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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Effects of composted dairy manure on soil chemical properties and forage yield and nutritive value of coastal Bermudagrass [Cynodon dactylon (L.) Pers.]

Helton, Thomas J. 17 February 2005 (has links)
Research was conducted to compare the effects of composted dairy manure and raw dairy manure alone, or in combination with supplemental inorganic fertilizer, on soil chemical properties and Coastal bermudagrass [Cynodon dactylon (L.) Pers.] yield and nutritive value. Composted dairy manure was surface applied at rates of 14 (125 kg N ha-1), 29 (250 kg N ha-1) and 57 (500 kg N ha-1) Mg dry matter (DM) ha-1, and raw dairy manure was surface applied at a rate of 54 (420 kg N ha-1) Mg DM ha-1 to established bermudagrass. Selected compost and manure plots received supplemental inorganic N at rates of 56, 84 and 112 kg ha-1 cutting-1 or 112 kg ha-1 cutting-1 of supplemental N with supplemental inorganic phosphorus or potassium at rates of 112 kg P2O5 ha-1 yr-1 and 112 kg K2O ha-1 cutting-1, respectively. Composted dairy manure (29 and 57 Mg DM ha-1) or raw manure alone increased cumulative forage yields compared to the untreated check in both years of the study, but were less than those obtained using only inorganic fertilizer. Application of 56 kg N ha-1 cutting-1 or more of supplemental N to compost (29 and 57 Mg DM ha-1) or iv manure produced forage yields that were equal to or greater than those obtained using inorganic fertilizer alone. However, increasing compost rate did not increase tissue N concentrations regardless of supplemental inorganic N rate. Yield and tissue K concentrations were increased in the second growing season when supplemental inorganic K was applied to 29 Mg ha-1 of compost or 54 Mg ha-1 of raw dairy manure. No yield response was observed when supplemental inorganic P was applied to compost or manure. Soil pH and concentrations of NH4, NO3, K, Ca, Mg and Mn were increased by application of compost or manure. Soil P concentrations in the 0 to 5-cm zone exceeded 200 mg kg-1 when compost was applied at the high rate. Dairy manure compost was an effective nutrient source for bermudagrass hay production, but will require the use of supplemental N and, in some cases, K to achieve yields comparable to inorganic fertilizer.
82

Evaluation of selected new technologies for animal waste pollution control

Lazenby, Lynn Anne 30 October 2006 (has links)
In 1998, two upper North Bosque River segments were designated as impaired due to the nonpoint source (NPS) pollution of phosphorus (P) to these segments in the watershed. As a result, two Total Maximum Daily Loads (TMDLs) were applied which called for the reduction of annual loading and annual average soluble reactive P (Sol P) concentrations by 50 %. This study was conducted to evaluate the efficacy of two prospective new technologies, an Electrocoagulation (EC) system, and a Geotube® dewatering system to potentially aid the dairy farmers in meeting the goals set by the TMDLs. The EC system analyzed in this study used chemical pretreatment to coagulate and separate solids in effluent pumped from the dairy lagoon; the liquid then flowed over charged iron electrodes giving off ions that cause coagulation and precipitation of P and other metals. Overall, the performance of the system was consistently highly effective in reducing total phosphorus (TP) and Sol P, on average, reducing these constituents by 96% and 99.6% respectively from the dairy lagoon effluent. However this consistency did not hold for the rest of the analytes. In the Geotube® dewatering system geotextile tubes were utilized to dewater dairy lagoon effluent. Results showed this system performed very well in filtering solids from the dairy lagoon effluent, removing an average of 93.5 % of the total solids between the two pumping and dewatering events of March and April. It was effective in removing nutrients and metals as well. The average percent reduction of TP and Sol P for the two events were very high at 97% and 85 % respectively.
83

Optimering av biogasproduktion från gödsel / Optimization of Biogas Production from Manure

