For decades, mainstream domestic wastewater treatment has relied on activated sludge processes to remove organic matter, and on biological nutrient removal systems like the A2/O process to remove nutrients. Recently, membrane filtration was also added to the realm of possible technologies for domestic wastewater treatment, with aerobic membrane bioreactors (MBRs) becoming increasingly popular, especially for decentralized, and small to medium scale applications. However, the aerobic activated sludge and MBR processes, which are often combined with biological nutrient removal processes, have high energy costs associated with supplying oxygen to the process, and end up converting the organic matter into CO2 and high amounts of microbial biomass, instead of more useful byproducts. In order to remedy the aforementioned shortcomings of the aerobic processes, anaerobic wastewater treatment has been a focus of research, with anaerobic baffled reactors (ABRs) and anaerobic membrane bioreactors (AnMBRs) having shown promise for achieving acceptable organic matter removal performance, along with potential to be energy neutral or positive through biogas production. In addition, phototrophic technologies, such as algal photobioreactors, have recently been shown to be able to remove nutrients from waste streams, while at the same time having the potential to be used as feedstock to produce biofuels. In this dissertation, a novel concentrically-baffled reactor (CBR) was designed that has the potential to reduce heat loss by transfering more of the heat between reactor zones than traditional baffled reactor designs, which will increase energy efficiency for heated systems. A prototype CBR was operated abiotically under varying hydraulic retention times (HRTs) from 4 h to 24 h, and achieved over 90% removal of total suspended solids (TSS) for all HRTs tested with feed particle sizes below 1.7 mm. In parallel with the baffled reactor research, phototrophic membrane bioreactors (PMBRs) were tested with low aeration conditions to decrease their energy demand, which resulted in nitrification-dominated systems. A phototrophic technology was developed for increasing the pH of waste streams to potentially aid pH-sensitive nutrient recovery processes. Phototrophic pH increase from 6.42±0.13 to 8.87±0.06 was achieved using batch reactors, and an increase of pH from 6.73 to 8.61 was recorded during a continuous reactor trial. Finally, the CBR was combined with a post-CBR membrane filtration process, and two PMBRs treating the effluent and permeate streams from the CBR in order to achieve complete organic matter and nutrient removal. The combined systems were tested both for high strength-high HRT and low strength-low HRT scenarios. Using the combined CBR-PMBR system, over 90% TN and TP removal were possible for 10 d HRT operation at high-strength feed conditions, with post-CBR membrane filtration. COD removal over 90% was possible for both high-strength and low-strength scenarios under all conditions tested.

<p>Converting a nutrient management plan from commercial fertilizers to poultry litter helps effectively utilize waste from the nearly 10 billion broiler birds across the United States. Nine field scale watersheds from the USDA ARS Grassland, Soil and Water Research Laboratory near Riesel, TX were evaluated for P inputs and P outputs to determine phosphorus budgets for 15 years of annual application of poultry litter ranging from 75 – 219 kg P ha^-1 yr^-1 on cultivated and pasture/grazed fields. The cumulative net P continued to increase regardless of the application rate and had a positive relationship with soil level P (Mehlich-3 P) and flow weighted mean concentration (FWMC) for dissolved reactive P for both cultivated and pasture managed fields. We assessed hydrological connectivity within two nested watersheds by using the before-after-control-impact (BACI) design. Results showed hydrological connectivity during high rainfall years whereas low rainfall years had minimal connectivity compared to the controls. These results suggest the P contributions from upstream fields receiving poultry litter, even at high application rates, did not exhibit a treatment effect during the low rainfall years at downslope monitoring stations. </p><p><br></p> <p>As nutrient source variability increases in nutrient management plans, improving our ability to differentiate P sources and their fate in soils is critical. We evaluated soils with unique P inputs: inorganic P, poultry litter, and cattle grazing for isotopic signatures by forming silver phosphate and determining the δ¹⁸O_P. Isotopic signatures of the oxygen molecules which are strongly bound to P, provided signatures of 17.09‰, 18.00‰, and 17.20‰ for fields receiving commercial fertilizer, poultry manure, and cattle grazed, respectively. Significant effort was made to determine critical steps in the method to successfully precipitate Ag₃PO₄for analysis. Results show adding a cation removal step as well as monitoring and adjusting pH throughout the method increases probability of successful Ag₃PO₄precipitation. Findings from this study provide a valuable framework for future analysis to confirm unique δ¹⁸O_P signatures which can be used to differentiate the fate of different phosphorus sources in agricultural systems.</p>

