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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.
171

AVALIAÇÃO DA CICLAGEM DE NUTRIENTES EM SISTEMAS INTEGRADOS DE PRODUÇÃO AGROPECUÁRIA NO SUBTRÓPICO BRASILEIRO

Oliveira, Flavia de 31 August 2018 (has links)
Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-11-20T18:16:09Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Flavia de Oliveira.pdf: 1587499 bytes, checksum: 2fb58a43f13e11f2b66666d67ce47b88 (MD5) / Made available in DSpace on 2018-11-20T18:16:09Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Flavia de Oliveira.pdf: 1587499 bytes, checksum: 2fb58a43f13e11f2b66666d67ce47b88 (MD5) Previous issue date: 2018-08-31 / Sistemas integrados de produção agropecuária (SIPA) integram em um mesmo espaço vários componentes, tais como lavoura, pastagens, animais, bem como árvores de forma sinérgica. Quando bem manejado, pode trazer a sustentabilidade para a propriedade. Um dos desafios em tais sistemas é o entendimento da dinâmica de nutrientes e o possível reaproveitamento destes pela cultura sucessora. O objetivo deste trabalho foi avaliar o aporte de liteira e dos macronutrientes, como nitrogênio (N), fósforo (P), potássio (K) e enxofre (S) em SIPA, com ausência e presença de árvores (~159 árvores ha-1), submetidos a doses de nitrogênio (90 e 180 kg N ha-1, N90 e N180, respectivamente) na fase pastagem. O experimento foi conduzido no Instituto Agronômico do Paraná, município de Ponta Grossa, Paraná. O delineamento experimental utilizado foi o de blocos ao acaso com quatro tratamentos e três repetições. De modo a melhor representar o ambiente arborizado, foi feita a subdivisão da unidade experimental em três posições entre linha das árvores. O experimento iniciou em 2006, com o plantio de árvores em arranjo de 14 x 3m. Durante o inverno cultiva-se aveia preta e azevém, pastejada por bovinos de corte, e, durante o verão, soja/milho. O presente experimento iniciou na fase pastagem de 2013, a qual antecedeu a cultura do milho (safra 2013/2014), estendendo-se até a fase pastagem no inverno de 2014. Durante a lavoura de milho e pastagem (2014), foram inseridos litter bags com os resíduos da cultura anterior, no momento das suas respectivas semeaduras. Aos 8, 15, 30, 60, 90, 120, 153 e 165 dias após a semeadura do milho e da pastagem foram coletadas as amostras dos litter bags, pesadas suas respectivas massas secas (MS) e quantificados os macronutrientes. Também foram calculadas as taxas de decomposição do resíduo e da liberação de macronutrientes. Em geral, a quantidade inicial de resíduo, tanto da pastagem como do milho, foi inferior nos tratamentos com árvores (-28%). Diferenças significativas foram observadas entre os tratamentos nos teores iniciais em N (variando de 12 no ILPF N90 até 14 g/kg no ILPF N180) do resíduo da pastagem e para os teores iniciais de K (variando entre 6,5 no ILP N90 até 12 g/kg no ILPF N90) e S (variando de 0,68 ILPF N90 até 0,91g/kg ILP N90) no resíduo do milho. As posições entre as linhas das árvores afetaram apenas os teores iniciais de N e S dos resíduos. Em relação a dinâmica de decomposição dos resíduos e liberação de macronutrientes, diferenças significativas entre os tratamentos foram observadas somente para decomposição do resíduo da pastagem e liberação de P do mesmo. A fração ativa da MS da pastagem variou entre 44 (ILPF N90) a 59 % (ILP N180). O tempo de meia vida (T1/2) variou entre 11 (ILP N90) e 54 (ILPF N180) dias para MS e entre 6 (ILP N90) e 21 (ILPF N90) dias para o P. O T1/2 do N foi de 19 dias, enquanto que para K e S foi de 13 dias. Em relação ao resíduo do milho, o T1/2 variou entre 5 (no caso de N) e 24 (no caso de P) dias. No mínimo 44% do resíduo proveniente da pastagem foi decomposto ao longo dos 165 dias de exposição à campo dos litter bags. Em relação ao resíduo do milho, 30% foi decomposto ao longo de 90 dias, independente do tratamento. Máximas liberações (37; 2,8; 62 e 2,5 kg/há de N, P, K e S, respectivamente) de nutrientes foram observadas no ILP N180 para o resíduo da pastagem, principalmente em função da maior quantidade de resíduo inicial neste tratamento. Para o resíduo do milho, máximas liberações ocorreram no ILP N90 para N (48 kg/ha), P (17,4 kg/ha) e S (4,8 kg/ha), em função da maior quantidade de resíduo inicial neste tratamento, e no ILPF N90 