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A study was initiated in 1989 to examine the effects of applying excess liquid hog manure with mineral fertilizers to corn and forage crops. Manure was applied yearly at twice the recommended level either in the spring, fall or a combination of both spring and fall applications. Mineral fertilizers were applied at recommended levels to plots receiving only mineral fertilizers and to manure treatment plots. Two control plots received no fertilizers. / During the summer of 1999, soil samples were taken at a depth of 0--2 cm and analysed using different phosphorus extractants. Six runoff events were sampled and analysed for different phosphorus fractions. / Strong correlations were found in corn plots between average dissolved reactive phosphorus concentrations in runoff and soil test phosphorus concentrations. Timing of manure application had a significant impact on both soil and runoff phosphorus concentrations. Runoff from forage plots had significantly higher concentrations of dissolved phosphorus, but phosphorus loads were greater from corn plots due to higher runoff volumes. Corn plots released significantly higher particulate phosphorus concentrations than forage plots because of higher sediment loads in runoff from corn plots.

A study was conducted to test the effects that different high fibre sources and their varying inclusion levels had on the characteristics of the excreta (faeces, urine and the slurry), and on odour from the slurry of growing pigs. Faeces and urine characteristics were tested from 52 pigs fed rations containing grass hay (GH), lucerne hay (LH), maize cobs (MC), maize stover (MS) and sunflower husk (SH) diets at inclusion levels up to 400 g/kg as fed basis. Faecal output, faecal consistency and nitrogen were influenced by fibre type (P <0.01) and inclusion level (P <0.01). Nitrogen content in faeces and urine was also affected by dietary fibre inclusion. Increasing fibre inclusion levelled to a reduction in urinary nitrogen content, indicating nitrogen repartitioning from urine to faeces, thereby minimizing nitrogen volatilization. The slurry from pigs fed on LH, MC and SH at levels up to 160 g/kg was tested for chemical composition and odour offensiveness. The slurry was incubated for 16 days. The pH and nitrogen content varied among fibre types and incubation period (P <0.05). Isobutyrate and butyrate concentrations varied with fibre type and the incubation period tested (P <0.01). Using panellists, the SH containing rations resulted in low odour offensiveness score. Maize cob-containing diets resulted in the largest odour scores, with (mean rank of 2.2 and 4.3 for SH and MC, respectively). To reduce odour offensiveness from piggeries, sunflower husk was recommended as an alternative feed ingredient for growing pigs. / Thesis (M.Sc.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

Agricultural systems are known to emit nitrous oxide (N2O)---a potent greenhouse gas. The roving flux tower measuring system of Agriculture and Agri-Food Canada was used to make continuous measurements of N2O fluxes in an edible pea field in Western Quebec in 2003-04 and then in an alfalfa-timothy forage field in Eastern Ontario in 2004-05. The experiment was designed to capture, at the field scale, the expected large N2O emissions occurring as a result of fertilizer application for a year, in relation to both large precipitation events and spring thaw. / Growing season N2O emissions averaged 0.5 to 5 mg N2 O-N m-2 d-1 with peaks following snow melt (between 5 and 8 mg N2O-N m-2 d-1) and manure applications (8 to 37 mg N2O-N m-2 d -1). Although generally small (&lt;0.25 mg N2O-N m -2 d-1), emissions were detectable during the fall and winter, indicating the importance of including them in annual emission totals. / The measurements were used to verify the performance of the simulation model DNDC (DeNitrification-DeComposition) in estimating N2O emissions from legumes and in response to dairy manure application. Sensitivity tests were also carried out in which baseline input values were modified. Results suggest that the current model version (DNDC8.9) requires further modification prior to application for estimating greenhouse gas emissions in national accounting systems.

