Browsing by Subject "phosphorus"
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Item Biogas Production and Nutrient Recovery from Waste Streams(2013-07) Ye, YulinAbstract Waste streams such as municipal wastewater and animal manure contain organic materials and nutrients that can be converted and recovered for bioenergy and renewable fertilizer production. In the first part of this thesis, the anaerobic co-digestion of dairy manure with kitchen waste and chicken fat was studied for the purpose of increasing biogas production. The methane yields of co-digestion substrates mixed at different ratios were determined by bio-methane potential tests. The highest methane yield, which was 114% higher than the baseline, was observed when dairy manure was mixed with kitchen waste and chicken fat at the ratio of 1:2:2 (volatile solids based). The mixed substrates were then fed to a lab-scale continuous stirred-tank reactor. The co-digestion was stable and biogas production was 1559�195 mL biogas/L·day at organic loading rate as high as 6.8g COD/L*day. In the second part, a new approach was proposed for phosphorus removal and recovery from wastewater. Nine strains were identified to have the capability of high phosphorus removal and storage comparable to Polyphosphate Accumulating Organisms (PAOs) in the Enhanced Biological Phosphorus Removal (EBPR) process. Batch experiment using synthetic wastewater showed that Mucor circinelloides can remove ~ 72-82% phosphorus when P to COD ratio was roughly 1:100. The phosphorus recovered from wastewater in the form of polyphosphate-containing fungal biomass could be used as fertilizer, providing a potential alternative to biological nutrient removal and a solution to sustainable agriculture.Item Calcium Phosphate Mineralization as a Nexus of Geosphere–Biosphere interactions(2017-10) Crosby, ChrisThere is arguably no more direct example of the dynamic relationship between the geosphere and the biosphere than the element phosphorus. Originally sourced from the rocky material of Earth, phosphorus enters the biosphere as the highly charged phosphate ion that is incorporated into every cell of every organism, and eventually returns to the geosphere in sedimentary phosphate rock. Although both igneous and sedimentary phosphate rock is mined for use in fertilizers, mineable phosphate rock is not evenly distributed across the Earth which imbues this vital resource with global economic significance and makes it an important issue in international relations, with wide-ranging implications for global human population growth trends. Phosphorus-related research is conducted in a wide variety of fields, including the medical and dental sciences, environmental and agricultural sciences, wastewater treatment technology, geology and mining. Indeed, there are many angles from which to explore the function and importance of phosphorus. In this thesis, I focus on some of the aspects of the phosphorus-related interplay between the geosphere and the biosphere through both 1) the ancient rock record, through analysis and interpretation of ~2 billion year old phosphate rock carrying an imprint of the biologically influenced cycling of phosphorus and 2) the modern, through laboratory experiments designed to elucidate details of the nucleation and precipitation of solid calcium-phosphate minerals in proximity with biological material. My work in the rock record carries significance for our understanding of the co-evolution of a relatively young, only recently oxygenated Earth and coeval life as it evolved to adapt to this changing environment. In addressing challenges inherent in determining bona fide biogenicity of putative microfossils, this work is also relevant to the field of micropaleontology. Finally, I offer a newly developed apparatus and protocol for use in the experimental examination of mineral precipitation over time and in the context of polymeric matrices such as those implicated in both biologically directed mineralization and biologically influenced precipitation of calcium-phosphate minerals and their precursors.Item Carbon and Phosphorus Dynamics in Restored Minnesota Peatlands(2022-04) Wille, EmilieWhile many peatlands have been drained for anthropogenic purposes across the world, there is currently high interest in restoring peatlands for carbon and nutrient cycling benefits. Peat holds a disproportionate amount of the world’s soil carbon, making peatlands promising ecosystems for mitigating greenhouse gas emissions and climate change. Additionally, peatlands can sequester phosphorus (P) and prevent it from causing eutrophication in downstream waters, but they can also act as a P source under high runoff conditions. This study aimed to investigate the factors impacting 1) peat carbon