Agronomy and Crop Sciences Commons^™

Plasticity Of Sorghum Biomass And Inflorescence Traits In Response To Nitrogen Application, Kyle M. Linders

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nitrogen is an essential nutrient required for growth and development in plants. Insufficient nitrogen availability can reduce vegetative growth and grain yield. However, nitrogen is a costly input for farmers, is energy intensive to manufacture, and runoff of excess nitrogen fertilizer impacts water quality. Compared to its close relative, maize, sorghum has much greater resilience to nitrogen and water deficit, and heat stress, allowing sorghum to be grown with fewer inputs and on marginal land. Variation in total biomass accumulation and grain yield between sorghum accessions, as well as between nitrogen conditions, can be largely explained by differences in vegetative …

Dicamba Air Concentrations In Eastern Arkansas And Impact On Soybean, Maria Leticia Zaccaro-Gruener, Jason K. Norsworthy, Chad B. Brabham, L. Tom Barber, Trenton Roberts, Andronikos Mauromostakos, Thomas C. Mueller

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

Damage to non–dicamba resistant (non-DR) soybean [Glycine max (L.) Merr.] has been frequent in geographies where dicamba-resistant (DR) soybean and cotton (Gossypium hirsutum L.) have been grown and sprayed with the herbicide in recent years. Off-target movement field trials were conducted in northwest Arkansas to determine the relationship between dicamba concentration in the air and the extent of symptomology on non-DR soybean. Additionally, the frequency and concentration of dicamba in air samples at two locations in eastern Arkansas and environmental conditions that impacted the detection of the herbicide in air samples were evaluated. Treatment applications included dicamba at …

Irrigation-As-A-Service For Smallholder Farmers, Ishani Lal

Department of Agricultural Economics: Dissertations, Theses, and Student Research

Irrigation is a crucial management practice that can help increase food security among smallholders globally while mitigating climate change impacts. High-efficiency irrigation technologies such as drip kits and sprinkler systems are relatively expensive and smallholder farmers cannot afford them to buffer crop yields against low precipitation. In many developing countries, farmers participate in robust informal markets for renting and sharing of irrigation equipment. Such services may be operated by farmers or via a third party such as irrigation start-ups, water user associations, non-governmental organizations, or even government agencies. These services are referred to collectively as Irrigation-as-a-Service (IaaS).

The objective of …

Influence Of Cover Crops On Soybean Yield And Partial Returns As An Alternative To Double-Crop Soybean In Arkansas, Drew Kirkpatrick, Trenton L. Roberts, Kris Brye, Jeremy Ross

Crop, Soil and Environmental Sciences Faculty Publications and Presentations

The number of hectares dedicated to winter wheat (Triticum aestivum L.) in the southern United States has been trending downward for almost a decade, presenting an opportunity for producers to utilize alternatives in their soybean [Glycine max (L.) Merr.] rotations, such as winter cover crops. A study was established to compare the cover crops to traditional cropping systems by determining the effect each had on a successive soybean crop and to examine partial economic returns. Cropping systems implemented were winter fallow, winter wheat, and seven cover crop treatments, including cereal rye (Secale cereale L.), black-seeded oat ( …

Investigating Effect Of Seed Source And Developing Germination Protocols To Improve Success In Restoration Of Arkansas Tallgrass Prairies, Rhiannon Spencerosa

Graduate Theses and Dissertations

American tallgrass prairie has faced losses estimated at 87-98% of original land area since European settlement. Native seeds are often used to supplement struggling or extinct plant populations in tallgrass prairie restoration and establishment sites. Two main considerations in restoration and establishment are from where to source seed and how to obtain high germination rates. In order to determine the effect of seed source, a common garden experiment was performed in Fayetteville, Arkansas in 2022 with five prairie species: Andropogon gerardii (big bluestem), Bouteloua curtipendula (sideoats grama), Panicum virgatum (switchgrass), Schizachyrium scoparium (little bluestem), and Sorghastrum nutans (Indiangrass). Seed was …

