Residual Effects Of Nitrogen Fertilization On Soil Nitrogen Pools And Corn Growth,
2016
Purdue University
Residual Effects Of Nitrogen Fertilization On Soil Nitrogen Pools And Corn Growth, Meghan E. Moser
Open Access Theses
Given the dynamic nature of soil nitrogen (N), inorganic N fertilization to corn (Zea mays L.) has potential to alter N pool balance by creating an accumulation or depletion of soil N. Current corn N recommendations in the common corn-soybean rotation of Indiana strive to find the best N rate that maximizes producer profit. Increasing our understanding of soil N will inform producers if they should adjust fertilizer rates for corn to influence maintenance of organic N and Carbon. Our objective was to determine residual N effects from fertilized corn in a corn-soybean rotation by measuring (1) soil N …
Annual Forage Cropping-Systems For Midwestern Ruminant Livestock Production,
2016
Purdue University
Annual Forage Cropping-Systems For Midwestern Ruminant Livestock Production, John Ernest Mcmillan
Open Access Dissertations
Annual forage cropping systems are a vital aspect of livestock forage production. One area where this production system can be enhanced is the integration of novel annual forages into conventional cropping systems. Two separate projects were conducted to investigate alternative forage options in annual forage production. In the first discussed research trial, two sets of crops were sown following soft red winter wheat (Triticum aestivum L.) grain harvest, at two nitrogen application rates 56 and 112 kg ha-1 . The first set of crops were C4 summer annuals seeded within two weeks of wheat grain harvest and included, brown …
Managing Corn Residue And Double Cropped Forages In Crop And Livestock Systems,
2016
University of Nebraska-Lincoln
Managing Corn Residue And Double Cropped Forages In Crop And Livestock Systems, Kristen M. Ulmer
Department of Animal Science: Dissertations, Theses, and Student Research
Integrating crop and livestock systems leads to opportunities to utilize land resources; however, crop producers focus on grain yields and ground cover, while livestock producers see opportunity to graze corn residue or annual forages. After wheat harvest or corn silage harvest, above ground forage production for brassica mixes and oats is greater than forage oats or oat production after high moisture corn harvest. Grazing steers on forage crops after grain harvest provides moderate gains. While annual forages provide good quality forages, corn residue grazing and utilization is still a cost-effective feedstuff for cattle producers. In the short term, grain yields …
Evaluation Of A Cool-Season Grass-White Clover Mixture For Low-Nitrogen Input Lawns,
2016
Purdue University
Evaluation Of A Cool-Season Grass-White Clover Mixture For Low-Nitrogen Input Lawns, Gabriel Adam Macke
Open Access Theses
Turfgrass lawns require supplemental nitrogen (N) to maintain green color and seasonal shoot density. Improper lawn fertilization with excess N or phosphorus has the potential to contaminate both surface and groundwater. Thus, to reduce the reliance on supplemental N fertilization, alternative strategies or novel turf systems like grass-legume mixtures need explored. White clover ( Trifolium repens L.) is a stoloniferous legume that biologically fixes N from the atmosphere and adds N into the soil via mineralization. The objective of this field study was to evaluate the persistence and feasibility of a cool-season grass-clover lawn mixture. A lawn grass mixture with …
Cereal Rye Cover Crop Effects On Soil Physical And Chemical Properties In Southeastern Indiana,
2016
Purdue University
Cereal Rye Cover Crop Effects On Soil Physical And Chemical Properties In Southeastern Indiana, Joseph D. Rorick
Open Access Theses
Cover crops are growing in popularity in the Midwest, although questions remain about how to include them most effectively in a corn-soybean ( Zea mays L. - Glycine max L.) rotation. This study was conducted to determine the effects of cereal rye ( Secale cereale L.) on soil bulk density and water retention, soil organic carbon, soil nitrogen, and water stable aggregate mean weight diameter after four years of cover crop growth and the effects on soil moisture over a five year period. The study was conducted at the Southeast Purdue Agricultural Center (SEPAC) on silt loam soils. A 14 …
Genetic Study Of Carotenoids In Maize Grain (Zea Mays L.),
2016
Purdue University
Genetic Study Of Carotenoids In Maize Grain (Zea Mays L.), Oscar Rafael Espejel Venado
Open Access Theses