dioxide (CO2) flux and 2) mobilization of peat P to porewater in a restored bog and fen in Minnesota. Peat CO2 flux was monitored in-situ throughout the growing season in conjunction with peat type, water table depth, and temperature. Peat columns from each site were saturated and subjected to controlled laboratory incubations to relate porewater ortho-P content to temperature and porewater aluminum (Al), calcium (Ca), and iron (Fe) content. A higher water table was significantly related to lower peat CO2 flux in the fen, and peat CO2 flux across both sites was higher in regions with more decomposed peat. During the peak of the growing season, CO2 flux was much higher in the fen than the bog, but both sites had similarly low CO2 flux at the end of the growing season. It is important that restoration ecologists consider a peatland’s water table when restoring a site’s hydrological, ecological, and biogeochemical functioning in order to achieve the greatest carbon benefit. Higher porewater ortho-P corresponded to higher dissolved porewater Al, Ca, and Fe. Additionally, higher initial peat Ca was significantly related to lower porewater P. These ions play a role in binding and mobilizing P, and their dynamics can help researchers predict and mitigate P release and subsequent export.Item Characterization of streams and rivers in the Minnesota River Basin Critical Observatory: water chemistry and biological field collections, 2013-2016(2017-09-06) Dolph, Christine, L.; Hansen, Amy, T.; Kemmitt, Katie, L.; Janke, Ben; Rorer, Michelle; Winikoff, Sarah; Baker, Anna; Boardman, Evelyn; Finlay, Jacques, C.; dolph008@umn.edu; Dolph, Christine, L.This dataset was collected to inform the Water, Sustainability and Climate Minnesota River Basin Observatory, and was supported by the National Science Foundation under Grant No. 1209402 Water, Sustainability and Climate (WSC) – Category 2, Collaborative: Climate and human dynamics as amplifiers of natural change: a framework for vulnerability assessment and mitigation planning. The dataset contains point locations, watershed areas and water quality information for 231 ditch, stream, river and wetland sites located in the Le Sueur River, Chippewa River, Cottonwood River, Cannon River, Wantonwan River and Blue Earth River basins of Minnesota. Study sites ranged in size from 1st order ditches and streams to an 8th order river. Each of these sites was sampled at least once between 2013-2016 (most sites were sampled multiple times) for one or more of the following parameters: 1) water chemistry (total dissolved nitrogen, nitrate-N, nitrite-N, ammonium-N, particulate nitrogen, soluble reactive phosphorus, total dissolved phosphorus, particulate phosphorus, total phosphorus, dissolved organic carbon, dissolved inorganic carbon, particulate carbon, chlorophyll a, total suspended solids, volatile suspended solids, delta-H-2 and delta-O-18 stable isotopes of site water, specific UV absorbance (SUVA) of site water, fluorescence index (FI) of site water); 2) stable isotopes (delta-C-13, delta-N-15, delta-H-2) of invertebrate consumers, particulate carbon and potential food sources; 3) denitrification rates and characteristics of benthic sediment in agricultural drainage ditches; and 4) stream discharge. This dataset also includes spatial data files containing study site locations and watershed areas delineated for each site.Item Characterizing phosphorus impacts on crop yields, soil nutrient profiles, and water quality in soils at risk of flooding for several phosphorus-based fertilizers of varying source and rate(2024-07) Malone, RoryIn the Red River Valley of northwestern Minnesota, phosphorus (P) is the main nutrient of concern that threatens the Lake Winnipeg watershed. Climate change has altered crop production in the Northern Great Plains, as increased summer temperatures have brought corn and soybean rotations to northern regions. Consequentially, farmers in the Red River Valley are implementing P rates for two years at once on corn-soybean rotations which do not have long-established fertility documentation in the region. Additionally, soluble orthophosphate (ortho-P) release from calcareous, alkaline soils to spring floodwater over agricultural fields is understudied. To characterize the impact of phosphorus-based fertilizers by source and rate on crop yields, soil nutrient concentrations, biomass nutrients, and nitrogen mineralization, field trials with corn and soybean rotations were conducted over two years at the University of Minnesota’s Northwest Research & Outreach Center, followed by a laboratory incubation study to characterize dissolved P release from the treatments over eight weeks of a cool, anaerobic, saturated environment designed to replicate spring flooding. Treatments