Soil Science Commons^™

Metabolomics In The Dryland Critical Zone: The Role Of Soil Metabolites In Phosphorus Acquisition, Kalpana Kukreja

Open Access Theses & Dissertations

Earth's Critical Zone (CZ) plays a key role in sustaining life through carbon, water, and nutrient cycling from the top of the canopy to the groundwater. A key feature of critical zone research is the integration of multiple interdisciplinary techniques. An emerging set of techniques that can add to this approach is the field of metabolomics, the quantification and study of comprehensive metabolite profiles. In this dissertation, I apply metabolomics to address knowledge gaps in dryland critical zone ecosystems, specifically how soil metabolite dynamics influence biogeochemical processes, and with a particular emphasis on phosphorus (P) cycling in the Chihuahuan Desert. …

Impacts Of Climate-Smart Agriculture On Greenhouse Gas Emissions In Southeast Arkansas Cotton, Cassandra Seuferling

Graduate Theses and Dissertations

Increasing concerns of climate change have led to the evaluation of greenhouse gas (GHG) emissions [i.e., carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)] from agroecosystems, particularly cotton (Gossypium hirsutum) production. Technology improvement and conservation agriculture methods [i.e., reduced-tillage (RT) instead of conventional tillage (CT) and the use of cover crops (CC)] require further evaluation regarding GHG emissions from Arkansas cotton production. The first objective of the study was to evaluate four gas-flux-determination methods [i.e., linear or exponential regression models, with negative fluxes (WNF) included in the dataset or replacing negative fluxes (RNF)] on CO2, CH4, and N2O fluxes …

Integrated Geophysical, Geotechnical, And Mineralogical Characterization Of Expansive Weches Formation Soils In East Texas: Implications For Infrastructure Design, Samuel Annobil

Electronic Theses and Dissertations

This study investigates the geotechnical, geophysical, and mineralogical characteristics of soils derived from the Weches Formation in Nacogdoches County, East Texas, with emphasis on the relationships among electrical resistivity, moisture condition, compaction state, and mineralogical composition. The Weches Formation is well known for producing clay-rich, moisture-sensitive soils that pose challenges to subgrade performance because of their plasticity and swelling behavior. Representative soil samples were collected and subjected to laboratory testing, including particle size analysis, Atterberg limits, Standard Proctor compaction, free swell tests, electrical resistivity measurements, and X-ray diffraction (XRD) mineralogical analysis. The soils are predominantly fine-grained and clay-rich, with USCS …

Sequential Products Of Anaerobic Denitrification In Calcareous And Noncalcareous Soils By Use Of The Gas Chromatograph, Grant S. Cooper

All Graduate Theses and Dissertations, Fall 2023 to Present

The sequential products of anaerobic denitrification were determined on seven Western soils (four alkaline, two acid, and one neutral) by soil and gas analysis. The soils with 1% alfalfa and added KNO3 were incubated at moistures slightly greater than field capacity and with an atmosphere of He. The soils and gases were periodically analyzed and balance sheets prepared. The sequence of NO3-->NO2-->N2O-->N2 operated in all soils. The rates of nitrogen interchanges and maximal amounts of nitrate, N2O2 and N2 were determined. From this data it was postulated that the rate-limiting process for denitrification in acid soils is …

Optimization Of Physalis Angulata L. Callus Induction And Salinity-Induced Antioxidant Production, Firstian Naufal Sistyananda, Erni Suminar, Anne Nuraini, Muhamad Kadapi, Murgayanti, Syariful Mubarok, Rahmat Budiarto, Eddy Renaldi, Kusumiyati

Jurnal Kultivasi

Groundcherry (Physalis angulata L.) is a plant with many medicinal potentials due to its rich secondary metabolites such as phenolic and flavonoid. However, conventional agriculture practices are still limited, especially in Indonesia. This study was divided into two stages. The first stage was conducted to determine optimal 6-BAP and 2,4-D combination for callus induction, while the second stage was conducted to determine callus phenolic, flavonoid, and antioxidant response to salinity stress. The first stage was arranged in factorial completely randomized design with two factors: 6-BAP (0, 2, and 4 mg/L) and 2,4-D (0, 0.5, 1, and 1.5 mg/L). The second …

