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Contin, Marco. "ATP concentration in the soil microbial biomass". Thesis, Coventry University, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270692.
Pełny tekst źródłaHart, Murray. "Effects of pesticides on the soil microbial biomass and microbial activity". Thesis, University of Nottingham, 1995. http://eprints.nottingham.ac.uk/11542/.
Pełny tekst źródłaBarajas-Aceves, Martha. "Soil microbial biomass and organic matter dynamics in metal-contaminated soils". Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260604.
Pełny tekst źródłaWu, Dan Hua. "The effect of water potential on soil microbial biomass". Thesis, University of Aberdeen, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.290290.
Pełny tekst źródłaPuri, Geeta. "The contribution of soil microbial nitrogen to the gross rate of N mineralisation in a temperate woodland soil". Thesis, University of Reading, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384882.
Pełny tekst źródłaEhaliotis, Constantinos. "Nitrogen turnover during decomposition of recalcitrant plant residues in acid soils". Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243408.
Pełny tekst źródłaAl, Fassi Fahad Abdulrahman. "The microbial ecology of heathland soil with special reference to factors affecting microbial biomass and activity". Thesis, University of Sheffield, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318137.
Pełny tekst źródłaBol, Roland Adrianus Phillippus Franciscus. "The effect of liming on the phenolic compounds in the soil". Thesis, Bangor University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385807.
Pełny tekst źródłaCarter, Jonathan Philip. "Population biology of Trichoderma spp. used as inoculants". Thesis, University of Reading, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329046.
Pełny tekst źródłaSANTOS, Uemeson José dos. "Frações do carbono e indicadores biológicos em solo do semiárido sob diferentes usos e coberturas vegetais". Universidade Federal Rural de Pernambuco, 2016. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6570.
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The land use in Caatinga has caused changes in their properties, as well as behavior and quality of organic matter. extractive character changes, agro pastoral and agricultural biome has taken this to an unsustainable condition, with profound changes in the dynamics and the stock C and its fractions, linked to changes in the microbial community that plays an important role in nutrient cycling in the soil. The objective of this study was to evaluate changes in soil C, its labile and recalcitrant but the activity and microbial diversity in soils under different vegetation covers and historical uses. seven areas were studied which consisted of native forest (F) without human action, forest with predominance of mimosa (AF) and the other with ipe (IP); three areas converted into farmland irrigated elephant grass (EG), irrigated corn (MI) and corn without irrigation (M); and a farmyard area (NF). They were collected in different areas samples at depths of 0-5, 5-10 and 10-20 cm, respectively. Evaluated the total stocks of C and N, water-soluble carbon (CSA) and the C cumulative mineralized after 32 days of incubation, the carbon oxidizable fractions (F1, F2, F3 and F4) and its fractions humic soil (C-FAH C-FAF and C-HUM), C microbial biomass, microbial quotient (qMIC) and structure the microbial community by phospholipid fatty acid analysis (PFLA). The conversion of the savanna for maize cultivation causes a decrease of 56 and 38% in stocks of C and N in the soil. The larger C stocks were observed in AF coverage, while for N, M stood out with lower stocks of this element and also below at all depths to the CSA. The C mineralizable showed linear behavior, observing a reduction in average C mineralized accumulated up to 21.03% in the intermediate depth. The AF, F and IP coverage had higher carbon content in oxidizable fractions for all depths evaluated. The AF area showed higher C levels in labile forms. The C of humic fractions showed inventories in C-FAF fractions and C-FAH 3.59 and 3.73 t ha-1, respectively for AF area; and 22.64 t ha-1 in C-HUM fraction for EG. The area with MI showed greater efficiency in the use of C for microorganisms at different depths. For CBM, coverage with F had a higher concentration, down to 78.32% in depth. Further total Pflas EG concentrations were observed in the area with a larger population of bacteria and fungi in relation to the predominance of gram positive bacteria over gram negative. F1 fractions, CSA and CHUN contributed most significantly to the increase in the stock of C and N soil. Areas converted agícola production, has the potential to change the fractions of COS and microbial activity, especially when it is making use of irrigation in these environments. The EG coverage was more efficient in the use of C and preservation of MOS, combined with a high microbial community, providing better soil quality.
A utilização do solo sob Caatinga tem ocasionado alterações nas suas propriedades, assim como no comportamento e na qualidade da matéria orgânica. Alterações de caráter extrativista, agropastoril e agrícola tem levado esse bioma a uma condição de insustentabilidade, com profundas alterações na dinâmica e no estoque do C e suas frações, atreladas às modificações na comunidade microbiana que exerce importante função na ciclagem de nutrientes no solo. O objetivo do trabalho foi avaliar as alterações no C do solo, suas frações lábeis e recalcitrantes além da atividade e diversidade microbiana em solos sob diferentes coberturas vegetais e históricos de usos. Foram estudadas sete áreas que consistiram em floresta nativa (F) sem ação antrópica, floresta com predominância de angico (AF) e outra com ipê (IP); três áreas convertidas em cultivos agrícolas de capim elefante irrigado (EG), milho irrigado (MI) e milho sem irrigação (M); e uma área de capoeira (NF). Foram coletadas nas diferentes áreas amostras nas profundidades de 0-5, 5-10 e 10-20 cm, respectivamente. Avaliaram-se os estoques totais de C e N, carbono solúvel em água (CSA) e o C mineralizável acumulado aos 32 dias de incubação, as frações oxidáveis do carbono (F1, F2, F3 e F4) e suas frações nas substâncias húmicas do solo (C-FAH, C-FAF e C-HUM), o C da biomassa microbiana, quociente microbiano (qMIC) e a estrutura da comunidade microbiana através da análise de fosfolipídeos de ácidos graxos (PFLA). A conversão da caatinga para o cultivo de milho ocasionou diminuição de 56 e 38% nos estoques de C e N no solo. Os maiores estoques de C foram observados na cobertura AF, enquanto para o N, o M destacou-se com menores estoques deste elemento, sendo também inferior em todas as profundidades para o CSA. O C mineralizável apresentou comportamento linear, observando-se uma redução na média de C mineralizado acumulado de até 21,03% na profundidade intermediária. As coberturas AF, F e IP obtiveram maiores teores de carbono nas frações oxidáveis para todas as profundidades avaliadas. A área AF apresentou maiores teores de C nas formas lábeis. O C das frações húmicas, apresentaram estoques nas frações C-FAF e C-FAH de 3,59 e 3,73 t ha-1, respectivamente para área AF; e 22,64 t ha-1 na fração C-HUM para EG. A área com MI demonstrou maior eficiência na utilização do C pelos microrganismos nas diferentes profundidades. Para o CBM, a cobertura com F obteve maior concentração, com redução de até 78,32% em profundidade. Maiores concentrações de PFLAs totais foram observadas na área EG, com uma maior população de bactérias em relação aos fungos e maior predominância de bactérias gram positivas em relação as gram negativas. As frações F1, CSA e a C-HUM contribuíram de forma mais expressiva para o aumento do estoque de C e N do solo. Áreas convertidas para produção agícola, tem o potencial de alterar as frações do COS e atividade microbiana, sobretudo quando faz o uso de irrigação nesses ambientes. A cobertura EG foi mais eficiente na utilização do C e preservação da MOS, aliada a uma alta comunidade microbiana, proporcionando melhor qualidade do solo.
Stark, S. (Sari). "Reindeer grazing and soil nutrient cycling in boreal and tundra ecosystems". Doctoral thesis, University of Oulu, 2002. http://urn.fi/urn:isbn:9514266927.
Pełny tekst źródłaWong, Vanessa, i u2514228@anu edu au. "The effects of salinity and sodicity on soil organic carbon stocks and fluxes". The Australian National University. Faculty of Science, 2007. http://thesis.anu.edu.au./public/adt-ANU20080428.223144.
Pełny tekst źródłaMurphy, Margretta A., i Margretta A. Murphy. "Interactions of Wildfire, Landscape Position, and Soil Depth in Structuring Post-Fire Soil Microbial Communities". Thesis, The University of Arizona, 2016. http://hdl.handle.net/10150/621017.
Pełny tekst źródłaLopes, Elizabeth Barretto de Menezes. "Diversidade metabólica em solo tratado com biossólidos". Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-29042002-160938/.
Pełny tekst źródłaThe use of biosolids in agricultural and/or forestry soils has been an acceptable practice to dispose as well as to improve physical, chemical and biological soil properties. However, the impacts of biosolids application on microbial community structures and metabolic diversity in agricultural soils are relatively unknown. The aim of this work was to determine quantitative and qualitative alterations in the metabolic diversity of a clay soil upon treatment with biosolids. A clay soil was amended with the equivalent to 6, 12, 24 and 48 Mg ha-1 of biosolids from the City of Franca (SP) Sewage Treatment Plant. A control without biosolids was also used. Four repetitions per treatment were used, totalizing 20 sub-parcels. Sub-parcels were incubated for 1, 2, 4, 8 and 16 weeks, after incorporating the biosolids, totaling 120 microcosms. After the incubation period, soil samples were collected to determine pH, Basal Respiration (BR), Substrate Induced Respiration (SIR), C-biomass, Metabolic Quotient (qCO2) and Metabolic Diversity. A transient increase in soil pH was observed in the treatments with the higher concentrations of biosolids, compared to the control without biosolids. After 16 weeks of incubation, the pH of soils with biosolids was lower than in the control without biosolids. The C-biomass also showed a transient increase in soils with biosolids at early time points, and did not statistically differ from the control at late time points. Transient increases in metabolic activities, based on BR, SIR and AWCD (Average Well Color Development), were observed in soils with the higher concentrations of biosolids at early time points. Higher values of qCO2 in soils with higher concentrations of biosolids at the earliest and latest time points suggests stressing conditions to the microbial community and alterations in microbial community structure. The utilization of C-substrates by the soil microbial community was greatly affected by the concentration of biosolids added and by the incubation time. Higher values of Substrate Richness (S) and Metabolic Diversity (H) in the soils with the higher concentrations of biosolids at early time points indicate that biosolids stimulate the activity of soil microorganisms and contribute with new activities. The similarities between the C-sources utilization profiles in the soil amended with biosolids and the control were lower in soils with the higher concentrations of biosolids. The similarities of C-source utilization profiles in the soils with biosolids and the control increased during the incubation time. Soils amended with the higher concentrations of biosolids showed metabolic activities not observed in the control soil at the early time points. The ability to use several C-sources was lost at the latest time point. In general, the results suggest that the incorporation of biosolids to the clay soil disturbs soil microbial physiology and that the successive application of biosolids to the soil may significantly alter the soil metabolic activities.
