Agronomy and Crop Sciences Commons^™

Identification And Utilization Of Genetic Determinants Of Trait Measurement Errors In Image-Based, High-Throughput Phenotyping, Yan Zhou, Aaron Kusmec, Seyed Vahid Mirnezami, Lakshmi Attigala, Srikant Srinivasan, Talukder Zaki Jubery, James Schnable, Maria G. Salas Fernandez, Baskar Ganapathysubramanian, Patrick S. Schnable

Department of Agronomy and Horticulture: Faculty Publications

The accuracy of trait measurements greatly affects the quality of genetic analyses. During automated phenotyping, trait measurement errors, i.e., differences between automatically extracted trait values and ground truth, are often treated as random effects that can be controlled by increasing population sizes and/or replication number. By contrast, there is some evidence that trait measurement errors may be partially under genetic control. Consistent with this hypothesis, we observed substantial non-random, genetic contributions to trait measurement errors for five maize (Zea mays) tassel traits collected using an image-based phenotyping platform. The phenotyping accuracy varied according to whether a tassel exhibited …

Evaluation Of Corn Agronomic Management Practices Following A Rye Cover Crop, Daniel John Quinn

Theses and Dissertations--Plant and Soil Sciences

Fall implementation of a rye (Secale cereale L.) cover crop (RCC) prior to spring corn (Zea mays L.) planting is a management practice used to improve soil conservation, water quality, and limit herbicide dependence. However, corn growth and yield following a RCC is often reduced due to early-season nitrogen (N) stress and decreased plant emergence, which can limit RCC adoption. The objective(s) of this research were to evaluate corn agronomic management practices (e.g., N and seeding rate management, in-furrow (IF) starter use) following a RCC and determine which management practices can be used to limit corn stress following …

Incorporation Of Summer Annual Mixtures Into Grazing Systems In Kentucky, Kelly Marie Mercier

Theses and Dissertations--Plant and Soil Sciences

Utilizing summer annual grass-legume forage mixtures has the potential to improve forage yield and nutritive characteristics, and/or animal performance during times when cool-season pasture growth is limited by high temperatures. Legumes can utilize atmospheric nitrogen, which can increase crude protein and forage digestibility in mixtures. As nitrogen application generally improves both the yield and nutritive characteristics of summer annual forages, but can have a negative effect on legume competitiveness, nitrogen fertilizer recommendations for legume-containing summer annual mixtures are not well established.

Two experiments were conducted to determine the feasibility of utilizing summer annual mixtures in Kentucky, USA. The first experiment …

Enhancing Agroecosystem Phosphorus Management: Root Phenotyping And Decomposition For Improved Phosphorus Cycling, Rebecca Kay Mcgrail

Theses and Dissertations--Plant and Soil Sciences

Plant roots are often overlooked when making nutrient management decisions. Evaluating differences in P acquisition strategies and cycling resulting from years of shoot-specific plant breeding will aid in reducing fertilizer inputs, with the ultimate goal of improving economic sustainability of crop production and preservation of ecosystem services. To achieve this goal, this research screened a diverse panel of winter wheat cultivars that included old and modern, dwarfed and wild type varieties for physical and chemical root phenotypes related to P acquisition. Old cultivars had larger root systems with more roots that grew two times faster than intermediate/modern cultivars. Wild type …

Quantifying The Impacts Of An Integrated Crop-Livestock System On Plant Nutrient Accumulation, Crop Yield, And Economic Performance, Teerath Singh Rai

Electronic Theses and Dissertations

Integrated crop-livestock systems (ICLs), if managed properly, have the potential for enhancing crop production and economics. Cover crops in ICL can be grazed to provide feed for livestock and improve nutrient recycling. This dissertation focused on assessing the impacts of ICL on crop yield and economics using field and modeling studies. Specific objectives of this dissertation are: (i) evaluating the impacts of the ICL on crop yield, and economic performance in a 3-yr oat (Avena sativa L.) – maize (Zea mays L.) – soybean (Glycine max (L.) Merr.) rotation, (ii) assessing the impacts of the ICL on maize biomass accumulation, …

Arkansas Corn And Grain Sorghum Performance Tests 2020, J. F. Carlin, R. D. Bond, R. B. Morgan

Arkansas Agricultural Experiment Station Research Series

Corn and grain sorghum performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture. The tests provide information to companies marketing seed within the state and aid the Arkansas Cooperative Extension Service in formulating recommendations for producers.

The 2020 corn performance tests contained 85 hybrids and were conducted at the Northeast Research and Extension Center (NEREC) at Keiser, the Lon Mann Cotton Research Station (LMCRS) near Marianna, the Bell Farming Company (BFC) near Des Arc, the Pine Tree Research Station (PTRS) near Colt, the Rohwer Research Station (RRS) near Rohwer, and the Rice …

Arkansas Soybean Performance Tests 2020, J. F. Carlin, R. D. Bond, R. B. Morgan

Arkansas Agricultural Experiment Station Research Series

Soybean variety and strain performance tests are conducted each year in Arkansas by the University of Arkansas System Division of Agriculture’s Arkansas Crop Variety Improvement Program. The tests provide information to companies developing varieties and/or marketing seed within the State, and aid the Arkansas Cooperative Extension Service in formulating variety recommendations for soybean producers.

