Agronomy and Crop Sciences Commons^™

Sensitivity Of Soybean And Rice To Dicamba, Owen Wesley France

Graduate Theses and Dissertations

Although the integration of dicamba as a postemergence (POST) herbicide has proven useful in controlling many herbicide-resistant weeds, its damage to soybean at low rates, such as supplied by drift and volatility, has been well-documented. Injury to other crops, such as rice, from off-target movement of dicamba and other commonly used herbicides, such as glyphosate, may also occur. Practical options for mitigating injury and yield loss to soybean and other crops from dicamba off-target movement could prove beneficial if dicamba continues to be used during summer months. Experiments were conducted to determine the effects of multiple agricultural practices, including cultivar …

Evaluation Of Nitrous Oxide Emissions From Furrow-Irrigated Rice On A Silt-Loam Soil In Arkansas, Jordan M. Slayden

Graduate Theses and Dissertations

As the number one rice (Oryza sativa)-producing state in the United States, Arkansas also ranks fourth as the largest user of groundwater. Recently, due to the development of drought- resistant hybrid cultivars, the furrow-irrigated rice production system has become an increasingly popular alternative to traditional flood-irrigated production with respect to conserving groundwater and maintaining yield. However, other environmental parameters, like greenhouse gas emissions, specifically nitrous oxide (N2O), have yet to be evaluated under furrow-irrigated rice. The objectives of this study were to i) evaluate the effects of site position (i.e., up-, mid-, and down-slope) and tillage treatment [i.e., conventional tillage …

Recapture And Reuse Of Nitrogen And Phosphorus From Rendered Animal Materials To Enhance Nutrient Use Efficiency And Produce Quality In Agricultural Crop, Bhupinder Jatana

All Dissertations

The current fertilizer regime heavily relies on inorganic fertilizers to meet the crop nitrogen (N) and phosphorus (P) demand. However, the United States has a limited N production capacity, with 50% N demand met through imports. On the other hand, the nonrenewable natural reserves of P are being depleted at an unprecedented rate and are expected to be exhausted with in next 100 years. Additionally, high solubility/liability of the field applied inorganic fertilizers often results in lower nutrient use efficiency (NUE;

The MBM led to rapid N mineralization, with 35% of the applied N mineralized within the first five days …

Distillers' Grains: Past, Present, And Future Economic Analyses, Daniel E. Gertner

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

This thesis is comprised of four chapters, each of which discusses or conducts economic research related to the distillers’ grains market. The first three chapters are meant to be standalone papers. Chapter four provides potential paths forward in distillers’ grains research based on the findings of the first three chapters and concludes the thesis.

The first chapter conducts a comprehensive literature review that categorizes and summarizes economic research on distillers’ grains products. This section shows how the physical market has moved beyond the current academic understanding of market products and structure. Existing research finds that traditional distillers’ grains products positively …

How Do Cover Crops Change Soil Health In A No-Till System?, Aysha Kirsten Tapp Ross

Electronic Theses and Dissertations

Nutrient levels and aggregation measurements are currently the most accurate means to measure soil health. It has been suggested that bacterial and fungal communities may prove to be a more accurate measure of soil health. In this study soil microbe communities and nutrient levels were compared in rye cover cropped soils to measure for differences between treatments. Effects between the microbial communities and environmental measurements were also measured within those treatments to test for correlations between soil health measures and microbial communities. The plots were put in a biennial corn (Zea mays L.) and soybean (Glycine max …

The Impact Of Beneficial Organisms In Corn Agroecosystems, Callie Rosalind Braley

Doctor of Plant Health Program: Dissertations and Student Research

Corn is one of the world’s, and Nebraska’s, most important crops. Millions of acres are planted to corn each year in the Cornhusker State. However, each year there are a plethora of arthropod, weed, and microorganism pests that rob farmers of reaching their maximum yield potential. There are many options available to manage these pests in corn agroecosystems, but one option is often underutilized: beneficial organisms. For each pest, there are a variety of natural enemies that can assist in mitigating the damage caused by pests.