included the following commonly used fertilizers: monoammonium phosphate (MAP, NPK: 11-52-0), MicroEssentials SZ (MESZ, NPK-Zn: 12-40-0-10S-1), and 25% Struvite/Crystal Green (NPK: 5-28-0). While increased fertilizer rates resulted in slightly higher yields for some datasets, two-year rates of P-based fertilizer did not make differences in crop yields. These field trials indicate that applying excess phosphorus to save time does not impact yields, but simply increases phosphorus available in soil water to run off under flooded conditions. Laboratory incubation of mesocosms from field samples by fertilizer source and rate at two depths (0-15 cm and 15-30 cm) showed distinct release of soluble P from the soil to water between treatments. Ortho-P release from soil to surface water and pH increased over time, with ortho-P being greater in concentration in the surface layer. The 3-week mark was a significant point in spikes of ortho-P release in both surface and subsurface soil layers, which characterizes a timeline for water quality concerns in spring flooding of agricultural fields, after iron reduction occurs and previously sorbed phosphorus is released. MAP + Struvite and MESZ at double rates had consistently higher dissolved ortho-P release, possibly due to the addition of magnesium and zinc. While double rates were not noticeable by crop yield in a second-year soybean rotation, double rates showed distinct risk of runoff to floodwaters in simulated conditions.Item Cyanobacteria phenology and toxicity across six Minnesota temperate lakes(2022-10) Egan, LeahCyanobacteria harmful algal blooms (cHABs) represent both chronic and emerging water quality threats in lakes globally and are the consequence of complex, interacting stressors. While we know that water temperature, nutrient loading and availability, and water column mixing conditions are important drivers of cHABs, the combination of abiotic conditions leading to bloom development, maintenance, and toxicity remain poorly understood across different lake types. To better understand relationships among cyanobacteria abundances and composition, toxin concentrations, and nutrient conditions, we monitored six temperate Minnesota lakes with differing watershed land uses and lake morphometric characteristics across a latitudinal gradient. This project combined limnological approaches, comprehensive phytoplankton community analyses using taxonomic approaches, and advanced analytical characterization of toxin molecules to determine mechanisms leading to bloom formation and toxicity. Findings show that our study lakes had differing bloom phenologies influenced by different community assemblages and nutrient limitation states. The southern lakes had contrastingly different watershed land uses, such that Peltier Lake was predominantly urbanized, and Carrie Like was highly agricultural, which led differing nutrient growth conditions. Peltier (low N:P) experienced chronic surface blooms, whereas Carrie (extremely high N:P) did not. In Peltier Lake, the dominant cyanobacteria taxa present switched midsummer from nitrogen fixers (Dolichospermum spp.) to non-nitrogen fixers (Microcystis spp.) which tracked with decreasing nitrogen to phosphorus ratios. This community shift was counterintuitive based on changes in nutrient deficient growth conditions, suggesting that other drivers were likely impacting the shift in dominant cyanobacteria genera. Random Forest Models predicted major drivers of cyanotoxins in the bloom dominated lake, Peltier, to be in-lake growth conditions including dissolved organic carbon, soluble reactive phosphorus, and total phosphorus concentrations. Cyanotoxins were surprisingly detected in all lakes, including our least productive systems such as a northernly located lake, White Iron, and we observed a gradient of microcystin congeners present among our sample lakes. Cyanotoxin production can vary at the species (strain) level, therefore, it is essential to determine abiotic drivers of cHABs for various strains in differing lake types to properly inform management and mitigation of future system specific HABs.Item Data and R code supporting "Uncovering state-dependent relationships in shallow lakes using Bayesian latent variable regression"(2017-10-03) Vitense, Kelsey; Hanson, Mark A; Herwig, Brian R; Zimmer, Kyle D; Fieberg, John R; viten003@umn.edu; Vitense, KelseyThis repository contains the data and R code used to conduct the analyses in the article "Uncovering state-dependent relationships in shallow lakes using Bayesian latent variable regression" in Ecological Applications.Item Designing Metal-Organic-Frameworks For Selective Biomass Catalysis(2020-03) Dorneles de Mello, MatheusMetal-organic frameworks (MOFs) are microporous materials with