Williamson, J. C. "Estimation of total and active microbial biomass in soils subjected to long-term storage and restoration". Thesis, Bangor University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381751.
Pełny tekst źródłaLancaster, Sarah Renee. "Soil microbial response to glyphosate-base cotton pest management systems". [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-2636.
Pełny tekst źródłaKnight, Bruce Philip. "Heavy metal speciation and bioavailability to microbes". Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243803.
Pełny tekst źródłaLin, Qimei. "A comparison of methods for estimating soil microbial biomass and its partition into bacteria and fungi". Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.260542.
Pełny tekst źródłaVicente, Giovana Cristina Maschio Pelagio. "Atributos microbiológicos, físicos e químicos de solos na região oeste paulista". Universidade do Oeste Paulista, 2010. http://bdtd.unoeste.br:8080/tede/handle/tede/379.
Pełny tekst źródłaThe fertility and microbial activity in soil have been often used to indicate changes in soil quality. The microbial activity directly interacts with environmental conditions, soil types and different agricultural production systems used. Despite advances in this area, it is still a great challenge to define good indicators of soil quality, their interactions and behavior over time. Thus, the aim of this study was to assess the current state of soils under pastures in the western region of São Paulo using the evaluation and correlation of the microbial attributes and soil fertility. We performed on 108 soil samples, collected in settled pastures, analysis of thirteen variables in a laboratory within the microbial attributes, fertility and soil texture. The findings of the evaluation of the microbial demonstrated that microbial biomass had the lowest coefficient of variation, normal distribution of frequency and significantly correlated with most variables analyzed, on the other side, within the attributes of fertility of the soil, pH had the lowest rate variation while the phosphorus content demonstrated large variations with disproportionately high frequency among other variables, indicating the current status of soil degradation. The soil microbial biomass can be considered a good indicator for microbiological evaluation in these soils. The principal component analysis demonstrated that 51% of the variation was concentrated in the axis 1 and 2, which is considered representative for multivariate environmental assessment
A fertilidade e a atividade microbiana em solo têm sido utilizadas com frequencia para indicar mudanças na qualidade do solo. A atividade microbiana interage diretamente com as condições ambientais, classes de solo e diferentes sistemas de produção agrícola utilizados. Apesar dos avanços nesta área ainda é um grande desafio a definição de bons indicadores de qualidade do solo, suas interações e comportamento ao longo do tempo. Desta forma, o objetivo desse estudo foi verificar o estado atual de solos sob pastagens na região oeste paulista utilizando-se da avaliação e correlação de atributos microbiológicos e de fertilidade do solo. Foram realizadas em 108 amostras de solos, coletadas em áreas de pastagens estabelecidas, análises de treze variáveis em laboratório, dentro dos atributos microbiológicos, de fertilidade e granulométrico do solo. Os resultados encontrados na avaliação dos atributos microbiológicos demonstraram que a biomassa microbiana apresentou o menor coeficiente de variação, distribuição normal de freqüência e correlação significativa com a maioria das variáveis analisadas, por outro lado dentro dos atributos de fertilidade do solo o pH apresentou o menor coeficiente de variação enquanto que o teor fósforo apresentou grande variação com freqüência desproporcional indicando junto com outras variáveis o estado atual de degradação do solo. A biomassa microbiana do solo pode ser considerada como bom indicador para avaliação microbiológica nestes solos. A análise de componentes principais apresentou que 51% da variação concentrou-se dentro do eixo 1 e 2 o que é considerado representativa para avaliação ambiental multivariada
Knewtson, Sharon Joy Blanton. "Studies in vegetable and high tunnel production on the Central Great Plains". Diss., Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/926.
Pełny tekst źródłaChandar, Krishan. "The effects of heavy metals from past applications of sewage sludge on soil microbial biomass and miocrobial activity". Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.293755.
Pełny tekst źródłaChen, Yujuan. "The Influence of Urban Soil Rehabilitation on Soil Carbon Dynamics, Greenhouse Gas Emission, and Stormwater Mitigation". Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/51240.
Pełny tekst źródłaPh. D.
Johnson, David. "Soil microbial biomass and activity and plant nutrition in semi-natural ecosystems subjected to pollutant nitrogen deposition". Thesis, University of Sheffield, 1998. http://etheses.whiterose.ac.uk/15149/.
Pełny tekst źródłaMurugan, Rajasekaran [Verfasser]. "Effects of grassland conversion and tillage intensities on soil microbial biomass, residues and community structure / Rajasekaran Murugan". Kassel : Universitätsbibliothek Kassel, 2013. http://d-nb.info/1044695528/34.
Pełny tekst źródłaBorges, Clovis Daniel [UNESP]. "Alterações microbianas do solo sob sistema de semeadura direta e rotação de culturas". Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/94944.
Pełny tekst źródłaFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
A rotação de culturas é um processo de cultivo que pode modernizar e aumentar o rendimento da atividade agropecuária de forma sustentável agregando maior qualidade ao solo. Os objetivos deste estudo foram: (I) avaliar o efeito dos sistemas culturais em plantio direto conduzidos em rotação de culturas e monitorar as alterações das propriedades microbiológicas bioindicadoras da qualidade do solo; (II) investigar as mudanças bioquímicas nos solos decorrentes da adição de diferentes tamanhos de resíduos de soja e milho durante o período de incubação. Foram determinados as biomassas microbianas- C, N e P (CBM, NBM e PBM, respectivamente), a atividade respiratória (C-CO2) e das enzimas desidrogenase, fosfatase e urease, conteúdo do carbono orgânico (Corg), carbono solúvel (Csol), fósforo orgânico (Porg), matéria orgânica (MO), potencial de mineralização do N. O quociente metabólico (qCO2) e microbiano (qMIC) do solo foram calculados. Experimento (I): A avaliação foi realizada em amostras de solo coletadas após a colheita das culturas de verão do ano agrícola 2007/2008, na camada de 0-0,15 m de profundidade em um experimento conduzido sob sistema de semeadura direta, por seis anos. O delineamento experimental foi em blocos casualizados com esquema de faixas com três repetições. As sequências utilizadas foram as monoculturas de soja (Glycine max L.) (SS) e de milho (Zea mays L.) (MM) e a rotação de culturas soja/milho (SM). As culturas de inverno foram milho, girassol (Helianthus anuus L.), nabo forrageiro (Raphanus sativus L.), milheto (Pennisetum americanum (L.) Leeke), guandu (Cajanus cajan (L.) Millsp), sorgo (Sorghum bicolor (L.) Moench) e crotalária (Crotalária juncea L.). O conteúdo da biomassa microbiana-C, N e P do solo aumentou significativamente...
Crop rotation is a practice of growing dissimilar plants that can modernize and increase the farm economy in a sustainable form for adding more quality to the soil. The aims of this study were: (I) evaluate the effect of crop sequences under no-tillage systems on changes in the soil microbiological properties; (II) investigate the biochemistries changes during the incubation of the soil added with different sizes particles of soybean and corn. There were determined the contents of microbial biomass-C, N and P, the production of C-CO2, the activities of the enzymes dehydrogenase, urease and phosphatase, the organic carbon (Corg), soluble carbon (Csol), organic phosphorous (Porg) and organic matter (MO) contents and the potential of mineralization N. The soil metabolic (qCO2) and microbial (qMIC) quotients were calculated. Experiment (I): The evaluation was performed in soil samples collected after the summer crops harvest, on 2007/2008 growing season, at 0-0.15 m soil depth layer on an experiment conducted under no-tillage system through six years. The experimental had a completely randomized block design, in strips plots with three replications. The crop sequences were continuous soybean (Glycine max L.) (SS), continuous corn (Zea mays L.) (MM), and crop rotation soybean/corn (SM). Winter crops were corn, sunflower (Helianthus anuus L.), radish (Raphanus sativus L.), pearl millet (Pennisetum americanum (L.) Leeke), pigeon pea (Cajanus cajan (L.) Millsp), grain sorghum (Sorghum bicolor (L.) Moench) and sunn hemp (Crotalária juncea L.). The content of microbial biomass-C, N and P in the soil increased significantly in crop sequence SM compared to continuous crop. The interactions SM-millet and MMsorghum influenced the content of biomass-C, SM-hemp and SM-millet in the biomass-N content... (Summary complete electronic access click below)
Antunes, Carlos Henrique. "AVALIAÇÃO DA COMUNIDADE MICROBIANA DO SOLO EM UM SISTEMA DE PLANTIO DIRETO SOB DIFERENTES CONDIÇÕES DE CALAGEM E APLICAÇÃO DE NITROGÊNIO". Universidade Estadual de Ponta Grossa, 2018. http://tede2.uepg.br/jspui/handle/prefix/2507.