Many beneficial organisms exist, and they can be grouped by the type of pest …

Intricacies In Agronomic Management: The Role Of Interdisciplinary Education, Adam M. Striegel

Doctor of Plant Health Program: Dissertations and Student Research

As a science, agronomy is built upon the connection of inter-disciplinary fields of study. Management (M) of various discipline considerations (and their subsequent interactions) can be influenced by and have significant effects on genetic by environment (GxE) expression. This has led to the promotion of GxExM systems. However, optimizing GxExM programs requires extensive, interdisciplinary knowledge. To evaluate interdisciplinary training provided in undergraduate education, 11 four-year universities were selected in the United States that offer baccalaureate degree majors in agronomy or crop science. Surveys of undergraduate programs of study were conducted, with all required coursework separated into general degree components (general …

Comparing Machine Learning Techniques With State-Of-The-Art Parametric Prediction Models For Predicting Soybean Traits, Susweta Ray

Department of Statistics: Dissertations, Theses, and Student Research

Soybean is a significant source of protein and oil, and also widely used as animal feed. Thus, developing lines that are superior in terms of yield, protein and oil content is important to feed the ever-growing population. As opposed to the high-cost phenotyping, genotyping is both cost and time efficient for breeders while evaluating new lines in different environments (location-year combinations) can be costly. Several Genomic prediction (GP) methods have been developed to use the marker and environment data effectively to predict the yield or other relevant phenotypic traits of crops. Our study compares a conventional GP method (GBLUP), a …

The Medium-Term Impacts Of Integrated Crop–Livestock Systems On Crop Yield And Economic Performance, Teerath Singh Rai, Thandiwe Nleya, Sandeep Kumar, Peter Saxton, Tong Wang, Yubing Fan

Agronomy, Horticulture and Plant Science Faculty Publications

Integrated crop–livestock (ICL) systems are diverse production systems that can improve resource utilization through spatially or temporally rotating land among crop, livestock, and pasture uses. However, research on whether the enhanced resource utilization translates to greater crop productivity is still warranted. A field experiment was initiated at South Dakota State University in 2016 to determine the impacts of integrating cover crops and livestock grazing into a crop rotation of oat (Avena sativa L.)–maize (Zea mays L.)–soybean [Glycine max (L.) Merr.]. The objectives were to (a) determine the medium-term (4–6 yr) impacts of cover crops and livestock grazing …

Arkansas Corn And Grain Sorghum Performance Tests 2021, J. F. Carlin, R. B. Morgan, R. D. Bond

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 2021 corn performance tests contained 70 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 Rohwer Research Station (RRS) near Rohwer, and the Rice Research and Extension Center (RREC) near Stuttgart. The …

Economic Potash Fertilizer Rate Recommendations, Kimberly B. Oliver

Graduate Theses and Dissertations

This thesis is comprised of two studies that estimate profit-maximizing potassium (K) fertilizer application rates for various crops across different time periods. Estimation of profit-maximizing fertilizer-K rate (K*) for both studies considered the initial soil test level of K (STK) and yield response information, as traditional recommendations do, and added crop price and the cost of fertilizer. Profit maximum occurs where the marginal revenue from additional yield is equal to the marginal cost of applying an additional unit of fertilizer-K. The first study calculated K* for corn (Zea mays) and cotton (Gossypium hirsutum) and compared results to previous studies on …

Integrated Weed Management Strategies For Palmer Amaranth (Amaranthus Palmeri) In Cotton And Soybean Production Systems, Rodger Bruce Farr

Graduate Theses and Dissertations

Management of Palmer amaranth [Amaranthus palmeri (S.) Wats.] in the Midsouth in soybean [Glycine max (L.)] and cotton (Gossypium hirsutum L.) production systems has become increasingly troublesome due to resistance to many of the commonly utilized herbicides in these systems. Developments have been made to utilize new chemistries as well as incorporate integrated weed management strategies to control Palmer amaranth, but questions have risen given the economic feasibility or effectiveness of these new strategies. Additionally, regulation has limited producers’ abilities to utilize some herbicide chemistries. As a result, experiments were conducted to 1) understand the utility of isoxaflutole in isoxaflutole-tolerant …

Effects Of Nitrogen Management And Cultivar On Strawberry Production Under Disease Pressure, Kamille A. Garcia-Brucher

Master's Theses

Effects of nitrogen management and cultivar on strawberry production under disease pressure