a wide range of pore sizes and functionalities, making them attractive for a variety of potential applications in catalysis, separations, sensing, and gas storage. Associated with the global demand for clean energy sources to find alternatives to fossil fuels, their use as catalysts for biomass conversion to chemicals finds potential application. The performance of MOFs in these applications is dependent on how stable they are upon modifications to their tunable frameworks. Such modifications include acid treatment, ligand, and cluster functionalization that can be performed by direct synthesis or post-synthesis modification, as desired for optimum performance. This dissertation focuses on using synthetic methods that may enable the tailoring the microstructure of MOFs towards their use for catalysis of biomass. We discuss the use of a method called acid modulation to introduce missing-ligands defects and open Lewis acid sites into the framework of UiO-66 to make it an active and selective catalyst for glucose isomerization to fructose in alcohol media. We demonstrate that upon the alcohol choice, the selectivity of the reaction to fructose can change drastically by favoring other reaction pathways. Furthermore, we investigate the reaction mechanism of glucose isomerization into UiO-66 and identify that glucose reacts via a 1,2-hydride transfer mechanism similar to what was reported for Sn-zeolites. We report the synthesis and installation of phosphonic acid moieties into the ligands of UiO-66 and UiO-67 as a way to introduce Brønsted acidity to these materials by a post-synthesis ligand exchange method. The active sites of P-UiO-66 are elucidated by a combination of solid-state NMR and DFT calculations. P-UiO66 is reported to be active and selective for several acid-catalyzed reactions such as alcohol dehydration and furans dehydra-decyclization with site-time yields approaching that of highly selective phosphoric acid zeolites, holding promise for its use in this and other reactions for the biomass conversion to chemicals. The tunability of MOFs combined with the PSM method and synthesis of phosphonic acids can provide accurate control of the density of active sites with a uniform distribution throughout the framework.Item Development of a Mathematical Model to Predict the Role of Surface Runoff and Groundwater Flow in Overfertilization of Surface Waters(Water Resources Research Center, University of Minnesota, 1971-06) Johnson, Jack D.; Straub, Conrad P.A nutrient enrichment accounting mathematical model was devised for the New Prague watershed in Minnesota. The New Prague watershed is 23.3 square miles in area and is predominately a rural watershed. Model input data was collected over a 2 1/2 year period from a stream gauging station and two automatic sampling stations. Over 800 water samples were analyzed. Extensive effort was placed on better understanding the nitrogen and phosphorus cycles. It is evident that the spring runoff process and accumulative winter fertilizer applications constitute the major portion of diffuse sources of nutrients in the watershed. Point sources from feedlots and municipal and industrial effluents contribute only 11 percent of the annual EN (total nitrogen, four components) and 7 percent TP (total phosphorus). Disperse sources accounted for 89 percent of EN and 93 percent of TP, with spring runoff in the two months of March and April accounting for 79 percent of the annual EN and 64 percent of the TP. The nutrient output from the watershed could be decreased by increasing penetration of the large amounts of EN and TP in snowpacks into the soil through land terracing to restart rapid spring runoffs and sub-surface drains to allow rapid drainage during the crop season.Item Effects of Swine Manure Applications on Soil Nutrient Levels and Phosphorous Loss Risk: Results from a Southwest Minnesota Monitoring Project and the Application of the Minnesota Phosphorous Index(University of Minnesota Extension Service and University of Minnesota Department of Soil, Water, and Climate, 2007) Koehler, Robert; Lewandowski, Ann; Moncrief, JohnItem Evaluation of Phosphorus Content Among Plant- and Animal-Based Protein Products: Implications for Dietary Recommendations in Chronic Kidney Disease(2022-05) Fons, AlexandriaKidney function is imperative for human health, especially due to its unique physiologic role in waste regulation. However, approximately 15% of American adults experience diminishing kidney function, which causes substances such as phosphorus (P) to accumulate in the blood, leading to cardiac and skeletal abnormalities. One primary treatment to mitigate elevated serum P levels is to restrict P consumption in the diet. However, this is a largely unsuccessful endeavor due to the