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A Comparison Of Milled Rice Fissuring Kinetics Of Hybrid And Pureline Cultivars, Semehar Haile Tesfaye Dec 2013

A Comparison Of Milled Rice Fissuring Kinetics Of Hybrid And Pureline Cultivars, Semehar Haile Tesfaye

Theses and Dissertations

Over the past decade, the use of hybrid rice cultivars has greatly increased, and this has led to questions about the processing behavior of hybrid cultivars. This study compares the milled rice fissuring kinetics of hybrid and pureline cultivars. Also, this study elucidates the effects of kernel type (long-grain vs. medium-grain rice cultivars), surface lipid content (SLC), and kernel thickness on fissuring rates.

Three hybrid (CL XL745, CL XL729 and XL753) and five pureline (Wells, CL151, Cheniere, Jupiter and CL261) cultivar lots were procured. Jupiter and CL261 are medium-grain cultivars, whereas the rest are long-grain cultivars. Two experiments were conducted ...


Long-Term Residue And Water Management Effects On Soil Respiration And Soil Aggregate Stability In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Sharon Faye Smith Dec 2013

Long-Term Residue And Water Management Effects On Soil Respiration And Soil Aggregate Stability In A Wheat-Soybean, Double-Crop System In Eastern Arkansas, Sharon Faye Smith

Theses and Dissertations

Sustainability in agriculture is paramount to assuring continued production from our most naturally fertile soils. Storing carbon (C) in soil as organic matter through sustainable agricultural management practices can both remove atmospheric C and improve soil quality. The objective of this study was to evaluate the long-term effects of water management (irrigation and dryland), residue management [burn and no-burn, conventional (CT) and no-tillage (NT)] and residue/fertility level (high and low) on soil respiration and aggregate stability in a wheat- (Triticum aestivum L.) soybean [Glycine max (L.) Merr.], double-crop system in a silt-loam soil (Aquic Fraglossudalf) in the Mississippi River ...


Quantitative Trait Loci Associated With Waterlogging Tolerance In A Soft Red Winter Wheat Mapping Population, Diana Carolina Ballesteros Benavides Dec 2013

Quantitative Trait Loci Associated With Waterlogging Tolerance In A Soft Red Winter Wheat Mapping Population, Diana Carolina Ballesteros Benavides

Theses and Dissertations

Waterlogging is caused when water stays superficially in the soil for an extended period of time, creating an anaerobic environment which decreases plant growth and grain yield at maturity. Despite the impact of waterlogging on wheat production both globally and in the southeastern U.S., very little is known about the genetic control of waterlogging tolerance in wheat. The objective of this study was to determine the amount of genetic variation for vegetative stage waterlogging tolerance present within a wheat recombinant inbred line (RIL) population and to identify quantitative trait loci (QTL) associated with tolerance and productivity. Experiments were carried ...


Risk Return Of Farmer-Elevator Contracts For Soybeans And Corn In Arkansas, Marei Undine Houpert Dec 2013

Risk Return Of Farmer-Elevator Contracts For Soybeans And Corn In Arkansas, Marei Undine Houpert

Theses and Dissertations

In Arkansas the contribution of Agriculture to the states GDP is comparatively high. To help farmer's return risk the grain industry developed several marketing tools to support farmers. Literature in this research field finds different results for different locations, commodities, marketing tools and marketing years. As Agriculture in Arkansas is important for its economy this study focuses on soybeans and corn produced in the fertile north-eastern area of Arkansas that uses Memphis Tennessee as a spot market palace. The examined marketing tools are pre-harvest futures hedges and forward contracts as well as post-harvest storage strategies and minimum price contracts ...


Sources Of Variability In Agronomic Weed Seed Predation: Time, Space, Habitat, And Hyperpredation, Sonja K. Birthisel Dec 2013

Sources Of Variability In Agronomic Weed Seed Predation: Time, Space, Habitat, And Hyperpredation, Sonja K. Birthisel

Electronic Theses and Dissertations

Weed seed predation is an ecosystem service that benefits farmers by decreasing seedbank inputs, thereby reducing weed pressure in subsequent growing seasons. Seed predation can be considerable, but is highly variable. Sources of variability may include time, space, habitat, and trophic interactions such as hyperpredation. Two experiments were conducted to measure the impacts of these sources of variability on weed seed predation rates in Maine mixed vegetable agroecosystems.