Pro-Vitamin A (proVA) carotenoids, which are converted into retinol (Vitamin A) in the human body, have been the subject of human nutrition studies and are a target for biofortification of staple crops. Historically, β-carotene has been the principal target for enhancing levels of proVA, yet there is recent interest in enhancing the proVA carotenoid β-cryptoxanthin. Studies have shown that β-cryptoxanthin has excellent bioavailability, and its use in maize may be nearly as effective as β-carotene in providing retinol. The primary aim of this study was to gain a better understanding of the genetic control of levels of β-cryptoxanthin, conversion of …
Physiological Aspects Of Relative Changes In Nitrogen And Plant Density Stress Tolerances Over A 38-Year Period Of Us Maize Hybrid Introductions,
2016
Purdue University
Physiological Aspects Of Relative Changes In Nitrogen And Plant Density Stress Tolerances Over A 38-Year Period Of Us Maize Hybrid Introductions, Keru Chen
Open Access Dissertations
Incremental gains in grain yield of maize hybrids over the decades are the consequence of genotype, environment and management interactions. Historically, genetic improvements in newer hybrids have included longer active grain filling periods (achieved by advancing silking and extending functional stay green in maize leaves); stronger source and sink during grain filling; enhanced tolerance to higher density; and canopy architecture changes. Newer hybrids were known to accumulate more dry matter and nitrogen in the post-silking period, but achieving a more comprehensive knowledge of pre-silking and post-silking dynamics required further understanding of dry matter and nitrogen partitioning in individual organs, as …
The Biology And Management Of Palmer Amaranth (Amaranthus Palmeri S. Wats) In Indiana,
2016
Purdue University
The Biology And Management Of Palmer Amaranth (Amaranthus Palmeri S. Wats) In Indiana, Douglas J. Spaunhorst
Open Access Dissertations
Palmer amaranth is a pernicious summer annual weed that has evolved resistance to six herbicide sites of action in the U.S. and threatens agriculture production. In 2011, Palmer amaranth was identified in flood plains in two southern Indiana counties (Posey and Vanderburgh). Determining if Palmer amaranth can survive and reproduce in northern Indiana may provide insight if this weed will be problematic for northern row crop producers. The objectives of our research were to identify fields containing Palmer amaranth and determine the distribution of herbicide resistance traits in Indiana; determine the influence of tillage frequency and tillage intervals on Palmer …
Determination Of Plant Architecture And Component Phenotyping Based On Time-Lapse Image Analysis,
2016
University of Nebraska-Lincoln
Determination Of Plant Architecture And Component Phenotyping Based On Time-Lapse Image Analysis, Srinidhi Bashyam
School of Computing: Dissertations, Theses, and Student Research
Plant breeding and the development of new food production depend on accurate measurement of different phenotypes (observable physical traits) of a plant. The plant phenotypes play a very important role in the agronomic production. The successful computation of plant phenotypes largely depends on the determination of the architecture of the plant, i.e., the arrangement of its parts (leaves, stems, flowers, etc.) relative to each other, and how the size, shape, and positions of those parts change over time. Researchers and breeders extract valuable information from these types of data to make an informed decision on which individuals to advance to …
Winter Desiccation Prevention And Recovery In Turfgrass,
2016
University of Nebraska-Lincoln
Winter Desiccation Prevention And Recovery In Turfgrass, Darrell James Michael
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
Desiccating winters in the Northern Great Plains can lead to widespread turf death. This loss of turf results in poor aesthetics and can be financially burdensome. Financial implications include the cost of re-establishing turf and the loss of potential revenue from poor playing conditions in the spring which can both be devastating for financial success. The winter of 2013-2014 was particularly devastating, leaving many golf course superintendents re-evaluating their desiccation prevention management plans. There are many prevention practices available to turf managers that vary greatly in affordability, effectiveness, and labor. These prevention practices aim to prevent excessive water loss and …
Quantitative Trait Loci (Qtl) For Salt Tolerance In Soybean And Physiological Response To Salt Stress During Early Growth Stage,