Made available in DSpace on 2014-06-11T19:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-05-06Bitstream added on 2014-06-13T20:45:16Z : No. of bitstreams: 1 silva_aa_dr_jabo.pdf: 637049 bytes, checksum: 5ae6ccd522ca36efab6ebab2ca5ea62e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Sansuy S.A. Industria de Plasticos / Universidade Federal de Uberlandia / A necessidade de ampliação de atitudes que levam o meio rural a buscar a sustentabilidade e a implantação do uso da biodigestão anaeróbia tem sido incentivada por se tratar de um mecanismo de desenvolvimento limpo que alia a importância do tratamento dos resíduos agropecuários (dejetos), geração de energia (biogás) e biofertilizante. Desenvolveu-se um estudo em que se focou a hipótese que a implantação de sistema de tratamento de dejetos, com o uso de biodigestor anaeróbio e o aproveitamento dos seus produtos, o biofertilizante, poderia substituir a adubação mineral nitrogenada de cobertura no cultivo de forrageiras e que essa prática poderia reduzir o custo de adubação e promover ganhos adicionais com a geração de energia elétrica e ganhos ambientais, com a redução de emissão de metano e produção do biogás. Utilizou-se como ferramenta para embasar a hipótese três cultivos de forrageira, um de sorgo e dois de milho. Observou-se que a aplicação de biofertilizante e composto bovino não promoveram aumentos significativos na produtividade das culturas. Paralelamente desenvolveu-se a implantação de um biodigestor de manta de PVC flexível que serviu de parâmetros para a simulação da viabilidade econômica de um sistema de criação de bovino para 100 vacas leiteiras e um sistema de criação de suínos de ciclo completo para 500 matrizes. Conclui-se que projetos que contemplam o princípio da interdisciplinaridade podem auxiliar de maneira mais efetiva na tomada de decisão de implantação de soluções ambientalmente corretas que podem ser também economicamente viáveis. / Because of the need for expansion of attitudes that lead to rural areas to seek sustainability. The introduction of the use of anaerobic digestion has been encouraged by the case of a clean development mechanism that combines the importance of processing of agricultural waste (manure), generation of energy (biogas) and biofertilizer. Has developed a study that focused on the hypothesis that the deployment system for the treatment of waste using anaerobic biodigest and use products, the biofertilizer, could replace mineral nitrogen fertilization in coverage the cultivation of fodder and that this practice could reduce the cost of fertilizer and promote additional gains in the generation of electric energy and environmental gains, such as reducing the emission of methane. It was used as a tool for the hypothesis based three of forage crops, one the sorghum and two maize. It was observed that the application of biofertilizer and compost cattle did not promote significant increases in productivity of crops. Developed in parallel to implement a blanket biodigest of flexible PVC that served as parameters for the simulation of the economic viability of a system for creating and veal to 100 dairy cows and a pig breeding cycle of full matrix for 500. It is concluded that projects that include the principle of interdisciplinarity can assist more effectively in decision making for the deployment of environmentally correct solutions that can be economically viable.

Made available in DSpace on 2016-12-08T15:50:04Z (GMT). No. of bitstreams: 1 PGMS14DA020.pdf: 1241701 bytes, checksum: 696adecfb227383e0ee8edb226ce8b1e (MD5) Previous issue date: 2014-01-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Practices of soil management and use of animal manure as a source of fertilizer affect emissions of greenhouse gases (GHG), which contribute to global warming. The main greenhouse gases produced in agriculture, in addition to carbon dioxide, are nitrous oxide (N2O) and methane (CH4), being issued mainly by the use of animal manure and rice cultivation, respectively. Therefore, three studies were conducted to evaluate the effect of management practices on emissions of N2O and CH4. In study I, the soil was a Humic Dystrudept and the effect of conventional tillage (CT) and no tillage (NT) with and without the application of liquid swine manure systems (DLS) was evaluated. In study II, under the same soil type, the effect of addition of nitrification inhibitor dicyandiamide (DCD) to liquid swine manure (DLS) on the mitigation of greenhouse gases was evaluated. In study III, the soil was a Typic Albaqualf, the effect of continuous and intermittent flooding systems in emissions of CH4 and N2O emissions during the rice cultivation systems were evaluated. Air samples were collected in static chambers and concentration of N2O and CH4 determined by gas chromatography. Approximately 2/3 of the annual N2O emission occurred during the first 90 days after application of DLS. At the end of about a year, the emission factor for N2O in treatments with and without the application of DLS ranged 1-5% of the N applied. The N2O emissions were controlled mainly by the availability of nitrate, total soil porosity filled with water, soil temperature and microbial activity (CO2 flux). The use of DCD with manure reduced approximately 60% of cumulative N2O emissions from NT. The soil revolving on CT may have reduced the efficiency of the inhibitor on N2O emissions, suggesting the need for increased dose of DCD in this soil management. The DCD, delays the onset of nitrate in the soil after application of DLS, reducing N losses and pollution potential of manure. On the Study III, it was found that intermittent irrigation with 60% saturated soil reduced emissions of CH4 about 90% compared to continuous flooding. This system can represent a promising practice in mitigating N2O and CH4 emissions without reducing productivity in rice / Práticas de manejo do solo e utilização de dejetos animais como fonte de fertilizantes afetam as emissões de gases de efeito estufa (GEE), as quais agravam o aquecimento global. Os principais gases de efeito estufa produzidos na agricultura, além do gás carbônico, são o óxido nitroso (N2O) e metano (CH4), sendo emitidos principalmente pela utilização de dejetos animais e no cultivo do arroz irrigado, respectivamente. Diante disso, três estudos foram conduzidos com o objetivo de avaliar o efeito de práticas de manejo nas emissões de N2O e CH4. No estudo I, em um Cambissolo Húmico, avaliou-se o efeito dos sistemas de preparo convencional (PC) e plantio direto (PD) com e sem a aplicação de dejeto líquido de suínos (DLS). No estudo II, em um Cambissolo Húmico, foi avaliado o efeito da adição do inibidor de nitrificação dicianodiamida (DCD) a dejetos suínos na mitigação dos gases. No estudo III, em um Planossolo Háplico, foi avaliado o efeito dos sistemas de alagamento contínuo e intermitente nas emissões de CH4 e N2O durante o cultivo de arroz. Amostras de ar foram coletadas em câmaras estáticas e a concentração de N2O e CH4 foi determinada por cromatografia gasosa. Aproximadamente 2/3 da emissão anual de N2O ocorreu durante os primeiros 90 dias após a aplicação do DLS. Ao final de aproximadamente um ano o fator de emissão de N2O nos tratamentos com e sem a aplicação de DLS variou de 1 a 5% do N aplicado. As emissões de N2O foram controladas principalmente pela disponibilidade de nitrato, porosidade total do solo preenchida por água, temperatura do solo e atividade microbiana (fluxo de CO2). A utilização de DCD junto aos dejetos reduziu aproximadamente 60% das emissões acumuladas de N2O no PD. O 10 revolvimento do solo no PC pode ter reduzido a eficiência do inibidor nas emissões de N2O, sugerindo a necessidade de maior dose de DCD neste sistema de manejo do solo. A DCD, ao retardar o aparecimento de nitrato no solo após a aplicação de DLS, reduz as perdas de N e o potencial poluidor dos dejetos. Com relação ao estudo III, verificou-se que o sistema de irrigação intermitente com 60% de saturação do solo reduziu as emissões de CH4 em cerca de 90% em relação ao sistema de alagamento contínuo. Esse sistema pode ser uma prática promissora na mitigação das emissões de N2O e CH4, sem redução de produtividade na cultura do arroz