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O aporte de N na forma assimilável pelas plantas (NH4+) em diversos ecossistemas é realizado principalmente pelos organismos diazotróficos, e os mesmos vêm sendo pesquisados amplamente em todo o mundo. O N se configura como um dos nutrientes que apresenta grande importância no crescimento e desenvolvimento das plantas devido a sua função estrutural, pois faz parte da molécula de compostos orgânicos,como os aminoácidos e proteínas, sendo ainda ativador de muitas enzimas. Os adubos amoniacais são os mais comumente utilizados como fonte de nitrogênio nas atividades agrícolas. Contudo, a sua utilização acarreta em aumentos significativos da acidificação do solo, provenientes dos processos de nitrificação. O solo é um sistema complexo e as práticas de manejo podem afetar significativamente as comunidades microbianas que realizam muitos processos de suma importância para a produtividade e sustentabilidade. O objetivo desse trabalho foi avaliar o impacto na comunidade microbiana de um solo com a adição de N e calagem sob cobertura na aveia preta em um sistema de plantio direto de longa duração. As coletas de solo foram realizadas em cinco tratamentos distintos, distribuídos aleatoriamente em triplicatas na área experimental: SC (sem cobertura de inverno); CC (com cobertura de inverno); CC+ N (com cobertura de inverno + nitrogênio); CC+C (com cobertura de inverno + calcário) e CC+C+N (com cobertura de inverno + calcário + nitrogênio). Avaliaram-se os atributos químicos do solo, o carbono da massa microbiana, a respiração basal, o quociente metabólico, o NMP dos diazotrofos, o número de nódulos, a massa seca dos nódulos, a massa seca da raiz e parte aérea da soja, bem como utilizou-se a técnica da Biolog Ecoplate para analisar o consumo de fontes de carbono entre os tratamentos, a fim de verificar suas similaridades e diferenças. Constatou-se que as condições químicas como o pH influenciaram diretamente o crescimento e o desenvolvimento da comunidade microbiana em vários parâmetros estudados. Os níveis de carbono da massa microbiana do solo, bem como a respiração basal e o quociente metabólico variaram entre os tratamentos, sendo o tratamento CC+ N o que apresentou um maior distúrbio na biomassa microbiana causado pelo seu manejo. Em relação às bactérias diazotróficas do solo, ficou evidente que a população teve forte influência da aplicação de N e de calcário, se mostrando nula no tratamento CC+C+N, contudo a população de bactérias noduladoras não teve influência negativa nos diferentes tratamentos.Observou-se que o houve um consumo diferente pelas comunidades de para determinados subgrupos de fontes de carbono. É notável a importância do estudo acerca das características e potenciais das bactérias diazotróficas, a fim de promover um avanço nas tecnologias para maximizar a produtividade de culturas que apresentam grande valor econômico para os produtores.
The contribution of N in the form assimilable by the plants (NH4 +) in several ecosystems is carried out mainly by the diazotrophic organisms, and they have been researched widely around the world. N is one of the nutrients that has great importance in the growth and development of plants due to its structural function, since it is part of the molecule of organic compounds, such as amino acids and proteins, being still activator of many enzymes. Ammoniac fertilizers are most commonly used as a source of nitrogen in agricultural activities. However, their use leads to significant increases in soil acidification from nitrification processes. Soil is a complex system and management practices can significantly affect microbial communities that perform many processes of paramount importance for productivity and sustainability. The objective of this work was to evaluate the impact on the microbial community of a soil with the addition of N and liming under cover in black oats in a long - term no - tillage system. Soil samples were collected in five different treatments, randomly distributed in triplicates in the experimental area: SC CC (without winter cover); CC (with winter cover); CC + N (with winter + nitrogen coverage); CC + C (with winter cover + limestone) and CC + C + N (with winter cover + limestone + nitrogen).Soil chemical, microbial mass carbon, basal respiration, metabolic quotient, diazotrophs NMP, number of nodules, nodule dry mass, dry mass of the root and shoot of the soybean were evaluated, as well as using the Biolog Ecoplate technique to analyze the consumption of carbon sources between treatments in order to verify their similarities and differences. It was found that chemical conditions such as pH directly influenced the growth and development of the microbial community in several parameters studied. The carbon levels of the soil microbial mass, as well as the basal respiration and the metabolic quotient varied among the treatments, being the treatment CC + N that presented a greater disturbance in the microbial biomass caused by its handling. In relation to the diazotrophic bacteria of the soil, it was evident that the population had a strong influence of the application of N and limestone, if it was null in the treatment CC + C + N, however the population of nodulating bacteria did not have negative influence in the different treatments. It was observed that there was a different consumption by the communities of for certain subgroups of carbon sources. The importance of the study of the characteristics and potentials of diazotrophic bacteria is remarkable in order to promote an advance in the technologies to maximize the productivity of crops that present great economic value to the producers.
Ashman, M. R. "The influence of selective physical factors on the immobilisation and release of N from the soil microbial biomass". Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283607.
Pełny tekst źródłaAllen, Michael Frederick. "The effects of earthworms on carbon and nitrogen flows through the soil microbial biomass in a corn agroecosystem". The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299759760.
Pełny tekst źródłaRocha, Mariana de Melo [UNESP]. "Parâmetros microbiológicos no sistema de plantio direto e convencional em solos com diferentes teores de argila". Universidade Estadual Paulista (UNESP), 2002. http://hdl.handle.net/11449/101744.
Pełny tekst źródłaFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O manejo agrícola altera, em muito, as características físicas, químicas e biológicas dos solos. A cultura e as condições climáticas, assim como o tipo de solo propriamente dito, afetam a decomposição da matéria orgânica do solo e, consequentemente, a biogeociclagem dos nutrientes. A matéria orgânica é uma característica importante em relação à fertilidade do solo, de modo que o impacto do uso do solo precisa ser avaliado principalmente em agroecossistemas. O conhecimento dos efeitos do uso da terra e das práticas agrícolas sobre a comunidade microbiana é de fundamental importância, em vista das importantes funções que os microorganismos desempenham no solo e que irão se refletir na produtividade agrícola. Neste sentido, uma avaliação da biomassa microbiana e de microorganismos do solo pode evidenciar diversas alterações no ecossistema do solo que estão associadas ao teor de argila e/ou sistemas de plantio. No presente estudo, caracterizou-se a camada superficial do perfil de solos sob plantio direto e plantio convencional em quatro fazendas no Brasil em relação a alguns de seus componentes microbiológicos. Para tanto, analisou-se, mensalmente, a respiração do solo, a biomassa microbiana e grupos de microorganismos. A avaliação da biomassa microbiana foi feita através da técnica da fumigação-incubação (FI), utilizando-se a Equação: [(C-CO2 liberado pelo solo fumigado, no período de 0-10 dias de incubação) - (C-CO2 liberado pelo solo não-fumigado, ao longo de 10-20 dias de incubação)]/0,45. Os cálculos indicaram um conteúdo de carbono da biomassa microbiana significativamente maior nos solos sob sistema de plantio direto em relação àqueles sob plantio convencional, na camada amostrada (0-10 cm de profundidade). Quantidades significativamente maiores...
The crop management changes greatly the physical, chemical and biological soil properties. Furthermore, the crop and soil types, and the climatic conditions would affect on soil organic matter decomposition and on nutrients biogeociclying. Soil organic matter is a important characteristic in relationship soil fertility. The knowledge about effects on soil using and agriculture practices on soil microbial communities is very important, due to the function that microorganisms have in soil and it was going to in soil fertility. In this sense, evaluation of the soil microbial biomass and micro-organisms greatly aids predictions several changes in the soil ecosystems are associated with reduced tillage as compared with conventional tillage. Surface soils from long-term no-till and conventional tillage plots at four Brazil farms were characterised for microbial components. Soil respiration, microbial biomass carbon and counts of microorganisms were measured at intervals monthly. The evaluation of microbial biomass carbon was done by fumigation-incubation technique (FI). For calculating the soil microbial biomass carbon, the equation used was: Equation = [(CO2-C evolved by fumigated soil, 0-10 days) - (CO2-C evolved by unfumigated soil, 10-20 days)]/0,45. Significantly greater amounts of CO2-C were released from no-till than from conventional tilled soils. qCO2 values were not significantly different between tillage systems. This observation confirms that the tillage affected biological activity in those soils, further that qCO2 values didn't have significantily different which two tillage systems, in studied soils. Number both fungi and bacteria were assayed by Most Probable Number (MPN) by the agar drop counting technique and the microorganisms groups were calculated using by traditional Most Probable Number (MPN) method...(Complete abstract, click electronic access below)
FERREIRA, Juscélia da Silva. "Estoque de carbono e atividade microbiana em sistemas silvipastoris na zona da mata de Pernambuco". Universidade Federal Rural de Pernambuco, 2015. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/4824.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The conversion of native vegetation áreas into pastures may contribute to the emission of greenhouse effect gases, due to the soil use change. The use of silvopastoral systems, which integrate legume tree species and grasses, may be a viable option to mitigate these emissions and increase soil carbon and nitrogen stocks. This work aimed to evaluate carbon stock (EC) and microbial activity in silvopastoral systems in the Forest Zone of Pernambuco. To this end, soil samplings were done at the dry and rainy seasons in an experiment evaluating signal grass (Brachiaria decumbens Stapf) with sabiá (Mimosa caesalpiniifolia Benth) or gliricidia (Gliricidia sepium (Jacq.) Steud.). Soil samples were taken up to 100 cm depth at 0, ,4 and 8 m from the legume strip, and up to 20 cm at 0,2,4,6 e 8 m from the legume strip for biological analysis. Total organic carbon (COT), total nitrogen (NT), soil organic matter chemical fractioning (fractions fulvic acid – AF; humic acid – AH and humin –HUM), soil density, microbial biomass carbon (Cmic), soil basal respiration (RBS) were determined and metabolic quocient (qCO2) and carbon stock (EC) were calculated. There was no significant difference (p>0.10) for Cmic for the distances from the legume strip at the rainy season. Significant difference was found for RBS at the rainy season for legume strip distances and soil depth layers. There was no significant difference (p >0.10) for Cmic between legume strips distances for the rainy season, while there was significant differences (p<0.10) for RBS between legume strip distances and soil layers. At the dry season, the highest qCO2 was at the 0-10 cm layer, 2 m away from the legum strip. There was significant difference between systems and legume strip distances for COT at the dry season, with the highest contents at 8 and 4 m for gliricidia and sabiá, respectively. EC had significant differences (p<0.10) between soil layers at the dry season, with higher values at the 20-60 layers, while at the rainy season there was only a significant difference at the 0-10 layer at 8 m from the legume strips, when sabiá values were 33% higher than gliricidia ones. Significant difference (p<0.10) was found for NT between layers on both seasons, with higher values going from the upper to the deeper layers. In general the AF fraction was the smallest, with higher values for all three fractions (AF, AH and HUM) for sabiá. Biological activity, as represented by Cmic and RBS, confirmed the silvopastoral systems capability of maintaining soil microbiota. The the higher C content in more stable fractions in sabiá indicates it to be more efficient in carbon sequestration. The silvopastoral system had EC similar to other cropping systems, but it might increase in a longer term of evaluation.