Response Of Chlorophyll, Morphology, And Yield Of Several East Java Superior Soybean (Glycine Max L.) Varieties To Levels Of Salinity, Puji Lestari Tarigan, Ida Retno Moeljani, Fadila Suryandika, Hadi Munarko

Jurnal Kultivasi

Soybean production has been extended to saline areas. This development is a strategy to expand planting areas to suboptimal land to increase worldwide production. To support cultivation in these locations, it is necessary to develop superior varieties that are resistant to salinity and provide supporting technological inputs. In saline conditions, soybeans may face stress that leads to morphological, physiological, and yield disturbances. Consequently, the response of several soybeans in East Java should be observed. This study is a pot experiment and arranged in a Factorial Completely Randomized Design (CRD) consisting of two factors, soybean varieties and NaCl concentrations. The treatments …

Growth Of Vanilla Cuttings Under Modified Acid Soil Media And Application Of Several Plant Growth Regulators, Rifqi Raditya Kurniawan, Yugi Rahayu Ahadiyat, Etik Wukir Tini

Jurnal Kultivasi

This research aimed to optimize the growth of vanilla (Vanilla planifolia) cuttings in acid soils by modifying the growing media and applying several types of plant growth regulators (PGRs). Several types of PGRs, including synthetic compounds such as indole-3-acetic acid (IAA) and 6-benzylaminopurine (BAP), as well as natural extracts from shallot (Allium ascalonicum L.) and moringa leaves (Moringa oleifera), were tested to enhance plant performance in acid-growing conditions. The primary objectives were to determine the optimal soil amendment formula and the most effective PGR type for promoting vanilla growth, and to develop a measurable, easy-to-use PGR formulation accessible to farmers. …

Effects Of Phosphate-Solubilizing Fungi On Phosphorus Availability, Retention, And Soil Chemical Properties In Shallot Cultivated On Andisols Of North Sumatra, Agustina Erlinda Marpaung, Tengku Sabrina, Abdul Rauf, Dwi Ningsih Susilowati

Jurnal Kultivasi

The availability of phosphorus (P) is one of the main limiting factors for plant productivity in Andisol soils due to the strong fixation of P by allophane clay minerals, aluminum and iron oxides. Giving the phosphate solubilizing fungi (PSF) is an alternative to increase available P which plants can use to increase the yield. This study aimed to evaluate the effectiveness of phosphate-solubilizing fungi (PSF) in improving P availability on Andisol. The experiment used a block randomized design (BRD) with three replications. The first factor is Andisol soil origin (Soil 1 and Soil 2) and the second is isolate of …

Warming Climate Amplifies Vapor Pressure Deficit Limits On Gross Primary Productivity, Shiqin Xu, Nate G. Mcdowell, Tim R. Mcvicar, Diego G. Miralles, Stephen Sitch, Pablo Sanchez-Martinez, Joshua B. Fisher, Pierre Friedlingstein, Hylke E. Beck, Matthew F. Mccabe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ongoing climate warming may profoundly impact terrestrial gross primary productivity (GPP), a key component of the global carbon cycle. However, uncertainty in the relative roles of atmospheric water demand (vapor pressure deficit, VPD) and root-zone soil moisture (SM) limits predictions of drought impacts on GPP. Here, we show that growing-season GPP was more strongly constrained by VPD than SM globally, based on observation-constrained model estimates, satellite retrievals and Dynamic Global Vegetation Model simulations. The importance of VPD increased with higher temperatures and more severe and prolonged droughts. This pattern reflects VPD’s critical role in regulating stomatal conductance and plant hydraulic …

Effects Of Soil Amelioration On Wheat Growth, Nutrition, And Soil Microbiome Dynamics In Sandy Soil, Shompa Akter, Sultan Mia, M. Asaduzzaman Prodhan, Gaus Azam, Zakaria Solaiman, Kadambot H M Siddique