Influence Of Cover Cropping And Nitrogen Fertilization On Soil Properties And Cotton Productivity, Christianah Oladoye

All Dissertations

Conservation practices with cover crops have proven to be effective in nutrient enrichment, increased yield, and environmental stability. Field studies were conducted from 2019 to 2022 to evaluate the short-term effect of No cover crop [NC], RYE, a mix of rye + vetch [R+V], and mix of five species (radish, rye, vetch, clover, and lupin) [5W] on short term soil physical, chemical properties, cotton growth, and lint yield. Cover crops were planted in November and terminated in May of each year. Soil dry and wet aggregate fractions (0-0.05 m) and soil compaction (0-0.4 m depth) were measured at termination. The …

Winter Hardy Small Cereals For Grazing Or Silage In Eastern Nebraska, Abigail M. Sartin

Department of Animal Science: Dissertations, Theses, and Student Research

Two, 3-year studies were conducted to evaluate the value of cereal rye, winter wheat, and winter triticale as forage sources for either for silage or early spring grazing. For silage, the objective was to evaluate species and maturity effects on dry matter yield, nutritive value, and fermentation of small cereal silage. There are no major differences between wheat, rye, or triticale in terms of the relative timing of each species reached each maturity stage. There are no differences among species in dry matter (DM) yield, except for wheat which tends to decline at soft dough due to senescence of the …

Effect Of Nanobubble-Oxygenated Water For Irrigation Of Sand-Based Golf Course Putting Greens, Eric Deboer

Graduate Theses and Dissertations

Nanobubbles (NBs) are sub-micron, stable cavities of gas. The properties of NBs theoretically allow long bubble residence times and high gas dissolution rates resulting in the supersaturation of oxygen in water. Adequate soil aeration is a constant concern for producers of agricultural and horticultural crops. Because of their unique properties, NBs have been investigated for oxygenating water used in the irrigation of various agricultural and horticultural crops to increase soil oxygen concentration. Creeping bentgrass (Agrostis stolonifera L.) is the most widely used turfgrass for golf course putting green surfaces. Golf course superintendents use various methods to increase soil oxygen in …

A Deep Learning Framework For Processing And Classification Of Hyperspectral Rice Seed Images Grown Under High Day And Night Temperatures, Víctor Díaz-Martínez, Jairo Orozco-Sandoval, Vidya Manian, Balpreet K. Dhatt, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

A framework combining two powerful tools of hyperspectral imaging and deep learning for the processing and classification of hyperspectral images (HSI) of rice seeds is presented. A seed-based approach that trains a three-dimensional convolutional neural network (3D-CNN) using the full seed spectral hypercube for classifying the seed images from high day and high night temperatures, both including a control group, is developed. A pixel-based seed classification approach is implemented using a deep neural network (DNN). The seed and pixel-based deep learning architectures are validated and tested using hyperspectral images from five different rice seed treatments with six different high temperature …

Corn Grain Marketing Strategy Unbiasing For 2023, Matthew Stockton, Shannon Sand

Cornhusker Economics

Discusses cognitive biasing errors that may be employed--in the context of corn market strategizing--such as the Dunning-Krueger effect, availability or distancing bias, gambler's fallacy, and anchoring bias.

Entropy And Energy Profiles Of Chemical Reactions, Johannes C. B. Dietschreit, Dennis J. Diestler, Rafael Gómez-Bombarelli

Department of Agronomy and Horticulture: Faculty Publications

The description of chemical processes at the molecular level is often facilitated by use of reaction coordinates, or collective variables (CVs). The CV measures the progress of the reaction and allows the construction of profiles that track the evolution of a specific property as the reaction progresses. Whereas CVs are routinely used, especially alongside enhanced sampling techniques, links between profiles and thermodynamic state functions and reaction rate constants are not rigorously exploited. Here, we report a unified treatment of such reaction profiles. Tractable expressions are derived for the free-energy, internal-energy, and entropy profiles as functions of only the CV. We …

