Physical Sciences and Mathematics Commons^™

Breeding Milestones Correspond With Changes To Wheat Rhizosphere Biogeochemistry That Affect P Acquisition, Rebecca Kay Mcgrail, David A. Van Sanford, David H. Mcnear Jr.

Plant and Soil Sciences Faculty Publications

Breeding wheat (Triticum aestivum L.) has resulted in small gains in improved nutrient acquisition and use as numerous traits are involved. In this study, we evaluated the impact of breeding on P-acquisition and identified both plant and soil variables that could be used to inform the selection of germplasm with increased P acquisition efficiency. We previously screened a historic panel of winter wheat cultivars for root system architecture and root tip organic acid content when grown in P-deficient solution/agar and used these characteristics together with breeding history to develop a predicted P extraction potential (PEP). We tested the validity …

A Method For Phenotyping Roots Of Large Plants, Brian Rinehart, Hanna J. Poffenbarger, Daniel Lau, David H. Mcnear

Plant and Soil Sciences Faculty Publications

Linking root traits to plant functions can enable crop improvement for yield and ecosystem functions. However, plant breeding efforts targeting belowground traits are limited by appropriate phenotyping methods for large root systems. While advances have been made allowing for imaging large in situ root systems, many of these methods are inaccessible due to expensive technology requirements. The aim of this work was to develop a plant phenotyping platform and analysis method suitable for assessing root traits of large, intact root systems. With the use of a purpose-built imaging table and automated photo capture system, machine learning-based image segmentation, and off-the-shelf …

Are Soybean Models Ready For Climate Change Food Impact Assessments?, Kritika Kothari, Rafael Battisti, Kenneth J. Boote, Sotirios V. Archontoulis, Adriana Confalone, Julie Constantin, Santiago V. Cuadra, Philippe Debaeke, Babacar Faye, Brian Grant, Gerrit Hoogenboom, Qi Jing, Michael Van Der Laan, Fernando Antônio Macena Da Silva, Fabio R. Marin, Alireza Nehbandani, Claas Nendel, Larry C. Purcell, Budong Qian, Alex C. Ruane, Céline Schoving, Evandro H. F. M. Silva, Ward Smith, Afshin Soltani, Amit Srivastava, Nilson A. Vieira Jr., Stacey Slone, Montserrat Salmerón

Plant and Soil Sciences Faculty Publications

An accurate estimation of crop yield under climate change scenarios is essential to quantify our ability to feed a growing population and develop agronomic adaptations to meet future food demand. A coordinated evaluation of yield simulations from process-based eco-physiological models for climate change impact assessment is still missing for soybean, the most widely grown grain legume and the main source of protein in our food chain. In this first soybean multi-model study, we used ten prominent models capable of simulating soybean yield under varying temperature and atmospheric CO₂ concentration [CO₂] to quantify the uncertainty in soybean yield …

How Much Margin Is Left For Degrading Agricultural Soils? The Coming Soil Crises, Maheteme Gebremedhin, Mark S. Coyne, Karamat R. Sistani

Plant and Soil Sciences Faculty Publications

Agricultural soils are in peril. Multiple lines of observational and empirical evidence suggest that we are losing the world’s fertile soils at an alarming rate, worsening the on-going global food crisis. It is increasingly clear that the risk of soil crises driven by erratic precipitation, warming air, and farming mismanagement is coming sooner rather than later. At this critical time, society cannot avoid looking for ways to curb soil crises. We argue that now is the right time for science-based mitigation strategies and new insights to protect soils. We offer four research priority areas that society needs to address. Arresting …

Auxin/Cytokinin Antagonistic Control Of The Shoot/Root Growth Ratio And Its Relevance For Adaptation To Drought And Nutrient Deficiency Stresses, Jasmina Kurepa, Jan A. Smalle