Grain and Other Field Crops Research Articles

Purpose Cropping regions in Western Australia (WA) face multiple soil constraints including acidity, nutrient deficiencies, compaction and water repellence, which limit crop productivity. Developing sustainable soil management strategies is therefore crucial. This study evaluates the effects of soil amendments—lime, gypsum, clay, compost, and synthetic fertilisers on soil health, nutrient availability, microbial function and wheat production. Methods A glasshouse experiment was conducted using undisturbed soil cores collected in a polyvinyl chloride (PVC) column from a field trial site where four treatments were applied: Control (no amendment), CLG (clay, lime, gypsum), CLG + NPK (CLG + nitrogen, phosphorus, and potassium fertilisers), and …

Recent Wetland Elevation Dynamics In Coastal Louisiana, Usa, Elizabeth Harris

LSU Master's Theses

Coastal marshes globally are increasingly vulnerable to accelerating relative sea-level rise (RSLR), which threatens their capacity to maintain elevation through feedbacks among sediment supply, vegetation productivity, hydrology, and soil processes. Although many marshes can persist under moderate rates of sea-level rise through vertical accretion and belowground biomass production, this resilience is strongly constrained by sediment availability and subsurface processes such as autocompaction and organic matter decomposition. High accretion is often assumed to confer marsh resilience; however, subsurface processes, particularly autocompaction driven by surface loading, can substantially offset elevation gains. Coastal Louisiana experiences among the highest rates of RSLR worldwide due …

Weed Seed Burial And Long-Term Viability Following Soil Inversion, Catherine Borger, Sultan Mia, Gaus Azam, Stephen Davies

Grain and Other Field Crops Research Articles

Strategic soil inversion is advocated as a periodic weed management strategy, typically recommended every 4 to 8 yr if the goal is to delay the evolution of herbicide resistance. It is assumed that the weed seeds buried during the inversion process will lose viability during this period. However, long-term seedbank persistence following soil inversion has not been investigated. If the buried seeds retain viability, subsequent inversions or other deep-tillage operations may return them to the soil surface, potentially replenishing the weed seedbank. The current study identified 30 sites within the wheatbelt of Western Australia (in 2020) that had previously been …

Regional Drought Modulation By Enso And Iod As Indicated By The Standardized Precipitation Index, Arpit Tiwari, Preethi Nanjundan, Tanu Sharma, Ravi Ranjan Kumar, Satyaban Bishoyi Ratna

Northeast Journal of Complex Systems (NEJCS)

Understanding the modulation of drought by large-scale ocean–atmosphere teleconnections is crucial for strengthening drought prediction and resilience in India. This study investigates the influence of the El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) on meteorological drought characteristics across India from 1950 to 2024 using the Standardized Precipitation Index (SPI) at a 12-month timescale. Drought events were quantified in terms of frequency, duration, severity, and intensity and linked to ENSO–IOD variability through composite, correlation, and mediation analyses. Results reveal that El Niño events consistently correspond to widespread and severe droughts, particularly over central and southern India, with drought …

Ecovoltaic Solar Energy Development Creates Novel Microclimate, Temperature, And Soil Moisture Patterns Under Solar Panels In A Warm Desert, Juan Pinos, Seth M. Munson, Claire C. Karban, Matthew D. Petrie

Life Sciences Faculty Research

Background As solar energy development expands in desert regions, new installation practices and solar technologies seek to balance ecosystem conservation and energy generation (ecovoltaics). The Gemini Solar Project, a large ecovoltaic facility located in the northeastern Mojave Desert, employed low impact installation methods to reduce disturbance of the desert ecosystem within arrays of bifacial panels mounted on solar tracking systems. We evaluated microclimate and environmental conditions across five locations: four within-facility microsites (underneath solar panels, east and west panel driplines, and interspaces between panel rows) and one in the undisturbed desert outside the facility. Results Under panel microsites experienced lower …