Özdemir, Gonca January 2009 (has links)
<p>                      In this study, the bioconversion of manure and silage to biogas by an anaerobic digestion process in batch reactors was studied. Biogas is a valuable alternative energy source, mainly in rural areas. The main aim for the environment is to use biogas as a fuel instead of crude oil or natural gas. In this study, two different parameters were studied to observe the changes in methane productivity. The first three reactors were shaken once per week and the following three reactors were shaken 5 times per week. The results showed that mixing has no major effect on the methane production yield. In the second six reactors a mixture of 1% and 3% silage was added and the results were recorded. When the data from the reactors with just manure was compared to the reactors with 1% and 3% silage, it was seen that the silage increased the production rate and total gas produced. The process stabilization took a long time for digestion with the 3% silage possibly caused by release of too much fatty acids.</p>
84

Ammonia recovery from digested dairy manure as nitrogen fertilizer

Jiang, Anping. January 2009 (has links) (PDF)
Thesis (Ph. D.)--Washington State University, December 2009. / Title from PDF title page (viewed on Feb. 19, 2010). "Department of Biological Systems Engineering." Includes bibliographical references.
85

Mitigating Gas Emissions from Liquid Manure Storage Systems: Management Practices, Measurements and Modeling

Wood, Jeffrey 24 April 2013 (has links)
Livestock agriculture is a source of methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions. A comprehensive approach aimed at mitigating these emissions is needed to reduce the environmental footprint of agriculture. This thesis examined three aspects of a comprehensive mitigation strategy which included: evaluating a management consideration, improving flux measurement techniques, and modeling emissions. The relationships between total solids (TS), gas emissions and surface crust dynamics were assessed. Diurnal and long–term CH4 and N2O flux variations were examined in the context of improving discrete sampling protocols. Finally, a mechanistic model that predicts CH4 emissions from manure slurries was evaluated. Over long–term storage, the crusts were not effective in mitigating total gas emissions because the slurries remained open to the atmosphere for a significant portion of the time. Total CH4 and NH3 emissions were related linearly to TS, while N2O exhibited a sigmoid response. The linear response to TS observed for CH4 and NH3 occurred despite varying crust conditions suggesting that the availability of substrates in slurries is the more important regulator of emissions over long–term storage. Diurnal CH4 and N2O flux variations were linked with the diurnal surface temperature (T0) cycle, with the strength of the relationship depending on surface crust conditions. An assessment of discrete sampling protocols revealed that sampling intervals should be ≤7 d. In terms of the timing, it is best to sample these gases when the T0 is closest to the daily mean, which would typically be before 0900 h or after 1700 h. A mechanistic model of CH4 emissions from slurries was evaluated. The model was most accurate during the first 47 d of storage, after which the accuracy decreased. However, total emissions estimated over 145 d were within –21.1 to 6.0% of measured emissions for slurries with TS 3.2%, 5.8% and 8.2%. Emissions were also modeled using the USEPA inventory method. There was relatively good agreement between the USEPA and mechanistic models, with relative percent differences ranging from 19.9 to 37.3%, which is encouraging from the standpoint of advancing greenhouse gas inventory methods. / Ontario Graduate Scholarship
86

An investigation of sainfoin condensed tannin dynamics in manured perennial forage production