Chapter One of this thesis describes a series of landscape-level field experiments conducted to quantify the effects of time, space, and habitat on seed predation rates. Seed assays, with and without vertebrate ...


Forage And Biomass Dual-Purpose Harvest System Using Native Warm-Season Grasses, David Weston Mcintosh Dec 2013

Forage And Biomass Dual-Purpose Harvest System Using Native Warm-Season Grasses, David Weston Mcintosh

Masters Theses

There has been increasing interest in utilizing native warm-season grasses (NWSGs), especially switchgrass, as a biomass feedstock for cellulosic ethanol production. Millions of hectares of crop and pasture in the mid-South are forecast to potentially be planted with switchgrass for biomass feedstock production. This could have a substantial impact on the region’s cattle industry, reducing forage production hectares. This study was conducted to determine the effect of early season harvest timing on forage and biomass of NWSGs designed for use in cellulosic ethanol production. The over-all hypothesis was to determine if an early forage harvest can be included in ...


Improving The Efficiency Of Fall Applied N With Cover Crops, Corey Lacey Nov 2013

Improving The Efficiency Of Fall Applied N With Cover Crops, Corey Lacey

Theses and Dissertations

Nitrate loss studies in Midwestern tile-drained fields have found that fall applied nitrogen (N) resulted in elevated nitrate concentrations in tile water during both the corn and soybean year of a 2 year rotation. The effectiveness of cover crops to reduce nitrate leaching when N is spring applied has been well demonstrated, however there is a dearth of knowledge on the ability of cover crops to reduce nitrate leaching in a system where N is fall applied. Thus, the objectives of this research were to (i) investigate the efficacy of winter cover crops to reduce nitrate leaching from fall applied ...


Systems Evaluation Of Shallow Anhydrous Ammonia Placements, Rates, And Timing On Maize Plant Uniformity, Yield And N Use Efficiency, Péter Kovács Oct 2013

Systems Evaluation Of Shallow Anhydrous Ammonia Placements, Rates, And Timing On Maize Plant Uniformity, Yield And N Use Efficiency, Péter Kovács

Open Access Dissertations

Farmers face increasing expectations from society to be more environmentally conscious and energy efficient with their fertilizer management practices during maize (Zea mays L.) production. With the advent of precision guidance systems, maize farmers in various tillage systems have more options in pre-plant nutrient banding relative to the intended crop rows or throughout the entire growing season. Field studies were conducted between 2010 and 2012 near West Lafayette, IN to identify best management practices to enhance maize plant uniformity, yield and nitrogen (N) efficiencies.

Anhydrous ammonia (NH3) placement during pre-plant application is of interest because of concerns for possible ...


Observation-Based Algorithm Development For Subsurface Hydrology In Northern Temperate Wetlands, Chun-Mei Chiu Oct 2013

Observation-Based Algorithm Development For Subsurface Hydrology In Northern Temperate Wetlands, Chun-Mei Chiu

Open Access Dissertations

This study investigates wetland subsurface hydrology, as well as biogeochemistry - which is strongly influenced by water and temperature dynamics - as these interactions are expected to be highly significant, yet remain poorly represented in current ecosystem and climate models.

Northern wetlands have received widespread public attention due to steadily increasing summer mean global temperatures, extreme precipitation events and higher rates of natural greenhouse gas emissions, as well as the significant impacts on them due to human activities. The goal of my graduate research has been to improve quantification of the role of subsurface hydrology in northern wetlands by using a macroscale ...


The Effects Of Planting Techniques On Maize Grain Yield And Silage Production, Tyler D. Kaufman Sep 2013

The Effects Of Planting Techniques On Maize Grain Yield And Silage Production, Tyler D. Kaufman

Theses and Dissertations

This thesis is a comprehensive analysis of the effects of seed orientation, row direction and planting population on grain yield, kernel composition, and silage yield and composition. Producers are striving to increase profit by efficiently using their available land area to maximize crop production. However, little research is available testing the effect of seed orientation on grain or silage production. Quantifying the impacts of seed orientation and row direction on grain and silage is essential for maximum crop production. Dissemination of the results should benefit grain and silage producer.

Two experiments were conducted to evaluate the effects of manipulating seed ...