Fruit growers in Utah and other areas across the Intermountain West are faced with growing production challenges stemming from declining soil quality and water resources. Population growth presents challenges in terms of the cost and availability of land, but also presents opportunities in the form of new marketing options such as organic fruit. Few certified organic fruit orchards are operating in Utah currently, which is attributed to a lack of locally tested and adapted organic management practices. An organic peach orchard trial evaluated the effectiveness of different organic management approaches to enhance soil quality and conserve water without compromise to fruit tree growth and fertility. Two tree-row treatments: ‘straw mulch' (Triticum aestivum L.) and ‘living mulch’ (Lobularia maritima (L.) Desv.) were tested in combination with two alleyway groundcovers: ‘grass’ (Festuca rubra L. with Lolium perenne L.) and a legume, ‘Birdsfoot trefoil’ (Lotus corniculatus L.). The novel systems were compared with industry standards, tillage and weed fabric tree-rows with grass alleyways. Trefoil alleyway biomass deposited into tree-rows contributed an estimated 6.24 kg biomass and 0.21 kg total N/tree annually. Trefoil treatments had higher levels of organic carbon (C) and nitrogen (N), inorganic N, microbial biomass and enzyme activities, suggesting trefoil alleyways enhanced soil nutrient cycling, as well as C and N reserves in comparison to grass and tillage treatments. A functional gene array analysis was conducted to describe the mechanisms, microbial functional composition and diversity underlying the observed soil processes, however few differences were detected in soil community structure between soils under different orchard floor management. Significantly lower leaf δ15N in trees grown with trefoil compared to grass, and an association between root biomass, diameter and trunk cross-sectional area (TCSA) suggests nitrogen sources derived from the trefoil groundcover contributed to improved fruit tree vigor. Few differences resulted among orchard treatments for water use (mm/week). Trends indicated slightly higher water use in trefoil over grass, but not enough to offset observed soil quality and tree growth benefits. These findings suggest, trefoil alleyways may provide ecological benefits such as improved soil quality and efficient nutrient cycling, without substantial increases in water use.

This study analyzes the change in whole-farm net revenues and nutrient reduction from the implementation of five best management practices (BMPs) on a typical beef and beef-poultry farm in Shenandoah County. Whole-farm net revenues, resource allocation, nutrient loss reductions, and the cost efficiency of reducing nutrient losses were analyzed to assess which BMPs are the most cost efficient to implement, assuming the baseline scenarios have no voluntarily applied BMPs. The effects of stacking additional BMPs, in combinations of two or more, were also assessed. No-till cropping, winter wheat cover crop, herbaceous riparian buffer, fencing, and P-based NMP were the BMPs that were analyzed. Incentive payments from state and federal governments were incorporated into the cost of BMP adoption. A brief analysis of a farmer's time value of money, with respect to incentive payments, was also conducted. Results indicated that no-till crop management was the most cost efficient BMP, and was the only BMP to increase net revenues for both farm models. Fencing and P-based NMP were the least cost efficient for the beef farm. For the beef-poultry farm, fencing was the least cost efficient. The implications of this study are that farmers that choose to adopt BMP should evaluate both their interests in maintaining (or increasing) farm net revenues along with their interest in improving water quality through the reduction of nutrient losses. There is potential for implementing multiple BMPs, while increasing net revenues from a farm's baseline scenario. For farmers and policy makers, no-till cropping can be a profitable and therefore cost efficient BMP to implement. Incentive payments are intended to encourage the adoption of BMPs by subsidizing a portion of the start-up costs. Policy makers should attempt to make cost-share payments reflect nutrient reduction goals. This can be done by analyzing both the compliance cost to farmers and the nutrient reduction effectiveness of BMPs. / Master of Science

No description available.

No description available.

Over the last two decades, livestock operations have become highly concentrated due to growing trends towards larger, more confined facilities and a decrease in cropland on smaller farms. This has led to greater amounts of excess manure nutrients on farms, increasing the potential for nutrient pollution of water bodies from runoff. The purpose of this study was to determine if enhanced biological phosphorus removal (EBPR) is a viable alternative for managing excess manure nutrients on dairy farms. Assessment of EBPR involved the investigation of various aspects of wastewater treatment modeling and design and farm nutrient management. The fermentation potential (volatile fatty acid (VFA) production) of dairy manure was determined through laboratory analysis to be 15.3% of the total COD. Total VFA production was composed of 57, 23, and 20% acetic, propionic, and butyric acids, respectively. The EBPR component of the BioWin wastewater treatment model was evaluated through a sensitivity analysis. The parameters to which effluent phosphate (PO4) concentration was most sensitive were maximum specific growth rate, growth yield, aerobic PO4 uptake rate per unit poly-b-hydroxybutyrate (PHB) utilized, PHB yield from VFA, PO4 release per unit VFA uptake, and fraction of releasable PO4. An EBPR sequencing batch reactor (SBR) was designed for a dairy farm with 700 lactating cows and 325 ha of corn silage. An economic analysis of EBPR for dairy farms employing P-based manure applications was completed. The cost of hauling excess manure to nutrient deficient farms was the most significant expense in comparing costs of manure management with and without EBPR. For a herd of 700 lactating cows, utilizing EBPR was more economical for farms with 270 ha or less cropland, while EBPR did not offer an economic advantage for farms over 270 ha. / Master of Science