para K (82 kg/ha), em função do maior teor inicial em K. Portanto, tais quantidades cicladas devem ser consideradas no manejo da fertilização. Desbastes precisam ser intensificados no ILPF para reduzir o nível de sombreamento e evitar grandes reduções nas quantidades de resíduo, para otimizar os benefícios da ciclagem de nutrientes. / Integrated Crop Livestock Systems (ICLS) comprehend in a same space several components, such as grain and forages crops, animals and tree component of synergistic form. When well managed, it can bring sustainability to the property. One of the challenges in such systems is the understanding of the nutrient dynamics and the possible reutilization of these by the successor culture. The objective of this study was to evaluate the contribution of litter and macronutrients, such as nitrogen (N), phosphorus (P), potassium (K) and sulfur (S) in ICLS, with absence and presence of trees ), submitted to nitrogen doses (90 and 180 kg N ha-1, N90 and N180, respectively) in the pasture phase. The experiment was carried out at the Agronomic Institute of Paraná, municipality of Ponta Grossa, Paraná. The experimental design was a randomized block design with four treatments (ILP N90, ILP N180, ILPF N90 and ILPF N180, being ILP, integration of livestock and ILPF, integration of livestock and forest) and three replications. In order to better represents the wooded environment, the experimental unit was subdivided into three positions (1m, 3.5m and 7m distance from the tree line). The experiment began in 2006 with the planting of trees in arrangement of 14 x 3m. During winter, black oats and ryegrass are grazed by beef cattle and, in the summer, soybean/corn. The present experiment started in the pasture phase of 2013, which preceded the corn crop (crop 2013/2014), extending until the pasture stage in the winter of 2014. During maize and pasture (2014), litter bags were inserted with the residues from the previous crop, at the time of their respective sowing. The samples were collected at 8, 15, 30, 60, 90, 120, 153, and 165 days after sowing of maize and pasture. The samples were performed to dry masses (DM) measure and macronutrients determination. The rates of decomposition of the residue and the release of macronutrients were also calculated. Overall, the initial amount of residue from both pasture and maize was lower in tree treatments (-28%). Differences were observed between treatments at initial N contents (ranging from 12 in ILPF N90 to 14 g / kg in ILPF N180) of the pasture residue and for the initial K contents (ranging from 6.5 in ILP N90 to 12 g / kg in ILPF N90) and S (ranging from 0.68 ILPF N90 to 0.91 g / kg ILP N90) in the corn residue. The positions between the tree lines affected only the initial N and S contents of the residues. In relation to the dynamics of the decomposition of the residues and the release of macronutrients, significant differences between the treatments were observed only for the decomposition of the pasture residue and the release of P from the same. The active fraction of DM from pasture ranged from 44 (ILPF N90) to 59% (ILP N180). The half-life time (T1/2) varied between 11 (ILP N90) and 54 (ILPF N180) days for MS and between 6 (ILP N90) and 21 (ILPF N90) days for P. O T1/2 of N was 19 days, whereas for K and S it was 13 days. In relation to maize residue, T1/2 ranged from 5 (in the case of N) to 24 (in the case of P) days. At least 44% of the pasture residue was decomposed during the 165 days of exposure to litter bags. Regarding corn residue, 30% was decomposed over 90 days, regardless of the treatment. The maximum nutrient release (37, 2.8, 62 and 2.5 kg/ha of N, P, K and S respectively) was observed in the ILP N180 for the pasture residue, mainly due to the higher amount of initial residue in this treatment. For the maize residue, maximum releases occurred in ILP N90 for N (48 kg/ha), P (17.4 kg/ha) and S (4.8 kg / ha), due to the higher amount of initial residue in this treatment, and in ILPF N90 for K (82 kg / ha), as a function of the higher starting content in K. Therefore, such cycled quantities should be considered in the management of fertilization. Slabs need to be intensified in the ILPF to reduce the level of shading and avoid large reductions in residue amounts to optimize the benefits of nutrient cycling.
172