ubiquitous nature of P in the food supply, lack of transparency of P content in foods, association of P with protein-rich sources, and economic barriers to acquiring and preparing low P foods. One proposed method for addressing these concerns is transitioning the focus away from P-restricted diets to adopting plant-based eating patterns. However, widespread interest in plant-based eating has generated an emerging industry of ultra-processed plant-based meat alternatives which have unknown health consequences, and it remains unclear whether these products would be beneficial for patients with chronic kidney disease. Therefore, the study described in this thesis sought to investigate the P content of plant- and animal-based protein products through laboratory analysis and exploration of a nutrient database. Laboratory analysis included preparation of food products, freeze drying, ashing, and measurement of mineral content via ICP-OES. Results from this research revealed wide variation in P content and P-to-protein ratios among products in addition to an underestimation of P content of foods in a nutrient database. Further, examining these products illuminated the immense use of phosphorus additives in the food supply and the great discrepancy of cost between plant and animal protein products. The work discussed in this thesis provides foundational knowledge on new-to-market plant protein products, which supplies the groundwork for future research on mineral analysis, bioaccessibility, and bioavailability of food products to ultimately understand the connection between consumption of these foods and the effect on serum P and health outcomes to modify and strengthen dietary recommendations for chronic kidney disease.Item Global effects of soil and climate on leaf photosynthetic traits and rates(Wiley, 2015) Maire, Vincent; Wright, Ian J; Prentice, I. Colin; Batjes, Niels H; Bhaskar, Radika; Bodegom, Peter M; Cornwell, Will K; Ellsworth, David; Niinemets, Ülo; Ordonez, Alejandro; Reich, Peter B; Santiago, Louis SAim The influence of soil properties on photosynthetic traits in higher plants is poorly quantified in comparison with that of climate. We address this situation by quantifying the unique and joint contributions to global leaf-trait variation from soils and climate. Location Terrestrial ecosystems world-wide. Methods Using a trait dataset comprising 1509 species from 288 sites, with climate and soil data derived from global datasets, we quantified the effects of 20 soil and 26 climate variables on light-saturated photosynthetic rate (Aarea), stomatal conductance (gs), leaf nitrogen and phosphorus (Narea and Parea) and specific leaf area (SLA) using mixed regression models and multivariate analyses. Results Soil variables were stronger predictors of leaf traits than climatic variables, except for SLA. On average, Narea, Parea and Aarea increased and SLA decreased with increasing soil pH and with increasing site aridity. gs declined and Parea increased with soil available P (Pavail). Narea was unrelated to total soil N. Joint effects of soil and climate dominated over their unique effects on Narea and Parea, while unique effects of soils dominated for Aarea and gs. Path analysis indicated that variation in Aarea reflected the combined independent influences of Narea and gs, the former promoted by high pH and aridity and the latter by low Pavail. Main conclusions Three environmental variables were key for explaining variation in leaf traits: soil pH and Pavail, and the climatic moisture index (the ratio of precipitation to potential evapotranspiration). Although the reliability of global soil datasets lags behind that of climate datasets, our results nonetheless provide compelling evidence that both can be jointly used in broad-scale analyses, and that effects uniquely attributable to soil properties are important determinants of leaf photosynthetic traits and rates. A significant future challenge is to better disentangle the covarying physiological, ecological and evolutionary mechanisms that underpin trait–environment relationships.Item Host Diet and Pathogen Diversity: How Soil Nutrients Affect Plant Virus Interactions(2017-12) Kendig, AmyHuman activities and management choices can impact the spread and intensity of diseases in plant and animal populations. For example, high nutrient inputs to terrestrial and aquatic systems may enhance pathogen success or aid hosts in resisting and tolerating disease. Because nutrient supply rates and ratios mediate interactions among free-living species, they may also influence interactions between hosts and pathogens. Further, it is increasingly clear that infections involve multiple different kinds of pathogens, and their interactions may also be mediated by environmental