Agricultural Science Commons^™

De-Intensification Of Grasslands: Understanding The Processes To Find The Balance, K. C. Hodgkinson

IGC Proceedings (1977-2023)

There is a growing trend in Australia and other developed countries for deintensification of animal production from grasslands and for grasslands to be used for purposes other than livestock grazing. These shifts are occurring for a variety of reasons including unsustainable land management practices, environmental pollution, loss of conservation value, poor commodity prices and declining rural infra-structure and communities. In Australia, the shifts are under way in agricultural grasslands, where sown pastures occur in a matrix of semi-natural woodlands, but less so in the other three major natural grasslands that forms the arid and semi-arid rangelands.

The conversion of natural …

De-Intensification Of Grasslands: Current State And Trends, Michael Duru, Bernard Hubert

IGC Proceedings (1977-2023)

De-intensified use of grasslands, and more generally of the livestock systems they support, has been triggered by a growing sensitivity of citizens to environmental quality (nitrogen) and quality of animal products, and by the warnings addressed to political authorities by scientists about the environmental consequences of economic imbalances (decreasing biodiversity, drop in soil fertility, greenhouse effect), and in particular of food overproduction in Europe.

From an ecological standpoint, grassland de-intensification must be envisaged whenever the techniques implemented disrupt resource sustainability. The grassland resource itself may be at risk when a rate of vegetation offtake by herbivores that is incompatible with …

The Future Of The Big Sagebrush Ecosystem: Plant Community Response To Grazing, Wildfire, And Invasive Annual Grass In A Changing Climate, Margaret Eleanor England

Theses, Dissertations and Capstones

Climate change is increasingly affecting the plant communities across the world. In the Western United States, these changes are affecting plant communities and their risk of invasive species, as well as the frequency and severity of wildfire. Big sagebrush (Artemisia tridentata Nutt.) ecosystems of the Western United States are facing threats of increasingly frequent wildfire and invasion of the annual grass cheatgrass (Bromus tectorum L.), which may be exacerbated by global climate change. Past studies have found cheatgrass to exhibit a positive feedback loop with wildfire, and climate change is expected to facilitate expansion of the cheatgrass …

A Phytobacterial Tir Domain Effector Manipulates Nad+ To Promote Virulence, Samuel Eastman, Thomas Smith, Mark A. Zaydman, Panya Kim, Samuel Martinez, Neha Damaraju, Aaron Diantonio, Jeffrey Milbrandt, Thomas Clemente, James R. Alfano, Ming Guo

Department of Agronomy and Horticulture: Faculty Publications

The Pseudomonas syringae DC3000 type III effector HopAM1 suppresses plant immunity and contains a Toll/interleukin-1 receptor (TIR) domain homologous to immunity-related TIR domains of plant nucleotide-binding leucine-rich repeat receptors that hydrolyze nicotinamide adenine dinucleotide (NAD+) and activate immunity. In vitro and in vivo assays were conducted to determine if HopAM1 hydrolyzes NAD+ and if the activity is essential for HopAM1’s suppression of plant immunity and contribution to virulence. HPLC and LC-MS were utilized to analyze metabolites produced from NAD+ by HopAM1 in vitro and in both yeast and plants. Agrobacterium-mediated transient expression and in planta inoculation assays were performed to …

Bedstraw Eradication Program 2021/22: Annual Report To Grain Growers, Department Of Primary Industries And Regional Development, Western Australia

Agriculture reports

Three-horned bedstraw is a competitive weed that can cause considerable yield loss in crops, and its seeds contaminate fodder and grain. To stop the weed becoming established in Western Australia and impacting production, WA grain/seed/hay growers (via the Grains, Seeds and Hay Industry Funding Scheme) fund the Bedstraw Eradication Program.