Phosphorus (P) is a nutrient of concern in the Chesapeake Bay watershed due to nutrient imbalances in areas with confined animal feeding operations. By converting poultry litter to an ash via thermal conversion, nutrients are concentrated and are economical to ship out of nutrient surplus watersheds to nutrient deficient regions, such as the corn-belt. We initiated incubation and field studies on sandy loam soils to test P and potassium (K) availability from poultry litter ash (PLA). Four PLA products, derived from different sources using different combustion techniques, and 2 biochar products were characterized. Poultry litter (PL) co-products were compared to a no-fertilizer control and inorganic P (triple super phosphate; TSP) and inorganic K (muriate of potash; KCl) fertilizer at similar rates. In the incubation study, standard fertilizers (TSP and PL) had the greatest initial availability for P (55.50% TSP; 9.13% PL) and K (97.99% PL), respectively. The PL co-products varied in availabilities based on thermo-conversion system from 1.60- 8.63% for P to 8.14- 88.10% for K. One ash co-product (ASH4) produced similar availabilities to the industry standard fertilizers after 56 days. In conclusion, co-products from combustion thermo-conversion systems were found be superior to gasification and pyrolysis systems when the desire was to produce the most plant available P and K dense PL co-products. In the field studies, yield, Mehlich-I extractable soil nutrients, plant tissue and grain samples, and organic matter content was used to compare treatments. Poultry litter ash co-products were highly variable due to the thermo-conversion system and feedstock of formation. If all ideal combustion criteria are met, then PL co-products are feasible to use as fertilizer sources, but will need to be individually analyzed for nutrient content before making application recommendations. A greater amount of the co-products will have to be applied to meet the same nutrient availability of the standards due to their lower availability. Fresh PL tends to be the better fertilizer due to its added N content, which is lost in thermo-conversion systems and would have to be supplemented with the ash co-products. Biochars tend to be less available than their ash counter parts. More research using the water soluble availabilities instead of the total concentration nutrients of the co-products are needed to be able to identify stronger relationships with standard fertilizers. / Master of Science

This research was focused on increasing the efficiency of upland cotton production in the northern cotton belt through the use of new fertilizer formulations, placement, and timings. The objectives of the experiments reported in this thesis were to: 1) evaluate the effects of side-dress potassium (K), sulfur (S), and boron (B) formulation and application timing on tissue nutrient levels during the bloom period; 2) evaluate lint yield response of cotton to different formulations of nitrogen (N), K, S and B applied at side-dress; and 3) compare 5x5 banding (5 cm beside and 5cm below the seed) and deep placement of complete N-P-K-S blends to current nutrient management strategies on early season plant growth, nodes above white flower, total nodes, petiole nutrient concentrations during bloom, and lint yield. Tissue S and B concentrations were increased more often than K concentrations when the nutrients were applied with side-dress N. When evaluating P and K placement, petiole P levels were found to be significantly higher in unfertilized plots when no side-dress N was applied. Phosphorus and K placement and/or rate had no effect on lint yield when N was applied at side-dress during the study. Environmental conditions potentially influenced the response to P and K placement as 5x5 placement produced yields significantly higher during 2013 growing season at location 1, while deep placement produced significantly higher yields in 2014 at location 3. As a result, Virginia nutrient management recommendations for cotton have been updated to incorporate management strategies to maximize lint yields. / Master of Science

Prior to the development of programing and outreach materials it is important for Extension outreach and education professionals to assess the educational needs and preference of the communities they serve. Survey data was gathered from residents of Cedar City, UT, in an effort to gain an understanding of current lawn management practices and the resources homeowners utilize when making management decisions. In addition, soil samples were collected from a subset of participants to compare nutrient levels to management practices. Survey results found that homeowners accessed multiple sources, with preferences leaning towards the use of friends and family members, the internet, and the point of purchase. Few homeowners are aware of and utilize educational resources and services provided by Extension. This is especially true for those under the age of 50, which poses a challenge to Extension professionals to find effective ways to reach younger generations. It was difficult to form associations between nutrient levels and management practices Although, there was a strong association between those with excessive phosphorus concentration and the application of biosolids. More research needs to be done to examine the distribution and end use of biosolids.