive and woody plants. The practice cost and unit size of various invasive and woody plant management strategies, such as mulching, brush management, and pre- scribed burning, are different from state to state. We aimed to compare and examine the association between practice cost ($/acre[ac]) and standard unit size of practice (acre) of mulching, brush management, and pre- scribed burning strategies in nine US Great Plains states, including Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, …

Implementation Of Epigenetic Variation In Sorghum Selection And Implications For Crop Resilience Breeding, Dikungwa Ketumile, Xiaodong Yang, Robersy Sanchez, Hardik Kundariya, John F. Rajewski, Ismail M. Dweikat, Sally A. Mackenzie

Department of Agronomy and Horticulture: Faculty Publications

Crop resilience and yield stability are complex traits essential for food security. Sorghum bicolor is an important grain crop that shows promise for its natural resilience to drought and potential for marginal land production. We have developed sorghum lines in the Tx430 genetic background suppressed for MSH1 expression as a means of inducing de novo epigenetic variation, and have used these materials to evaluate changes in plant growth vigor. Plant crossing and selection in two distinct environments revealed features of phenotypic plasticity derived from MSH1 manipulation. Introduction of an epigenetic variation to an isogenic sorghum population, in the absence of …

Assessment Of Bacterial Inoculant Delivery Methods For Cereal Crops, Yen Ning Chai, Stephanie Futrell, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Despite growing evidence that plant growth-promoting bacteria can be used to improve crop vigor, a comparison of the different methods of delivery to determine which is optimal has not been published. An optimal inoculation method ensures that the inoculant colonizes the host plant so that its potential for plant growth-promotion is fully evaluated. The objective of this study was to compare the efficacy of three seed coating methods, seedling priming, and soil drench for delivering three bacterial inoculants to the sorghum rhizosphere and root endosphere. The methods were compared across multiple time points under axenic conditions and colonization efficiency was …

Seed-Shattering Phenology At Soybean Harvest Of Economically Important Weeds In Multiple Regions Of The United States. Part 3: Drivers Of Seed Shatter, Lauren M. Schwartz-Lazaro, Lovreet S. Shergill, Jeffrey A. Evans, Muthukumar V. Bagavathiannan, Shawn C. Beam, Mandy D. Bish, Jason A. Bond, Kevin W. Bradley, William S. Curran, Adam S. Davis, Wesley J. Everman, Michael L. Flessner, Steven C. Haring, Nicholas R. Jordan, Nicholas E. Korres, John L. Lindquist, Jason K. Norsworthy, Tameka L. Sanders, Larry E. Steckel, Mark J. Vangessel, Blake Young, Steven B. Mirsky

Department of Agronomy and Horticulture: Faculty Publications

Seed retention, and ultimately seed shatter, are extremely important for the efficacy of harvest weed seed control (HWSC) and are likely influenced by various agroecological and environmental factors. Field studies investigated seed-shattering phenology of 22 weed species across three soybean [Glycine max (L.) Merr.]-producing regions in the United States. We further evaluated the potential drivers of seed shatter in terms of weather conditions, growing degree days, and plant biomass. Based on the results, weather conditions had no consistent impact on weed seed shatter. However, there was a positive correlation between individual weed plant biomass and delayed weed seed-shattering rates during …

Corn Nitrogen Nutrition Index Prediction Improved By Integrating Genetic, Environmental, And Management Factors With Active Canopy Sensing Using Machine Learning, Dan Li, Yuxin Miao, Curtis J. Ransom, Gregory Mac Bean, Newell R. Kitchen, Fabián G. Fernández, John E. Sawyer, James J. Camberato, Paul R. Carter, Richard B. Ferguson, David W. Franzen, Carrie A. M. Laboski, Emerson D. Nafziger, John F. Shanahan

Department of Agronomy and Horticulture: Faculty Publications

Accurate nitrogen (N) diagnosis early in the growing season across diverse soil, weather, and management conditions is challenging. Strategies using multi-source data are hypothesized to perform significantly better than approaches using crop sensing information alone. The objective of this study was to evaluate, across diverse environments, the potential for integrating genetic (e.g., comparative relative maturity and growing degree units to key developmental growth stages), environmental (e.g., soil and weather), and management (e.g., seeding rate, irrigation, previous crop, and preplant N rate) information with active canopy sensor data for improved corn N nutrition index (NNI) prediction using machine learning methods. Thirteen …