Kamille Garcia-Brucher

California strawberry growers face increasing regulatory pressures to manage nitrogen (N) applications in their production system. Standard practice in the California strawberry industry is to apply a synthetic pre-plant controlled release fertilizer (CRF) to ensure the crop has sufficient N during winter establishment. Some research from the UC Cooperative Extension suggests this practice is not efficient at delivering N to the crop since most of the N is released from CRF before strawberry crop N uptake is significant. Another concern for California strawberry growers is loss …

Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer

Graduate Theses and Dissertations

This thesis compares the responses of organic yields and conventional yields towards climate variations. To achieve this objective, weather variables such as growing season weather conditions (average temperature, precipitation, cloud cover, relative humidity, drought index), weather anomalies, the occurrence of severe or extreme droughts and excessive rainfalls, are combined with 23 data sets gathered from previous studies that compare organic and conventional yields from the same location and time periods. To narrow the scope, the thesis focuses on soybean, maize, and wheat production in Europe and North America. Study-level fixed-effects models are used to control for any time-invariant factors such …

Nutrient Uptake And Management Strategies In Recirculating Hydroponic Systems, Lauren Leigh Houston

Graduate Theses and Dissertations

Nutrient management in recirculating hydroponic systems requires the periodic replenishment of water and nutrients to the nutrient solution reservoir. Common nutrient management strategies, such as replenishing the reservoir with fresh solution and maintaining a constant solution electrical conductivity (EC), can lead to ion accumulation and nutrient imbalances since nutrients are taken up by roots and depleted from solution at different rates. To avoid nutritional disorders, commercial growers typically dump and replace the hydroponic solution periodically, which is wasteful and has an economic cost. A potential alternative is to specially formulate the nutrient replenishment solution to balance the supply of nutrients …

Crispr Gene Editing Drivers, Barriers And Prospects: A Comparative Study Among Plant Scientists Globally, Adriaan Johannes De Lange

Graduate Theses and Dissertations

The introduction of CRISPR gene editing into food crops has potential to contribute to food security and sustainable food production globally. To date, most scientific studies have focused on consumer perception of CRISPR gene edited foods or the potential benefits and risks of the CRISPR technology and none have focused on the perceptions of plant scientists concerning CRISPR gene editing. This study aimed to explore the investments, functions, barriers, benefits for specific crops and beneficiaries of CRISPR gene editing according to plant scientists, by distributing an online survey in which 1,040 plant scientists active across six continents and in both …

Optimization And Resistance Mitigation Of Dicamba And Glufosinate In Xtendflex® Crops, Grant Lawson Priess

Graduate Theses and Dissertations

The commercial launch of XtendFlex® crops enabled the use of dicamba, glufosinate, and glyphosate in-season. Utilizing herbicides that target different sites of action within troublesome weeds has been a tactic proposed to mitigate the likelihood of target-site resistance evolving; however, if interactions of the herbicides are detrimental to control of weedy species the likelihood of metabolic resistance increases. The objective of this research was to: 1) optimize efficacy and economic benefits of dicamba, glufosinate, and glyphosate; 2) characterize any interactions that were observed; 3) understand the mechanisms responsible for the reductions in weed control; 4) attempt to overcome interactions that …

Precise Nitrogen Recommendations Improve Economic And Environmental Outcomes In Arkansas Rice Production, Cristin Roberts

Graduate Theses and Dissertations

Soil testing has become an increasingly important tool in making agronomically efficient production management decisions. N-STaR is a N test used in rice production and is unique in its ability to selectively quantify soil organic-N compounds which are readily mineralizable for plant N uptake and contribute to growth and yield. This study uses historical (2002–2018) adoption rates of N-STaR, which is funded through Rice Checkoff funds, to calculate the total cost savings from N-STaR adoption. These cost savings alone would be the “typical” benefits used in a benefit-cost ratio of a public ally funded research program like N-STaR. However, we …

Mitigating Rice Injury Caused By Florpyrauxifen-Benzyl And Optimizing Florpyrauxifen-Benzyl Rate And Timing For Use In Furrow-Irrigated Rice, James Winston Beesinger

Graduate Theses and Dissertations

Florpyrauxifen-benzyl (synthetic auxin, WSSA Group 4) is a postemergence, broad-spectrum herbicide labeled for use in Mid-South rice (Oryza sativa L.) production. Introduction of florpyrauxifen-benzyl to Arkansas rice production led to observations of varying levels of injury caused by the herbicide across cultivars and environments. Findings from previous research indicated hybrid long-grain rice and medium-grain rice were more susceptible to florpyrauxifen-benzyl and hypotheses were formed using this research regarding the impact of environmental conditions on the amount of injury observed. Concerns of yield loss, delay in maturity and loss of groundcover as well as questions regarding the ability of florpyrauxifen-benzyl to …