nutrients. The goal of my dissertation research was to understand how soil nutrients affect interactions among plant viruses and the consequences of these interactions for disease dynamics. We used field-collected data to determine how nutrients, among other factors, affected spatial patterns of viruses in grasslands. We found that virus pairs frequently co-occurred, and phosphorus (P) addition promoted the aggregation of one pair. Then, we performed growth chamber experiments to evaluate how nitrogen (N) and P mediated within-host interactions between two viruses, disease severity, and transmission to new hosts. We found that pathogens coexisted within hosts and occasionally benefitted from increased N. Disease severity was not strongly influenced by soil nutrients, but modeling results indicated that this outcome depended on the mechanism behind virulence. Finally, we found that the viruses were likely to coexist at the host population scale, despite inhibition that occurred during transmission. These results indicate that soil N and P influence some aspects of the system, but are not the main drivers behind virus diversity. This research contributes to a growing body of knowledge about the mechanisms linking environmental nutrients to disease across systems.Item In search of the phosphorus legacy: merging hydrological and biogeochemical approaches to understand phosphorus dynamics in streams.(2022-09) Pawlowski, EthanNutrient and sediment pollution of surface waters remains a critical challenge for improving water quality. Phosphorus and sediment export to lakes and rivers has resulted in diminished water quality placing drinking water supplies, human health, recreation opportunities, and aquatic ecosystems at risk. Understanding both biogeochemical processing and transport of phosphorus and fine sediments (a major sorbent of phosphorus) in stream channels is required to understand the legacy effects of agricultural land management decisions and the effects of mitigation strategies. I focused my thesis on sediment and phosphorus dynamics in Midwestern USA watersheds by examining three parts: (1) using the Nutrient Tracking Tool (NTT) with physical site characteristics to target areas for revegetation, and to compare this field-scale tool with watershed export data; (2) a combination of tracer experiments with transient-storage modeling and biogeochemical assessment to understand phosphorus and sediment dynamics at base flow within Plum Creek, WI; and (3) the inventory and assessment of fallout radionuclides as a potential sediment fingerprint in the upper Midwest. To assess potential load reductions using revegetation, the nutrient tracking tool (NTT) was used with a scoring system to identify areas where vegetation mitigation could be implemented within three selected Fox River, WI sub-watersheds. A corn-soybean rotation, an implementation of a 10-m vegetated buffer, a full forest conversion, and tiling were modeled and assessed. The corn-soybean results were aggregated and compared to watershed level gauge data in two sub-watersheds. Edge of field data was compared to modeled results using multiple parameterization schemes. The agricultural areas that scored higher and were untiled showed greater potential nutrient and sediment export reduction when vegetation mitigation was implemented in the model. Aggregated watershed results showed disparities between modeled and measured phosphorus exports but modeled sediment export fell within observed gauge data ranges. Field specific parameter adjustments resulted in more accurate modeled results compared to measured edge of field data, but needed further refinement. Targeted mitigation using vegetation based on the scoring system was shown to be a helpful tool for nutrient and sediment reductions when modeled. Using a field scale model aggregated to the watershed scale presents tradeoffs regarding processes found beyond the edge of field. To understand in-channel processes, a fluorescent fine particle surrogate, bromide, and phosphate were injected and sampled under base flow conditions within two stream reaches that are representative of the lower and upper Plum Creek, WI, watershed. Grab samples were analyzed and breakthrough curves were modeled utilizing the one-dimensional transport with inflow and storage (OTIS) model. Sediment and stream water samples were analyzed for equilibrium phosphate concentration determination to gain a better understanding of phosphorus dynamics and the potential time lags associated with phosphorus delivery from agricultural fields to downstream water bodies when used in conjunction with transport parameters determined by OTIS. Results indicate sediments within Plum Creek have a large potential to sorb dissolved phosphorus entering