Predicting Munsell Color For Turfgrass Leaves, William L. Berndt, Roch E. Gaussoin

Department of Agronomy and Horticulture: Faculty Publications

Linking turfgrass color to hue, value, chroma (H V/C) in the Munsell Plant Tissue Color Book is a visual comparison process for specifying and communicating plant color. If subjectivity of visual comparison can be mitigated, then accuracy of color matching may be improved. Research was conducted to develop an algorithm predicting H V/C from CIE-xyY color (xyY) in digital images of leaves of four turfgrasses. First, value-chroma (V/C) arrays for Munsell hue groups 5Y, 2.5GY, 5GY, 7.5GY, 10GY, and 2.5G were converted to xyY. Next, chromaticity (xy) plots from each array were fitted with …

Response Of Soil Biochemical And Physical Properties To Long Term Prairie Cordgrass And Kura Clover Intercropping System, Vaishnavi Varikuti

Electronic Theses and Dissertations

Prairie cordgrass (Spartina pectinata) (PCG) is a warm-season perennial grass that can be used as a biofuel feedstock and can be grown on marginal lands. Previous studies on intercropping of a perennial legume i.e., kura clover (Trifolium ambiguum) (KC) with PCG can improve soil biochemical properties, increase biomass production, mitigate greenhouse gas (GHG) emissions while reducing the chemical fertilizer requirement. However, there is a lack of evidence about the effects of PCG production on soil biochemical and physical properties during the cropping season and at deeper soil depths in reference to support plant growth, environmental implications and enhance the soil …

Southeast South Dakota Experiment Farm Annual Progress Report, 2022, Southeast South Dakota Research Farm

Agricultural Experiment Station and Research Farm Annual Reports

This is an annual report of the research program at the Southeast South Dakota Research Farm in cooperation with South Dakota Agricultural Experiment Station and the SDSU College of Agriculture, Food, and Environmental Sciences and has special significance for those engaged in agriculture and the agriculturally related businesses in the ten county area of Southeast South Dakota. The results shown are not necessarily complete or conclusive. Interpretations given are tentative because additional data resulting from continuation of these experiments may result in conclusions different from those based on any one year.

Characterization Of Salt And Drought Tolerance In Sunflower (Helianthus Annuus L.), Sevgi Saylak

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

Consequent to the increasing world population, food sources are needed to be increased to meet the nutritional needs. However, due to natural processes and agricultural activities, the most destructive environmental factors that limit crop production, soil salinity, and drought-exposed areas are growing. As one of the major oilseed crops, sunflower (Helianthus annuus L.), is considered to be moderately tolerant to salt and drought. Although it can grow in arid to semi-arid regions, increasing salinity and drought might adversely affect sunflower production. This study aimed to investigate several sunflower germplasms' morphological responses to salt and drought stresses. For this purpose, …

Effects Of Conservation Management Practices On Soil Health And Crop Yields In Eastern South Dakota, Alex Mclain

Electronic Theses and Dissertations

Conservation management practice adoption on agricultural land has increased in recent years due to increasing public and private investment. The anticipated impact of increasing conservation management practice adoption are reduced greenhouse gas emissions and improved soil, water, and air quality. Understanding how these conservation management practices affect agricultural producers economically is vital to properly incentivize these practices. The existing literature on how conservation management practices affect soil health and crop yields is mixed and generally has been conducted on experimental research stations. These studies may not fully account for the on-farm effects of conservation management practices. The objectives of this …

Soil Hydro-Physical Properties, Computed Tomography Measured Pore Parameters, And Soil Health Indicators As Influenced By Tillage And Crop Rotation Systems, Goutham Thotakuri

Electronic Theses and Dissertations

Long-term tillage and crop rotation systems are important agricultural management practices as these can have direct impact on the soil’s key properties. The objectives of this study were to (ⅰ) quantify the soil pore characteristics under long-term tillage and crop rotation using X-ray computed tomography (XCT) and to assess the relationships between XCT-measured pore parameters and soil hydro-physical properties; and (ⅱ) evaluate the impacts of long-term tillage and crop rotation on select soil health indicators. The objective (ⅰ) was carried out at Haskell Agricultural Laboratory (HAL), Concord, NE; and objective (ⅰi) was carried out at South Central Agricultural Laboratory (SCAL), …

