Agronomy and Crop Sciences Commons^™

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 …

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 …

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, 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 …

The Biology And Management Of Waterhemp In Indiana, Joseph M. Heneghan

Open Access Theses

Waterhemp is a dioecious weed species indigenous to the Midwestern United states yet it has only recently become problematic in agronomic crop production in Indiana. Waterhemp is a small-seeded broadleaf which has increased in prevalence in conjunction with an increase in conservation tillage practices. Waterhemp germinates and emerges from the top 3 cm of soil and is known to exhibit extended periods of continual emergence, longer than most other summer annual weed species that are typically present in agronomic production settings. As a C4 species, waterhemp then grows rapidly and is capable of producing thousands of seeds, while effectively competing …

Automatic Extraction Of Plots From Geo-Registered Uas Imagery Of Crop Fields With Complex Planting Schemes, Anthony A. Hearst

Open Access Theses

Complex planting schemes are common in experimental crop fields and can make it difficult to extract plots of interest from high-resolution imagery of the fields gathered by Unmanned Aircraft Systems (UAS). This prevents UAS imagery from being applied in High-Throughput Precision Phenotyping and other areas of agricultural research. If the imagery is accurately geo-registered, then it may be possible to extract plots from the imagery based on their map coordinates. To test this approach, a UAS was used to acquire visual imagery of 5 ha of soybean fields containing 6.0 m2 plots in a complex planting scheme. Sixteen artificial targets …

Analyzing The Importance Of Diversifying Beyond Tobacco For Small-Scale Farmers In Malawi, Mphatso Charity Mbulukwa

Open Access Theses

This thesis analyses potential agricultural alternatives to production and marketing of tobacco in Malawi. I study existing patterns of crop and income diversification and factors that limit crop diversification. I also provide an analysis of the current profitability of different important cash crop alternatives that are commonly grown among smallholder farmers and compare their profitability to that of tobacco.

Following a review and synthesis of available literature on alternatives to tobacco, analysis is presented that relies upon data collected in 2009 from 380 households in Kasungu and Machinga districts of Malawi. Simpsons Index of diversification was used to measure the …

Defining Management Strategies To Maximize Net Soil Carbon And Nitrogen Retention In Turfgrass Systems, Quincy D. Law

Open Access Theses

Soil carbon (C) sequestration has been proposed as a method to reduce atmospheric carbon dioxide (CO2 ). Managed turf areas are both a source and a sink for greenhouse gases (GHGs) including CO 2 , methane (CH4 ), and nitrous oxide (N2 O), among others. Management practices, including turfgrass selection and mowing, influence the amount of C and N stored in the soil, as well as the direct and indirect GHG emissions. Thus, the objective of this research was to determine how turfgrass selection (both species and cultivar) and mowing practices (such as frequency and grass clipping management) influence the …

Creating Initial Digital Soil Properties Map Of Afghanistan, Shams R. Rahmani

Open Access Theses

Afghanistan is a country with a population of more than 31 million people and is located in south central Asia. The total arable land in the country is 12%, 5% is irrigated and the remaining 7% is rainfed. Due to the lack of available soil information, poor farming practices and land management planning severely affect the yield of agriculture products. In order to ensure sustainable agriculture and prevent land degradation problems, understanding spatial variability of soil is crucial. The overall objective of this research study was to use digital soil mapping techniques to identify the soil resources and generate a …

Liquid Swine Manure Application Timing And Instincttm Impacts On Net Soil Nitrogen Mineralization And Corn Yield, Min Xu

Open Access Theses

Nitrogen (N) is one of the most expensive variable input costs for corn production. Optimized manure management is essential to ensure maximum crop N utilization and to reduce the risk of N loss. A field study was conducted in central Indiana from 2011-2013 to assess liquid swine ( Sus scrofa L.) manure N availability when applied at different times or co-applied with InstinctTM , a microencapsulated form of nitrapyrin. Soil inorganic N contents, soil N mineralization, corn yield, grain N content, whole plant N concentrations of corn at the V6 growth stage, and ear leaf N concentrations of corn at …

Assessing Positional Accuracy And Correcting Point Data For Digital Soil Mapping At Varying Scales, Minerva J. Dorantes

Open Access Theses

Accuracy, timeliness, and the effect of scale of soil maps are rarely assessed. The recent increase in the use of GIS technologies and modelling software in natural resources and land management, has increased the demand for soil information at a finer resolution worldwide. Most of the world's developing countries rely on soils information at a scale that is too coarse for practical planning, and have obstacles impeding collection of new data, such as civil war and a lack of collection resources. The United States has an exhaustive collection of soils data at a fine scale. However, its location information is …

Agronomic And Genetic Characterization Of Aluminum Tolerance In A Recombinant Inbred Population Of Sorghum [Sorghum Bicolor (L.) Moench], Amanda Christine Easterly