the stream channel and reduce dissolved loads at the individual reach scale. These results suggest a large potential for discrepancies between mitigation implementation and noticeable water quality improvements when considering base flow transport and storage metrics. Fallout radionuclides beryllium-7 and lead-210 were measured at the St. Paul Weather Station, MN and at the Marcell Experimental Forest by collecting bulk deposition. Event-based sampling was completed in St. Paul whereas weekly sampling was done at the Marcell Experimental Forest in order to compare results with data from the National Atmospheric Deposition Program. Results showed that neither beryllium-7 nor lead-210 were correlated with precipitation inputs, but showed seasonal patterns with peak deposition occurring during the summer months. Beryllium-7 was weakly correlated with precipitation at the Marcell Experimental Forest and showed some correlation with sulfate and chloride deposition but the correlation was not strong enough that either sulfate or chloride could be used as a predictor of beryllium-7 deposition. Cumulative deposition followed a linear trend and could be useful for predicting deposition or filling data gaps in areas with scant depositional records or in remote settings.Item Maximum Application Rates for Land Treatment of Septage(Water Resources Research Center, University of Minnesota, 1983-05) Anderson, James L.; Clanton, C.J.; Hansel, M.J.; Machmeier, R.E.During 1980, septage was applied in rates of 1120 and 1500 kg of nitrogen per hectare to three different soil textures in an attempt to determine maximum loading rates. These rates resulted in increased concentrations of nitrates in the soil water for a Hubbard loamy Sanci, Waukegan silt loam and Lester clay loam, indicating that the application rates exceeded the maximum rate that the soils could treat. The first year's results indicate that soil type, application rates and soil depth resulted in no significant difference in total Kjeldahl nitrogen, ammonia, fecal streptococcus and fecal coliforms in the soil water samples. Nitrate concentrations, however, were significantly different between the soils, application rates and soil depths. For the Hubbard loamy sand, rainfall had a larger effect on nitrate concentrations and movement within the soil profile than for the Waukegan silt loam or Lester clay 1oam. 0n the Waukegan silt loam and Lester clay loam there was relatively little change in the nitrate concentration in the soil profile during the period when septage was applied twice a week. After the design loading had been applied to the soil and no further applications made, a sharp increase in nitrate concentrations was observed in the soil profile. This probably resulted from changing the anaerobic surface layer to an aerobic condition resulting in nitrification and subsequent movement of nitrates through the profile following a rainfall event. With no additional septage application, the second year's data indicate a significant difference in nitrate-N between soils, application rates, and depths. Generally, the nitrate concentrations in the Hubbard loamy sand and Waukegan silt loam were less than the first year, but the concentrations in the Lester clay loam were higher than the first year. This indicates that nitrification and nitrate movement in the Lester clay loam are slower than the other two soils. Application resulted in a significant increase in the concentration of soil water calcium, magnesium, sodium and potassium during the first year of the study. However, there was no increase in the phosphorus content of the soil water.Item The Minnesota Phosphorus Index: Assessing Risk of Phosphorus Loss from Cropland(University of Minnesota Extension Service, 2006) Lewandowski, Ann; Moncrief, John; Drewitz, MattThe Minnesota Phosphorus Index (MN P Index) is a model with the primary purpose of estimating P loss risk. The computerized version of the model is available in the zipped folder on this record. The MN P Index is used when a more accurate estimate is needed (e.g., on sites with multiple risk factors), or to estimate P loss risk unrelated to manure applications (e.g., to identify P loss sites within a watershed). The MN P Index helps users identify and refine site-specific methods to reduce P loss by considering the interaction of a wide range of risk factors including landscape characteristics, cropping and tillage practices, and P application methods.Item Minnesota Pollution Control Agency Wild Rice Sulfate Standard Mesocosm Study: Water, Sediment, and Porewater "Synoptic" Sampling 2013 and 2015(2017-05-30) Myrbo, Amy; amyrbo@umn.edu; Myrbo, AmyThis dataset represents opportunistic, "synoptic" sampling of 30 experimental mesocosms for chemical