Plant and Soil Sciences Faculty Publications

The hormones auxin and cytokinin regulate numerous aspects of plant development and often act as an antagonistic hormone pair. One of the more striking examples of the auxin/cytokinin antagonism involves regulation of the shoot/root growth ratio in which cytokinin promotes shoot and inhibits root growth, whereas auxin does the opposite. Control of the shoot/root growth ratio is essential for the survival of terrestrial plants because it allows growth adaptations to water and mineral nutrient availability in the soil. Because a decrease in shoot growth combined with an increase in root growth leads to survival under drought stress and nutrient limiting …

Soil Health – It's Not All Biology, Mark S. Coyne, E. M. Pena-Yewtukhiw, John H. Grove, A. C. Sant'anna, D. Mata-Padrino

Plant and Soil Sciences Faculty Publications

Soil Health research tends to bias to a biology/microbiology emphasis. We believe this bias neglects important physical and chemical interactions in soil that are crucial to soil function. We offer several examples illustrating this bias, and how it may misrepresent management practices that have the greatest influence on Soil Health. Four suggestions are given as approaches to mitigate this bias. By appreciating soil structure as a foundation for Soil Health and its microbial community, we believe better recommendations can be made to assist the farm community in its stewardship of soil as a critical natural resource.

Legacy Effects Of Intercropping And Nitrogen Fertilization On Soil N Cycling, Nitrous Oxide Emissions, And The Soil Microbial Community In Tropical Maize Production, Lucas P. Canisares, Hanna J. Poffenbarger, Eoin L. Brodie, Patrick O. Sorensen, Ulas Karaoz, Daniel M. Villegas, Jacobo Arango, Letusa Momesso, Carlos Alexandre Costa Crusciol, Heitor Cantarella

Plant and Soil Sciences Faculty Publications

Maize-forage grasses intercropping systems have been increasingly adopted by farmers because of their capacity to recycle nutrients, provide mulch, and add C to soil. However, grasses have been shown to increase nitrous oxide (N₂O) emissions. Some tropical grasses cause biological nitrification inhibition (BNI) which could mitigate N₂O emissions in the maize cycle but the reactions of the N cycle and the microbial changes that explain the N₂O emissions are little known in such intercropping systems. With this in mind, we explored intercropping of forage grasses (Brachiaria brizantha and Brachiaria humidicola) with distinct …

Impact Of Nitrogen Rate In Conventional And Organic Production Systems On Yield And Bread Baking Quality Of Soft Red Winter Wheat, Ammar Al-Zubade, Timothy D. Phillips, Mark A. Williams, Krista L. Jacobsen, David Van Sanford

Plant and Soil Sciences Faculty Publications

Soft red winter wheat (SRW) is characterized by high yield and relatively low protein content. In Kentucky, there is growing demand from local artisan bread bakers for regionally produced flour, requiring production of grain with increased protein content and/or strength. The objective of this two-year field experiment was to evaluate the effect of nitrogen (N) management on five cultivars of winter wheat on yield and bread baking quality traits of modern and landrace SRW cultivars (Triticum aestivum L.). All five cultivars were evaluated using two N application rates in conventional and organic production systems. All traits measured were significantly …

Nitrogen And Rainfall Effects On Crop Growth—Experimental Results And Scenario Analyses, Saadi Sattar Shahadha, Ole O. Wendroth, Dianyuan Ding

Plant and Soil Sciences Faculty Publications

Nitrogen (N) fertilization is critical for crop growth; however, its effect on crop growth and evapotranspiration (ETc) behaviors under different amounts of rainfall is not well understood. As such, there is a need for studying the impact of nitrogen application rates and rainfall amounts on crop growth and ETc components. Agricultural system models help to fill this knowledge gap, e.g., the Root Zone Water Quality Model (RZWQM2), which integrates crop growth-related processes. The objective of this study is to investigate the effect of the nitrogen application rate on crop growth, soil water dynamics, and ETc behavior under different rainfall amounts …