Garlic Curing: Post-Harvest Nutrient Remobilization From Leaves To Cloves, Mary L. Books

Graduate Theses/Dissertations

Garlic (Allium sativum L.) is grown on small and large scales worldwide. After harvesting, garlic undergoes a drying process for long-term preservation, called curing. Some producers cure with leaves intact, while others will remove and discard the leaves, curing only the bulbs. Due to the ability of plants to remobilize nutrients from leaves to underground storage organs, such as bulbs, the curing method of garlic may affect clove nutrient content. This study explores nutrient remobilization responses in garlic when cured with leaves intact compared to leaves separated from bulbs. Four cultivars of garlic, German White, Chesnok Red, Romanian Red, and …

Field Validation Of A Farmer Supplied Data Approach To Close Soybean Yield Gaps In The Us North Central Region, José F. Andrade, Spyridon Mourtzinis, Juan I. Rattalino Edreira, Shawn P. Conley, John Gaska, Herman J. Kandel, Laura E. Lindsey, Seth Naeve, Scott Nelson, Maninder P. Singhi, Laura J. Thompson, James E. Specht, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

CONTEXT: Producer-reported data can be used to identify suites of management practices that lead to higher yield and profit. However, a rigorous validation of the approach in relation to its potential impact on farmer yield and profit is lacking.

OBJECTIVE: This study aimed to validate a producer-data approach on its capability to guide on-farm evaluation of management practices with greatest potential for increasing producer yield and profit. We show proof of concept using soybean in the North Central US region as a case study.

METHODS: We used a combination of regression tree analysis and a spatial framework to determine practices …

A New Perspective When Examining Maize Fertilizer Nitrogen Use Efficiency, Incrementally, Newell R. Kitchen, Curtis J. Ransom, James S. Schepers, Jerry L. Hatfield, Raymond Massey, Scott T. Drummond

Department of Agronomy and Horticulture: Faculty Publications

For maize (Zea mays L.), nitrogen (N) fertilizer use is often summarized from field to global scales using average N use efficiency (NUE). But expressing NUE as averages is misleading because grain increase to added N diminishes near optimal yield. Thus, environmental risks increase as economic benefits decrease. Here, we use empirical datasets obtained in North America of maize grain yield response to N fertilizer (n = 189) to create and interpret incremental NUE (iNUE), or the change in NUE with change in N fertilization. We show for those last units of N applied to reach economic optimal N …

Inactivation Of The Entire Arabidopsis Group Ii Gh3s Confers Tolerance To Salinity And Water Deficit, Rubén Casanova-Sáez, Eduardo Mateo-Bonmatí, Jan Šimura, Aleš Pěnčík, Ondřej Novák, Paul Staswick, Karin Ljung

Department of Agronomy and Horticulture: Faculty Publications

Indole-3-acetic acid (IAA) controls a plethora of developmental processes. Thus, regulation of its concentration is of great relevance for plant performance. Cellular IAA concentration depends on its transport, biosynthesis and the various pathways for IAA inactivation, including oxidation and conjugation.

Group II members of the GRETCHEN HAGEN 3 (GH3) gene family code for acyl acid amido synthetases catalysing the conjugation of IAA to amino acids. However, the high degree of functional redundancy among them has hampered thorough analysis of their roles in plant development.