Relations biodiversité-fonctionnement dans le contexte du changement climatique : application à la décomposition des litières en région méditerranéenne

Santonja, Mathieu 08 December 2014 (has links)
L'objectif de cette thèse est d'étudier le processus de décomposition des litières en région méditerranéenne et comment ce processus pouvait être affecté par le changement climatique. Dans un premier temps, nous avons abordé le rôle de la qualité et de la diversité des litières sur le processus de décomposition dans deux écosystèmes typiques de la région méditerranéenne française : la forêt à chêne et la garrigue à chêne kermès. Dans un second temps, nous avons étudié l'impact du changement climatique (via un stress hydrique aggravé) sur le processus de décomposition.Nous avons montré des effets de la diversité des litières sur le processus de décomposition et sur la structure des communautés d'organismes décomposeurs. Dans la forêt, les espèces compagnes de Q. pubescens favorisent la diversité et l'abondance des communautés d'organismes décomposeurs ainsi qu'un processus de décomposition plus efficace. A l'opposé, dans la garrigue, c'est l'espèce structurante qui favorise la décomposition et les décomposeurs.En ce qui concerne l'évolution de la relation diversité des litières - processus de décomposition dans un contexte de changement climatique, on observe une forte diminution des interactions synergiques en forêt (excepté à forte diversité végétale), alors qu'à l'opposé, cela entraine, en garrigue, une meilleure complémentarité entre les espèces avec une forte augmentation des effets synergiques.Mes résultats suggèrent que la diversité des communautés végétales joue un rôle important sur le processus de décomposition et mettent en avant que le maintien de cette diversité semble nécessaire dans un contexte de changement climatique. / L'objectif de cette thèse est d'étudier le processus de décomposition des litières en région méditerranéenne et comment ce processus pouvait être affecté par le changement climatique. Dans un premier temps, nous avons abordé le rôle de la qualité et de la diversité des litières sur le processus de décomposition dans deux écosystèmes typiques de la région méditerranéenne française : la forêt à chêne et la garrigue à chêne kermès. Dans un second temps, nous avons étudié l'impact du changement climatique (via un stress hydrique aggravé) sur le processus de décomposition.Nous avons montré des effets de la diversité des litières sur le processus de décomposition et sur la structure des communautés d'organismes décomposeurs. Dans la forêt, les espèces compagnes de Q. pubescens favorisent la diversité et l'abondance des communautés d'organismes décomposeurs ainsi qu'un processus de décomposition plus efficace. A l'opposé, dans la garrigue, c'est l'espèce structurante qui favorise la décomposition et les décomposeurs.En ce qui concerne l'évolution de la relation diversité des litières - processus de décomposition dans un contexte de changement climatique, on observe une forte diminution des interactions synergiques en forêt (excepté à forte diversité végétale), alors qu'à l'opposé, cela entraine, en garrigue, une meilleure complémentarité entre les espèces avec une forte augmentation des effets synergiques.Mes résultats suggèrent que la diversité des communautés végétales joue un rôle important sur le processus de décomposition et mettent en avant que le maintien de cette diversité semble nécessaire dans un contexte de changement climatique.
173