Preservation Of Nutrients In Cool- And Warm-Season Forages At Different Stages Of Maturity And Management, Jason Allen Shultz Aug 2013

Preservation Of Nutrients In Cool- And Warm-Season Forages At Different Stages Of Maturity And Management, Jason Allen Shultz

Masters Theses

The overall goals of the studies described in this thesis were to investigate management practices of tall fescue and native warm-season grasses (NWSG) and find the best time to harvest and method to preserve forage quality. Study one investigated the effects of maturity on tall fescue and switchgrass and the effects of preservation method on forage quality. This study confirmed that maturity reduced forage quality in both tall fescue and switchgrass. Both tall fescue and switchgrass were successfully preserved as haylage or hay and did not differ in forage quality. Forages harvested before mid-May met the TDN and CP requirements ...


Toward Direct Biosynthesis Of Drop-In Ready Biofuels In Plants: Rapid Screening And Functional Genomic Characterization Of Plant-Derived Advanced Biofuels And Implications For Coproduction In Lignocellulosic Feedstocks, Blake Lee Joyce Aug 2013

Toward Direct Biosynthesis Of Drop-In Ready Biofuels In Plants: Rapid Screening And Functional Genomic Characterization Of Plant-Derived Advanced Biofuels And Implications For Coproduction In Lignocellulosic Feedstocks, Blake Lee Joyce

Doctoral Dissertations

Advanced biofuels that are “drop-in” ready, completely fungible with petroleum fuels, and require minimal infrastructure to process a finished fuel could provide transportation fuels in rural or developing areas. Five oils extracted from Pittosporum resiniferum, Copaifera reticulata, and surrogate oils for Cymbopogon flexuosus, C. martinii, and Dictamnus albus in B20 blends were sent for ASTM International biodiesel testing and run in homogenous charge combustion ignition engines to determine combustion properties and emissions. All oils tested lowered cloud point. Oils derived from Copaifera reticulata also lowered indicated specific fuel consumption and had emissions similar to the ultra-low sulfur diesel control. Characterization ...


Selecting Drought Tolerant Soybean Genotypes Using Qtls Associated With Shoot Ureide And Nitrogen Concentrations, Alejandro Bolton Aug 2013

Selecting Drought Tolerant Soybean Genotypes Using Qtls Associated With Shoot Ureide And Nitrogen Concentrations, Alejandro Bolton

Theses and Dissertations

In soybean, nitrogen fixation is more sensitive to drought than other physiological processes like photosynthesis. The sensitivity of nitrogen fixation to drought has been associated with high shoot concentrations of ureide and nitrogen under well-watered conditions. Previous research by Hwang et al. (2013) detected quantitative trait loci (QTLs) in a KS4895 by Jackson population associated with shoot ureide and nitrogen concentrations. The present research evaluated the use of these QTLs in selecting genotypes with drought tolerant nitrogen fixation. Our objectives were to compare actual versus expected phenotype of recombinant inbreed lines (RILs) selected using molecular markers, and to evaluate the ...


Study Of Thermotolerance Mechanism In Gossypium Hirsutum Through Identification Of Heat Stress Genes, Jin Zhang Aug 2013

Study Of Thermotolerance Mechanism In Gossypium Hirsutum Through Identification Of Heat Stress Genes, Jin Zhang

Theses and Dissertations

ABSTRACT

Heat stress causes major losses to cotton seed and lint yield. Introduction of heat stress tolerance to Arkansas cotton varieties is highly desirable. However, very little is known about the molecular basis of heat stress tolerance in cotton. The present study attempted to identify heat stress tolerance genes in two heat-tolerant cotton cultivars, VH260 and MNH456, originating from Pakistan. Towards this, the expression profile of the cotton orthologs of sevenArabidopsisheat stress tolerance genes was studied in these two cultivars, and compared with the two heat-susceptible cotton cultivars, ST213 and ST4288, originating from Mississippi Delta region. In addition, physiological parameters ...


Soybean (Glycine Max) Response To Imazosulfuron Drift And Carryover From Rice (Oryza Sativa), Sandeep Singh Rana Aug 2013

Soybean (Glycine Max) Response To Imazosulfuron Drift And Carryover From Rice (Oryza Sativa), Sandeep Singh Rana

Theses and Dissertations

In the Midsouth, soybean is often grown in close proximity to rice or in rotation with rice. Herbicides used in rice can injure soybean via drift or carryover. Consequently, field trials were conducted to determine the response of soybean (cv. AG 4703) to imazosulfuron drift and carryover (at Fayetteville, Marianna, Keiser and Pine Tree, AR) from rice. To assess the potential for carryover, soybean was planted into rice fields treated the previous year with imazosulfuron (rotation study). To evaluate in-season sensitivity of soybean to imazosulfuron (tolerance study) relative to halosulfuron, a common sulfonylurea herbicide applied to rice, both imazosulfuron and ...