Enhancing Urban Garden Capacity By Linking Biodiversity And Ecosystem Function, Mary T. Nguyen, Carleen Rauh, Shelby Gresch, Charlotte Correiro, Heidi Elmendorf, Adriane Fugh-Berman, Gina Wimp, Alexandra L. Decandia

Virginia Journal of Science

Urban agriculture broadly describes food and plant cultivation in metropolitan areas. While biodiversity is thought to support ecosystem health and resilience, the relationship between above-ground and below-ground diversity has been understudied in urban green spaces. This study examines plant, animal, bacterial, and fungal diversity across three distinct urban habitats: a turf lawn, a forb garden, and a farming space. Using bacterial 16S rRNA and fungal ITS2 sequencing, soil nutrient analyses, and surveys of vegetation and wildlife, we connect diverse philosophies in urban agriculture to their role in advancing community diversity and ecosystem function. We found that different urban gardens support …

Combatting Desertification Scientifically: Where Feasible, Where Necessary, Bojie Fu, Yanxu Liu, Shuai Wang, Yijia Wang, Guipeng Cui, Yue Guo

Bulletin of Chinese Academy of Sciences (Chinese Version)

China has made remarkable achievements in combating desertification, achieving “zero net growth” in land degradation. With the goal of scientifically improving the relationship between humans and nature in drylands, the continuous exploration of new concepts, methods, and pathways for scientific desertification control will contribute to advancing the harmony between humans and nature in China’s drylands. Based on the definitions of desertification, ecological restoration baselines, and the contributions of nature to humans, we clarified the scientific implications of “controlling desertification where it is feasible and necessary”. We discussed the shift in China’s desertification prevention and control direction from “humans advancing while …

Biogeochemical Controls On Phosphorus Transport And Legacy Storage Across A Coastal Watershed, Lee Potter

LSU Doctoral Dissertations

Excess phosphorus (P) loading is a key driver of eutrophication and harmful algal blooms (HABs) in aquatic systems worldwide. This relationship is of increasing concern in coastal Louisiana, where climate variability, altered hydrology, and land-use change converge, resulting in increased hydrologic and nutrient loading into coastal systems. This dissertation examines controls on P cycling in the Lake Pontchartrain Basin through a multi-scale framework linking estuarine processes, watershed loading, climate and weather patterns, and sediment dynamics. The dissertation begins with an overview of the study region, P dynamics, and changes in hydrology and nutrient loading patterns. Chapter 2 presents a spatial …

Environmental Impact Of Preventative Fire-Retardant Applications On Soil Water Chemistry, Patrick C. Michelsen

Master's Theses

Between 1992 and 2012, 84% of all documented wildfires were started by humans. These fires often start around high-risk locations such as power lines and roadsides where fuel loads are near these potential human-caused ignition sources. Point source ignition sites that are surrounded by shrubs or grasslands are especially important because fires that occur within these biomes are responsible for far more destruction of property than forest fires. One strategy that is effective at mitigating the spread of fires from ignition sites that are within grassland or shrub biomes are preventative fire-retardant products (PFRPs). These PFRPs differ from traditional fire-retardant …

Wayne E. Sabbe Arkansas Soil Fertility Studies 2025, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil-test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

Soil Re-Engineering In Western Australia, Part I: A Novel Approach For Rapid And Lasting Improvement Of Soil Physical And Chemical Properties, Gaus Azam, Chad Reynolds

Natural Resources Research Articles

Context

Soil acidity, high soil strength, and poor subsoil structure are major constraints to crop productivity in coarse-textured and texture-contrast soils of southern Australia. These interacting limitations restrict root growth, reduce access to subsoil water and nutrients, and constrain yield potential in water-limited environments. While deep tillage and surface liming have been used to address individual constraints, their benefits are often short-lived and insufficient to overcome multiple subsoil limitations simultaneously. Aims

This study aimed to evaluate the short- and long-term effects of soil profile re-engineering on soil physical, chemical, and hydrological properties, and to determine the persistence of these changes …