Ecophysiology and ecosystem-level impacts of an invasive C4 perennial grass, Bothriochloa ischaemum

Basham, Tamara Sue 11 February 2014 (has links)
The anthropogenic introduction of species into new ecosystems is a global phenomenon, and identifying the mechanisms by which some introduced species become dominant in their introduced ranges (i.e., invasive) is crucial to predicting, preventing, and mitigating the impacts of biological invasions. Introduced perennial C₄ grasses are invading semi-arid grassland and savanna ecosystems throughout the south-central U.S. We hypothesized that in these semi-arid ecosystems, where variable precipitation patterns strongly influence vegetation dynamics, the success of an invasive plant species may be due in part to ecophysiological traits that enable high performance in response to unpredictable water availability. We also hypothesized that increased primary productivity and decreased plant input quality associated with these grass invasions have the potential to alter ecosystem carbon and nitrogen cycling and storage by altering the ratio of inputs (productivity) to outputs (decomposition/respiration). We tested the first hypothesis by quantifying ecophysiological performance differences between an invasive C₄ grass, Bothriochloa ischaemum, and co-occurring C₃ and C₄ native grasses under wet and dry conditions in the field and under two levels of simulated precipitation frequencies in a greenhouse experiment. We tested the second hypothesis by examining whether increased primary productivity and decreased C₃:C₄ grass ratios in savanna grass-matrices associated with B. ischaemum invasion altered (1) plant input quality and thus nutrient cycling and/or (2) net ecosystem carbon uptake in invaded areas. B. ischaemum's success as an invader was not directly related to its ability to cope with precipitation variability and availability, but its ability to rapidly produce large amounts of biomass may allow it to directly out-compete native species. B. ischaemum invasion decreased plant input quality and soil nitrogen availability. B. ischaemum invasion shifted ecosystem C-uptake from being nearly year-round to occurring predominantly in the summer. Greater C-uptake during the summer and under drier conditions compensated for a shorter growing seasons in B. ischaemum-invaded areas and cumulative annual NEE was similar between invaded and native-dominated areas. We conclude that B. ischaemum's impacts on soil nitrogen availability and plant-canopy microhabitat may allow it to exclude native species from invaded areas, but that its impacts on ecosystem C sequestration may be small. / text
174

Response of needle-litter decomposition and soil nitrogen mineralization to logging-debris manipulation and competing vegetation control in western Oregon and Washington /

Meehan, Nathan Andrew. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 96-107). Also available on the World Wide Web.
175

Analýza stáda a vlivů působících na reprodukční užitkovost prasnic

MUŽÍKOVÁ, Martina January 2017 (has links)
The aim was selected in a commercial breeding (AGRO Vodňany a.s.) to analyze and evaluate herd reproductive performance of sows used for the production of piglets (final hybrids). The analysis was focused on the age structure of the sow, when the first and second litter was 28.8% on the 3rd to 5th litter 23.5% and the sixth and other litters of sows 47.7%.The annual renewal of the herd was culled 22.9% and 25.5% included sows for breeding.This breeding is used natural reproduction, where for the purposes of reproduction bred four boars lines of 48 (White paternity x Pietrain).The average gestation length breeding was 115.2 of days. In 2016, it was born an average of 13.8 piglet per litter, of which 11.5 piglet of live and been preserved was 10.2 piglet per litter.The length of the farrowing interval was 171,1 days and the onset of estrus after weaning piglets was an average of 4.9 days.Weaning is in monitored husbandry carried out between 28 to 31 day age of piglets.Part of this work was to evaluate zoohygiene also at stud and compared with the results of performance farms in the Czech Republic and recommendations for improving the results of husbandry evaluated. When comparing the results of selected indicators identified in Agro Vodňany a.s. with selected data published by the Czech Statistical Office for the South Bohemian Region and the Czech Republic in 2016, it was found that the number of piglets born per sow in the Czech Republic was 30.1 piglets. Piglets was born25.1 in South Bohemia and 24.3piglets was born per sow in Vodňany. The death of piglets from the number of births in the Czech Republic was 10.6% in the South Region accounted for 15.6% and in Vodňany it was 11.9%.The number of surviving piglets per sow in the Czech Republic was 26.9 piglets in South Bohemia have been preserved 21.3 piglet per sow and Vodnany during the reporting period have been preserved 21.4 piglets per sow.
176

Acumulação e decomposição da serapilheira e distribuição de organismos edáficos em área de caatinga na Paraíba, Brasil / Litter accumulation and decomposition and soil biota distribution in a caatinga forest site of Paraíba, Brazil.