A conversão de áreas de vegetação nativa em pastagem pode contribuir para a emissão de gases de efeito estufa, ocasionada pela mudança no uso do solo. O uso de sistemas silvipastoris, que integram espécies arbóreas leguminosas e gramíneas, pode ser uma opção viável para mitigar essas emissões com aumento do estoque de carbono e nitrogênio no solo. O objetivo do trabalho foi avaliar o estoque de carbono (EC) e atividade microbiana em sistemas silvipastoris na Zona da Mata de Pernambuco. Para isso foi realizada coleta de solo nos períodos seco e chuvoso em experimento avaliando consórcios de braquiária (Brachiaria decumbens Stapf.) com sabiá (Mimosa caesalpiniifolia Benth) ou com gliricídia (Gliricidia sepium (Jacq.) Steud.). Foram retiradas amostras de solo até 100 cm de profundidade aos 0,4,e 8 m de distância da faixa da leguminosa, e até os 20 cm em pontos com 0,2,4,6 e 8 m de distância da faixa da leguminosa para análises biológicas. Foram determinados carbono orgânico total (COT), nitrogênio total (NT), fracionamento químico da matéria orgânica do solo (fração ácido fúlvico-AF; ácido húmico-AH e humina-HUM), densidade do solo, carbono da biomassa microbiana (Cmic), respiração basal do solo (RBS) e calculado o quociente metabólico (qCO2) e estoque de carbono (EC). Não houve diferença significativa (p>0,10) para Cmic entre distâncias da faixa da leguminosa no período chuvoso. A RBS apresentou diferença significativa (p<0,10) no período chuvoso entre distâncias da faixa da leguminosa e camadas. No período seco, o maior valor de quociente metabólico (qCO2) ocorreu na camada de 0-10 cm, na distância 2. Houve diferença significativa entre sistemas e distâncias da faixa da leguminosa para COT no período seco, com os maiores teores nas distâncias 8 e 4, para gliricídia e sabiá, respectivamente. Houve diferença significativa (p<0,10) entre camadas no EC no período seco, com maior estoque nas camadas de 20-60 cm. No período chuvoso observou-se maior uniformidade do EC, com diferença significativa apenas na camada de 0-10 cm na posição 8 com sabiá 33% superior. Para NT ocorreu diferença significativa (p<0,10) entre camadas com teores que variaram nos dois períodos avaliados, com maior concentração nas camadas superficiais reduzindo em profundidade. Para o fracionamento químico, no geral, a fração AF apresentou os menores teores de C, com os maiores teores das três frações (AF, AH e HUM) no consórcio com sabiá. A atividade biológica refletida pelos valores de Cmic e RBS comprovou a capacidade dos sistemas silvipastoris em sustentar a microbiota do solo. Os maiores teores de C nas frações mais estáveis no consórcio com sabiá o destacou com maior eficiência de reter carbono. O sistema silvipastoril apresentou EC semelhante a outros sistemas de manejo, mas não se descarta possibilidade de maior retenção de C em uma avaliação do experimento a longo prazo.
Ouimet, Nicole. "Laboratory measurements of soil microbial biomass and nitrogen mineralization from two Chinese soils as influenced by long-term applications of manure and inorganic fertilizers". Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68236.
Pełny tekst źródłaAraújo, Marcus Vinícius Forzani. "O impacto do manejo do cultivo de cana-de-açúcar (Saccharum sp.) e de pastagem (Brachiaria decumbens) na microbiota do solo". Universidade Federal de Goiás, 2017. http://repositorio.bc.ufg.br/tede/handle/tede/8291.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Characterized as extremely important, the soil is a complex environment and it shelters a great diversity of microorganisms. However, little is known about the diversity and ecology of the soil microbiota. Thus, the first part of this dissertation reviews the methodological evolution used to characterize the diversity and abundance of microorganisms found in soil. The second part consists of the application of two methodologies reviewed in the previous chapter, serial dilution and solid medium plating, to estimate free-living nitrogen fixing microorganisms, and fumigation-extraction to estimate soil microbial biomass (BMS). The last part employs the most modern microbial soil characterization technique, the metagenomics of 16S rRNA. Hence, our initial hypothesis was that sugarcane fields’ soils would have better soil microbiological indicators than grasslands’ soils. The results confirmed that the hypothesis was partially correct, and it was possible to find about 140% more free-living diazotrophic colony-forming units (CFUs) and a 17% richer alpha diversity in sugarcane fields’ soils than in grasslands’ soils. The beta diversity between sugarcane plantations and pastures presented clear differences. However, sugarcane fields’ soils obtained about 25% less BMS than grasslands’ soils. In relation to the bacterial phyla, the grasslands have more Actinobacteria, Chloroflexi and Planctomycetes and sugarcane fields have a greater number of TM7 and bacteria that were not identified, being Proteobacteria and Acidobacteria the dominating phyla in both types of soil. Although the results of nitrogen fixers and microbial biomass appear to be conflicting, it is an indication that the diazotrophic community undergoes with a diverse biotic and abiotic influences than the total community of soil microorganisms, and thus respond differently.
Caracterizado como de extrema importância, o solo é um ambiente complexo e que abriga uma grande diversidade de micro-organismos. Entretanto ainda pouco se sabe sobre a diversidade e ecologia da microbiota do solo. Deste modo, a primeira parte desta dissertação revisa a evolução metodológica empregada para caracterizar a diversidade e abundância dos micro-organismos encontrados no solo. A segunda parte consiste na aplicação de duas metodologias revisadas no capítulo anterior, a de diluição seriada e plaqueamento em meio sólido, para estimar micro-organismos fixadores de nitrogênio de vida-livre, e a fumigação-extração, para estimar a biomassa microbiana do solo (BMS). E a última parte emprega a técnica mais moderna de caracterização das comunidades microbianas de solo, a técnica de metagenômica de 16S rRNA. À vista disso, a nossa hipótese inicial era que solos de canavial teriam indicadores microbiológicos de solo melhores do que solos de pastagem. Os resultados comprovaram que a hipótese estava parcialmente correta, sendo possível encontrar cerca de 140% a mais de Unidades Formadoras de Colônias (UFCs) de diazotróficos de vida-livre e uma diversidade alfa 17% mais rica em solos de canaviais do que em solos de pastagens. A diversidade beta entre canaviais e pastagens apresentou diferenças nítidas. Entretanto, os solos de canaviais obtiveram cerca de 25% a menos de biomassa microbiana do solo do que solos de pastagens. Em relação aos filos bacterianos, os pastos possuem mais Actinobacteria, Chloroflexi e Planctomycetes e canaviais possuem maior número de TM7 e bactérias que não foram identificados, sendo Proteobacteria e Acidobacteria os filos dominantes nos dois tipos de solo. Apesar de parecerem conflitantes os resultados de fixadores de nitrogênio e biomassa microbiana, é um indicativo de que a comunidade de diazotróficos sofrem influências bióticas e abióticas diversas do que a comunidade total de micro-organismos do solo, e desta forma, respondem de forma diferente.
Ferraresi, Tatiana Maris. "Espectroscopias de infravermelho próximo e médio na quantificação de atributos do solo, com ênfase na matéria orgânica e na biomassa microbiana". Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/75/75132/tde-26072010-144538/.
Pełny tekst źródłaOrganic matter and microbial biomass are sensible ways to indicate soil quality as well as carbon and nitrogen stocks. These properties, added to clay, silt and sand contents, have been helped to choose sustainable agronomic soil managements. Current methods for organic matter (Walkley-Black modified by EMBRAPA SOLOS, 1997) and microbial biomass (Vance et al., 1987a) determinations have been widely used despite the generation of toxic waste and large time requirement for analyzing a small number of samples. Spectroscopy, in turn, has been shown a clean and rapid alternative method for this purpose. Thus, the aim of the study was to evaluate the near-infrared reflectance spectroscopy (NIRS) and the mid-infrared diffuse reflectance spectroscopy (DRIFTS) on soil organic matter, microbial biomass and texture determination. Clay, silt, sand, total organic carbon and microbial carbon contents as even as microbial quotient are accurately quantified by infrared spectroscopy. In general, DRIFTS provided better results.
Neto, Marcos Siqueira. "\"Estoque de carbono e nitrogênio do solo com diferentes usos no Cerrado em Rio Verde (GO)\"". Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/64/64132/tde-11042007-113740/.