Evidence Of Nickel And Other Trace Elements And Their Relationship To Clinical Findings In Acute Mesoamerican Nephropathy: A Case-Control Analysis, Rebecca S. B. Fischer, Jason M. Unrine, Chandan Vangala, Wayne T. Sanderson, Sreedhar Mandayam, Kristy O. Murray

Plant and Soil Sciences Faculty Publications

BACKGROUND: Although there are several hypothesized etiologies of Mesoamerican Nephropathy (MeN), evidence has not yet pointed to the underlying cause. Exposure to various trace elements can cause the clinical features observed in MeN.

METHODS AND FINDINGS: We measured 15 trace elements, including heavy metals, in renal case-patients (n = 18) and healthy controls (n = 36) in a MeN high-risk region of Nicaragua. Toenails clippings from study participants were analyzed using inductively coupled plasma mass spectrometry. A case-control analysis was performed, and concentrations were also analyzed over participant characteristics and clinical parameters. Nickel (Ni) concentrations were significantly higher in toenails …

Recent Shrinkage And Fragmentation Of Bluegrass Landscape In Kentucky, Bo Tao, Yanjun Yang, Jia Yang, S. Ray Smith, James F. Fox, Alex C. Ruane, Jinze Liu, Wei Ren

Plant and Soil Sciences Faculty Publications

The Bluegrass Region is an area in north-central Kentucky with unique natural and cultural significance, which possesses some of the most fertile soils in the world. Over recent decades, land use and land cover changes have threatened the protection of the unique natural, scenic, and historic resources in this region. In this study, we applied a fragmentation model and a set of landscape metrics together with the satellite-derived USDA Cropland Data Layer to examine the shrinkage and fragmentation of grassland in the Bluegrass Region, Kentucky during 2008–2018. Our results showed that recent land use change across the Bluegrass Region is …

Global Pattern And Change Of Cropland Soil Organic Carbon During 1901-2010: Roles Of Climate, Atmospheric Chemistry, Land Use And Management, Wei Ren, Kamaljit Banger, Bo Tao, Jia Yang, Yawen Huang, Hanqin Tian

Plant and Soil Sciences Faculty Publications

Soil organic carbon (SOC) in croplands is a key property of soil quality for ensuring food security and agricultural sustainability, and also plays a central role in the global carbon (C) budget. When managed sustainably, soils may play a critical role in mitigating climate change by sequestering C and decreasing greenhouse gas emissions into the atmosphere. However, the magnitude and spatio-temporal patterns of global cropland SOC are far from well constrained due to high land surface heterogeneity, complicated mechanisms, and multiple influencing factors. Here, we use a process-based agroecosystem model (DLEM-Ag) in combination with diverse spatially-explicit gridded environmental data to …

Soil Net Nitrogen Mineralisation Across Global Grasslands, A. C. Risch, S. Zimmerman, R. Ochoa-Hueso, M. Schütz, B. Frey, J. L. Firn, P. A. Fay, F. Hagedorn, E. T. Borer, E. W. Seabloom, W. S. Harpole, J. M. H. Knops, Rebecca L. Mcculley, A. A. D. Broadbent, C. J. Stevens, M. L. Silveria, P. B. Adler, S. Báez, L. A. Biederman, J. M. Blair

Plant and Soil Sciences Faculty Publications

Soil nitrogen mineralisation (N_min), the conversion of organic into inorganic N, is important for productivity and nutrient cycling. The balance between mineralisation and immobilisation (net N_min) varies with soil properties and climate. However, because most global-scale assessments of net N_min are laboratory-based, its regulation under field-conditions and implications for real-world soil functioning remain uncertain. Here, we explore the drivers of realised (field) and potential (laboratory) soil net N_min across 30 grasslands worldwide. We find that realised N_min is largely explained by temperature of the wettest quarter, microbial biomass, clay content and bulk density. …