Divergent Metabolic Changes In Rhizomes Of Lowland And Upland Switchgrass (Panicum Virgatum) From Early Season Through Dormancy Onset, Nathan A. Palmer, Gautam Sarath, Michael J. Bowman, Aaron J. Saathoff, Serge J. Edmé, Robert B. Mitchell, Christian M. Tobias, Soundararajan Madhavan, Erin D. Scully, Scott E. Sattler

Department of Agronomy and Horticulture: Faculty Publications

High-biomass-yielding southerly adapted switchgrasses (Panicum virgatum L.) frequently suffer from unpredictable winter hardiness at more northerly sites arising from damage to rhizomes that prevent effective spring regrowth. Previously, changes occurring over the growing season in rhizomes sampled from a cold-adapted tetraploid upland cultivar, Summer, demonstrated a role for abscisic acid (ABA), starch accumulation, and transcriptional reprogramming as drivers of dormancy onset and potential keys to rhizome health during winter dormancy. Here, rhizome metabolism of a high-yielding southerly adapted tetraploid switchgrass cultivar, Kanlow—which is a significant source of genetics for yield improvement—was studied over a growing season at a northern …

Differential Behaviour Of Guineagrass (Panicum Maximum Jacq.) Hybrids, With Different Al+3 Reactions, As To Major Nutrient Translocations To The Leaves, R. S. Paterniani, J. A. Usberti Jr., J. C. Werner

IGC Proceedings (1977-2023)

Most of the Brazilian cultivated pasture fields presents soils with high Al⁺³ levels and liming is economically unfeasible. So, there is an urgent need for grasses with good forage yielding potentials that can withstand Al⁺³ deleterious effects (abnormal root development: short, thick and poorly branched roots, which are unable to effectively translocate water and essential nutrients to the leaves) (Foy, 1984); as a consequence, susceptible genetic materials have their field persistences greatly affected, mainly during drought periods. Researches on Al⁺³ reaction are usually compare supposedly resistant/tolerant genotypes with a resistant control check; doing so, the genotypic effect …

Animal Performance And Productivity Of New Ecotypes Of Brachiaria Brizantha In Brazil, Valéria P. B. Euclides, Manuel C. M. Macedo, Cacilda B. Do Valle, R. Flores, M. P. Oliveira

IGC Proceedings (1977-2023)

Brazil has the competitive advantage of a very dynamic and cost effective animal production system on pastures over other countries. The pursuit for more productive forages that will result in higher quality beef at a lower cost is then justified. Brachiaria is the most important forage genus utilised in Brazil, thus an intense search for new cultivars amongst collected and introduced ecotypes from Africa is underway. Following agronomic evaluation of this material in plots, 8 pre-selected Brachiaria ecotypes were tested under intermittent grazing in paddocks (Euclides et al., 2001). Continuing on the process of cultivar development, two out of …

Development Of A Bahiagrass Paspalum Notatum Flugge With Increased Short-Day Biomass, P. Mislevy, Ann R. Blount, T. R. Sinclair

IGC Proceedings (1977-2023)

Low herbage productivity of subtropical grasses during the short-day winter months of October through to March can place a severe burden on livestock producers in Southeastern U.S. Researchers at the University of Florida (Sinclair et al., 2001) hypothesised that the decrease in forage production might result from physiological dormancy induced by short day length. A study using artificial lights to extend the day length demonstrated that maintaining the day length at 15 hr during the short-day length period increased 'Pensacola' bahiagrass P. notatum Flugge saure Parodi forage yield 122% when compared with normal photoperiod (Mislevy et al., 2001). …

Genetic And Molecular Characterization Of Temperate And Tropical Forage Maize Inbred Lines, B. Alarcón-Zúñiga, E. Valadez-Moctezuma, T. Cervantes-Martinez, T. Cervantes-Santana, M. Mendoza‐Rodriguez

