Earth Sciences Commons^™

Role Of Fires, Herbicides And Fertilizer In Manipulating Shrub/Grass Balance In Mediterranean Grasslands, Zalmen Henkin

IGC Proceedings (1977-2023)

The decline of traditional pastoral systems has highlighted the problem of managing shrub encroachment in shrublands of the Mediterranean region, especially in marginal habitats. Ephemeral grasslands appear after fire in Mediterranean shrub communities on phosphorus-deficient soils, but natural successional processes rapidly led to their dominance. In a study, aimed at reducing the rate of successional change and extending the period of grassland dominance, phosphorus was applied after fire to improve herbaceous growth and two years later the regenerating Sarcopoterium spinosum shrubs were controlled with selective herbicide. Subsequently, the vegetation in the treated areas was monitored for more than 20 consecutive …

The Changing Patterns In Grasslands And Soil Fertility Along The Eastern Eurasian Steppe Transect Across China–Mongolia–Russia, Xiangyang Hou, Leonid Ubugunov, S. Tserendash, Haijun Chen, Wenjun Han, Xiangjun Yun, Ding Yong, Wang Zhen, Lei Ji

IGC Proceedings (1977-2023)

This paper analyses the adaptation and change in species along the north-south Eastern Eurasian Steppe Transect across China – Mongolia – Russia and considers the implications for climate change and management. The plant community diversity, above-ground biomass, N:P ratios of community and of dominant species, soil N (nitrogen), soil P (phosphorus) and AP (available phosphorus) contents were studied along a 1400 km north-south transect. The main findings were: (1) the community diversity and productivity decreased with the increase in latitude and a significant negative correlation was found between the many plant characteristics and latitude (P < 0.05) – decreasing diversity, biomass and N:P ratios; (2) soil AP content was lowest in Inner Mongolia, whereas no significant change in soil total P with latitude was found in China-Mongolia-Russia transect, a significant positive correlation was detected between the soil nutrient (N and AP) and latitude (P < 0.05); (3) a significant positive correlation was evident between plant community P content and soil AP content (P < 0.01), but a negative correlation was found between community N:P ratio and soil AP content (P < 0.05). The soil AP content can be used as a soil properties indicator to reflect the plant communities P content and N: P ratio. It is suggested that greater human activities in Inner Mongolia may be an important factor affecting soil AP content, community N:P and plant growth.

Spatial Variability Of Soil Phosphorus In Grazing Systems, Mark Trotter, Warwick B. Badgery, Joshua Barron, Chris Guppy, Rebecca Haling, David Mitchell, Geoff Millar

IGC Proceedings (1977-2023)

Phosphorus (P) use efficiency has been identified as a key issue for Australian grazing systems. This project examined the spatial variability in soil P concentration from two separate surveys of grazed pasture fields. A field on the central tablelands of NSW had a range in Bray P of 1.2 to 140 mg/kg and a COV of 107%. The other field on the northern tablelands of NSW reported a range in Colwell P from 13.0 to 121.1 mg/kg and a COV of 59%. Maps of the spatial variability of soil P demonstrated that there is a relationship with field elevation. Application …

Serpentinization As A Route To Liberating Phosphorus On Habitable Worlds, Matthew Pasek, Arthur Omran, Carolyn Lang, Maheen Gull, Josh Abbatiello, Tian Feng, Lyle Garong, Heather Abbott-Lyon

School of Geosciences Faculty and Staff Publications

Planetary habitability is in part governed by nutrient availability, including the availability of the element phosphorus. The nutrient phosphorus plays roles in various necessary biochemical functions, and its biogeochemical cycling has been proposed to be extremely slow due to a strong coupling to the rock cycle via mineral weathering. Here we show a route to P liberation from water-rock reactions that are thought to be common throughout the Solar System. We report the speciation of phosphorus in serpentinite rocks to include the ion phosphite (HPO32- with P3+) and show that reduction of phosphate to phosphite is predicted from thermodynamic models …

Corn Response To Wastewater-Recycled Phosphorus Fertilizers, Shane R. Ylagan, Kristofor R. Brye