Evaluation Of Corn Herbicide Programs With And Without Atrazine, Jason K. Norsworthy, Jacob Thomas Richburg, L. Tom Barber, Trenton Roberts, Edward Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Atrazine is a foundational herbicide in corn (Zea mays L.) because of its broad-spectrum weed control and utility for pre-emergence or postemergence applications. Extensive atrazine use has led to traces in groundwater, surface water, and aquifers. This research explored corn herbicide regimes with little or no atrazine. Pre-emergence herbicide treatments [S-metolachlor (0.955 lb acre^–1); saflufenacil (0.054 oz acre^–1) plus dimethenamid-P (0.473 lb acre^–1)] and postemergence herbicide mixtures [bicyclopyrone (0.040 lb acre^–1) plus mesotrione (0.161 lb acre^–1) plus S-metolachlor (1.429 lb acre^–1); thiencarbazone-methyl (0.013 lb …

Earthworm Density Differences Among Tallgrass Prairies Over Time In The Ozark Highlands, Carlee Hensley, Kristofor R. Brye, Mary C. Savin, Edward E. Gbur, Lisa S. Wood

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

To mitigate the loss of tallgrass prairies through fragmentation and conversion to other land uses, prairie restoration efforts have been undertaken to reclaim areas that have been previously used for agricultural production. Earthworms are a key component of the soil ecology of natural, undisturbed ecosystems. However, limited research exists on earthworm populations in prairie restorations and how earthworm densities may change over time. The objectives of this study were (a) to evaluate earthworm densities in the upper 20 cm of soil over time (i.e., May 2007 and May 2019) in a native prairie and chronosequence of three prairie restorations (i.e., …

Wastewater-Recovered Struvite Effects On Total Extractable Phosphorus Compared With Other Phosphorus Sources, Ryder Anderson, Kristofor R. Brye, Lauren Greenlee, Trenton L. Roberts, Edward Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Intentional precipitation of the phosphorus (P)-containing mineral struvite (MgNH₄PO₄ · 6H₂O) is an attractive option in sustainable water management due to the ability to recover P from various waste sources. Limited research has assessed struvite's potential as a fertilizer P source in agronomic soils compared with other conventional fertilizer P sources under flooded soil conditions, common for lowland rice (Oryza sativa L.). The objective of this study was to evaluate total extractable soil P over time from a wastewater-recovered struvite (ST) material in a plant-less soil incubation with two silt-loam (SiL) and a silty …

Electrochemically Precipitated Struvite Effects On Extractable Nutrients Compared With Other Fertilizer-Phosphorus Sources, Ryder Anderson, Kristofor R. Brye, Laszlo Kekedy-Nagy, Lauren Greenlee, Edward Gbur, Trenton Roberts

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Recovery of struvite, or magnesium ammonium phosphate (MgNH₄PO₄ · 6H₂O), from wastewater streams may provide an alternative to traditional P fertilizers. Little research has assessed the behavior of struvite relative to other commercially available, fertilizer-P sources in historically row-cropped soils in the United States. The objective of this study was to evaluate total extractable P and other nutrients from electrochemically (ECST) and chemically precipitated struvite (CPST) compared with triple superphosphate (TSP), diammonium phosphate (DAP), monoammonium phosphate (MAP), and rock phosphate (RP) in a moist-soil incubation without plants using varying soil textures (loam, silt loam, and …

Characterizing Expansiveness And Iron Reducibility Of Red-Clay Soils For The Purpose Of On-Site Wastewater System Placement In Arkansas, Bailey Darnell, Kristofor R. Brye, Larry T. West, Lisa S. Wood, David M. Miller

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The lack of iron-reducing capability in some red soils poses an issue for determining the suitability for on-site wastewater treatment systems (OSWWTS). The Arkansas Department of Health allows for placement of OSWWTS in certain red-clay soils that have the potential for iron reduction and do not show expansiveness upon wetting, but only in the Ozark Highlands (Major Land Resource Area [MLRA] 116A), which is referred to as the red-soil exception. The objectives of this study were (a) to confirm the nonexpansiveness and iron reducibility of select soils in the Ozark Highlands that meet the criteria for the red-soil exception, and …

Earthworm Differences Among Mound Positions In Native Prairies In The Ozark Highlands, Carlee D. Hensley, Kristofor R. Brye, Mary C. Savin, Lisa S. Wood, Edward E. Gbur

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Mounded, tallgrass prairie ecosystems are a unique, endangered ecosystem due to severe disturbance for agricultural production and/or urban expansion. Limited research exists on earthworm (Lumbricus terrestris) dynamics in mounded, tallgrass prairies, particularly in the Ozark Highlands region of northwestern Arkansas. The objectives of this study were to evaluate the effects of soil moisture regime (SMR), landscape position (LP), and sample date on earthworm densities in the top 20 cm of soil in two mounded, native prairies in the Ozark Highlands region of northwestern Arkansas. Juvenile and total earthworm densities were five times greater (P < .05) in the udic- and aquic-inter-mound combinations than any other SMR-LP combination in October 2018 and May 2019, respectively. Adult earthworm densities were two times greater (P < .05) in the aquic-inter-mound at Searles Prairie than any other SMR-LP combination in either mounded prairie. Juvenile earthworm densities were three times greater (P < .05) in May 2019 than in May 2018 at Chesney Prairie, but adult and total earthworm density did not change over the same period of time. Combined across all data, juvenile and total earthworm densities were positively correlated (P …