Effects Of Varying Spring Hollow Tine Aerification Size And Timing On Bentgrass Greens, Lewis Hubbard Jr Aug 2013

Effects Of Varying Spring Hollow Tine Aerification Size And Timing On Bentgrass Greens, Lewis Hubbard Jr

All Dissertations

The desire to maintain optimal turfgrass and surface properties often leads turfgrass managers to minimize impact from cultural practices like hollow tine aerification (HTA). Comprehensive research is essential to developing aerification programs which allow optimal use of turfgrass surfaces without sacrificing overall turf health.
A two-year field experiment was conducted on a 14-year-old U.S. Golf Association (USGA)-specified Crenshaw creeping bentgrass [Agrostis stolonifera L. var palustris (Huds.)] research putting green in Clemson, SC, to evaluate the effects of varying spring HTA size and timing on turfgrass, surface, organic matter (OM), and soil properties.
Spring HTA treatments included 1.2-cm ...


Glufosinate Tolerance Of Widestrike And Liberty-Link Cotton Varieties And The Recoverability Of Upland Cotton Following Terminal Removal, Jason Sweeney Aug 2013

Glufosinate Tolerance Of Widestrike And Liberty-Link Cotton Varieties And The Recoverability Of Upland Cotton Following Terminal Removal, Jason Sweeney

All Theses

Sweeney, Jason Allen. Glufosinate Tolerance of WideStrike¨ and LibertyLink¨ Cotton Varieties and the Recoverability of Cotton Following Terminal Removal. (Under the direction of Dr. Michael A. Jones).
To evaluate the effects of topical application of glufosinate (Liberty 280SL, 24.5% glufosinate-ammonium salt) on cotton varieties with WideStrike¨ and LibertyLink¨ technologies, two field experiments were conducted in 2011 and 2012 at the Pee Dee Research and Education Center (PDREC) in Florence, SC. In the first experiment, five WideStrike¨ cotton varieties (Phytogen [PHY] 367WRF, PHY 375WRF, PHY 440W, PHY 499WRF, and PHY 565WRF) and three LibertyLink¨ cotton varieties (FiberMax [FM] 1773LLB2, FM ...


Distribution And Control Of Glyphosate-Resistant Johnsongrass (Sorghum Halepense) In Arkansas Soybean, Dennis Brent Johnson Aug 2013

Distribution And Control Of Glyphosate-Resistant Johnsongrass (Sorghum Halepense) In Arkansas Soybean, Dennis Brent Johnson

Theses and Dissertations

Johnsongrass, once the most persistent and troublesome grass weed of row crops throughout the southern U.S., has previously been confirmed resistant to the acetolactate synthase (ALS) and acetyl-coenzyme A carboxylase-inhibiting herbicides in the Midsouth and has recently evolved resistance to glyphosate in Arkansas. The goal of this research was to establish the geographical distribution of herbicide-resistant johnsongrass in Arkansas and to develop herbicide programs for controlling glyphosate-resistant johnsongrass in Arkansas soybean. Johnsongrass accessions were collected from 14 counties in the Mississippi River Delta region of Arkansas and screened for resistance to four of the most commonly used postemergence herbicides ...


Business Strategy For A Newly Designed Husk Fly Trap, Taylor Denney Jun 2013

Business Strategy For A Newly Designed Husk Fly Trap, Taylor Denney

BioResource and Agricultural Engineering

This senior project discusses the analysis, evaluation and business strategy for a newly designed Husk Fly Trap from Ag Chem Wholesalers located in Yuba City, California. This prototype is designed to hold 2 to 3 weeks’ worth of Ammonium Carbonate and alleviate the hassle of monitoring the Walnut Husk Fly. This system is cost affective, able to hold the same amount, or 2 – 3 weeks, of Ammonium Carbonate as a “supercharged” trap. The Prototype Trap is easier to handle by not having to replace blown away traps or ruined sticky cards saving Pest Control Advisors time and allowing them to ...