Climate Change Impacts On Winter Wheat Yield In Northern China, Xiu Geng, Fang Wang, Wei Ren, Zhixin Hao

Plant and Soil Sciences Faculty Publications

Exploring the impacts of climate change on agriculture is one of important topics with respect to climate change. We quantitatively examined the impacts of climate change on winter wheat yield in Northern China using the Cobb–Douglas production function. Utilizing time-series data of agricultural production and meteorological observations from 1981 to 2016, the impacts of climatic factors on wheat production were assessed. It was found that the contribution of climatic factors to winter wheat yield per unit area (WYPA) was 0.762–1.921% in absolute terms. Growing season average temperature (GSAT) had a negative impact on WYPA for the period of 1981–2016. A …

Root Hair Single Cell Type Specific Profiles Of Gene Expression And Alternative Polyadenylation Under Cadmium Stress, Jingyi Cao, Congting Ye, Guijie Hao, Carole Dabney-Smith, Arthur G. Hunt, Qingshun Q. Li

Plant and Soil Sciences Faculty Publications

Transcriptional networks are tightly controlled in plant development and stress responses. Alternative polyadenylation (APA) has been found to regulate gene expression under abiotic stress by increasing the heterogeneity at mRNA 3′-ends. Heavy metals like cadmium pollute water and soil due to mining and industry applications. Understanding how plants cope with heavy metal stress remains an interesting question. The Arabidopsis root hair was chosen as a single cell model to investigate the functional role of APA in cadmium stress response. Primary root growth inhibition and defective root hair morphotypes were observed. Poly(A) tag (PAT) libraries from single cell types, i.e., root …

Gamete Nuclear Migration In Animals And Plants, Umma Fatema, Mohammad F. Ali, Zheng Hu, Anthony J. Clark, Tomokazu Kawashima

Plant and Soil Sciences Faculty Publications

The migration of male and female gamete nuclei to each other in the fertilized egg is a prerequisite for the blending of genetic materials and the initiation of the next generation. Interestingly, many differences have been found in the mechanism of gamete nuclear movement among animals and plants. Female to male gamete nuclear movement in animals and brown algae relies on microtubules. By contrast, in flowering plants, the male gamete nucleus is carried to the female gamete nucleus by the filamentous actin cytoskeleton. As techniques have developed from light, electron, fluorescence, immunofluorescence, and confocal microscopy to live-cell time-lapse imaging using …

Trans-Cinnamic Acid-Induced Leaf Expansion Involves An Auxin-Independent Component, Jasmina Kurepa, Jan A. Smalle

Plant and Soil Sciences Faculty Publications

The phenylpropanoid pathway, the source of a large array of compounds with diverse functions, starts with the synthesis of trans-cinnamic acid (t-CA) that is converted by cinnamate-4-hydroxylase (C4H) into p-coumaric acid. We have recently shown that in Arabidopsis, exogenous t-CA promotes leaf growth by increasing cell expansion and that this response requires auxin signaling. We have also shown that cell expansion is increased in C4H loss-of-function mutants. Here we provide further evidence that leaf growth is enhanced by either t-CA or a t-CA derivative that accumulates upstream of C4H. We also show that …

Nitrogen Fertilizer Suppresses Mineralization Of Soil Organic Matter In Maize Agroecosystems, Navreet K. Mahal, William R. Osterholz, Fernando E. Miguez, Hanna J. Poffenbarger, John E. Sawyer, Daniel C. Olk, Sotirios V. Archontoulis, Michael J. Castellano

Plant and Soil Sciences Faculty Publications

The possibility that N fertilizer increases soil organic matter (SOM) mineralization and, as a result, reduces SOM stocks has led to a great debate about the long-term sustainability of maize-based agroecosystems as well as the best method to estimate fertilizer N use efficiency (FNUE). Much of this debate is because synthetic N fertilizer can positively or negatively affect SOM mineralization via several direct and indirect pathways. Here, we test a series of hypotheses to determine the direction, magnitude, and mechanism of N fertilizer effect on SOM mineralization and discuss the implications for methods to estimate FNUE. We measured the effect …