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4 · 6H2O) is an understudied material that can be created from P- and nitrogen (N)-containing wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple superphosphate (TSP) on corn (Zea mays) response in a greenhouse pot study. …

The Prebiotic Provenance Of Semi-Aqueous Solvents, Jennifer L. Lago, Bradley T. Burcar, Nicholas V. Hud, Rio Febrian, Christopher A. Mehta, Paul J. Bracher, Zachary D. Atlas, Matthew A. Pasek

School of Geosciences Faculty and Staff Publications

The numerous and varied roles of phosphorylated organic molecules in biochemistry suggest they may have been important to the origin of life. The prominence of phosphorylated molecules presents a conundrum given that phosphorylation is a thermodynamically unfavorable, endergonic process in water, and most natural sources of phosphate are poorly soluble. We recently demonstrated that a semi-aqueous solvent consisting of urea, ammonium formate, and water (UAFW) supports the dissolution of phosphate and the phosphorylation of nucleosides. However, the prebiotic feasibility and robustness of the UAFW system are unclear. Here, we study the UAFW system as a medium in which phosphate minerals …

Biogeochemical Controls Of Surface Ocean Phosphate, Adam C. Martiny, Michael W. Lomas, Weiwei Fu, Philip W. Boyd, Yuh-Ling L. Chen, Gregory A. Cutter, Michael J. Ellwood, Ken Furuya, Fuminori Hasshihama, Jota Kanda, David M. Karl, Taketoshi Kodama, Qian P. Li, Jian Ma, Thierry Moutin, E. Malcolm S. Woodward, J. Keith Moore

OES Faculty Publications

Surface ocean phosphate is commonly below the standard analytical detection limits, leading to an incomplete picture of the global variation and biogeochemical role of phosphate. A global compilation of phosphate measured using high-sensitivity methods revealed several previously unrecognized low-phosphate areas and clear regional differences. Both observational climatologies and Earth system models (ESMs) systematically overestimated surface phosphate. Furthermore, ESMs misrepresented the relationships between phosphate, phytoplankton biomass, and primary productivity. Atmospheric iron input and nitrogen fixation are known important controls on surface phosphate, but model simulations showed that differences in the iron-to-macronutrient ratio in the vertical nutrient supply and surface lateral transport …

Sand And Pumice Filter Amended With Activated Carbon And Biochar For Phosphorus Retention, James Jihoon Kang, Marissa Davila, Sergio I. Mireles, Jungseok Ho

School of Earth, Environmental, & Marine Sciences Faculty Publications

Phosphorus (P) loss via stormwater runoff is a water quality concern. The objective of this study was to investigate two commercial biochars relative to an activated carbon as an additive to geomedia (sand and pumice) for P removal. The batch adsorption experiment was conducted to assess P sorption of the geomedia and carbon materials while the leaching experiment was conducted in sand and pumice columns amended with carbon materials (5 % by weight). The batch adsorption test revealed that only activated carbon showed an appreciable P adsorption up to 19 %. Tested biochar materials showed no adsorption capacity for P …

Limitations To Photosynthesis In Silver Bow And Blacktail Creeks, Isaiah Robertson

Graduate Theses & Non-Theses

Throughout Silver Bow Creek’s history, consideration of the photosynthetic communities that make heterotrophic life possible have often been overlooked since macroinvertebrates made up a majority of ecosystem health assessments. Silver Bow Creek has had minimal biological research outside of macroinvertebrate surveys, especially as it pertains to photosynthetic organisms. This study assessed the photosynthetic communities of Silver Bow Creek and their limitations by limiting available light and comparing uptake of nutrients during a 23-day incubation experiment conducted at four sites along the flow of Silver Bow Creek and Blacktail Creek. At each site, nine one-liter microcosms, filled with creek water and …

Nitrogen And Phosphorus Uptake In An Urban Stream Ecosystem, Nicolette A. Sheffield