In this work, we generated an Arabidopsis gh3.1,2,3,4,5,6,9,17 (gh3oct) mutant to knock out the group II …

Root Exudates Impact Plant Performance Under Abiotic Stress, Yen Ning Chai, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Plant root exudates serve pivotal roles in supporting plant development and interactions with the physicochemical and biological factors in the rhizosphere. Under stress conditions, root exudation is involved in enhancing plant resource-use efficiency and facilitating the crosstalk between plant and soil microbes to ameliorate stress. Although there are a large number of root exudates that remain to be characterized, recent technological advancements have allowed for the function of many exudate compounds to be elucidated. In this review, we discuss current knowledge about the key root exudates that modulate plant resource-use efficiency under various abiotic stresses including drought, aluminum toxicity, phosphorus, …

Ecological Intensification With Soil Health Practices Demonstrates Positive Impacts On Multiple Soil Properties: A Large-Scale Farmer-Led Experiment, Fernanda Souza Krupek, Daren D. Redfearn, Kent M. Eskridge, Andrea Basche

Department of Agronomy and Horticulture: Faculty Publications

Improving soil health is critical to reversing trends of soil degradation and is of increasing interest to a range of stakeholders including policymakers, agricultural industry leaders, food companies, and farmers. Crop and soil management practices focused on ecological functions can be effective in restoring fundamental biological, chemical and physical soil properties. The call for ecological intensification of agricultural systems has the potential to improve soil health and input-use efficiency. In this study, we developed a framework to classify spatial and temporal ecological intensification with soil health practices: tillage, crop rotation, cover crop, organic amendment, and crop-livestock integration. We applied this …

Phosphorus Use And Management Based On Fertilizer Placement, Rate Of Application, And Soil Biota In No-Till Situations, Brennan Alexander Bingham Lewis

Electronic Theses and Dissertations

Phosphorus (P) pollution has become a concern among multiple scientific organizations as it leads to eutrophication, an algal bloom that depletes lacustrine and marine ecosystems of native species. Multiple strategies can be implemented to reduce phosphorus loss from agriculture fields, which is often implicated as a cause of eutrophication. Soil phosphorus chemistry results in phosphate fertilizers absorbing to clay minerals over time. Soil phosphorus is lost from agricultural fields primarily through wind and water erosion. No-till practices prevent soil erosion, which reduces the phosphorus from loading into waterways. Fertilizer placement affects phosphorus loss. Surface application of phosphorus fertilizers increases the …

Biochar: Properties And Potential Benefits For Agricultural Soil In Rwanda, Andromede Uwase

Honors Program: Senior Projects (Public)

Physical and chemical soil degradation is becoming a major challenge for agricultural productivity in Rwanda, which is the most important part of the country’s economy. The wide spreading soil degradation in Rwanda is mainly a result of naturally poor soils coupled with unsustainable soil management leading to, for example, accelerated soil erosion, acidification, nutrient loss, compaction, and to decreasing yields. Biochar, as an end product of pyrolysis of biomass in the absence of oxygen, has been proposed as a soil amendment in remediation strategies because of its positive effects on soil productivity relevant parameters such as soil pH, structure, nutrient …

Footprints On The Prairie: Examining The Interlocking Land Histories Of The Liberty Prairie Reserve, Illinois, Anna M. Burns

Scripps Senior Theses

This thesis begins with the local history of the Liberty Prairie, the land where I conducted the ecological field-work that I later discuss in my second thesis on soil microbiome diversity (“Examining Soil Microbial Diversity in Transition Zones Between Corn Fields and Restored Prairie in the Upper Midwest"). I examine the Indigenous histories of the land, and the conflicts between the Bodwéwadmi and Euro-American settlers that resulted in the land being farmed for cattle, corn, and soy for over a hundred and fifty years. I then take a step back and analyze the broader historical contexts of Midwestern Corn Belt …

Examining Soil Microbial Diversity In Transition Zones Between Corn Fields And Restored Prairie In The Upper Midwest, Anna M. Burns

Scripps Senior Theses

Prairies were once the largest ecosystem in North America, but agriculture and settlement has destroyed up to 99% of their pre-colonization extent. Prairie restorations are a strategy to recover the biodiversity and carbon sequestration functions of these grasslands, but typically occur in isolated strips between agricultural fields. My thesis analyzes how effective prairie restorations in the Liberty Prairie (northeastern Illinois) are at recovering the diversity of the prairie soil microbiome, focusing on verrucomicrobia abundance, alpha diversity, and soil physical characteristics.

