Agronomy and Crop Sciences Commons^™

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 …

Effect Of Planting Date And Cultivar Maturity In Edamame Quality And Harvest Window, David Octor Moseley, Marcos Da Silva, Leandro Mozzoni, Moldir Orazaly, Liliana Florez-Palacios, Andrea Acuna, Chengjun Wu, Pengyin Chen

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Edamame is a food-grade soybean [Glycine max (L.) Merr.] that is harvested immature between the R6 and R7 reproductive stages. To be labeled as a premium product, the edamame market demands large pod size and intense green color. A staggered harvest season is critical for the commercial industry to post-harvest process the crop in a timely manner. Currently, there is little information to assist in predicting the optimum time to harvest edamame when the pods are at their collective largest size and greenest color. The objectives of this study were to assess the impact of cultivar, planting date, and …

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 …

Molecular And Physiological Responses Of Rice And Weedy Rice To Heat And Drought Stress, Leonard Bonilha Piveta, Nilda Roma-Burgos, Jose Alberto Noldin, Vivian Ebeling Viana, Claudia De Oliveira, Fabiane Pinto Lamego, Luis Antonio De Avila

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Rice is the staple food for about half of the world population. Rice grain yield and quality are affected by climatic changes. Arguably, rice cultivars’ genetic diversity is diminished from decades of breeding using narrow germplasm, requiring introgressions from other Oryza species, weedy or wild. Weedy rice has high genetic diversity, which is an essential resource for rice crop improvement. Here, we analyzed the phenotypic, physiological, and molecular profiles of two rice cultivars (IRGA 424 and SCS119 Rubi) and five weedy rice (WR), from five different Brazilian regions, in response to heat and drought stress. Drought and heat stress affected …

Seed-Shattering Phenology At Soybean Harvest Of Economically Important Weeds In Multiple Regions Of The United States. Part 2: Grass Species, Lauren M. Schwartz-Lazaro, Lovreet S. Shergill, Jeffrey A. Evans, Muthukumar V. Bagavathiannan, Shawn C. Beam, Mandy Bish, Jason A. Bond, Kevin W. Bradley, William C. Curran, Adam S. Davis, Wesley J. Everman, Michael L. Flessner, Steven C. Haring, Nicholas R. Jordan, John L. Lindquist, Jason K. Norsworthy, Tameka Sanders, Larry E. Steckel, Mark J. Vangessel, Blake Young, Steven B. Mirsky

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Seed shatter is an important weediness trait on which the efficacy of harvest weed seed control (HWSC) depends. The level of seed shatter in a species is likely influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter of eight economically important grass weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to 4 wk after maturity at multiple sites spread across 11 states in the southern, northern, and mid-Atlantic United States. From soybean maturity to 4 wk after maturity, cumulative percent seed shatter was lowest in the southern U.S. regions and …

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 …