Theses and Dissertations

Urban stream ecosystems are faced with high input levels of nitrogen (N) and phosphorus (P) from anthropogenic activities. N and P are important to plant growth and stream health; however, high levels can lead to algal blooms and eutrophication, a harmful effect to both aquatic life and water quality. Common urban sources of N and P include fertilizer, atmospheric deposition, stormwater outfall, and leaf-litter decomposition. Common urban stream features such as a flashier hydrograph, altered channel stability and morphology, increase in nutrient output (such as N and P), and heat retention, have been shown to result in an overall decrease …

Modeled Affinity Constants For Phosphorus Adsorption And Desorption Due To Saltwater Intrusion, Yasemin Taşcı

USF Tampa Graduate Theses and Dissertations

It is important to understand the processes that regulate phosphorus (P) fluxes to coastal environments, because P is an important nutrient in coastal ecosystems. Phosphorus adsorbs to the surface of minerals in sediment and bedrock, and an influx of seawater can cause some of that P to desorb, raising the P concentration of ambient water. Although seawater-induced P desorption is thought to be an important source of P to coastal environments, the chemical reactions that underlie it have not been established. Previous work provides some relevant surface reactions and associated affinity constants between various aqueous P species and the surface …

Phosphorus And Potassium Fertilizer Application Strategies In Corn–Soybean Rotations, Timothy J. Boring, Kurt D. Thelen, James E. Board, Jason L. De Bruin, Chad D. Lee, Seth L. Naeve, William J. Ross, Wade A. Kent, Landon L. Ries

Plant and Soil Sciences Faculty Publications

To determine if current university fertilizer rate and timing recommendations pose a limitation to high-yield corn (Zea mays subsp. mays) and soybean (Glycine max) production, this study compared annual Phosphorous (P) and Potassium (K) fertilizer applications to biennial fertilizer applications, applied at 1× and 2× recommended rates in corn–soybean rotations located in Minnesota (MN), Iowa (IA), Michigan (MI), Arkansas (AR), and Louisiana (LA). At locations with either soil test P or K in the sub-optimal range, corn grain yield was significantly increased with fertilizer application at five of sixteen site years, while soybean seed yield was significantly …

Nutrient Transport And Storage In A Karst Spring-Reservoir System During Baseflow, Missouri Ozarks, Heather A. Moule

Graduate Theses/Dissertations

Urban and agricultural land uses are important sources of nitrogen and phosphorus which, if in excess, can cause eutrophication in lakes and rivers. There have been few studies of nutrient transport and storage in karst spring and reservoir connected stream systems draining the Missouri Ozarks. This study aims to link the baseflow nutrient contributions of Sanders Spring to downstream reservoir outflow and the Headwaters South Dry Sac River Watershed in Springfield, Missouri. Water samples were collected seasonally and analyzed for total nitrogen (TN), total phosphorus (TP), and several other water quality parameters. Discharge was also monitored to calculate water and …

Stream Water And Soil Water Chemistry After The Table Mountain Wildfire, Washington, Usa, Vincent J. Roccanova

All Master's Theses

Analyses of major and trace elements, major ions, and nutrient concentrations were made to investigate how stream water and soil water chemistry changed over 16 months following the Table Mountain wildfire. Sites with different burn severity were also compared. The fire occurred in 2012 in Kittitas County, north of Ellensburg, Washington. Samples were collected at severely burned, moderately burned, and unburned field sites from within and adjacent to the wildfire perimeter. Total nitrogen concentrations increased in the second year after the fire in both the severely and moderately burned sites. In contrast, total phosphorus was variable at all three sites …

Biologically Available Phosphorus In Biocrust-Dominated Soils Of The Chihuahuan Desert, Grace Margaret Crain

Open Access Theses & Dissertations

In desert soils, phosphorus (P) is an important limiting nutrient and its cycling characteristics are less understood compared to nitrogen and carbon. Phosphorus cycling is controlled by both geochemical and biological factors. Traditionally, P availability has been characterized via sequential extraction analyses such as Hedley fractionation, but newly developed extraction methods allow for the examination of more biologically relevant P fractions, providing insight on mechanisms of P acquisition by plants and microbes. We examined these P cycling features in the context of biological soil crusts (biocrusts), which have been found to be important drivers of nutrient cycling and have the …