Arkansas Soybean Research Studies 2020, Jeremy Ross

Arkansas Agricultural Experiment Station Research Series

The 2020 Arkansas Soybean Research Studies includes research reports on topics pertaining to soybean across several disciplines from breeding to post-harvest processing. Research reports contained in this publication may represent preliminary or only data from a single year or limited results; therefore, these results should not be used as a basis for long-term recommendations. Several research reports in this publication will appear in other University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station publications. This duplication is the result of the overlap in research coverage between disciplines and our effort to inform Arkansas soybean producers of the research …

Small Grain Cereal Cover Crops For Late Fall Or Early Spring Grazing, Kallie J. Calus

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

Beef cattle operations are confronted with early spring and late fall forage deficiencies. Producers in integrated crop and livestock systems can fill forage gaps using cover crops as a forage source in between cash crops.

A five-year study evaluating forage production, growing calf performance and economics of grazing an oats cover crop planted after corn silage (CS) and high moisture corn (HMC) corn harvests was conducted. The economic analysis accounted for costs of establishing and grazing the oats and the value of calf gain to determine fall grazing system profitability. Steers had greater average daily gain grazing oats after CS …

Impact Of Planting Arrangement And Drill Row Spacing For Direct-Seeded, Delayed Flood Rice, Mary Jane Lytle

Graduate Theses and Dissertations

Direct-seeding is the most frequently utilized planting practice in Arkansas and Mid-South rice (Oryza sativa L.) production. Enhanced plant density and more rapid rice canopy formation may result from the implementation of innovative plant arrangements and spacings. Studies were initiated in 2019 and continued into 2020 to examine different cultural management practice experiments, including evaluating the impacts of planting arrangement, row spacing, and seeding rates on rice stand density, canopy coverage, grain yield, and milling yield. These small-plot trials were conducted at two locations, a silt loam site and a clay site, representative of soils produced to rice in eastern …

Soil Health Monitoring And Management In Corn And Soybean Agroecosystems Of The Midwestern U.S., Bradley S. Crookston

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil health is a concept and condition of the soil where measurable soil properties represent the capacity of a soil fulfilling its intended use, such as producing crops, without constraint to its agro-ecological quality. Soil health assessments are used to estimate the health of a soil by assessing soil biological, chemical, and physical attributes, called soil health indicators, and scoring them on a scale, usually 0 to 100, to guide soil and crop management. However, there are few large-scale analyses of soil health assessment scores and their relationships with crop yield. Understanding how soil health assessments relate to crop yield …

Forage Production From Perennial Vs. Annual Crop R~ On In Sandy Soils In Egypt, Z. Abdelhalim, O. Niemeläinen, I. A. Hanna, A. M. Rammah

IGC Proceedings (1977-2023)

Forage production was studied on newly reclaimed sandy soil in Egypt trom perennial lucerne (Medicago sativa L.) and two annual crop rotations. The cropping systems were: A) lucerne, B) berseem clover (Trifolium alexandrinum L.) in the winter followed by pearl millet (Pennisetum glaucum R. Br. Emend. Stantz.) in the summer and C) triticale (XX Triticosecale Wittm.) (forage cut + grain harvest) in the winter followed by maize (Zea mays L.) (grain + stover) in the summer. Mean annual dry matter yields (t ha^-1 ) were 20.65, 26.59 and 27.48 from A, B and C, respectively. However, …

Carry-Over Effect In Forage Rotations On Newly Reclaimed Sandy Soil In Egypt, Z. Abdelhalim, O. Niemeläinen, I. A. Hanna, A. M. Rammah

IGC Proceedings (1977-2023)

This study was carried out to investigate the carry-over effect of a preceding crop on the productivity of the following crop in various rotations in newly reclaimed lands in Egypt. The productivity of peanut (Arachis hypogaea L.), soyabean (Glycine max (L.) Merr.), maize (Zea mays L.) and pearl millet (Pennisetum glaucum (L.) R. Br.) in summer season were much higher following berseem (Trifolium alexandrinum L.) or lentil (Lens culinaris Medic) than after wheat (Triticum aestivum L.) or barley (Hordeum vulgare L.) in both years of the study. Soyabean was the best summer …