Kazuk, Robert William 18 January 2011 (has links)
Condensed tannins (CT) play an integral role in terrestrial nutrient cycling. Despite being the fourth most abundant terrestrial biochemical product, the regulatory processes of tannin production in plants and their subsequent ecological influences are not completely understood. The defining characteristic of CT’s is their affinity for proteins, though they willingly interact with minerals, carbohydrates, and other polyphenolic compounds. Previous tannin investigations in agriculture have centred on bioactivity related to ruminant digestive physiology and pathology. These studies have revealed that CT’s have the potential to increase liveweight gain, wool production, and sheep ovulation rates, prevent pasture bloat, reduce enteric and stockpiled manure greenhouse gas (GHG) emissions, and control gastrointestinal parasites. The present study has explored how tannin-containing resident plant material and applied manure derived from tannin-containing beef cattle diets influences tame forage biomass yield, proximate analysis, and tannin production, as well as residual fall soil nutrient status, in southern Manitoba. To test these hypotheses, we conducted an experiment over two growing seasons (2007-2008) where in the fall of 2007, both tannin-derived (sainfoin, Onobrychis viciifolia) and non-tannin (alfalfa, Medicago sativa) composted beef manures were applied at a rate of 44.8 t/ha in a randomized split plot fashion, including a manure-free control, on a four repetition randomized complete block design which included both tannin-containing and non-tannin containing forage monocultures and mixtures. Plant samples were harvested in two cuts, and soil measurements were taken in the fall of both years. It was found that across all sainfoin treatments, manure origin did not have a significant effect on plant CT concentration, which was extremely variable within treatments and cuts. Over four harvest dates, sainfoin CT concentrations ranged from 14.1 g/kg to 91.9 g/kg in monoculture plots, and 16.6 g/kg to 123 g/kg when grown in a mixture with meadow brome. In most cases, the presence of either manure type did not significantly affect soil nutrient status or forage yield, though results were similarly variable. Using a stepwise regression which included all soil and plant measurements across all cuts and treatments, it was found that NDF (R2 = 0.548) and plant phosphorus (R2 = 0.126) were the only significant model contributors to tannin concentration in sainfoin at P < 0.15. These findings suggest that nutrient effects of beef cattle manure are not realized in either plant or soil in the year following application, and consequently, that tannin agronomy requires longer-term analysis.
87

The application of thermophilic anaerobic digestion in the degradation of poultry waste

Wetzel, Sharon January 2001 (has links)
No description available.
88

Bacterial community ecology and fate in integrated livestock production systems

Hamm, Ainsley 28 July 2014 (has links)
The application of animal manure as a fertilizer source is a common practice in Western Canada. Manure acts as an organic amendment, while providing an economic means of restoring soil nutrients imperative to plant growth. This being said, manure is also microbiologically active, capable of introducing new bacteria into the soil and groundwater environments. The development of high-throughput molecular techniques has provided a means of characterizing the bacterial communities of animal manures, and ecosystems affected by their presence. This study examined the impact of pig slurry amendments on the bacterial communities of soil, groundwater, and the hindgut of grazing cattle over the growing season using three common molecular methods (Terminal-restriction fragment length polymorphism (T-RFLP), Sanger sequencing, and pyrosequencing). T-RFLP results show that sample occasion had more of an impact on the bacterial communities in cattle, soil and groundwater than slurry application. T-RFLP, Sanger sequencing and pyrosequencing characterized the pig slurry as being dominated by Firmicutes, specifically Clostridium spp. Sanger sequencing confirmed that very few classified genera present in the pig slurry were common to the three other environments. Pyrosequencing provided a more in-depth characterization of soil and groundwater over the growing season following the application of slurry. Firmicutes were again dominant in the pig slurry, and were comprised mainly of Clostridium spp. Slurry treated soils had greater relative abundance of Firmicutes, specifically Clostridium spp., compared to unamended soil. Pyrosequencing identified only one groundwater sequence out of 13,578 sequences that was common to the pig slurry, which indicates very little transfer from slurry to groundwater. Pyrosequencing was then performed on an annual cropping system to compare the impact of manures (solid dairy, and solid pig), and synthetic N on the bacterial community of soil in the short- (within a growing season) and medium-term (after three successive years). Solid pig manure treatments revealed greater diversity compared to synthetic and control treatments and diversity was also higher at post-harvest than post-planting. Bacterial communities between treatments were distinct in the short-term but returned to their original structure by the end of the growing season indicating a resilient soil bacterial community.
89