Assessing Variation In Us Soybean Seed Composition (Protein And Oil), Yared Assefa, Larry C. Purcell, Montse Salmeron, Seth Naeve, Shaun N. Casteel, Péter Kovács, Sotirios Archontoulis, Mark Licht, Fred Below, Herman Kandel, Laura E. Lindsey, John Gaska, Shawn Conley, Charles Shapiro, John M. Orlowski, Bobby R. Golden, Gurpreet Kaur, Maninderpal Singh, Kurt Thelen, Randall Laurenz, Dan Davidson, Ignacio A. Ciampitti

Plant and Soil Sciences Faculty Publications

Soybean [Glycine max (L.) Merr.] seed composition and yield are a function of genetics (G), environment (E), and management (M) practices, but contribution of each factor to seed composition and yield are not well understood. The goal of this synthesis-analysis was to identify the main effects of G, E, and M factors on seed composition (protein and oil concentration) and yield. The entire dataset (13,574 data points) consisted of 21 studies conducted across the United States (US) between 2002 and 2017 with varying treatments and all reporting seed yield and composition. Environment (E), defined as site-year, was the dominant …

Effect Of Stoniness On The Hydraulic Properties Of A Soil From An Evaporation Experiment Using The Wind And Inverse Estimation Methods, Nerea Arias, Iñigo Virto, Alberto Enrique, Paloma Bescansa, Riley Walton, Ole O. Wendroth

Plant and Soil Sciences Faculty Publications

Stony soils are distributed all over the world. The study of their characteristics has gained importance lately due to their increasing use as agricultural soils. The effect that rock fragments exert on the soil hydraulic properties is difficult to measure in situ, and is usually derived from the fine earth properties. However, the corrections used so far do not seem accurate for all types of stony soils. Our objective was to assess the adequacy of estimating the hydraulic properties of a stony soil from the fine earth ones by correcting the latter by the volume occupied by rock fragments. To …

Genome-Wide Association Studies For Yield-Related Traits In Soft Red Winter Wheat Grown In Virginia, Brian P. Ward, Gina Brown-Guedira, Frederic L. Kolb, David A. Van Sanford, Priyanka Tyagi, Clay H. Sneller, Carl A. Griffey

Plant and Soil Sciences Faculty Publications

Grain yield is a trait of paramount importance in the breeding of all cereals. In wheat (Triticum aestivum L.), yield has steadily increased since the Green Revolution, though the current rate of increase is not forecasted to keep pace with demand due to growing world population and increasing affluence. While several genome-wide association studies (GWAS) on yield and related component traits have been performed in wheat, the previous lack of a reference genome has made comparisons between studies difficult. In this study, a GWAS for yield and yield-related traits was carried out on a population of 322 soft red …

Breeding For Resilience To Increasing Temperatures: A Field Trial Assessing Genetic Variation In Soft Red Winter Wheat, Kathleen Russell, David Van Sanford

Plant and Soil Sciences Faculty Publications

Breeding for resilience to climate change is a daunting prospect. Crop and climate models tell us that global wheat yields are likely to decline as the climate warms, causing a significant risk to global food security. High temperatures are known to affect crop development yet breeding for tolerance to heat stress is difficult to achieve in field environments. We conducted an active warming study over two years to quantify the effects of heat stress on genetic variation of soft red winter (SRW) wheat (Triticum aestivum L.). Forty SRW cultivars and breeding lines were chosen based on marker genotypes at …

Modulation Of Auxin And Cytokinin Responses By Early Steps Of The Phenylpropanoid Pathway, Jasmina Kurepa, Timothy E. Shull, Sumudu S. Karunadasa, Jan A. Smalle