Direct Drilling Of Soybean In A Pensacola Bahiagrass Pasture In The Northwest Region Of Rio Grande Do Sul, Brazil, R. B. Medeiros, J. Riboldi, J. C. De Saibro, J. E. G. Zambra

IGC Proceedings (1977-2023)

The response of methods of soil preparation (M₁=conventional tillage, and with notillage using the following herbicides M₂=50% Paraquat plus 50% Orizalin; M₃=50% Paraquat plus 50% Diquat and M₄=Paracol (20% Paraquat plus 20 Diuron)) and row spacing (E₁=17 cm, E₂=24 cm, E₃=51 cm and E₄=68 cm) on soybean grain yield direct drilled in an eight-year-old grazed sward of Bahiagrass cv. Pensacola (Paspalum notatum var. saurae Parodi) were studied in southern of Brazil. The results showed that direct drilling of soybean on Pensacola accompanied by …

Forage Quality Evaluation Of Chopped Elephantgrass Hay Through Intake And Digestibility Trial, E. M. De Aguiar, G. F. Da C. Lima, L. G. Da Paz

IGC Proceedings (1977-2023)

The research was carried out to evaluate forage quality of chopped elephantgrass (Pennisetum purpureum Schum.) hay and to define a proper stage for cutting and haymaking of this grass. Chemical composition, voluntary intake, and apparent digestibility of the hays were studied at five different growth stages (30, 48, 63, 76, and 91 days). Twenty-five common wethers were utilized in a completely randomized experimental design. Dry matter (DM) voluntary intake was not different (P> 0.05) from 30 to 63 days of regrowth and from 63 to 91 days and comprised 3.9; 3.5; 3.2; 2.1; and 2.4% of animal liveweight, respectively …

Seeding Rate Effects On Forage Mass And Vegetation Dynamics Of Cool-Season Grass Sod Interseeded With Sorghum-Sudangrass, John A. Guretzky, D. D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Interseeding annual warm-season grasses into perennial cool-season grasses has the potential to increase summer forage mass and nutritive value. Knowledge of how seeding rate affects annual warm-season grass establishment, forage mass, and vegetation dynamics remains limited. From 2016–2017, we conducted a field experiment evaluating the effects of seeding rates on sorghum-sudangrass (Sorghum bicolor x S. bicolor var. sudanense) density and forage mass and on the frequency of occurrence of plant species in cool-season grass sod in Lincoln, NE. The experiment had a completely randomized design consisting of six replicates of four seeding rates [0, 14, 28, and 35 …

Berseem Clover In Binary Mixtures With Oats, Triticale Or Barley For Silage And Late Season Grazing, S. M. Ross, J. R. King

IGC Proceedings (1977-2023)

An experiment was conducted at northerly latitudes with berseem clover (Trifolium alexandrinum L) in binary mixtures with oats (Avena sativa L.), barley (Hordeum vulgare L.) and triticale (X Triticosecale Wittmack). The effects of cereal species, variety and density were assessed for a two cut harvest. Total dry matter yields were 11.7 to 14.5 t ha^-1, with 7.8 to 10.2 t ha^-1 as silage, and 2.0 to 6.0 t ha^-1 as berseem regrowth. Berseem regrowth added an average of 4.0 t ha^-1 in forage yield. Total yields did not differ with cereal …

Forage Productivity Of Panicum Maximum Pastures In Two Different Agropastoral Systems, Tsutomu Kanno, Manuel C. M. Macedo, J. A. Bono, J. D. G. Santos Jr., M. R. Correa, L. G. R. Beretta

IGC Proceedings (1977-2023)

Forage productivity was evaluated for Panicum maximum pastures established after 4 years of soybean cultivation in the summer (PM-SO), and 4 years of rotation of soybeans in the summer and millet for winter grazing (PM-MI). In the PM-MI pasture, biomass and dry matter production were much lower than in the PM-SO, and the amount of copper and nitrogen in the top part of the plants in PM-MI were significantly lower than that in PM-SO. Thus, it was considered that the shortage of copper and nitrogen restricted photosynthesis and forage production in PM-MI.