Energy analysis of farm-based biogas plants in Sweden / Energianalys av gårdsbaserade biogasanläggningar i Sverige

Parmlind, Erik January 2014 (has links)
It is projected that energy demand worldwide will double from 2009 until 2050. There is a demand for additional clean renewable energy, which can be supplied by biogas. Farm-based biogas plants exist in small numbers in Sweden; for the benefit of society it important to increase their numbers throughout the country. The aim of this report is to create the tools to allow for a competent evaluation of newly built farm-based biogas plants from an energy efficiency and environmental perspective. In this thesis data from newly built plants has been analyzed to determine mistakes that could be avoided in future expansion. Research has been performed within the bounds of a SLF financed project focusing on the role of cooperation in achieving profitability and environmental benefits in farm based biogas plants. The thesis has found that the investment cost during the technical lifetime of the plant is 11-16 kWh/MWh and 2.65 – 3.65 kg CO2-eq. per MWh. The initial investment is repaid by a factor of at least 50 during the technical lifetime of the plant. Energy ratios have been calculated for two of the plants that express the usable energy produced from each. It has been found that 29 % of Högryd’s 2 GWh in energy production becomes usable electricity and heat; at Lövsta 62 % of its 10 GWh became usable electricity and heat. A larger biogas plant benefits from a higher electrical efficiency, however, the impact of the heat utilization is significant. Replacement of 120 MWh of oil and electricity reduces the import of fossil-fuels more than 1.5 GWh of wood chips.
90

An investigation of sainfoin condensed tannin dynamics in manured perennial forage production

Kazuk, Robert William 18 January 2011 (has links)
Condensed tannins (CT) play an integral role in terrestrial nutrient cycling. Despite being the fourth most abundant terrestrial biochemical product, the regulatory processes of tannin production in plants and their subsequent ecological influences are not completely understood. The defining characteristic of CT’s is their affinity for proteins, though they willingly interact with minerals, carbohydrates, and other polyphenolic compounds. Previous tannin investigations in agriculture have centred on bioactivity related to ruminant digestive physiology and pathology. These studies have revealed that CT’s have the potential to increase liveweight gain, wool production, and sheep ovulation rates, prevent pasture bloat, reduce enteric and stockpiled manure greenhouse gas (GHG) emissions, and control gastrointestinal parasites. The present study has explored how tannin-containing resident plant material and applied manure derived from tannin-containing beef cattle diets influences tame forage biomass yield, proximate analysis, and tannin production, as well as residual fall soil nutrient status, in southern Manitoba. To test these hypotheses, we conducted an experiment over two growing seasons (2007-2008) where in the fall of 2007, both tannin-derived (sainfoin, Onobrychis viciifolia) and non-tannin (alfalfa, Medicago sativa) composted beef manures were applied at a rate of 44.8 t/ha in a randomized split plot fashion, including a manure-free control, on a four repetition randomized complete block design which included both tannin-containing and non-tannin containing forage monocultures and mixtures. Plant samples were harvested in two cuts, and soil measurements were taken in the fall of both years. It was found that across all sainfoin treatments, manure origin did not have a significant effect on plant CT concentration, which was extremely variable within treatments and cuts. Over four harvest dates, sainfoin CT concentrations ranged from 14.1 g/kg to 91.9 g/kg in monoculture plots, and 16.6 g/kg to 123 g/kg when grown in a mixture with meadow brome. In most cases, the presence of either manure type did not significantly affect soil nutrient status or forage yield, though results were similarly variable. Using a stepwise regression which included all soil and plant measurements across all cuts and treatments, it was found that NDF (R2 = 0.548) and plant phosphorus (R2 = 0.126) were the only significant model contributors to tannin concentration in sainfoin at P < 0.15. These findings suggest that nutrient effects of beef cattle manure are not realized in either plant or soil in the year following application, and consequently, that tannin agronomy requires longer-term analysis.

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