Pełny tekst źródłaThe land-use change transforms the elements cycles in the soil, with alterations in the greenhouse gas (GHG) emissions. The time of implementation of the no-tillage system associated with a cover crop (NT) can recover the carbon (C) stocks in the soil and thus mitigate the global temperature increase due increasing GHG concentration. Therefore, the objective of this work was to evaluate the alterations of the soil carbon and nitrogen stocks following implementation time of no-tillage (NT) system taking as absolute reference the original condition (Cerradão) and, also, as relative reference, areas with other land use change, one under pasture, and other under conventional tillage. The study was done in areas located at Rio Verde (Goias state, Brazil) (17°50\' to 18°20\' S and 51°43\' to 50°19\' W), in a Oxisol (very clayed Red Dystrofic typic Latosol) with clay contents in the range 50 - 70 %. At each site, samples were taken randomly with subdivided parcels; these sites were divided in three sub-areas with six sampling locations and five depths (0-5, 5-10, 10-20, 20-30, 30-40 cm.). The sampled sites were three under ?Cerradão? (CE, 2CE and 3CE); one pasture (PA), one conventional tillage (CT), and seven situations under no-tillage system with an area recently converted from conventional tillage to no-tillage (NT 0), and areas with 4, 5, 7, 8, 10 and 12 years of implementation of the no-tillage (NT-4, NT-5, NT-7, NT-8, NT-10 and NT- 12). The variables studied were: physical and chemical attributes, the C and N stocks and the isotopic composition of 13C/12C and 15N/14N. The GHG emissions (CO2, N2O and CH4) were measured in CE, PA, CT and NT with 8, 10, and 12 years together with the quantity of inorganic-N and microbial C and N. The results of this study showed that these no-tillage systems guaranteed the physical attribute improvement with the decrease of the soil compaction and in the chemical attributes with increase of pH and of the availability of K, P, Ca and magnesium in the soil superficial layers. The carbon and nitrogen stocks were higher in ?Cerradão? (80 and 4 Mg ha-1, respectively to C and N). The lowest values in the carbon stocks were reported in NT-0, CT and PA (54; 62 and 64 Mg ha-1, respectively). The implementation time of no-tillage (NT) system increased the carbon stock in the soil, leading to carbon stock in the NT-12 area in the same level of the ?Cerradão? areas. The annual soil C accumulation in the NT system was calculated in 1,26 Mg ha-1 yr?1 (0-30 cm). For all areas, the average quantities of C and microbial-N and inorganic-N were found in CE, nitrate-N corresponded 60 % of the total. The highest total emission in C-equivalent was observed in PA (160 kg ha-1 yr-1), in CE it was 135 kg ha-1 yr-1, and amounted 121 and 129 135 kg ha-1 yr-1 for the CT and NT respectively. The carbon sequestration in the soil under (NT) for the studied situations was 1,13 Mg ha-1 yr-1. The No-tillage (NT) system studied showed to be an agricultural practice that improves the soil condition, promoting the increase of carbon stock without the increase of N2O and CH4 emissions, being thus an alternative to diminish the GHG emissions, and guaranteeing the sustainability of the productive system
Smaill, Simeon John. "The Effects Of Forestry Management Practices on Microbial Community Properties". Thesis, University of Canterbury. Biology, 2006. http://hdl.handle.net/10092/1382.
Pełny tekst źródłaKolodziej, Scott Michael. "Management effects on labile organic carbon pools". Texas A&M University, 2005. http://hdl.handle.net/1969.1/2424.
Pełny tekst źródłaOlofsson, Madelen. "On the investigation of chemical parameters reflecting microbial activity linked to nutrient availability in forest soil". Doctoral thesis, Mittuniversitetet, Avdelningen för naturvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-25994.
Pełny tekst źródłaFORE
Zaninetti, Rean Augusto. "Variação de atributos do solo na conversão da floresta primária em seringais em latossolo amarelo na Amazônia ocidental, Manaus-AM". Universidade Federal do Amazonas, 2012. http://tede.ufam.edu.br/handle/tede/3052.
Pełny tekst źródłaCoordenação de Aperfeiçoamento de Pessoal de Nível Superior
The cultivation of natural rubber can be an important alternative to planting large tracts of land degraded in the country, as they have good development in Oxisols, accumulating organic matter and improving nutrient cycling. Therefore the objective of this study was to evaluate through chemical and biological soil attributes, the potential of rubber in the balance, in stock and cycling of nutrients. For this, we studied a chronosequence consisting of a primary forest of reference and areas of rubber trees planted 5, 18, 19, 20 and 44 years ago, where it was taken five soil samples in each area, in 0-10 cm, 11-20 cm and 21-40 cm of depth, in this samples were determined the soil fertility, microbial biomass, organic matter fractionation and enzymatic activity. The results showed that removal of the forest resulted in an average reduction of 46% of the stock of organic carbon in soil, with respect to microbial biomass carbon, this reduction was 32%, regardless of age of the plantation. There was a predominance of the humin fraction, followed by humic and fulvic acids and enzyme activity was higher in soil under primary forest. The succession of primary forest to rubber plantations cause an increase in the microbial activity and does not make much change to the soil fertility. After 18 years of the cultivation there is recovery of half of the content of organic soil matter.
A heveicultura pode constituir importante alternativa de plantio para grandes extensões de terras degradadas pelo País, pois possuem bom desenvolvimento em Latossolos, acumulando matéria orgânica e melhorando a ciclagem de nutrientes. Por isto, o objetivo desse trabalho foi avaliar através de atributos químicos e biológicos do solo, o potencial da seringueira no equilíbrio, no estoque e na ciclagem de nutrientes. Para isso, foi estudada uma cronossequencia formada por uma floresta primária de referência e em áreas de cultivo de seringueira (Hevea spp.) plantadas há 5, 18, 19, 20 e 44 anos, onde foram coletadas cinco amostras de solo em cada área, nas profundidades 0-10 cm; 11-20 cm e 21-40 cm, nas quais foram determinada a fertilidade do solo, biomassa microbiana, fracionamento da matéria orgânica e atividade enzimática. Os resultados mostraram que a remoção da floresta ocasionou em diminuição média de 46% do estoque de carbono orgânico no solo, com relação ao C da biomassa microbiana, essa redução foi de 32%, independente da idade do seringal. Verificou-se o predomínio da fração humina, seguida pelas frações dos ácidos húmicos e ácidos fúlvicos e atividade enzimática sendo mais elevada nos solo sob floresta primária. A sucessão floresta primária para seringais causa aumento da atividade microbiana e pouco altera a fertilidade do solo. Após o décimo oitavo ano de idade do seringal há recuperação de metade do teor de matéria orgânica do solo.
Rocha, Mariana de Melo 1971. "Parâmetros microbiológicos no sistema de plantio direto e convencional em solos com diferentes teores de argila /". Botucatu : [s.n.], 2002. http://hdl.handle.net/11449/101744.
Pełny tekst źródłaResumo: O manejo agrícola altera, em muito, as características físicas, químicas e biológicas dos solos. A cultura e as condições climáticas, assim como o tipo de solo propriamente dito, afetam a decomposição da matéria orgânica do solo e, consequentemente, a biogeociclagem dos nutrientes. A matéria orgânica é uma característica importante em relação à fertilidade do solo, de modo que o impacto do uso do solo precisa ser avaliado principalmente em agroecossistemas. O conhecimento dos efeitos do uso da terra e das práticas agrícolas sobre a comunidade microbiana é de fundamental importância, em vista das importantes funções que os microorganismos desempenham no solo e que irão se refletir na produtividade agrícola. Neste sentido, uma avaliação da biomassa microbiana e de microorganismos do solo pode evidenciar diversas alterações no ecossistema do solo que estão associadas ao teor de argila e/ou sistemas de plantio. No presente estudo, caracterizou-se a camada superficial do perfil de solos sob plantio direto e plantio convencional em quatro fazendas no Brasil em relação a alguns de seus componentes microbiológicos. Para tanto, analisou-se, mensalmente, a respiração do solo, a biomassa microbiana e grupos de microorganismos. A avaliação da biomassa microbiana foi feita através da técnica da fumigação-incubação (FI), utilizando-se a Equação: [(C-CO2 liberado pelo solo fumigado, no período de 0-10 dias de incubação) - (C-CO2 liberado pelo solo não-fumigado, ao longo de 10-20 dias de incubação)]/0,45. Os cálculos indicaram um conteúdo de carbono da biomassa microbiana significativamente maior nos solos sob sistema de plantio direto em relação àqueles sob plantio convencional, na camada amostrada (0-10 cm de profundidade). Quantidades significativamente maiores ...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The crop management changes greatly the physical, chemical and biological soil properties. Furthermore, the crop and soil types, and the climatic conditions would affect on soil organic matter decomposition and on nutrients biogeociclying. Soil organic matter is a important characteristic in relationship soil fertility. The knowledge about effects on soil using and agriculture practices on soil microbial communities is very important, due to the function that microorganisms have in soil and it was going to in soil fertility. In this sense, evaluation of the soil microbial biomass and micro-organisms greatly aids predictions several changes in the soil ecosystems are associated with reduced tillage as compared with conventional tillage. Surface soils from long-term no-till and conventional tillage plots at four Brazil farms were characterised for microbial components. Soil respiration, microbial biomass carbon and counts of microorganisms were measured at intervals monthly. The evaluation of microbial biomass carbon was done by fumigation-incubation technique (FI). For calculating the soil microbial biomass carbon, the equation used was: Equation = [(CO2-C evolved by fumigated soil, 0-10 days) - (CO2-C evolved by unfumigated soil, 10-20 days)]/0,45. Significantly greater amounts of CO2-C were released from no-till than from conventional tilled soils. qCO2 values were not significantly different between tillage systems. This observation confirms that the tillage affected biological activity in those soils, further that qCO2 values didn't have significantily different which two tillage systems, in studied soils. Number both fungi and bacteria were assayed by Most Probable Number (MPN) by the agar drop counting technique and the microorganisms groups were calculated using by traditional Most Probable Number (MPN) method...(Complete abstract, click electronic access below)
Doutor
Filho, Solismar de Paiva Venzke. "Biomassa microbiana do solo sob sistema de plantio direto na região de Campos Gerais, Tibagi, PR". Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/11/11138/tde-10022004-151043/.