2016
University of Arkansas, Fayetteville
Quantitative Trait Loci (Qtl) For Salt Tolerance In Soybean And Physiological Response To Salt Stress During Early Growth Stage, Cindy Massiel Lopez Ramirez
Graduate Theses and Dissertations
Soybean is a major cash crop used as a source of high–quality protein and oil. Salt stress is one of the main abiotic stresses causing significant yield losses in soybean, which is considered a moderately salt–sensitive crop. Breeding selection is a promising strategy to improve salt tolerance as soybean germplasm display wide variation in response to salinity stress. However, the physiological and genetic mechanisms for salt tolerance are not quite clear. The discovery of novel QTL/genes associated with salt tolerance facilitates the development of tolerant cultivars through marker-assisted selection (MAS). The objectives of this study were: 1) identify/confirm QTL associated …
Quantitative Trait Loci Mapping, Genome-Wide Association Analysis, And Gene Expression Of Salt Tolerance In Soybean,
2016
University of Arkansas, Fayetteville
Quantitative Trait Loci Mapping, Genome-Wide Association Analysis, And Gene Expression Of Salt Tolerance In Soybean, Ailan Zeng
Graduate Theses and Dissertations
Salt stress is a common abiotic stress causing yield reduction in soybean. There are differential responses, namely tolerance (excluder) and intolerance (includer), among soybean germplasm. However, the genetic and physiological mechanism for salt tolerance is not clear. Identification of novel QTL for salt tolerance and genes that are differentially expressed under salt stress would help elucidate the salt tolerance mechanism and facilitate the development of salt tolerant cultivars through marker assisted selection (MAS). The objectives of this study were to identify new QTL or genes responsible for salt tolerance using three approaches: QTL mapping, association analysis, and RNA sequencing (RNA-seq). …
A Study Of Short-Season Winter Cover Crops For Organic High Tunnel Production Systems,
2016
University of Arkansas, Fayetteville
A Study Of Short-Season Winter Cover Crops For Organic High Tunnel Production Systems, Luke Riley Freeman
Graduate Theses and Dissertations
This two-year study investigated short-season winter cover crops to improve soil quality and growth of subsequent vegetable crops in an organic high tunnel production system. Five winter cover crop treatments including a nontreated control, Austrian winter peas (Pisum arvense), bell beans (Vicia faba), mustard (Brassica juncea cv. Kodiak), and Daikon radish (Raphanus sativus var. longipinnatus) were grown in a high tunnel in a randomized complete block design from mid-November to mid-March, mowed and incorporated into the soil, and followed by a succession of vegetable crops including tomato (Lycopersicon lycopersicum, cv. ‘Plum Dandy’) and broccoli (Brassica oleracea var. italica, cv. ‘Bay …
Liming Characteristics Of A High-Calcium, Dry Flue Gas Desulfurization By-Product And Its Effects On Runoff Water Quality,
2016
University of Arkansas, Fayetteville
Liming Characteristics Of A High-Calcium, Dry Flue Gas Desulfurization By-Product And Its Effects On Runoff Water Quality, Jason Richard Burgess-Conforti
Graduate Theses and Dissertations
In 2013, only 37% of the 32 million Mg of flue gas desulfurization (FGD) by-products generated in the United States were reused beneficially. If FGD by-products could be used as a beneficial soil amendment, millions of megagrams may be diverted away from surface impoundments and landfills. The purpose of this research was to identify the liming characteristics of a high-Ca dry FGD (DFGD) by-product in comparison to a Class-C fly ash (FA) and reagent-grade CaCO3, and to evaluate the effects of land application to a managed grassland on runoff, plant, and soil quality. Liming characteristics were determined by measuring the …
Characterization Of Ground Nozzles For Pesticide Applications,
2016
University of Nebraska-Lincoln
Characterization Of Ground Nozzles For Pesticide Applications, Ryan Henry
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
Pesticide applications are a common component of crop production systems in the United States (US). For row crop systems (e.g. corn, soybean, or wheat), pesticides are applied by ground, aerial, or chemigation methods. The exact method of pesticide delivery is not universally regulated/ prescribed in the US, and the equipment and application technique are largely defined by the individual applicator. A wide variety of choices and decisions must be made by applicators to result in a successful pesticide application. Examples of these choices include proper active ingredient(s), carrier volume and equipment (e.g. nozzle type, spacing, and operating pressure) selection while …