Plant and Soil Sciences Faculty Publications

Background: The phenylpropanoid pathway is responsible for the synthesis of numerous compounds important for plant growth and responses to the environment. In the first committed step of phenylpropanoid biosynthesis, the enzyme phenylalanine ammonia-lyase (PAL) deaminates L-phenylalanine into trans-cinnamic acid that is then converted into p-coumaric acid by cinnamate-4-hydroxylase (C4H). Recent studies showed that the Kelch repeat F-box (KFB) protein family of ubiquitin ligases control phenylpropanoid biosynthesis by promoting the proteolysis of PAL. However, this ubiquitin ligase family, alternatively named Kiss Me Deadly (KMD), was also implicated in cytokinin signaling as it was shown to promote the degradation of …

Signature Of Obliquity And Eccentricity In Soil Chronosequences, Christopher Shepard, Jon D. Pelletier, Marcel G. Schaap, Craig Rasmussen

Plant and Soil Sciences Faculty Publications

Periodic shifts in Earth's orbit alter incoming solar radiation and drive Quaternary climate cycles. However, unambiguous detection of these orbitally driven climatic changes in records of terrestrial sedimentation and pedogenesis remains poorly defined, limiting our understanding of climate change‐landscape feedbacks, impairing our interpretation of terrestrial paleoclimate proxies, and limiting linkages among pedogenesis, sedimentation, and paleoclimatic change. Using a meta‐analysis, we show that Quaternary soil ages preserved in the modern record have periodicities of 41 and 98 kyr, consistent with orbital cycles. Further, soil ages predominantly date to periods of low rates of climatic change following rapid climate shifts associated with …

Effects Of Red Clover Isoflavones On Tall Fescue Seed Fermentation And Microbial Populations In Vitro, Emily A. Melchior, Jason K. Smith, Liesel G. Schneider, J. Travis Mulliniks, Gary E. Bates, Zachary D. Mcfarlane, Michael D. Flythe, James L. Klotz, Jack P. Goodman, Huihua Ji, Phillip R. Myer

Plant and Soil Sciences Faculty Publications

Negative impacts of endophyte-infected Lolium arundinaceum (Darbyshire) (tall fescue) are responsible for over $2 billion in losses to livestock producers annually. While the influence of endophyte-infected tall fescue has been studied for decades, mitigation methods have not been clearly elucidated. Isoflavones found in Trifolium pratense (red clover) have been the subject of recent research regarding tall fescue toxicosis mitigation. Therefore, the aim of this study was to determine the effect of ergovaline and red clover isoflavones on rumen microbial populations, fiber degradation, and volatile fatty acids (VFA) in an in vitro system. Using a dose of 1.10 mg × L …

Nutrient Addition And Drought Interact To Change The Structure And Decrease The Functional Diversity Of A Mediterranean Grassland, Carla Nogueira, Alice Nunes, Miguel N. Bugalho, Cristina Branquinho, Rebecca L. Mcculley, Maria Conceição Caldeira

Plant and Soil Sciences Faculty Publications

Anthropogenic activities are increasing nutrient availability and altering precipitation regimes. This may lead to critical changes in grasslands functioning. This is particularly important for grasslands in the Mediterranean Basin that have evolved in nutrient poor soils, and where more frequent and prolonged droughts are projected to occur. However, there is limited knowledge regarding the interacting effects of multiple nutrient inputs and rainfall variability on the plant functional structure and diversity of Mediterranean grasslands. We conducted a nutrient addition experiment in a Mediterranean grassland during four contrasting precipitation years. We established four treatments that varied in the number of added nutrients, …

Growth, Yield Performance And Quality Parameters Of Three Early Flowering Chia (Salvia Hispanica L.) Genotypes Cultivated In Southwestern Germany, Samantha J. Grimes, Timothy D. Phillips, Volker Hahn, Filippo Capezzone, Simone Graeff-Hönninger