The Potential For Phosphorus Release From Floodplain Soils: Temporal Variability And Management Strategies, Megan Amanda Reavis

Graduate Theses and Dissertations

Soils may contain large amounts of legacy phosphorus (P) due to past application of excess fertilizers, releasing P during runoff and flood events. As the level of P in soils increases, the release of P from the soils increases, but the temporal fluctuations of this release are not well known. Experiments were conducted to examine 1) the variability of soluble reactive P (SRP) release from the soil throughout a year and 2) the effect of repeated flooding and drying cycles on release rates. Soil cores were collected 7 times throughout a year from 2 sites within the Watershed Research and …

Nutrient Contamination From Non-Point Sources: Dissolved Phosphate In Surface And Subsurface Waters At Eku Meadowbrook Farm, Madison County, Kentucky, Hunter R. Evans, Reid E. Buskirk, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Farms are non-point sources for nutrient contaminants that drain into watersheds and contribute to eutrophication and other environmental problems. Eastern Kentucky University’s Meadowbrook Farm raises both crops and livestock, causing dissolved phosphorus in the form of orthophosphate (PO₄^3-) from fertilizer and animal manure to enter surface and subsurface waters, eventually flowing into Muddy Creek, a tributary of the Kentucky River.

We sampled surface water, springs, and water from French drains that emanate from the farm, and also sampled Muddy Creek waters from May through August 2016. Typically, 1 to 2 days after sampling, we colorimetrically measured dissolved …

Nutrient Addition Shifts Plant Community Composition Towards Earlier Flowering Species In Some Prairie Ecoregions In The U.S. Central Plains, Lori Biederman, Brent Mortensen, Philip Fay, Nicole Hagenah, Johannes Knops, Kimberly La Pierre, Ramesh Laungani, Eric Lind, Rebecca L. Mcculley, Sally Power, Eric Seabloom, Pedro Tognetti

Plant and Soil Sciences Faculty Publications

The distribution of flowering across the growing season is governed by each species’ evolutionary history and climatic variability. However, global change factors, such as eutrophication and invasion, can alter plant community composition and thus change the distribution of flowering across the growing season. We examined three ecoregions (tall-, mixed, and short-grass prairie) across the U.S. Central Plains to determine how nutrient (nitrogen (N), phosphorus, and potassium (+micronutrient)) addition alters the temporal patterns of plant flowering traits. We calculated total community flowering potential (FP) by distributing peak-season plant cover values across the growing season, allocating each species’ cover to only those …

Nutrient Loading Reduction In A Tile Drained Agricultural Watershed Through Watershed-Scale Cover Cropping: A High Resolution Analysis, Benjamin Gerald Bruening

Theses and Dissertations

Nutrient pollution originating from agricultural regions in the Midwest is a serious issue, leading to pollution of drinking water sources as well as large hypoxic zones in the Gulf of Mexico. The source of much of this contamination has been shown to be runoff from agricultural fields in the Upper Mississippi River Basin. One method that has been shown to reduce this pollution from the Upper Mississippi River Basin is the planting of winter cover crops. Winter cover crops such as rye and tillage radish have been shown to significantly reduce nitrate exported from agricultural fields, even in tile-drained watersheds …

Dynamics Of Nitrate, Phosphorus, And Suspended Sediment Transport In Two Agricultural Streams In Central Illinois, Luke W. Lampo

Theses and Dissertations

Nutrients such as nitrate and phosphorus are necessary for life, but excessive amounts can be detrimental. Large amounts of nutrients entering bodies of water can lead to hypoxic zones such as the one in the Gulf of Mexico. Nutrients are also problematic in drinking water reservoirs, as high concentrations of nitrate in drinking water can cause health conditions such as blue baby syndrome and high phosphorus concentrations can lead to algal blooms. Suspended sediment leads to reservoir sedimentation, habitat degradation, and is able to transport particulate nutrients. High nutrient and sediment concentrations are a recurring problem in the drinking water …

Dietary Effects On The Stoichiometry Of Growth, Regulation, And Wastes Of Ozark Stream Insect Detritivores, Halvor Matthew Halvorson