Effect Of Smooth Bromegrass Management On Grazing Cattle Dung Decomposition, Co2 Flux, And Soil Nutrient Movement,
2016
University of Nebraska-Lincoln
Effect Of Smooth Bromegrass Management On Grazing Cattle Dung Decomposition, Co2 Flux, And Soil Nutrient Movement, Bradley D. Schick
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
Rapid nutrient cycling improves forage quality and livestock production in pastures. Interseeding legumes may be a strategy to enhance N cycling, but effects of dung excreted from cattle grazing pastures with legumes on dung decomposition rates and soil N cycling have not been studied. Our objective was to evaluate how dung excreted from cattle grazing legume-interseeded, N-fertilized, and unfertilized smooth bromegrass (Bromus inermis Leyss.) pastures affects dung chemical composition, dry matter decomposition, CO2 flux, and N availability in soil. Freshly deposited dung from yearling steers grazing legume-interseeded, N-fertilized, and unfertilized pastures was collected and placed as pats in …
Arkansas Soybean Performance Tests 2016,
2016
University of Arkansas, Fayetteville
Arkansas Soybean Performance Tests 2016, R. D. Bond, J. A. Still, D. G. Dombek
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.
Mechanism Of Resistance, Gene Flow, And Integrated Management Of Ragweeds (Ambrosia) In Nebraska,
2016
University of Nebraska-Lincoln
Mechanism Of Resistance, Gene Flow, And Integrated Management Of Ragweeds (Ambrosia) In Nebraska, Zahoor Ahmad Ganie
Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research
Common ragweed (Ambrosia artemisiifolia L.) and giant ragweed (Ambrosia trifida L.) are native annual broadleaf weeds in the United States found in diverse agroecosystems, roadsides, and wastelands. They are economically important weed species in the Midwest and sources of pollen allergies. Confirmation of glyphosate-resistant (GR) common and giant ragweed in Nebraska justified the need to determine the mechanism of resistance, dispersal of resistance genes via pollen, and to develop an integrated management program. The objectives of this research were to: 1) determine the mechanism of glyphosate resistance in a common ragweed biotype from Nebraska; 2) evaluate the effect …
Selection Of Drought-Tolerant Soybean Lines Using A Field Screening Method And Identification Of Qtls For Slow Wilting And Nitrogen Fixation Associated With Drought-Tolerance,
2016
University of Arkansas, Fayetteville
Selection Of Drought-Tolerant Soybean Lines Using A Field Screening Method And Identification Of Qtls For Slow Wilting And Nitrogen Fixation Associated With Drought-Tolerance, Mirta Beatriz Dalzotto
Graduate Theses and Dissertations
Drought causes significant yield reductions in soybean. The development of drought-tolerant cultivars is an effective alternative to overcome this abiotic stress. Slow wilting, prolonged nitrogen fixation, and minimal yield reduction under water stress play an important role in evaluating breeding materials. Despite advances in knowledge about plant responses to drought conditions, there is little information on effective methodologies for phenotype screening in the field, and some QTLs have been identified for drought tolerance. Field screenings under drought and irrigated conditions are necessary to detect drought tolerant lines. In addition, QTLs and molecular makers associated with drought tolerance traits will greatly …
Soil And Plant Property Differences Among High-Yield Soybean Areas In Arkansas,
2016
University of Arkansas, Fayetteville
Soil And Plant Property Differences Among High-Yield Soybean Areas In Arkansas, Taylor Cass Adams
Graduate Theses and Dissertations
Continued achievement of soybean [Glycine max (L.) Merr.] yields greater than 6719 kg ha-1 (100 bu ac-1) will depend on decreasing the yield gap, which is contingent on gathering more information regarding the soil physical, chemical, and microbiological environment and the main plant factors contributing to high-yield soybean. Therefore, understanding the main factor differences between high- and average-yield areas may provide insight for making management decisions to increase yields. The objectives of this study were i) to evaluate the effects of region and soil depth on soil property differences between high- and average-soybean-yielding areas, ii) to determine which soil properties …