Souto, Patrícia Carneiro 30 March 2006 (has links)
Submitted by Katiane Souza (katyane.souza@gmail.com) on 2016-05-12T14:09:26Z No. of bitstreams: 1 arquivototal.pdf: 1764591 bytes, checksum: 8c79fbd17f4301ebf5fb2c42a5a71c72 (MD5) / Made available in DSpace on 2016-05-12T14:09:26Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1764591 bytes, checksum: 8c79fbd17f4301ebf5fb2c42a5a71c72 (MD5) Previous issue date: 2006-03-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Nutrient cycling is fundamental to forest maintenance, and involves the deposition of organic material, its decomposition and nutrient release for reabsorption by superior plants. These processes are regulated by biotic and abiotic factors that determine the environmental sustainability. This study had the objectives to determine the monthly litter production and the time necessary to the accumulated litter to disappear, characterize the process of decomposition, evaluate the microbial activity and the effect of climatic and soil conditions on it, determine the fluctuations of the microorganisms and mesofauna communities in a Caatinga forest site, and, finally, analyze liter quality in order to identify the different phases of the process of organic matter decomposition and nutrient enrichment. Field work was carried out at the RPPN of the Fazenda Tamanduá, located in Santa Terezinha (PB), from October 2003 to September 2004 (period 1 = P1) and from October 2004 to September 2005 (period 2 = P2) in seven transects systematically located in the RPPN area. Litter production were estimated from monthly litter collection from 20 1mx1m collector boxes randomly distributes in the transects. The collected litter was fractioned into leaves, stems, reproductive structures and miscellany, and then dried and weighed. Every three months the deposited litter on the soil was collected from 0,5mx0,5m frames, dried and weighed, to calculate the decomposition factor (K) and the time required to 50 and 95% of litter decomposition. The rate of litter decomposition was estimated in nylon bags with 30g of dried litter. These 480 nylon bags were divided equitably and placed around the 20 collector boxes. Every month, one nylon bag from each collector bag was recovered from the field and the litter inside was taken out, cleaned and weighed to determine its weight loss. Diurnal and nocturnal microbial activity was measured by means of soil respiration. Macronutrients composition of the deposited litter and in the litter inside the nylon bag was determined. Litter production during P1 and P2 was 1290.9 kg ha-1 and 1947.5 kg ha-1, respectively, totaling 3238.5 kg ha-1. Leaf, stem, reproductive structure and miscellany fractions corresponded to 64.14, 23.48, 10.9 and 1.46% of total litter production, respectively. More litter deposition was observed in the beginning of the dry season. The values of the coefficient of litter decomposition were 1.1 and 1.4 for P1 and P2, respectively, and mean a fast nutrient transfer from litter to soil. The time required to 50 and 95% litter decomposition was 229.9 and 996.4 days, respectively, in P1, and 178.8 and 770.1 days, respectively, in P2. Initial litter weight loss in nylon bags was fast due to the degradation of labile composts by microorganisms, and decreased afterward due to the more resistant and more lignified materials of the remaining litter. Fungi population was larger than the bacteria population, favored by soil water availability. Mesofauna was mainly represented by Diptera’s 67.24% of the total number of counted mesofauna individuals or of the total biomass of mesofauna individuals and Acarine’s (53.49%), in P1 and P2, respectively. The low values of Shannon (0.38) and Pielou (0.15) indexes denoted the distribution heterogeneity of the mesofauna representatives. The order of macronutrient concentrations in the accumulated litter was as follow: N > Ca > S > K > Mg > P. Litter P content was higher than the expected for dry tropical forests. / A ciclagem de nutrientes, fundamental para a manutenção das florestas, envolve desde a deposição de material orgânico, sua decomposição e disponibilidade de nutrientes para os vegetais superiores. Todos esse processos são regulados por fatores bióticos e abióticos que determinam a sustentabilidade do ambiente. Este trabalho teve como objetivos determinar a produção mensal de serapilheira e o tempo necessário para o desaparecimento da serapilheira acumulada; caracterizar o processo de decomposição; avaliar a atividade microbiana e a influência das condições edafoclimáticas durante esse processo; conhecer as flutuações das comunidades de microrganismos e da mesofauna do solo em área de caatinga e, por último, analisar a qualidade da serapilheira a fim de identificar as diferentes fases do processo de decomposição e concentração de nutrientes. O trabalho foi desenvolvido na RPPN pertencente à Fazenda Tamanduá, localizada no município de Santa Terezinha (PB), durante dois anos, sendo o período 1 compreendido de outubro/2003 a setembro/2004 e o período 2 compreendido de outubro/2004 a setembro/2005. Foram demarcados sete transectos, onde foram realizadas todas as avaliações. Para a produção da serapilheira, foram distribuídas 20 caixas coletoras de 1m x 1m, sendo mensalmente coletado todo o material precipitado, que foi separado nas seguintes frações: folhas, galhos, estruturas reprodutivas e miscelânea; depois foi seco em estufa e pesado. A cada três meses foi coletada a serapilheira acumulada no solo, utilizando-se uma moldura metálica de 0,50 m x 0,50 m. Todo o material acumulado na moldura foi retirado, seco em estufa e pesado, calculando-se assim o fator de decomposição K e o tempo necessário para decompor 50% e 95% da serapilheira. Na avaliação da taxa de decomposição da serapilheira, utilizou-se sacola de náilon contendo cada uma 30g de serapilheira previamente seca. Próximo de cada caixa coletora foram distribuídas 24 sacolas de náilon contendo serapilheira, totalizando 480 sacolas. Mensalmente foram coletadas 20 sacolas, sendo o material retirado, limpo e pesado para avaliar a perda de peso em relação ao inicial. Paralelamente, avaliou-se no campo, a atividade microbiana, medida pela respiração edáfica, nos turnos diurno e noturno. Determinou-se também a qualidade química da serapilheira depositada e a que foi decomposta nas sacolas de náilon, quanto à concentração dos macronutrientes. A produção de serapilheira durante o período 1 de estudo foi de 1290,95 kg ha-1 e 1947,56 kg ha-1 no período 2, totalizando 3.238,51 kg ha-1, sendo a fração folhas predominante na serapilheira devolvida ao solo com 64,14%, seguida da fração galhos (23,48%), estruturas reprodutivas (10,92%) e miscelânea (1,46%). A maior deposição ocorreu no início da estação seca, caracterizando a sazonalidade. Os coeficientes de decomposição (K) de 1,1 para o período 1 e, 1,4 para o período 2, indicam uma transferência mais rápida dos nutrientes contidos na serapilheira para o solo. O tempo necessário para decompor 50% e 95% da serapilheira foi de 229,9 dias e 996,4 dias, respectivamente, período 1. No período 2, o tempo de meia vida foi de 178,8 e 770,15 dias para decompor 95%.A maior perda de peso da serapilheira acondicionada nas sacolas de náilon ocorreram no início do período de exposição, resultado da degradação dos compostos lábeis pelos microrganismos, sendo a velocidade do processo diminuída ao longo do tempo, devido a permanência das partes mais resistentes e lignificadas da serapilheira. Quanto a microbiota, a maior população foi de fungos, em relação à de bactérias, estimulado, principalmente, pelas condições favoráveis na disponibilidade hídrica do solo. Os grupos predominantes da mesofauna foram Díptera com 67,24% no período 1 e Acarine com 53,49% no período 2. Os baixos valores nos índices de Shannon (0,38) e de Pielou (0,15), indicaram uma baixa uniformidade na distribuição dos indivíduos. Quanto à composição química da serapilheira, a serapilheira depositada apresentou concentração de nutrientes na seguinte ordem: N > Ca > > S > K > Mg > P, sendo os teores de P encontrados na serapilheira considerados elevados para florestas tropicais secas.
177