Graduate Theses and Dissertations

A widespread stressor, anthropogenic nitrogen (N) and phosphorus (P) pollution can increase resource nutrient content and alter animal community composition in freshwater ecosystems. In this dissertation, I used ecological stoichiometry theory to examine effects of diet nutrient content and leaf litter type on growth, regulation, and wastes of aquatic invertebrate detritivores. I tested effects of leaf litter diet carbon:phosphorus (C:P) on growth and stoichiometric regulation of the detritivorous caddisfly Pycnopsyche lepida and used results to determine a threshold elemental ratio of oak litter C:P=1620 that confers peak growth of this species. This empirical, growth-based approach provided a more accurate estimate …

Expansion Of The Manage Database With Forest And Drainage Studies, Daren R. Harmel, Laura E. Christianson, Matthew W. Mcbroom, Douglas R. Smith, Kori D. Higgs

Faculty Publications

The “Measured Annual Nutrient loads from AGricultural Environments” (MANAGE) database was published in 2006 to expand an early 1980s compilation of nutrient export (load) data from cultivated and pasture/range land at the field or farm scale. Then in 2008, MANAGE was updated with 15 additional studies, and nitrogen (N) and phosphorus (P) concentrations in runoff were added. Since then, MANAGE has undergone significant expansion adding N and P water quality along with relevant management and site characteristic data from: (1) 30 runoff studies from forested land uses, (2) 91 drainage water quality studies from drained land, and (3) 12 additional …

Modeled Inflow Validation & Nutrient Loading Estimation In Two Subwatersheds Of The Lower Laguna Madre, Hudson R. Deyoe, Warren Pulich, Nelun Fernando

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

University of Texas Rio Grande Valley will characterize nutrient loading rates into the Lower Laguna Madre for subwatersheds by monitoring stream flow and water quality (particularly total nitrogen and phosphorus). This information will be used to evaluate Texas Rainfall-Runoff model performance in estimating ungaged inflows and to establish a relationship between ungaged inflows and nutrient loading regimes to the Lower Laguna Madre. View on Map

Phosphorus Retention In A Lowland Neotropical Stream Following An Eight-Year Enrichment Experiment, Gaston E. Small, Marcelo Ardón, John H. Duff, Alan P. Jackman, Alonso Ramírez, Frank J. Triska, Catherine M. Pringle

United States Geological Survey: Staff Publications

Human alteration of the global P cycle has led to widespread P loading in freshwater ecosystems. Much research has been devoted to the capacity of wetlands and lakes to serve as long-term sinks for P inputs from the watershed, but we know much less about the potential of headwater streams to serve in this role. We assessed storage and retention of P in biotic and abiotic compartments after an 8-y experimental P addition to a 1st-order stream in a Neotropical wet forest. Sediment P extractions indicated that nearly all P storage was in the form of Fe- and Al-bound P …

Phosphorus Release Potential Of Agricultural Soils Of The United States, Rebecca A. Young

School of Natural Resources: Dissertations, Theses, and Student Research

Phosphorus (P) is one of the leading causes of surface water quality decline in the United States, leading to algal blooms and hypoxia in lakes and streams. Decreasing conservation funds dictate that agencies such as the Natural Resources Conservation Service, maximizes its effectiveness and efficiency in implementing practices to address P management and runoff on agricultural lands. Additional information on P behavior in soil is needed to improve P management plans to reduce pollution risk at the watershed, farm, and field scales. This research focuses on the development of total soil P release models, to be included into assessment and …

Validation Of Soil-Test-Based Phosphorus And Potassium Fertilizer Recommendations For Rice And Soybean, Matthew Scott Fryer

Graduate Theses and Dissertations

The science of soil-testing for nutrient management and fertilizer recommendations is widely accepted among scientists and agronomists. Although this science is unsurpassed in predicting soil nutrient availability, soil-test interpretations are seldom validated. Major research objectives for irrigated soybean [Glycine max (L.) Merr.] and direct-seeded, delayed-flood rice (Oryza sativa L.) were to: i) validate the accuracy of Mehlich-3 soil-test P (STP) and K (STK) interpretations and ii) published critical tissue-P and -K interpretations in predicting the yield response to fertilizer at different significance levels (p≤0.05 to 0.25), iii) examine how seed nutrient concentrations are influenced by fertilization and crop response to …