Tracking Spatial Regimes In Animal Communities: Implications For Resilience-Based Management, Caleb P. Roberts, Daniel R. Uden, Craig R. Allen, David G. Angeler, Larkin A. Powell, Brady W. Allred, Matthew O. Jones, Jeremy D. Maestas, Dirac L. Twidwell Jr

Department of Agronomy and Horticulture: Faculty Publications

Spatial regimes (the spatial extents of ecological states) exhibit strong spatiotemporal order as they expand or contract in response to retreating or encroaching adjacent spatial regimes (e.g., woody plant invasion of grasslands) and human management (e.g., fire treatments). New methods enable tracking spatial regime boundaries via vegetation landcover data, and this approach is being used for strategic management across biomes. A clear advancement would be incorporating animal community data to track spatial regime boundaries alongside vegetation data. In a 41,170-hectare grassland experiencing woody plant encroachment, we test the utility of using animal community data to track spatial regimes via two …

Water Use Characteristics Of Weeds: A Global Review, Best Practices, And Future Directions, Mandeep Singh, Meetpal Singh Kukal, Suat Irmak, Amit J. Jhala

Department of Agronomy and Horticulture: Faculty Publications

Weeds usually penalize crop yields by competing for resources, such as water, light, nutrients, and space. Most of the studies on the crop-weed competition domain are limited to assessing crop-yield losses due to weed pressure and other crop-weed interactions, overlooking the significant uptake of soil-water by weeds that exacerbates global water constraints and threatens the productivity and profitability. The objective of this review was to synthesize globally available quantitative data on weed water use (WU) sourced from 23 peer-reviewed publications (filtered from 233 publications via a multi-step protocol of inclusion criteria) with experimental investigations across space (3 continents), time (1927–2018), …

Management-Intensive Grazing Impacts On Total Escherichia Coli, E. Coli O157: H7, And Antibiotic Resistance Genes In A Riparian Stream, Laura M. Rubeck, James E. Wells, Kathy Hanford, Lisa M. Durso, Walter H. Schacht, Elaine D. Berry

Department of Agronomy and Horticulture: Faculty Publications

The impacts of management-intensive grazing (MIG) of cattle on concentrations of total Escherichia coli, total suspended solids (TSS), and nitrate-nitrite nitrogen (NO₃+NO₂-N), and occurrence of E. coli O157:H7 and selected antibiotic resistance genes (ARGs) in stream water and/or sediments were evaluated. Cattle were grazed for twoweek periods in May in each of three years. Overall, grazing increased total E. coli in downstream water by 0.89 log10 MPN/100 mL (p < 0.0001), and downstream total E. coli concentrations were higher than upstream over all sampling intervals. Downstream TSS levels also increased (p ≤ 0.0294) during grazing. In contrast, there was …

The Last Continuous Grasslands On Earth: Identification And Conservation Importance, Rheinhardt Scholtz, Dirac L. Twidwell Jr

Department of Agronomy and Horticulture: Faculty Publications

Grasslands are the most threatened and least protected biome. Yet, no study has been conducted to identify the last remaining continuous grasslands on Earth. Here, we used World Wildlife Fund (WWF) and International Union for Conservation of Nature (IUCN) classifications to measure the degree of intactness remaining for the world's grassland ecoregions. This analysis revealed three findings of critical conservation importance. First, only a few large, intact grasslands remain. Second, every continent with a grassland ecoregion considered in this study contains at least one relatively intact grassland ecoregion. Third, the largest remaining continuous grasslands identified in this analysis have persisted …

A Phytobacterial Tir Domain Effector Manipulates Nad+ To Promote Virulence, Samuel Eastman, Thomas Smith, Mark A. Zaydman, Panya Kim, Samuel Martinez, Neha Damaraju, Aaron Diantonio, Jeffrey Milbrandt, Thomas Clemente, James R. Alfano, Ming Guo