Open Access Theses

Acid soils are estimated to cover up to 30% of arable soils globally and lead to significant limitations on agricultural productivity, primarily through aluminum toxicity. In sorghum [Sorghum bicolor (L.) Moench], significant genetic variation exists for tolerance to phytotoxic species of aluminum; tolerance is conferred through the exudation of citrate at the root tip, binding aluminum in the soil rhizosphere. A gene in the multidrug and toxic compound extrusion (MATE) family is the primary tolerance locus in sorghum. The purpose of this research was to evaluate a recombinant inbred line (RIL) population of sorghum segregating for SbMATE to establish …

Managing Swine Manure In Double-Crop Soybean, Donald Joseph Graper

Open Access Theses

Animal production, especially swine (Sus scrofa domesticus ) and poultry, has increased in the United States prompting the need to manage the larger volume of manure beyond land applications to supply nitrogen (N) for corn (Zea mays ) production. Applying swine manure to soybean (Glycine max ) has been shown to increase grain yield due to N supply. The goal of this research was to determine if swine manure applications to double-crop soybean following wheat can limit manure N loading to the soil by extending management options, increase soybean biomass and grain production, and increase N removal …

Spatial And Temporal Distribution Of Fungicides Applied To Creeping Bentgrass, Kurt Ronald Hockemeyer

Open Access Theses

Turf managers often rely on fungicides to limit damage caused by root diseases. Since fungicides do not move basipetally, they are effective only when fungitoxic concentrations are delivered to the rhizosphere. This research focused on the distribution of modern fungicides in verdure, thatch, sand, and roots of creeping bentgrass (Agrostis stolonifera L. var. palustris (Huds.) Farw.) maintained as a putting green. Fungicides (azoxystrobin (methyl (E)-2-[2-[6-(2-cyanophenoxy)pyrimidin-4-yloxy]phenyl]-3-methoxyacrylate), propiconazole (1,2,4-Triazole, 1-((2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-yl)methyl), pyraclostrobin (carbamic acid, [2-[[[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxy]methyl]phenyl]methoxy-,methyl ester), and thiophanate-methyl (dimethyl 4,4'-o-phenylenebis[3-thioallophanate]) were applied to replicate field plots in a water volume of 815 L ha-1. Plots were sampled over time (0, 3, 7, 10, …

Application And Timing Effects Of Qoi And Dmi Fungicides And A Foliar Fertilizer On Overall Plant Health And Grain Yield In Corn, Jason Phillip Geis

Open Access Theses

The use of fungicides on corn has recently increased as a result of higher grain market prices, changes in cropping practices, higher disease incidence and severity, and the availability and marketing claims of new fungicides. Some of the marketed potential "plant health(TM)" benefits include improved tolerance to drought and heat, improved N utilization, and increased stalk strength. Previous studies have displayed delayed canopy senescence, changes in water use efficiency, and reduced ozone damage in controlled environments. Foliar fertilization has also increased in popularity in recent years due to an increase in grain prices, manufacturer claims, and product availability.

Large-scale field …

Effects Of Wheat Grain Moisture: Quality, Germination, And Relationship To Accumulated Growing Degree Days, Kirsten Thomas

Open Access Theses

Bread wheat (Triticum aestivum L.) is a cereal crop of global importance. As global demand increases, it is essential to increase the quality and efficiency of crop production. Harvesting wheat early provides an opportunity for increased grain quality, and it may also allow the grower to double-crop soybean ( Glycine max L.) after wheat more effectively. Our objectives were to determine if harvesting grain early, at high moisture would, 1) increase milling and baking quality and 2) improve germination potential. As a result of these objectives, we will develop a model to predict dry-down of wheat. Five soft red …

Quantifying Subsurface Hydrology Effects On Chemical Transport In Agriculture Drainage Ditches Using A 20 Meter Flume, Colton Eugene Yoder

Open Access Theses

Agriculture drainage ditches serve as the veins of the Midwestern agricultural landscapes. The transport of chemical fertilizers and pesticides in these ditches affects both local and downstream ecosystems. Although much research has already been conducted on chemical transport in streams and drainage ditches, as well as through drainage tiles, there has not been sufficient research on the effects of subsurface hydrology on nutrient storage and interactions between the stream water and the hyporheic zone. In this study, a 20-meter flume was filled with ditch sediment from Marshall Ditch at Purdue University's Agronomy Center for Research and Education in West Lafayette, …

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 …

Fate Of 17Α-Estradiol, 17Β-Estradiol, And Estrone In Agricultural Soils And Sediments, Michael L. Mashtare Jr

Open Access Dissertations

The shift to concentrated animal production facilities and increasing rural-urban migration has increased the localized land application of nearly 1 billion tons of manure and biosolids annually. Although these applications provide nutrients and contribute to soil tilth, they also serve as a source for an estimated 49 tons of the natural manure-borne estrogens, 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), and estrone (E1). While these estrogens are critical to endocrine systems, the low concentrations observed in the environment can disrupt endocrine function in non-target organisms, e.g., altering secondary sex characteristics which can lead to changes in wildlife communities.

Research presented here focuses on …