Is Atmospheric Phosphorus Pollution Altering Global Alpine Lake Stoichiometry?, Janice Brahney, Natalie Mahowald, Daniel S. Ward, Ashley P. Ballantyne, Jason C. Neff

Watershed Sciences Faculty Publications

Anthropogenic activities have significantly altered atmospheric chemistry and changed the global mobility of key macronutrients. Here we show that contemporary global patterns in nitrogen (N) and phosphorus (P) emissions drive large hemispheric variation in precipitation chemistry. These global patterns of nutrient emission and deposition (N:P) are in turn closely reflected in the water chemistry of naturally oligotrophic lakes (r2 = 0.81, p < 0.0001). Observed increases in anthropogenic N deposition play a role in nutrient concentrations (r2 = 0.20, p < 0.05); however, atmospheric deposition of P appears to be major contributor to this pattern (r2 = 0.65, p < 0.0001). Atmospheric simulations indicate a global increase in P deposition by 1.4 times the preindustrial rate largely due to increased dust and biomass burning emissions. Although changes in the mass flux of global P deposition are smaller than for N, the impacts on primary productivity may be greater because, on average, one unit of increased P deposition has 16 times the influence of one unit of N deposition. These stoichiometric considerations, combined with the evidence presented here, suggest that increases in P deposition may be a major driver of alpine Lake trophic status, particularly in the Southern Hemisphere. These results underscore the need for the broader scientific community to consider the impact of atmospheric phosphorus deposition on the water quality of naturally oligotrophic lakes.

Phosphorus Retention In A Lowland Neotropical Stream Following An Eight-Year Enrichment Experiment, Gaston E. Small, Marcelo Ardón, John H. Duff, Alan P. Jackman, Alonso Ramírez, Frank J. Triska, Catherine M. Pringle

United States Geological Survey: Staff Publications

Human alteration of the global P cycle has led to widespread P loading in freshwater ecosystems. Much research has been devoted to the capacity of wetlands and lakes to serve as long-term sinks for P inputs from the watershed, but we know much less about the potential of headwater streams to serve in this role. We assessed storage and retention of P in biotic and abiotic compartments after an 8-y experimental P addition to a 1st-order stream in a Neotropical wet forest. Sediment P extractions indicated that nearly all P storage was in the form of Fe- and Al-bound P …

Biogeochemical Cycling In Lake Superior Tributaries: Seasonality, Quantity And Quality Of Export, Ashley Anne Coble

Dissertations, Master's Theses and Master's Reports - Open

Seasonal and spatial variability in environmental factors may affect dissolved organic matter composition and nutrient transformation and retention in streams. The objective of this research was to quantify and describe seasonality, quantity, and quality of nutrient processing and export of ammonium (NH₄), soluble reactive phosphate (SRP), and dissolved organic carbon (DOC) into Lake Superior through intensive study in a small 1st order watershed coupled with snapshot measurements across 12 tributaries that varied in size, location, and wetland coverage. Our results suggest biodegradable C is exported from a small headwater stream year-round and that DOC mineralization rates can be …

Water Quality Of The Upper Little Miami River Watershed In Ohio: Impacts Of Natural And Anthropogenic Processes, David Allan Huff

Browse all Theses and Dissertations

Stream water quality is increasingly threatened by expanding anthropogenic activities, mainly through point source discharges and urban and agricultural runoffs of contaminants getting through a water body's watershed resulting in pollution. Concerns developed as to whether urban or agricultural type activities were causing most water quality impairment issues in the upper Little Miami River watershed in southwest Ohio.

Characterizing the upper Little Miami River (LMR) watershed with respect to water chemistry and Land Use/Land Cover (LULC) while evaluating the sources of any higher than expected natural parameter concentrations, with a strong emphasis on the nutrients phosphorus and nitrate, serves as …