Pełny tekst źródłaThe demand for information about the nutrient cycling in soils under no-tillage motivated the study about soil microbial biomass (SMB) variations in different texture soils submitted for a long period to this kind of management system. The usual sequence of crops adopted for more than 20 years in Campos Gerais, Tibagi (PR) is soybean/corn during the summer and wheat/oats during the winter. The objective was to keep track of the microbial-C and N variations during a crop rotation cycle in four areas: three of them have been cultivated for 12 years under the no-tillage system, with a clay (PD12-TmuA), a sandy clay (PD12-TA), and a sandy clay loam (PD12-TmeA) texture, and a fourth, 22 years under the no-tillage system with a sandy clay loam textural class (PD22-TA). Nine soil samplings were performed during a period of 18 months, each time collecting four soil layers (0-2,5; 2,5-5; 5-10; 10-20 cm). Several corn and soybean root parameters were also evaluated in PD22-TA to determine the influence of diverse crops (C4 and C3 plants) on the microbial biomass concentration in the soil profile. The ten-year difference in no-tillage system adoption caused and increase of microbial-C in PD22-TA in relation to PD12-TA in the deeper soil layers. The PD22-TA also showed, on average, 30,8 kg Nmic.ha -1 more microbial-N than the PD12-TA in the 0-20 cm, with a narrower range of variation. The divergence in texture among the 12-year no-till sites resulted in higher microbial-C and N means in the 0-20 cm soil layer, except for 20 days after the wheat sowing. PD12-TA and PD12-TmeA did not show significant differences in the microbial-C amounts only for the 0-5cm layer. Microbial-C was more positively correlated with N-NH4 + and N-NO3 - than microbial-N, independently of soil texture, time since no-till adoption and crop sequence. The corn root system totaled 1324 kg C ha -1 and 58 kg N ha -1 in the upper soil layer, with higher density per length and per active root dry mass, and more roots in decomposition. The soybean root system (392 kg C ha -1 and 21 kg N ha -1 ) contributed more with fine roots and density per length than the corn. The effect of the corn root system on microbial-C reached deeper soil layers than the soybean roots. Microbial-N was stimulated by fine and active root concentration and by roots in decomposition phase, probably due to higher labile C and N concentration released to the soil. It was concluded that the microbial-C increased in depth along the period of no-till adoption, while the microbial-N showed less variation in the 0-20 cm soil layer. Both microbial-C and N are influenced by soil texture, although similar textural classes under no-till can maintain similar microbial-C amounts in the 0-5 cm soil layer during the crop production system.
Kemzūra, Paulius. "Žemės dirbimo įtaka dirvožemio organinės anglies ir mikroorganizmų biomasės sankaupoms". Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140616_130929-96499.
Pełny tekst źródłaThe master work presents the results on soil organic carbon, humus, C/N ration, microbial biomass carbon, soil respiration in soil with different soil tillage systems in two soil depths (0-10; 10-20 cm). Results were obtained in 2009 and 2013 and presented. Object of the research – The Endocalcari-Endohypogleyic Cambisol, where in 2009 and 2013 pea crops (Pisum sativum L.) have been growing. Soil tillage impact on soil organic carbon and microbial biomass carbon pools has been investigated. Method of the research – experiments was installed in four replications. Research area – 126 m2, research plot – 84 m2. Variants in blocks were rendomized. Soil respiration and microbial biomass pools were investigated in 2009 and 2013 in June in pea crops. Experiment variants were as followed: conventional tillage, reduced tillage, no tillage and ecological soil management with conventional tillage. Research results. Different soil tillage systems and ecological soil management system with conventional tillage had impact on soil organic carbon, humus, C/N ration, soil respiration and microbial biomass carbon pools. The highest org. C, humus, microbial biomass carbon concentrations and soil respiration intensity have been found in ecological soil management system. The fertilization with siderate crop may effect it mainly. The lower soil tillage intensity influenced the increase in org. C, humus concentration in 0-10 cm soil depth. In other hand, also along with lower tillage intensity... [to full text]
Zorel, Daiane. "Atributos químicos e microbiológicos de solo cultivado com cana-de-açúcar sob manejo convencional e orgânico". Universidade Federal de São Carlos, 2011. https://repositorio.ufscar.br/handle/ufscar/115.
Pełny tekst źródłaThe identification of soil quality indicators that demonstrate the alterations occurred in areas under organic management is important to determine the sustainability of this kind of cultivation. The soil microbial biomass and activity have been considered as important indicators of soil quality, especially when different management systems are employed in agroecosystems. In this context, the aim of this work was to evaluate management systems (organic and conventional) of the sugar cane over the soil quality, analyzing the chemical attributes as organic matter, pH, potential acidity, aluminium, magnesium, calcium, potassium, cation-exchange capacity, (CEC), sum of bases (SB), and percent base saturation (%BS), as well as the microbiological attributes as number of fungi and bacteria, microbial biomass carbon (MBC), basal respiration (BR) and metabolic quotient (MQ). The soil analyses were taken in the period comprised between May/2009 and September/2010. Among the chemical parameters that most showed the alterations in soil caused by the management are pH, magnesium concentration, potential acidity, SB and %BS. Higher values obtained with these two last parameters in the organic systems with addition of compost and limestone (SOCA) or compost and corrective, especially, indicate soil fertility. There was no significant difference among the treatments concerning MBC probably because it is an area where only recently the experiments were established. An influence of the sampling period was observed, with high values in the higher rainfall period. Higher values of BR were detected in the organic systems, especially in May and August/2009, which was coincident with the higher rainfall period and temperature. Although no significant difference was verified, the higher values of MQ were verified in the conventional system. Concerning the number of fungi and bacteria, the microbial community seemed to respond better to the climate/rhizosphere than the treatments involving the different management systems. Among the parameters studied, the BR was the most effective parameter to detect changes that occur in the soil due to the management system, showing that the organic system altered the soil quality, which reflected in the microbial activity.
A identificação de indicadores de qualidade de solo que demonstrem as alterações ocorridas em áreas agrícolas é importante para determinar a sustentabilidade do sistema de cultivo. A biomassa e a atividade microbiana do solo têm sido apontadas como importantes indicadores de qualidade do solo, especialmente quando se avalia o efeito de diferentes sistemas de manejo em agroecossistemas. Neste contexto, o objetivo deste trabalho foi avaliar o efeito de sistemas de manejo (orgânico e convencional) da cana-de-açúcar sobre a qualidade do solo, analisando-se os atributos químicos como matéria orgânica, pH, acidez potencial, alumínio, magnésio, cálcio, potássio, capacidade de troca catiônica (CTC), soma de bases (SB), porcentagem por saturação de bases, (V %); e microbiológicos como número de bactérias e fungos, carbono da biomassa microbiana (CBM), respiração basal (RB) e quociente metabólico (qCO2). As análises de solo foram realizadas no período compreendido entre Maio/2009 a Setembro/2010. Entre os parâmetros químicos que mais mostraram as alterações no solo provocadas pelo manejo estão o pH, teor de magnésio, acidez potencial, SB e V%. Valores mais elevados obtidos com estes dois últimos parâmetros nos sistemas orgânicos com adição de composto e calcário (SOCA) ou composto e corretivo (SOCO), especialmente, indicam fertilidade do solo. Não houve diferença significativa entre os tratamentos quanto ao CBM provavelmente por ser área recém implantada. Houve influência da época de amostragem, observando-se valores mais altos na época de maior pluviosidade. Valores superiores de RB foram detectados nos sistemas orgânicos, especialmente em Maio e Agosto/2009, coincidente com períodos de maior pluviosidade e temperatura. Embora não tenha sido observada diferença significativa, os maiores valores de qCO2 foram verificados no sistema convencional. Em termos de contagem de fungos e bactérias, a biota microbiana do solo pareceu responder mais ao clima/rizosfera que aos tratamentos envolvendo os sistemas orgânico e convencional. Dentre os parâmetros estudados e no período de tempo analisado, a respiração basal foi o parâmetro mais efetivo para detectar mudanças que ocorreram no solo devido ao sistema de manejo, mostrando que o sistema orgânico alterou a qualidade do solo, refletindo na atividade microbiana.
Liao, Julia Den-Yue. "Woodland development and soil carbon and nitrogen dynamics and storage in a subtropical savanna ecosystem". Texas A&M University, 2004. http://hdl.handle.net/1969.1/1560.
Pełny tekst źródłaRigby, Deborah Monique. "Microbial Responses to Coarse Woody Debris in Juniperus and Pinus Woodlands". BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3515.
Pełny tekst źródłaFrazão, Leidivan Almeida. "Conversão do Cerrado em pastagem e sistemas agrícolas: efeitos na dinâmica da matéria orgânica do solo". Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-18092007-113334/.