Industrial Hemp As A Resource For Birds In Agroecosystems: Human–Wildlife Conflict Or Conservation Opportunity?, Emily A. Kotten, Iona Hennessy, Bryan M. Kluever, Zachary T. Brym, Bradley F. Blackwell, Lee A. Humberg, Page E. Klug

Human–Wildlife Interactions

Industrial hemp (Cannabis sativa L.; hemp) is an emerging crop in the United States with little known about bird use or the potential for birds to become an agricultural pest. We identified birds associated with hemp fields, using repeated visits to oilseed plots in North Dakota, USA (n = 6) and cannabinoid (CBD) plots in Florida, USA (n = 4) from August to November 2020. We did not control for plot area or density; our observations were descriptive only. We observed 10 species in hemp, 12 species flying over hemp, and 11 species both foraging in and …

"Demeter" Soil Monitoring System, Ryan Matthews, Rachel Rummer, Temilolu Fayomi, Alex Fuller

Williams Honors College, Honors Research Projects

The purpose of this project is to develop a soil monitoring system that can remotely sense and relay soil conditions back to a user. The deMETER soil probe, Demeter is the Greek goddess of the harvest, is designed to aid hobbyist gardeners, small-scale farms, and nurseries to monitor their dynamic soil conditions and maximize their harvest. The probe is a self-powered system that can monitor the moisture and essential nutrients of the soil profile to determine which areas should receive water and fertilizer. This would significantly cut water and fertilizer waste. The solution will include an embedded system with sensors …

Remote Sensing For Quantifying C3 And C4 Grass Ratios In Pastures, Jordyn Alyssa Bush

Theses and Dissertations--Plant and Soil Sciences

The following studies investigate the accuracy and practicality of exploiting the color dichotomy present between C₃ and C₄ grass species to estimate their respective proportions from drone or camera captured imagery. Understanding the proportions of C₃ and C₄ grasses in pastures is vital to sound decision making for livestock production. The ability to monitor these proportions remotely will also allow for large scale monitoring as well as detection of changes in botanical composition over time and in response to weather events, management, or climate change. A free green canopy cover (GCC) analyzing software, Canopeo, was used …

First Plant Cell Atlas Symposium Report, Selena L. Rice, Elena Lazarus, Christopher Anderton, Kenneth Birnbaum, Jenniofer Brophy, Benjamin Cole, Diane Dickel, David Ehrhardt, Noah Fahlgren, Margaret Frank, Elizabeth Haswell, Shao-Shan Carol Huang, Samuel Leiboff, Marc Libault, Marisa S. Otegui, Nicholas Provart, R. Glen Uhrig, Seung Y. Rhee, The Plant Cell Atlas Consortium

Department of Agronomy and Horticulture: Faculty Publications

The Plant Cell Atlas (PCA) community hosted a virtual symposium on December 9 and 10, 2021 on single cell and spatial omics technologies. The conference gathered almost 500 academic, industry, and government leaders to identify the needs and directions of the PCA community and to explore how establishing a data synthesis center would address these needs and accelerate progress. This report details the presentations and discussions focused on the possibility of a data synthesis center for a PCA and the expected impacts of such a center on advancing science and technology globally. Community discussions focused on topics such as data …

A Non-Destructive Approach For Measuring Rice Panicle-Level Photosynthetic Responses Using 3d-Image Reconstruction, Jaspinder Singh Dharni, Balpreet Kaur Dhatt, Puneet Paul, Tian Gao, Tala Awada, Paul Staswick, Jason Hupp, Hongfeng Yu, Harkamal Walia

Department of Agronomy and Horticulture: Faculty Publications

Our understanding of the physiological response of rice inflorescence (panicle) to environmental stresses is limited by the challenge of accurately determining panicle photosynthetic parameters and their impact on grain yield. This is primarily due to lack of a suitable gas exchange methodology for panicles, as well as non-destructive methods to accurately determine panicle surface area. To address these challenges, we have developed a custom panicle gas exchange cylinder compatible with the LiCor 6800 Infra-red Gas Analyzer. Accurate surface area measurements were determined with a 3D panicle imaging platform to normalize the panicle-level photosynthetic measurements. We observed differential responses in both …