A decomposição de detritos foliares de espécies nativas e exótica e a colonização de macroinvertebrados em um riacho tropical localizado na Floresta Nacional de Ipanema, SP, Brasil / The leaf litter decomposition in native and exotic species and the macro invertebrate colonization in a tropical river placed in the Floresta Nacional de Ipanema, SP, Brazil

Heidi Marcela Suarez Robayo 01 July 2016 (has links)
As matas riparias tem efeitos positivos sobre a qualidade da água em rios de baixa ordem. O cultivo e a substituição de plantas de espécies nativas por espécies exóticas, tem efeitos e impactos significativos na biodiversidade de ambientes aquáticos e terrestre. O cultivo de Eucalyptus ocupam áreas de importância biológica e ambiental, causando impactos que ainda são pouco estudados, interferindo no funcionamento dos cursos de água que são dependentes do material foliar disponível nas margens dos rios como fonte de energia e nutrientes. O presente trabalho comparou a decomposição de folhas de espécies nativas (Inga marginata e Matayba elaeagnoides) e folhas de uma espécie exótica (Eucalyptus grandis) durante as estações seca e chuvosa, num riacho localizado no interior da Floresta Nacional de Ipanema, unidade de conservação situada no sudeste do estado de São Paulo. Para a comparação foi utilizado o método de litter bags usando sacos de malha grossa plástica de 10 mm de abertura, por períodos de no máximo 60 dias. Neste período também foi avaliada a colonização de macroinvertebrados bentônicos em cada um dos tratamentos testados. Entre as estações (seca e chuvosa), as perdas de massa foliar foram distintas, assim também existiram diferenças entre as espécies de plantas testadas (Inga marginata, Matayba elaeagnoides e Eucalyptus grandis), sendo sempre maior a perda nas folhas de Inga marginata, seguida das folhas de Eucalyptus grandis e Matayba elaeagnoides, e obtendo os maiores valores de perda de massa na estação chuvosa. Foram identificados 801 indivíduos que colonizaram nos três tratamentos testados na época seca e 556 indivíduos que colonizaram nos tratamentos na época chuvosa, existindo uma relação entre os valores de perda de massa e a abundância de organismos macroinvertebrados para cada um dos tratamentos, sendo os tratamentos com maiores perdas os que tiveram maiores valores de organismos colonizados. Os maiores valores de perda de massa para a folha de Inga marginata foi maior em comparação dos outros tratamentos além de apresentar a maior quantidade de macroinvertebrados aquáticos colonizados nas duas épocas avaliadas. As famílias mais representativas foram: Chironomidae, Hyalellidae, Gomphidae, Calamoceratidae, Leptophlebiidae e Elmidae. Assim os grupos funcionais com maior presença foram os grupos coletor e predador, não existindo diferenças significativas na presença destes grupos. O grupo fragmentador foi o terceiro grupo mais representativo para os três tratamentos e nas duas épocas avaliadas. Nesse tipo de ambiente tropical, a comunidade de fungos e bactérias é rico e diverso, fazendo esse processo biológico, importante para a transformação das folhas em um recurso de maior facilidade de assimilação para seu aproveitamento, tornando assim as folhas mais acessíveis para os organismos invertebrados. Deste modo, por exemplo transformando as folhas de eucalipto em um recurso, sendo estas folhas também acondicionadas para o consumo dos organismos e podendo-se constituir como um recurso adicional para a biota e os organismos se adaptando para a assimilação deste recurso. A presença de folhas de eucalipto pode influenciar na colonização dos organismos invertebrados, podendo interferir no processo natural da colonização de macroinvertebrados aquáticos e alterando a disponibilidade de nutrientes dentro das teias tróficas destes sistemas aquáticos. / The crumbled vegetation has positive effects on water quality in a low river. The crop plants and replacement of native species by exotic species, has significant effects and impacts on biodiversity of aquatic and terrestrial environments. Eucalyptus cultivation occupies areas of biological and environmental importance, causing impacts that are still poorly studied, interfering with the operation of the waterways that depend on available vegetable waste on the banks of rivers as a source of energy and nutrients. This study compared the decomposition of leaves of native species (Inga marginata and Matayba elaeagnoides) and leaves of an exotic species (Eucalyptus grandis) during the dry and rainy seasons in a river located within of the Floresta Nacional de Ipanema, conservation unit located in the southeastern state of São Paulo. For the comparison, the litter bags method was used. Thus, networks of plastic coarse mesh with an opening of 10 mm maximum were used for periods of 60 days. In this period the colonization of bentic macroinvertebrates in each of the treatments was also evaluated. Between the seasons (dry and rainy), losses of plant mass were different among different species of evaluated plants (Inga marginata, Matayba elaeagnoides and Eucalyptus grandis), considering that the loss of leaves of Inga marginata was higher, followed by the Eucalyptus grandis and Matayba elaeagnoides leaves. As a result, the loss of mass in the rainy season was evident. Thus, 801 individuals that colonized the three treatments evaluated in the dry season and 556 individuals that colonized treatments in the rainy season were identified. As consequence, there is a relationship between the values of loss of plant material and abundance of macroinvertebrates organisms for each of the treatments. The treatments with higher losses those who had higher values of colonized organisms. The largest mass loss values for Inga marginata sheet was higher in comparison of other treatments as well as presenting the greatest amount of aquatic macroinvertebrates colonized in the two seasons evaluated. The most representative families were: Chironomidae, Hyalellidae, Gomphidae, Calamoceratidae, Leptophlebiidae and Elmidae. Thus, the functional groups with the largest presence were collectors and predators groups, with no significant differences in the presence of these groups, the shredder group was the third most representative group for the three treatments and two periods evaluated. In this type of tropical environment, the community of fungi and bacteria is abundant and diverse, making of this biological process, an important aspect for the transformation of leaves in a resource ease of assimilation for its use, allowing these to become more accessible for invertebrate organisms. Considering the previous information, this allowed the Eucalyptus leaves transform in a resource available for consumption of organisms and being able to be as an additional resource for biota and organisms adapting to the assimilation of this resource. Thus, the presence of Eucalyptus leaves can influence the colonization of invertebrate organisms, it may interfere with the natural process of colonization of aquatic macroinvertebrates and altering the availability of nutrients in the food chains of these aquatic ecosystems.
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Effect of the moisture heterogeneity of leaf litter layer on temporal and spatial variation in the litter heterotrophic respiration in a warm-temperate forest / 暖温帯林の落葉層における水分の不均質性が落葉分解呼吸の時空間変動に与える影響

Ataka, Mioko 23 March 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19032号 / 農博第2110号 / 新制||農||1031(附属図書館) / 学位論文||H27||N4914(農学部図書室) / 31983 / 京都大学大学院農学研究科地域環境科学専攻 / (主査)教授 谷 誠, 教授 北山 兼弘, 教授 本田 与一 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
179