Pełny tekst źródłaLand-use changes of Brazilian savanna (Cerrado) result in alterations of the soil organic matter (SOM). Managements practices with tillage accelerate the SOM decomposition, enhancing greenhouse gases emissions from the soil to the atmosphere. Therefore, the objective of this work was to evaluate the changes in the SOM dynamics of a Typic Quartzipisamment submitted to different uses and managements systems, using as reference the native system (Cerrado). The present study was conducted in areas located at Comodoro (Mato Grosso state, Brazil) (from 13º50\'00\" till 13º50\'03\" S and 59º37\'18\" W). At each site, samples were taken randomly within seven areas. Sampling activities were performed in July 2005 and February 2006 and the sample sites consist of an area of \"Cerrado\" (CER); pasture (CAP22); conventional tillage with soybean (CS1), rice-soybean succession (CAS3) and rice-soybean-sorghum or millet (CAS/Sor3 and CAS/M3) successions; and a field with no-tillage system (CAP13S/M5). Studied variables were: physical and chemical attributes, C and N stocks, isotopic composition of 13C/12C and 15N/14N, C and N content in the SOM fractions, quantity of inorganic N, microbial C and N biomass, metabolic quotient (qCO2), and the soil gases fluxes (CO2, N2O and CH4). The results of this study showed that all evaluated fields under conventional or no-tillage systems result in physical and chemical attribute improvement in relation to the pasture (CAP22), with soil compaction decrease, pH increase and improvement of the availability in phosphorus, calcium and magnesium. The C and N stocks were higher in areas CAS/Sor3 and CAS/M3, corresponding to the highest clay content. The area CAP13S/M5 showed similar clay content, but smaller C and N stocks, this result was attributed to the land-use: thirteen years as pastures without reform and also the short time of no-tillage implantation. Analyzing the SOM fractions, it was verified higher C and N contents in the 50 \'mü\'m fraction. The higher quantities of inorganic N in relation to the CER were found in area CAS/M3, and with exception of this area, ammonium was the predominant form of inorganic N. Higher quantities of the microbial C and N were obtained during the wet season, when all areas presented a cover crop. Among areas, the higher quantities of microbial C and N were obtained in CAP22. The fluxes of C-CO2, excepting area CAS/Sor3, were higher during the wet season, while the fluxes of N-N2O and C-CH4 were similar between seasons studied, because high standard deviations were calculated for each gas. The land use promoted alterations in SOM dynamic, however it was not possible to differentiate the best land use for this Typic Quartzipisamment, mainly due to the short time of no-tillage implantation, and the degradation of the pasture (although of the implantation time was higher)
Vasconcelos, Maria Cecília Alves de. "AVALIAÇÃO DOS INDICADORES QUÍMICOS E BIOLÓGICOS DE QUALIDADE DO SOLO DE CERRADO DEGRADADO APÓS O CULTIVO DE LEGUMINOSAS". Pontifícia Universidade Católica de Goiás, 2015. http://localhost:8080/tede/handle/tede/2545.
Pełny tekst źródłaAmong the parameters used by the scientific community, the biomass evaluation is the most precise one in terms of presenting the biological components of the soil. Intending to evaluate the potential of the legumes Campo Grande Stylo, calopo (Calopogonium mucunoides) and pigeon pea regarding the recovery of damaged soil, sixteen plats of these legumes were planted in latin square form for later microbial biomass analysis. The microbial biomass was analyzed according to the Vance et. (1987) principles. No significant differences were found compared to the fallow, although circumstances like the lack of precipitation, the time of the year and the production of dry matter affected the microbial biomass development. The studied legumes that presented the largest microbial biomass production were the Campo Grande Stylo and the calopo (Calopogonium mucunoides), showing a trend of improvement compared to the fallow. Despite the stress factors, the microbial biomass showed a trend of improvement on the plats where the legumes were seeded, and it can be considered a prior parameter of agrisystem changes.
Dentre os parâmetros utilizados pela comunidade científica, o que apresenta maior sensibilidade na caracterização dos componentes biológicos do solo é a avaliação de biomassa microbiana (BMS). Com o objetivo de avaliar o potencial das leguminosas Calopogônio, Estilosantes e feijão Guandu na recuperação dos solos degradados e na melhoria da biomassa microbiana, foi realizado o plantio das leguminosas e posterior análise da biomassa microbiana em dezesseis canteiros distribuídos em um quadrado latino. A biomassa microbiana foi analisada conforme os princípios de Vance et. (1987). Não foram encontradas diferenças significativas em relação ao pousio, porém fatores como a baixa pluviosidade, época de plantio e produção de massa seca influenciaram o desenvolvimento da BMS. As leguminosas estudadas que apresentaram maior produção de BMS foram o Estilosantes e o Calopogônio, evidenciando uma tendência de aumento em relação ao pousio. Mesmo com fatores de estresse, a biomassa microbiana nos canteiros com as leguminosas evidenciou um potencial de aumento, podendo ser considerado um parâmetro que antecede alterações no agrosistema.
Sucre, Eric Brandon. "Soil resource heterogeneity and site quality in Southern Appalachian hardwood forests: Impact of decomposing stumps, geology and salamander abundance". Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/29470.
Pełny tekst źródłaPh. D.
Moura, Alexandre Carvalho de. "Aspectos microbiológicos do sistema água residuária da suinocultura-solo". Universidade Estadual do Oeste do Parana, 2015. http://tede.unioeste.br:8080/tede/handle/tede/209.
Pełny tekst źródławastewater use in agricultural soils has been adapted as an important pratice for agriculture. Due to the reduction of the availability of the quality of water resources is becoming increasingly important to add value to the use of water. The swine wastewater is rich in organic matter, composed of various elements of chemical origin, physical and biological. Its addition in soil and water resources without previous studies and knowledge of its components, can cause changes in the soil, contamination of surface and groundwater, biology changes in these environments, as well as the contribution and accumulation of groups of microorganisms in the environment, including pathogens. Most studies on swine wastewater, mainly in Brazil, are restricted to its physical and chemical components, evaluating its impact directly on the ground, water bodies or in plant productivity. Few studies focus on the microbial composition of this type of waste and especially on the risk of environmental contamination by pathogenic microorganisms or even on the impact of this element in the soil microbial community. Thus these animal manure may have an important role as initiators of infectious diseases in animals and humans. Thus, this thesis consists of two papers. In the first article, a study was done to check the bacterial composition present in swine wastewater, and to verify the possibility of eliminating these microorganisms through the main anaerobic treatment systems used in Brazil. It was evaluated in particular pathogenic microorganisms of gastrointestinal origin of the pigs and microbial environmental markers. The wastewater samples were taken from pig farms that use bio-manure storage tanks and digesters as treatment methods for the waste. The results clearly showed the presence of biomarkers and pathogens in swine wastewater. Despite the possibility of decrease of certain microbial groups throughout the stages of the treatment process, no elimination of pathogens in either treatment systems. Thus, demonstrates the possibility of the spread of pathogens and microorganisms in the environment. In the second paper, the objective was to evaluate the effect of application of swine wastewater associated with mineral fertilizer in agriculture, after a long time of application of swine wastewater in the soil microbial community. Thus, samples were collected from soils after 18 production culture cycles, with the application of wastewater from pig farms and assessed the quantitative effects (basal respiration, microbial biomass and metabolic quotient) and qualitative (DGGE, biodiversity indices, correlation between the chemical conditions and soil microbial activity) in the soil microbial community. The results showed that the application of swine wastewater, especially after long time and in higher concentrations, can change the dynamics of soil microbial community, impacting the dump site. The results of these studies show the need for further studies to apply this type of waste in agricultural soils, in order to minimize the risk of environmental contamination and/ or spread of pathogens.
A utilização de água residuária em solos agrícolas vem sendo praticada como importante opção para agricultura. Devido à redução na disponibilidade de recursos hídricos, a reutilização de água residuária vem ganhando espaço na agricultura com a agregação de valor para o uso de água. A água residuária da suinocultura é rica em matéria orgânica, composta por diferentes elementos de origem química, física e biológica. Sua adição no solo e recursos hídricos, sem estudos prévios e conhecimento de seus componentes, pode provocar contaminação de águas superficiais e subterrâneas, alterações da biologia destes ambientes, bem como o aporte e acúmulo de grupos de microrganismos no ambiente, incluindo patógenos. A maior parte dos estudos sobre água residuária da suinocultura, principalmente no Brasil, se restringe aos seus componentes físicos e químicos, avaliando seu impacto diretamente sobre o solo, corpos d´agua ou na produtividade vegetal. Poucos estudos se concentram na composição microbiana deste tipo de resíduo e principalmente sobre o risco de contaminação ambiental por microrganismos patogênicos ou mesmo sobre o impacto deste elemento na comunidade microbiana do solo. Desta forma estes dejetos animais podem apresentar importante papel como iniciadores de doenças infecciosas em animais e seres humanos. Este trabalho de tese é constituído de dois artigos. No primeiro artigo, foi feito um estudo para verificar a composição bacteriana presente na água residuária da suinocultura, bem como verificar a possibilidade de eliminação destes microrganismos através dos principais sistemas de tratamento anaeróbicos utilizados no Brasil. Foram avaliados em especial os microrganismos patogênicos, de origem gastrointestinal dos suínos e bioindicadores microbianos. As amostras de água residuária utilizadas foram provenientes de granjas que utilizavam de sistemas anaeróbicos com esterqueiras e biodigestores no tratamento do resíduo. Os resultados obtidos mostraram claramente a presença de coliformes, mesofilos aeróbios, bolores e leveduras, enterococos e patógenos na água residuária da suinocultura. Apesar da possibilidade de decréscimo de determinados grupos microbianos ao longo das etapas dos processos de tratamento, não houve eliminação de patógenos em nenhum dos dois sistemas de tratamento, o que pode possibilitar a disseminação de microrganismos e patogenos no meio ambiente. No segundo artigo, o objetivo foi avaliar o efeito da aplicação da água residuária da suinocultura associada a adubação mineral, em área agrícola, após longo tempo de aplicação, na comunidade bacteriana do solo. Assim, foram coletadas amostras de solo com 18 ciclos de produção, com aplicação de água residuária de suinocultura e avaliados os efeitos quantitativos (respiração basal, biomassa microbiana e quociente metabólico) e qualitativos (DGGE) na comunidade bacteriana do solo. Os resultados mostraram que a aplicação de água residuária da suinocultura, principalmente após longo tempo e em concentrações maiores, pode alterar a dinâmica da comunidade bacteriana do solo, impactando no local de despejo. Os resultados dos artigos mostram a necessidade de maiores estudos para aplicação deste tipo de resíduo na agricultura, a fim de minimizar os riscos de contaminação ambiental e ou disseminação de patógenos.