IGC Proceedings (1977-2023)

The livestock feeding in the Central highland of Mexico is based on harvest, grazing and annual forage conservation, being forage maize the most important silage crop (Alarcón, 1995). Even though forage maize is extensively bred in Europe, USA and Asia since 1900's, this started in Mexico in the 1960's, and little is known about the genetic diversity in both agronomic and nutritive value traits. Our breeding program goals are to analyze combining ability of biomass and quality predictors and to study the genetic relationship of inbred lines between lowland tropical and temperate races from Mesa Central, by genetic and molecular …

Preliminary Performance Of Panicum Maximum Accessions And Hybrids In Brazil, Liana Jank, Rosangela M. S. Resende, S. Calixto, M. M. Gontijo Neto, V. A. Laura, Manuel C. M. Macedo, Cacilda B. Do Valle

IGC Proceedings (1977-2023)

Due to the lack of high quality forages adapted to the distinct ecosystems in Brazil, a national network to evaluate 14 accessions, 4 hybrids and 5 commercial standards of Panicum maximum was established in 2002, in 5 regions of Brazil (states of Mato Grosso do Sul, Acre, Rondônia, Minas Gerais and in the Federal District). Staff of the Embrapa Beef Cattle group co-ordinated the network and pre-selected the accessions and hybrids (Jank, 1995; Jank et al., 2001; Resende et al., 2004). We present their performance as to leaf dry matter yield (LDMY) and leaf percentage (LP) obtained from …

Effect Of Applied Biosolids To Bahiagrass Pastures On Copper Status Of Cattle, M. E. Tiffany, L. R. Mcdowell, G. A. O'Connor, N. S. Wilkinson

IGC Proceedings (1977-2023)

When grazing ruminants consume forages high in Mo but adequate in S, there is a risk of molybdenosis (a Mo-induced Cu deficiency). This occurs when Mo, S, and Cu join to form Cu-thiomolybdate complexes in the rumen that are not readily absorbed (Suttle, 1991). High dietary S reduces Cu absorption, possibly due to unabsorbable Cu sulphide formation, independent from its part in thiomolybdate complexes. The use of municipal sludge (biosolids) as a pasture fertiliser is of interest since some contain high Mo which may induce Cu deficiency. The objective of this study was to evaluate the performance and Cu status …

An In Vitro Investigation Of Forage Factors Which Affect The Production Of Conjugated Linoleic Acid And Trans Vaccenic Acid In The Rumen. Ii. Wilting & Cell Damage, Michael R. F. Lee, J. K. S. Tweed, Nigel D. Scollan, R. J. Dewhurst

IGC Proceedings (1977-2023)

Previous studies have shown that cis 9 trans 11 conjugated linoleic acid (CLA) concentrations are higher for summer milk produced from cows grazing fresh pastures than for winter milk when conserved forages are fed (Jahreis et al., 1997). Furthermore, Offer (2003) showed that a similar depression in milk fat CLA occurred if grass was simply cut and fed after a short wilt. This experiment investigated the effect of wilting on the production of CLA and trans vaccenic acid (TVA) in an in vitro rumen simulation, and whether any differences could be related to changes in plant structure. It was …

Effects Of Grassland Management On Herbage Lipid Composition And Consequences For Fatty Acids In Milk, Anjo Elgersma, P. Maudet, I. Witkowska, A. C. Wever

IGC Proceedings (1977-2023)

Herbage provides bulk feed and is the basis for ruminant nutrition. Herbage lipids, especially C18:3, are a major source of beneficial fatty acids (FA) in milk. These desired FA are unsaturated FA such as CLA (conjugated linoleic acid), especially the isomer rumenic acid, and also vaccenic acid, both trans omega-7 FA (Ellen & Elgersma, 2004). As information on lipids in forages is scarce, effects were studied of N application level and regrowth period on the lipid concentration and FA composition of perennial ryegrass (Lolium perenne L.), the most important forage in temperate climate zones. A linear relation had previously …