Poultry Litter Ash as an Alternative Fertilizer Source for Corn

Ervin, Clara 12 November 2019 (has links)
Poultry litter ash (PLA) is a co-product from manure-to-energy systems that originated in response to increased poultry litter (PL) volumes generated in concentrated poultry production regions. Investigating PLA as a crop fertilizer is an alternative solution to balancing poultry and crop regional nutrient cycling in the Commonwealth of Virginia. As the expanding world population places pressure on the poultry industry to meet consumption demands, increased PL production presents an obstacle to identify alternative uses for increased volumes. Currently, Virginia produces 44 million broilers with PL produced predominately in the Shenandoah Valley and Eastern Shore. Likewise, a growing world population places pressure on crop production areas and subsequently finite natural resources used for crop fertilization. Poultry litter ash is an alternative phosphorus (P) and potassium (K) source enhancing transportation logistics, repurposing PL nutrients, and offers dual purpose as a fertilizer and an energy source when compared to PL. Three PLA products [(fluidized bed bulk (FB Bulk), fluidized bed fly (FB Fly), and combustion Mix (CMix)], two manufactured co-products [(granulated poultry litter ash (GPLA), and ash coated urea (ACU)] were evaluated as P, K, and N sources for corn (Zea Mays L.) production in comparison to industry fertilizers [(PL, triple superphosphate (TSP), muriate of potash (KCL), and urea). A comprehensive examination of elemental composition, P speciation, P and K solubility, improved functionality into granulized forms, and field testing were conducted to discern PLA potential as an alternative fertilizer source. Poultry litter ash products were evaluated by total elemental analysis, backscatter-electron dispersive (BSED) microscopy, and X-ray absorption near edge structure (XANES) spectroscopy. Poultry litter ash elemental concentrations were highly variable ranging from 50.6 to 102.0 g P kg -1 and 62.6 to 120.0 g K kg -1 and were comparatively higher than PL concentrations. Phosphorus structures that provided and controlled P solubility were Ca and Ca-Mg-phosphate compounds. Spectroscopy confirmed Ca structures as predominately monetite (dicalcium phosphate anhydrous; CaHPO4; log K ̊ 0.30) and brushite (dicalcium phosphate dihydrate; CaHPO4.2H20; 0.63 log K ̊ ) species that were supported by BSED and elemental stoichiometric ratios (Ca:P; 1.12 to 1.71:1). Additionally, GPLA acidified from FB Fly had higher brushite and monetite percentages described by spectra models, translating into a more soluble Ca-phosphate species when compared to FB Fly original P species. Granulated poultry litter acidulation trials successfully identified a desired granulation point of 29% (14.5 g acid to 50 g PLA) phosphoric acid (75% H3PO4) acidulation. Acidulation dose response relationships created simple linear regression (SLR) equations that sufficiently (R2 > 0.80) described changes in total measurable P and water soluble P, pH, and exothermic reaction temperatures to increasing H3PO4 acidulation. Solubility tests included: sequential extraction, particle size effect on solubility, carbon effect on water soluble P, and Mehlich-1 extraction of PLA sources that confirmed decreased P solubility. A majority PLA P was found in bound plant unavailable fractions (87.7 to 97.7% P of total P). Granulated poultry litter ash had improved P plant available P of 36.0% P of total P. Carbon (C) effects on PLA P were examined by ashing PLA samples in a muffle furnace at 550 ̊C. Differences in total carbon content negatively impacted FB Bulk and CMix total P (1.30 and 4.56 g P kg -1); however, muffle furnace temperatures increased FB Fly total P by 6.74 g P kg -1. All fertilizer products were investigated under field conditions in separate P, K and N corn studies across Virginia coastal plain soils to determine fertilizer effects on corn plant parameters [(most mature leaf (V6), corn ear leaf (R1), and grain (R6)]. Poultry litter P treatments, averaged over rate, recorded highest yield in both years. At eight of nine field sites, FB Bulk resulted in numerically or significantly higher Mehlich-1 concentrations than other P sources post-harvest. Although Mehlich-1 P increased, yield and plant parameters did not; which leads to the conclusion that PLA sources increased soil residual P that did not translate into immediate plant availability recorded within a growing season. Across plant efficacy parameters examined, PLA K is a comparable nutrient source and improved plant parameters when compared to control. Eighteen out of twenty-one plant parameters examined found similar ACU and urea effects on N concentrations. Therefore, ACU is a comparable N source to urea. When compared to industry fertilizer sources, we concluded that PLA is a slowly available P source, decreased P availability negatively affected early plant growth, K is a comparable nutrient source and improved plant parameters compared to control, and ACU effectively provided N to maintain sufficient corn growth. In conclusion, PLA co-products serve as a densified nutrient source that may provide plant available nutrients if processed to aid in nutrient distribution to grain producing areas. / Doctor of Philosophy / Poultry litter ash (PLA) is a co-product from manure-to-energy systems that originated in response to increased poultry litter (PL) volumes generated in concentrated poultry production regions. Investigating PLA as an alternative crop fertilizer is essential to balancing poultry and crop regional nutrient cycling in the Commonwealth of Virginia. As the expanding world population places pressure on the poultry industry to meet consumption demands, heightened PL production presents an obstacle to identify alternative uses for increased volumes. Currently, Virginia produces 44,683,904 broilers with PL produced predominately in the Shenandoah Valley and Eastern Shore. Likewise, a growing world population places pressure on crop production areas and subsequently finite natural resources used for fertilization vital to maintaining crop yields. Poultry litter ash, a co-product from manure-to-energy systems, is an alternative phosphorus (P) and potassium (K) source enhancing transportation logistics, repurposing PL nutrients, and offers dual purpose as a fertilizer and an energy source when compared to PL. In this dissertation, three PLA products [(fluidized bed bulk (FB Bulk), fluidized bed fly (FB Fly), and combustion Mix (CMix)], two manufactured co-products [(granulated poultry litter ash (GPLA), and ash coated urea (ACU)] were evaluated as P, K, and N source for corn (Zea Mays L.) production in comparison to industry fertilizers (PL, triple superphosphate (TSP), muriate of potash (KCL), and urea). Each of the following chapters provides a comprehensive examination of the following topics: elemental composition, P speciation, P and K solubility, improved functionality into granulized forms, and field testing designed to provide parameters to conclude PLA potential as an alternative P, K and N source. In the second chapter, PLA products were evaluated by total elemental analysis, backscatter-electron dispersive (BSED) microscopy, and X-ray absorption near edge structure (XANES) spectroscopy. Poultry litter ash elemental concentrations are highly variable and are comparatively higher than PL concentrations. Phosphorus structure and species identified Ca as the primary element controlling P structure and subsequent solubility. The third component of this dissertation is granulation trials investigating phosphoric acid effects on granulizing and increasing total and water soluble P. Our results identified 29% (14.5 g acid to 50 g PLA) phosphoric acid acidulation for desired granule size. The third dissertation component examines PLA solubility. The results demonstrated PLA decreased P water solubility when compared to industry fertilizer sources. Granulated poultry litter ash demonstrated improved P plant availability due to the granulation process. The final and fourth dissertation components investigated PLA sources under field conditions in separate P, K and N corn studies across Virginia coastal plain soils to determine fertilizer effects on corn plant parameters. Minority of plant parameters tested revealed P control yielded numerically higher P concentrations than PLA P sources tested. Poultry litter P treatments, averaged over rate, recorded highest yield in both years. At eight of nine field sites, FB Bulk resulted in numerically or significantly higher Mehlich-1 concentrations than other P sources post-harvest. Although Mehlich-1 P concentrations increased, yield and plant parameters did not; which leads to the conclusion that PLA sources increased soil residual P that did not translate into immediate plant availability recorded within a growing season. Across plant efficacy parameters examined, PLA K is a comparable nutrient source and improved plant parameters when compared to controls. The majority of plant parameters examined found similar ACU and urea effects on N concentrations. Therefore, ACU is a comparable N source to urea. When compared to industry fertilizer sources, field results concluded that PLA is a slowly available P source, decreased P availability negatively affected early plant growth, K is a comparable nutrient source and improve plant parameters compared to control, ACU effectively provides N to maintain sufficient corn growth. In conclusion, PLA co-products serve as a densified nutrient source that may provide plant available nutrients if processed to aid in nutrient distribution to grain producing areas.
180