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Call number: LD2668 .T4 1984 M37 / Master of Science

Doctor of Philosophy / Department of Entomology / Ludek Zurek / The larval stages of Culicoides sonorensis Wirth and Jones, a confirmed vector of bluetongue and epizootic hemorrhagic disease viruses affecting ruminants in North America, have been observed to occur typically in animal waste enhanced muds. In this dissertation, I studied the larval development (first instar to adult stage) and oviposition (four-choice assays) of C. sonorensis on sterilized mud (autoclaved) enriched with manure of different farm animal species (dairy cattle, beef cattle, sheep, goats, pigs, horses, white-tailed deer, and chicken). In addition, to determine why only some manure-polluted sites are colonized by C. sonorensis even when they are in close proximity to each other, I examined the moisture levels and microbial concentrations (mud) and physicochemical characteristics (standing water) of a manure-overflow pond site producing C. sonorensis and compared them to nearby cattle stock pond site(s) that produced different Culicoides species. Finally, as the first step in examining the role of microbiome in various physiological functions of C. sonorensis and other suspected/potential vector Culicoides species, I assessed the bacterial communities in field-collected adult females of C. sonorensis, C. crepuscularis, C. haematopotus, and C. stellifer (Illumina sequencing of 16S rRNA gene). In larval development experiments, the proportion of adults emerged and development time to adult stage varied with manure type and its concentration present in the substrate. Mud supplemented with chicken manure did not support C. sonorensis development, mud enriched with white-tailed deer manure poorly supported midge development, while C. sonorensis development in mud enhanced with manure of sheep, goats, beef cattle, dairy cattle, pigs, and horses varied. In oviposition experiments, colonized females preferred to deposit eggs on substrates without animal manure over substrates with animal manure. In subsequent studies, the manure-overflow pond site that produced mainly C. sonorensis contained significantly higher total aerobic culturable bacteria, pH, salinity, total dissolved solids, and conductivity levels than cattle stock pond sites that produced different Culicoides species. Finally, bacterial composition of field-collected C. sonorensis adult females comprised mainly of the phyla Proteobacteria and Firmicutes, while the majority of bacterial taxa identified from C. crepuscularis, C. haematopotus, and C. stellifer belonged to Proteobacteria. An unidentified bacterial genus (related to Tumebacillus), Propionibacterium, and Curvibacter were detected commonly across all four midge species. These results suggest that manure of several farm animal species can contribute to C. sonorensis development in the field. However, oviposition preferences remain uncertain, as colonized females appeared to show aversion to animal manure, which is in contradiction to the typical presence of C. sonorensis larvae in animal waste enhanced muds. Nonetheless, variations in microbial and/or physicochemical conditions in the larval habitats likely play a role in the differential emergence of C. sonorensis from various manure-polluted sites. Moreover, some bacterial taxa are associated commonly with C. sonorensis and other suspected/potential vector Culicoides species. Future studies are needed to examine oviposition preferences of field-collected females, life history traits of adults emerging from various manure-enriched substrates, developmental requirements of larvae, and the role of microbiome in various physiological functions of the host including vector competence for orbiviruses.