Plant and Soil Sciences Faculty Publications

The combination of consumer’s ongoing demand for chia (Salvia hispanica L.) alongside the increased demand for regionally produced food products provided the impetus for this study. Its aim was to test if a regional cultivation of new chia genotypes, which were adapted to day lengths greater than 12 h, is feasible under Central European conditions. Therefore, three early flowering chia genotypes (Sahi Alba 914, W13.1, G8) were cultivated in a randomized block design at two experimental stations in Southwestern Germany (Ihinger Hof, Eckartsweier) over the course of two years (2015, 2016). Mean yields ranged from 100 to 1290 kg …

Iac Gene Expression In The Indole-3-Acetic Acid-Degrading Soil Bacterium Enterobacter Soli Lf7, Isaac V. Greenhut, Beryl L. Slezak, Johan H. J. Leveau

Plant and Soil Sciences Faculty Publications

We show for soil bacterium Enterobacter soli LF7 that the possession of an indole-3-acetic acid catabolic (iac) gene cluster is causatively linked to the ability to utilize the plant hormone indole-3-acetic acid (IAA) as a carbon and energy source. Genome-wide transcriptional profiling by mRNA sequencing revealed that these iac genes, chromosomally arranged as iacHABICDEFG and coding for the transformation of IAA to catechol, were the most highly induced (>29-fold) among the relatively few (iac cluster were genes for a major facilitator superfamily protein (mfs) and enzymes of the β-ketoadipate pathway (pcaIJD-catBCA), which channels …

Biomass Production Of Herbaceous Energy Crops In The United States: Field Trial Results And Yield Potential Maps From The Multiyear Regional Feedstock Partnership, Do Kyoung Lee, Ezra Aberle, Erik K. Anderson, William Anderson, Brian S. Baldwin, David Baltensperger, Michael Barrett, Jürg Blumenthal, Stacy Bonos, Joe Bouton, David I. Bransby, Charlie Brummer, Pane S. Burks, Chengci Chen, Christopher Daly, Josh Egenolf, Rodney L. Farris, John H. Fike, Roch Gaussoin, John R. Gill, Kenneth Gravois, Michael D. Halbleib, Anna Hale, Wayne Hanna, Keith Harmoney, Emily A. Heaton, Ron W. Heiniger, Lindsey Hoffman, Chang O. Hong, Gopal Kakani, David Williams, Linda Williams

Plant and Soil Sciences Faculty Publications

Current knowledge of yield potential and best agronomic management practices for perennial bioenergy grasses is primarily derived from small‐scale and short‐term studies, yet these studies inform policy at the national scale. In an effort to learn more about how bioenergy grasses perform across multiple locations and years, the U.S. Department of Energy (US DOE)/Sun Grant Initiative Regional Feedstock Partnership was initiated in 2008. The objectives of the Feedstock Partnership were to (1) provide a wide range of information for feedstock selection (species choice) and management practice options for a variety of regions and (2) develop national maps of potential feedstock …

Phosphorus And Potassium Fertilizer Application Strategies In Corn–Soybean Rotations, Timothy J. Boring, Kurt D. Thelen, James E. Board, Jason L. De Bruin, Chad D. Lee, Seth L. Naeve, William J. Ross, Wade A. Kent, Landon L. Ries

Plant and Soil Sciences Faculty Publications

To determine if current university fertilizer rate and timing recommendations pose a limitation to high-yield corn (Zea mays subsp. mays) and soybean (Glycine max) production, this study compared annual Phosphorous (P) and Potassium (K) fertilizer applications to biennial fertilizer applications, applied at 1× and 2× recommended rates in corn–soybean rotations located in Minnesota (MN), Iowa (IA), Michigan (MI), Arkansas (AR), and Louisiana (LA). At locations with either soil test P or K in the sub-optimal range, corn grain yield was significantly increased with fertilizer application at five of sixteen site years, while soybean seed yield was significantly …