parameters. The mesocosm experiments were undertaken by Dr. John Pastor (UMN-Duluth) and the Minnesota Pollution Control Agency (MPCA) to improve the understanding of why wild rice (Zizania palustris, manoomin, psin) is observed to thrive only in waters with low sulfate (SO4), and to contribute to evaluation of Minnesota Rules 7050.0224, promulgated in 1973, which seeks to limit the exposure of wild rice to sulfate concentrations exceeding 10 mg/L.The dataset is now released as manuscripts using it are being published.Item MSRC2019: Mass, moisture, nitrogen, and phosphorus in street sweepings collected from five cities in the Twin Cities Metropolitan Area, Minnesota(2020-09-21) Hobbie, Sarah E.; Baker, Lawrence A.; Finlay, Jacques C.; shobbie@umn.edu; Hobbie, Sarah E; Departments of Ecology, Evolution & Behavior, and Bioproducts & Biosystems EngineeringQuality of many urban water bodies is impaired because of phosphorus (P) loading from stormwater runoff. Trees near impervious surfaces contribute significantly to this P loading. Mounting evidence indicates that street sweeping, by removing nutrient-rich litterfall from streets, can effectively reduce inputs of pollutants to stormwater and reduce maintenance of downstream BMPs. Yet, street sweeping remains an underdeveloped BMP for P source reduction, as currently there is no easily implementable method for crediting sweeping practices that is approved by the Minnesota Pollution Control Agency (MPCA). Thus, water quality credits for street sweeping practices are typically not applied to permit conditions such as Total Maximum Daily Loads (TMDL) Waste Load Allocations in Minnesota. Through a UMN-MPCA-city partnership, we collected data on street sweeping loads including: sweeper volume, wet mass of solids, dry mass of solids, and nitrogen and phosphorus concentrations in sweepings and loads removed by different street sweeper types throughout the snow-free season (spring, summer, fall), across the range of tree canopy covers and species composition typical of Minnesota’s cities. Partner cities included Forest Lake, Minneapolis, Prior Lake, Roseville, and Shoreview.Item Predicting leaf functional traits from simple plant and climate attributers using the GLOPNET global data set(2007) Reich, Peter B; Wright, Ian J; Lusk, Christopher HKnowledge of leaf chemistry, physiology, and life span is essential for global vegetation modeling, but such data are scarce or lacking for some regions, especially in developing countries. Here we use data from 2021 species at 175 sites around the world from the GLOPNET compilation to show that key physiological traits that are difficult to measure (such as photosynthetic capacity) can be predicted from simple qualitative plant characteristics, climate information, easily measured (“soft”) leaf traits, or all of these in combination. The qualitative plant functional type (PFT) attributes examined are phylogeny (angiosperm or gymnosperm), growth form (grass, herb, shrub, or tree), and leaf phenology (deciduous vs. evergreen). These three PFT attributes explain between one-third and two-thirds of the variation in each of five quantitative leaf ecophysiological traits: specific leaf area (SLA), leaf life span, mass-based net photosynthetic capacity (Amass), nitrogen content (Nmass), and phosphorus content (Pmass). Alternatively, the combination of four simple, widely available climate metrics (mean annual temperature, mean annual precipitation, mean vapor pressure deficit, and solar irradiance) explain only 5–20% of the variation in those same five leaf traits. Adding the climate metrics to the qualitative PFTs as independent factors in the model increases explanatory power by 3–11% for the five traits. If a single easily measured leaf trait (SLA) is also included in the model along with qualitative plant traits and climate metrics, an additional 5–25% of the variation in the other four other leaf traits is explained, with the models accounting for 62%, 65%, 66%, and 73% of global variation in Nmass, Pmass, Amass, and leaf life span, respectively. Given the wide availability of the summary climate data and qualitative PFT data used in these analyses, they could be used to explain roughly half of global variation in the less accessible leaf traits (Amass, leaf life span, Nmass, Pmass); this can be augmented to two-thirds of all variation if climatic and PFT data are used in combination with the readily measured trait SLA. This shows encouraging possibilities of progress in developing general predictive equations for macro-ecology, global scaling, and global modeling.Item Proceedings of the 4th Drainage Water Management Field Day(2011-08-23) Strock, Jeffrey S.; Gupta, Satish; Sands, Gary; Ranaivoson, Andry; Hay, Chris; Talbot, Mike; Magner, Joe