Effects of birth weight, finishing feeder design, and dietary astaxanthin and ractopamine HCl on the growth, carcass, and pork quality characteristics of pigs; and meta-analyses to improve the prediction of pork fat quality

Bergstrom, Jonathan Robert January 1900 (has links)
Doctor of Philosophy / Department of Animal Sciences and Industry / Jim L. Nelssen / Eleven-thousand one-hundred eighty-five pigs were used in 11 experiments to determine effects of birth-weight, feeder design, and dietary astaxanthin (AX) and ractopamine HCl (RAC) on growth, carcass, and pork quality characteristics of pigs. Also, data from 27 experiments were used in meta-analyses to improve prediction of pork fat iodine value (IV). In Exp. 1, increased birth-weight resulted in greater (quadratic, P < 0.05) pre-weaning survivability, ADG, final BW, and likelihood of achieving full-value market at 181-d of age. In Exp. 2, 3, 4, 6, 7, and 8, pigs using the wet-dry feeder (WD) had greater (P < 0.05) ADG, ADFI, and final BW than those using the conventional dry feeder (CD). Pigs using WD had poorer (P < 0.05) G:F in Exp. 3 and 4, and increased (P < 0.05) HCW and backfat depth in Exp. 3, 4, 6, and 7, compared to pigs fed using CD. In Exp. 5, pigs using WD from 19 to 38 kg had decreased (P < 0.02) ADFI and better G:F than pigs using CD. Increased feeder opening of WD increased (P < 0.05) ADG, ADFI, and final BW in Exp. 5, 6, and 7; as well as HCW and backfat depth in Exp. 6 and 7. Reducing WD opening at 28- and 56-d in Exp. 7 decreased (P < 0.05) ADG, ADFI, and backfat depth. Different openings of CD had little effect on performance in Exp. 5 and 6. In Exp. 8, changing water-source of WD to a separate location during late-finishing reduced (P < 0.05) overall ADG, ADFI, and final BW. Limited responses to AX were observed in Exp. 9, 10, and 11, but ADG, G:F, final BW, HCW, and fat-free lean were improved (P < 0.05) for pigs fed RAC in Exp. 10 and 11. Total color change during retail display of LM chops for gilts and pigs fed RAC was reduced (P < 0.05) in Exp. 10 and 11, indicating their color shelf-life improved. In the meta-analyses, models using dietary PUFA with ADG, BW, or backfat depth improved the fat IV prediction from R2 = 0.45 to R2 = 0.90.

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