Department of Agronomy and Horticulture: Faculty Publications

The Pseudomonas syringae DC3000 type III effector HopAM1 suppresses plant immunity and contains a Toll/interleukin-1 receptor (TIR) domain homologous to immunity-related TIR domains of plant nucleotide-binding leucine-rich repeat receptors that hydrolyze nicotinamide adenine dinucleotide (NAD+) and activate immunity. In vitro and in vivo assays were conducted to determine if HopAM1 hydrolyzes NAD+ and if the activity is essential for HopAM1’s suppression of plant immunity and contribution to virulence. HPLC and LC-MS were utilized to analyze metabolites produced from NAD+ by HopAM1 in vitro and in both yeast and plants. Agrobacterium-mediated transient expression and in planta inoculation assays were performed to …

Predicting Munsell Color For Turfgrass Leaves, William L. Berndt, Roch E. Gaussoin

Department of Agronomy and Horticulture: Faculty Publications

Linking turfgrass color to hue, value, chroma (H V/C) in the Munsell Plant Tissue Color Book is a visual comparison process for specifying and communicating plant color. If subjectivity of visual comparison can be mitigated, then accuracy of color matching may be improved. Research was conducted to develop an algorithm predicting H V/C from CIE-xyY color (xyY) in digital images of leaves of four turfgrasses. First, value-chroma (V/C) arrays for Munsell hue groups 5Y, 2.5GY, 5GY, 7.5GY, 10GY, and 2.5G were converted to xyY. Next, chromaticity (xy) plots from each array were fitted with …

Role Of Seed Mixes, Biochar Soil Amendment, And The Soil Seed Bank In Improving Palouse Prairie Restoration, Kristine Snyder

EWU Masters Thesis Collection

The Palouse Prairie Ecoregion of Eastern Washington and Idaho is critically endangered. Eastern Washington University (EWU) has begun a ~120 acre campus prairie restoration; however, there is considerable uncertainty about the most effective restoration approach. Annual seeds and soil organic matter are important for succession and soil moisture, but their roles are unknown for Palouse prairie restoration. Additionally, the soil seedbank of the Palouse ecoregion is widely unknown but could provide insight into methods or species to use for restoration. My research aimed to determine the effects of seed mix diversity, annual seed addition, and soil organic matter (as biochar) …

Field Validation Of A Farmer Supplied Data Approach To Close Soybean Yield Gaps In The Us North Central Region, José F. Andrade, Spyridon Mourtzinis, Juan I. Rattalino Edreira, Shawn P. Conley, John Gaska, Herman J. Kandel, Laura E. Lindsey, Seth Naeve, Scott Nelson, Maninder P. Singhi, Laura J. Thompson, James E. Specht, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

CONTEXT: Producer-reported data can be used to identify suites of management practices that lead to higher yield and profit. However, a rigorous validation of the approach in relation to its potential impact on farmer yield and profit is lacking.

OBJECTIVE: This study aimed to validate a producer-data approach on its capability to guide on-farm evaluation of management practices with greatest potential for increasing producer yield and profit. We show proof of concept using soybean in the North Central US region as a case study.

METHODS: We used a combination of regression tree analysis and a spatial framework to determine practices …

A New Perspective When Examining Maize Fertilizer Nitrogen Use Efficiency, Incrementally, Newell R. Kitchen, Curtis J. Ransom, James S. Schepers, Jerry L. Hatfield, Raymond Massey, Scott T. Drummond

Department of Agronomy and Horticulture: Faculty Publications

For maize (Zea mays L.), nitrogen (N) fertilizer use is often summarized from field to global scales using average N use efficiency (NUE). But expressing NUE as averages is misleading because grain increase to added N diminishes near optimal yield. Thus, environmental risks increase as economic benefits decrease. Here, we use empirical datasets obtained in North America of maize grain yield response to N fertilizer (n = 189) to create and interpret incremental NUE (iNUE), or the change in NUE with change in N fertilization. We show for those last units of N applied to reach economic optimal N …