Identification Of Beneficial And Detrimental Bacteria Impacting Sorghum Responses To Drought Using Multi-Scale And Multisystem Microbiome Comparisons, Mingsheng Qi, Jeffrey C. Berry, Kira W. Veley, Lily O'Connor, Omri M. Finkel, Isai Salas-González, Molly Kuhs, Julietta Jupe, Emily Holcomb, Tijana Glavina Del Rio, Cody Creech, Peng Liu, Susannah G. Tringe, Jeffery L. Dangl, Daniel P. Schachtman, Rebecca S. Bart

Department of Agronomy and Horticulture: Faculty Publications

Drought is a major abiotic stress limiting agricultural productivity. Previous field-level experiments have demonstrated that drought decreases microbiome diversity in the root and rhizosphere. How these changes ultimately affect plant health remains elusive. Toward this end, we combined reductionist, transitional and ecological approaches, applied to the staple cereal crop sorghum to identify key root-associated microbes that robustly affect drought-stressed plant phenotypes. Fifty-three Arabidopsis-associated bacteria were applied to sorghum seeds and their effect on root growth was monitored. Two Arthrobacter strains caused root growth inhibition (RGI) in Arabidopsis and sorghum. In the context of synthetic communities, Variovorax strains were able to …

Evaluation Of Uav-Derived Multimodal Remote Sensing Data For Biomass Prediction And Drought Tolerance Assessment In Bioenergy Sorghum, Jiating Li, Daniel P. Schachtman, Cody F. Creech, Lin Wang, Yufeng Ge, Yeyin Shi

Department of Agronomy and Horticulture: Faculty Publications

Screening for drought tolerance is critical to ensure high biomass production of bioenergy sorghum in arid or semi-arid environments. The bottleneck in drought tolerance selection is the challenge of accurately predicting biomass for a large number of genotypes. Although biomass prediction by low-altitude remote sensing has been widely investigated on various crops, the performance of the predictions are not consistent, especially when applied in a breeding context with hundreds of genotypes. In some cases, biomass prediction of a large group of genotypes benefited from multimodal remote sensing data; while in other cases, the benefits were not obvious. In this study, …

Gaia Contributions To Agroecology By James Lovelock (1919-2022), Steve Gliessman, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

In writing about the history of agroecology we too often ignore the valuable contributions of British scientist James Lovelock who recently died on his 103rd birthday. A prolific inventor and influential theorist, Lovelock is best known for the Gaia hypothesis first proposed during his innovative work in the 1960s with the United States National Aeronautics and Space Administration. He suggested that ‘the biosphere has a regulatory effect on the Earth’s environment that acts to sustain life’ as written in Gaia: A New Look at Life on Earth (Lovelock 1979). Lovelock further proposed that humans have strongly impacted the planet’s capacity …

Temporal Changes In The Nutrient Content Of Cattle Dung In The Nebraska Sandhills Ecosystem, Amanda Shine, Martha Mamo, Gandura O. Abagandura, Walter Schacht, Jerry Volesky

Department of Agronomy and Horticulture: Faculty Publications

Dung excreted by cattle composes a significant portion of the nutrient inputs in a grazed ecosystem and can have wide-ranging effects on soil properties and vegetation. However, little research has been conducted on the nutrient dynamics of excreted dung in situ that has not been disturbed prior to field sampling. In this study, we analyzed 294 dung pats (1–24 days old) collected from a Nebraska Sandhills meadow to determine water-extractable organic carbon (WEOC), water-extractable nitrogen (WEN), water-extractable phosphorus (WEP), and percent dry matter (DM) changes over time. In addition, we investigated if sample handling - frozen storage – and the …