Effects Of Leaflet Orientation And Root Morphology On Physiological Traits And Yield In Soybeans., Richard Dewayne Johnson May 2013

Effects Of Leaflet Orientation And Root Morphology On Physiological Traits And Yield In Soybeans., Richard Dewayne Johnson

Doctoral Dissertations

Drought is the most important abiotic stress adversely affecting soybean (Glycine max (L.) Merr.) yield. Leaflet orientation has been shown to reduce leaflet temperatures and transpiration while root morphology has been related to slower wilting phenotypes. The objective of this study was to investigate effects of leaflet orientation and rooting morphology on whole plant transpiration, yield, water use efficiency, and other physiological traits in soybeans using grafting techniques, population lines, near-isogenic lines, and restrained leaf canopy experiments. Experiments were conducted in Knoxville, TN with additional yield trial plots at Springfield, Spring Hill, and Milan, TN. Data were collected on whole ...


Using The Ceres-Maize Model To Create A Geographically Explicit Grid Based Estimate Of Corn Yield Under Climate Change Scenarios, Ryan Zachary Johnston May 2013

Using The Ceres-Maize Model To Create A Geographically Explicit Grid Based Estimate Of Corn Yield Under Climate Change Scenarios, Ryan Zachary Johnston

Theses and Dissertations

The CERES-Maize model was evaluated in its capacity to predict both regional maize yield and water use within the United States Department of Agriculture (USDA) Economic Research Service (ERS) Region 1 between the years 1997-2007. A grid based, geospatially explicit method was developed to express the various rainfed and irrigated maize cultivars grown across the region. Overall, the calibrated model compared well for both physiological and yield parameters, producing significant linear relationships (p

The calibrated and validated CERES-Maize model was used to predict potential evapotranspiration and yield under three IPCC weather scenarios for the year 2050 to evaluate crop production ...


Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons May 2013

Dark Green Color Index As A Method Of Real-Time In-Season Corn Nitrogen Measurement And Fertilization, Upton Siddons

Theses and Dissertations

Corn (Zea mays L.) requires higher rates of nitrogen fertilizer than any other major U.S. crop partly because N fertilizers are subject to loss through various mechanisms. Because of this, corn may suffer from inadequate nitrogen fertilization or producers may over-apply nitrogen to compensate for early-season nitrogen losses. A timely, accurate, and precise method for measuring in-season corn N status is needed to allow producers to keep nitrogen use efficiency high within a growing season.

Using appropriate software, hue, saturation, and brightness values of digital images can be combined in a dark green color index (DGCI) which is closely ...


The Effect Of Photocatalytic Titanium Dioxide And Ultraviolet B Radiation On Sclerotinia Homoeocarpa Growth And Pathogenicity, Chun Hu May 2013

The Effect Of Photocatalytic Titanium Dioxide And Ultraviolet B Radiation On Sclerotinia Homoeocarpa Growth And Pathogenicity, Chun Hu

Masters Theses

Photocatalytic TiO₂ [titanium dioxide] generates strong oxidative effects when illuminated with ultraviolet (UV) light with wavelengths of less than 385 nm. UVB has wavelengths ranging from 280 to 315nm. Previous research indicates the oxidative species and UVB radiation can react and cause cellular damage to microorganisms, which may reduce Sclerotinia homoeocarpa growth and help to control dollar spot disease development. The objectives of this study were to investigate the interactions of TiO₂ and UVB radiation, both in vitro and in vivo, on the growth and development of dollar spot. Factorial treatments consisting of five rates of TiO₂ and three doses ...


Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays May 2013

Groundcover Management System And Nutrient Source Impact Physical Soil Quality Indicators In An Organically Managed Apple Orchard, Neal Mays

Theses and Dissertations

In March 2006, four groundcover management systems (GMS) and two nutrient sources (NS) were implemented for their ability to alter the soil physical condition of a newly established, organically managed apple (Malus x domestica Borkh.) orchard. Annual applications of municipal green compost (GC), shredded office paper (SP), wood chips (WC), and mow-blow (MB) grass mulch were utilized as GMS, and NS supplied to trees were from composted poultry litter (PL), a commercial organic fertilizer (CF), or an untreated control (NF) in a 4x3 factorial study. An established, conventionally-managed orchard was located adjacent to the organic research orchard on the same ...


Biodiesel Transesterification Byproducts As Soil Amendments, Solomon Parker May 2013

Biodiesel Transesterification Byproducts As Soil Amendments, Solomon Parker

Theses and Dissertations

For every ten kilograms of biodiesel that is produced from the transesterification of vegetable oil, approximately 1 kg of glycerol is produced as a byproduct. Also known as glycerin, it is a chemical used in many products including cosmetics, foods, and desiccants. However, the crude glycerol created during biodiesel production is tainted with potassium hydroxide and methanol making it unsuitable for commercial use without costly refinement. With increase in production of biodiesel driven by rising fuel prices, the market has become glutted with glycerol and it is on the threshold of becoming a waste product. Common methods for disposing glycerol ...


Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Arkansas: Resistance Mechanisms And Management Strategies, Griff Michael Griffith May 2013

Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Arkansas: Resistance Mechanisms And Management Strategies, Griff Michael Griffith

Theses and Dissertations

Since 2000, there have been thirteen weed species confirmed resistant (R) to glyphosate in the United States, six of those resistant species are present in Arkansas. The goal of this research was to confirm and to determine the level of resistance in two R Palmer amaranth biotypes from Mississippi (MC-R) and Lincoln (LC-R) Counties, Arkansas, and one susceptible (S) biotype from Clarendon County, South Carolina, which had never been exposed to glyphosate. Shikimic acid concentration over time was significantly greater in the S biotype than both the MC-R and LC-R biotypes. The lethal dose required to kill 50% (LD50 ...


Comparison Of Roundup Ready And Conventional Soybean (Glycine Max L.) Weed Control Systems For Optimizing Yield And Economic Profitability, Brittany Lee Gaban May 2013

Comparison Of Roundup Ready And Conventional Soybean (Glycine Max L.) Weed Control Systems For Optimizing Yield And Economic Profitability, Brittany Lee Gaban

Masters Theses

Research was conducted in 2010, 2011 and 2012 at the East Tennessee Research and Education Center in Knoxville, TN, in order to compare differences in soybean yield among differing levels of weed control within Roundup Ready® [Glyphosate-resistant] (RR)and conventional soybean cultivars to gain a better understanding of the impact different intensities of weed control have on RR and conventional cropping systems. Results determined that after applying the weed control regimens, there was no significant difference (p

Glyphosate resistant weeds introduce new challenges and create a more costly weed control regimen, especially when using a RR based soybean cultivation operation ...


Every Other Row Furrow Irrigation Trial, Jason Mast Feb 2013

Every Other Row Furrow Irrigation Trial, Jason Mast

Agricultural Education and Communication

Abstract

Silage corn yields are limited by irrigation effectiveness in the Central Valley of California. This experiment was conducted to determine if silage yield would suffer after altering irrigation methods and timing. The effects of irrigation method and timing were tested on field corn [Zea mays (DKC 67-86)]. The study was carried out in Denair, California on a Whitney Rocklin sandy loam. Silage tonnage, grain yield, and plant height were compared across four treatments with three repetitions of each treatment. The treatments were every other row, the grower’s standard practice, deficit, and a control. The experiment showed that every ...


The Effects Of Starter Fertilizer On Root And Shoot Growth Of Corn Hybrids And Seeding Rates And Plant-To-Plant Variability In Growth And Grain Yield, Warren Pierson Jan 2013

The Effects Of Starter Fertilizer On Root And Shoot Growth Of Corn Hybrids And Seeding Rates And Plant-To-Plant Variability In Growth And Grain Yield, Warren Pierson

Graduate Theses and Dissertations

Starter fertilizer often increases early-season growth of corn; however, yield responses have varied. Yield responses often occur on soils with low soil fertility, however, have occurred on soils with high fertility. Currently, farmers are attempting to reduce plant-to-plant variability in growth and development to maximize grain yield. Farmers have asked if placing starter fertilizer near the seed could reduce plant-to-plant variability with the hypothesis that uniform fertility will result in uniform plants. We conducted two experiments near Ames, Iowa, and Nashua, Iowa with similar treatments and data collection. Starter fertilizer was banded 5 cm below the seed and 5 cm ...


Effect Of Corn Stover Harvest And Winter Rye Cover Crop On Corn Nitrogen Fertilization, Jose L. Pantoja Jan 2013

Effect Of Corn Stover Harvest And Winter Rye Cover Crop On Corn Nitrogen Fertilization, Jose L. Pantoja

Graduate Theses and Dissertations

Improvement in N management to optimize corn N fertilization requirement and minimize NO33--N loss from agricultural fields is an ongoing need for continuous corn (Zea mays L.) and corn-soybean [Glycine max (L.) Merr.] production systems. This is especially important in Iowa as this state has the largest corn production across the U.S.A. The present dissertation includes two projects that evaluated corn response to N application and optimal fertilization rate. The first project evaluated the effect of corn stover harvest (SH) in continuous corn and the interaction with chisel plow and no-tillage systems; and the second project ...