Tischer, Alexander. "Ecological gradients caused by land-use change and land management alter soil microbial biomass and community functioning in a tropical mountain rainforest region of southern Ecuador". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-190211.
Pełny tekst źródłaSeit dem Übergang vom Holozän zum Anthropozän greift der Mensch immer stärker in globale und regionale Stoffkreisläufe ein. Durch die Zerstörung von Naturwäldern und Landnutzungswandel werden die Strukturen und die Funktionen der Ökosysteme stark verändert. Unangepasste Landnutzung führt zu Nährelementverlusten, die mittel- bis langfristige zur Bodendegradation und zur Reduktion von Bodenfunktionen führen. Solche Veränderungen sind insbesondere in den Tropen zu beobachten. Bodenmikroorganismen spielen in den Stoffkreisläufen eine zentrale Rolle. Zudem sind sie sensitive Bioindikatoren für den Zustand von Ökosystemen. Im Gegensatz dazu, werden die Bodenmikroorganismen noch nicht ausreichend für die Zustandsbewertung von Ökosystemen verwendet. In der vorliegenden Dissertation werden verschiedene Datenanalysen zu den Beziehungen von Landnutzungswandel (Naturwald, Weiden verschiedener Alter, sekundäre Sukzession) und den Eigenschaften der Bodenmikroorganismen in einer tropischen Bergregenwaldregion Süd-Ecuadors zusammengefasst. Ein besonderer Fokus lag darauf zu prüfen, ob die mikrobielle Biomasse und die Funktionen die von der mikrobiellen Gemeinschaft geleistet werden (z.B. Enzymaktivitäten) durch den Landnutzungswandel beeinflusst werden. Ein informations-theoretischer Ansatz wurde verwendet um verschiedene Erklärungsansätze der steuernden Faktoren vergleichend zu testen. Darüber hinaus wurden in einem Weidedüngungsexperiment die Reaktionen der ober- und der unterirdischen Ökosystemkomponenten auf die Anreicherung mit N und P getestet. Um die Ergebnisse auf eine breite wissenschaftliche Basis zu stellen wurde die Untersuchungen in den Kontext der Theorie die Ökologischen Stöchiometrie eingeordnet. Die C:N:P Stöchiometrie im Boden und in den Mikroorganismen veränderte sich durch den Landnutzungswandel und mit der Bodentiefe. Mit der Weideetablierung nahmen die C:N:P Verhältnisse im Boden deutlich ab, stiegen dann nach dem Verlassen der Weiden im Zuge der sekundären Sukzession wieder an. Das mikrobielle C:N Verhältnis variierte nur leicht, dagegen zeigten das C:P und N:P Verhältnis deutliche Veränderungen durch den Landnutzungswandel. Mit diesen Veränderungen in der Boden- und Organismenstöchiometrie waren auch Veränderungen in der Struktur der mikrobiellen Gemeinschaften verbunden. Deutliche positive Beziehungen existierten zwischen den saprotrophen Pilzen und den Protozoen. Die steigenden Mengen von Protozoen waren wiederrum mit sinkendem mikrobiellen N:P verbunden. Diese Muster weisen auf Veränderungen in den Bodennahrungsnetzten durch Landnutzungsänderungen hin. Sehr deutliche Abweichungen von globalen Mustern der C:N:P Stöchiometrie deuten darauf hin, dass der Landnutzungswandel signifikanten Einfluss auf die C:N:P Stöchiometrie ausübt. Der Landnutzungswandel beeinflusste auch die mikrobielle Biomasse, die Basalatmung, sowie die mikrobielle Aufnahme und Produktion von NH4-N im Boden. Dabei zeigten kombinierte Erklärungsansätze die adäquateren Beschreibungen der Muster. In den kombinierten Modellen zur Erklärung der mikrobiellen Biomasse und der mikrobiellen Leistungen überwogen Prädiktoren der mikrobiellen Ressourcen und der bodenchemischen Umwelt. Ein weiterer Schwerpunkt der Untersuchungen lag auf der Erfassung der Effekte des Land-nutzungswandels auf die Aktivität von extrazellulären Bodenenzymen. Bisher ist wenig darüber bekannt, welche Faktoren die katalytischen Eigenschaften steuern und beispielsweise, ob es Zusammenhänge zur mikrobiellen Gemeinschaftsstruktur gibt. Um diese Fragen näher zu beleuchten wurden sechs hydrolytische Enzyme basierend auf MUF-Substraten untersucht. Die mikrobielle Produktion von AP stand dabei in Zusammenhang mit dem niedrigen P-Status der untersuchten Böden. Das wurde besonders durch die hohe AP Produktion im Vergleich zu BG belegt. Im Allgemeinen konnten drei verschiedene Mechanismen festgestellt werden, die die Produktion der untersuchten EHEs vermutlich steuerten. 1.) Der P-Bedarf der Mikroorganismen regulierte die Produktion von AP, vorausgesetzt, dass ausreichend N und C zur Enzymsynthese zur Verfügung standen. 2.) Die Höhe der mikrobiellen Biomasse hat sich als wichtiger Faktor für die Produktion von CBH, BG und NAG gezeigt. Das deutet auf die konstitutive Produktion dieser Enzyme hin. 3.) Die substratinduzierte Produktion von Enzymen ist vermutlich entscheidend für die Aktivität von AG und XYL. Die Berücksichtigung der Enzymkinetiken, insbesondere der Michaelis-Menten-Konstante lieferte weitere Aufschlüsse über relevante Faktoren. Im Allgemeinen so scheint es, haben sich die mikrobiellen Gemeinschaften an die starken Umweltgradienten, die durch den Landnutzungswandel erzeugt worden angepasst. Im Vergleich zu den verfügbaren Daten aus Reinkulturen, wiesen die mikrobiellen Gemeinschaften der untersuchten Böden in der Regel eine deutlich höhere katalytische Effizienz auf. Auch für die Michaelis-Menten-Konstante sind die Faktoren enzymspezifisch. So ist für die Km von XYL der Boden-pH-Wert, für AP das C:N Verhältnis und für NAG die DOC-Menge entscheidend. Darüber hinaus haben sich deutliche Beziehungen zwischen der Menge an Gram(-)-Bakterien und der Substrataffinitäten von XYL und AP ergeben. Je höher die Gram(-)-Abundanz, desto höher war die Substrataffinität der Enzymsysteme. Gegenüber alter und degradierter Weiden, war der Umsatz der untersuchten Substrate im Oberboden der aktiv genutzten Weide drei- bis vierfach erhöht. In einem 5-jährigen Düngeexperiment in der Bergregenwaldregion der Anden Süd-Ecuadors wurden die Reaktionen des auf dieser Fläche N/P co-limitierten Grases (Setaria sphacelata), der Arbuskulären Mykorrhiza (AMF) sowie der Bodenmikroorganismen auf moderate N, P und N+P-Düngung untersucht. Die Zugabe von N+P erhöhte die oberirdische Biomasse (+61%) wohingegen die Wurzelbiomasse durch die Zugabe von P (+45%) anstieg. Die C:N:P Verhältnisse weisen auf veränderte P-Aufnahme oder Translokation von P in die Wurzeln hin. Im Besonderen verengte sich das Wurzel C:N and C:P in der P- und der N-Zugabe. Die aus dem Boden extrahierbaren C, N und P-Fraktionen wurden deutlich beeinflusst. Die Zugabe von P stimulierte die Biomasse Gram-(+)-Bakterien (+22%), die Abundanz der AMF (+46%) und die Brutto-N-Mineralisierung. Die Auswertungen deuten darauf hin, dass die Nährstoffanreicherung indirekt über die Veränderungen der Graswurzeln auf die Bodenorganismen wirkte. Die Ergebnisse bestätigen, dass N und P in den Reaktionen von co-limitierten Pflanzen eng miteinander verbunden sind. Vor allem aber steuert P grundlegend die Allokation von Ressourcen und wirkt damit auf andere Ökosystem-komponenten, z.B. auf die Struktur und Aktivität der Bodenmikroorganismen
Lupatini, Manoeli. "Mudança do uso da terra e tipo de solo são fatores determinantes de fungos e arqueas no bioma pampa". Universidade Federal de Santa Maria, 2012. http://repositorio.ufsm.br/handle/1/5558.
Pełny tekst źródłaLand-use change and soil type can have significant impact on microbial communities of soil. The Pampa biome in recent decades has undergone severe changes in landscape due to landuse change, mainly for the introduction of exotic tree plantation and croplands. Different landuse in Pampa biome were evaluated to determine the effect on the structure of soil microbial communities. Furthermore, due to the presence of various soil types present in this biome, we investigated whether different soil type harbor different microbial communities. Soil samples were collected at two sites with different land-uses (native grassland, native forest, exotic tree plantation and cropland) and in a typical toposequence in Pampa biome formed by Paleudult, Albaqualf and alluvial soils. The structure of soil microbial community (archaeal and fungal) was evaluated by RISA and soil functional capabilities were measured by microbial biomass carbon and metabolic quotient. We detected different patterns in fungal and archaeal community driven by land-use change and soil type showing that both factors are significant drivers of microbial community structure and activity. Acacia and Eucalyptus afforestation presented the most dissimilar communities when compared with natural vegetation. Although differences in the communities were detected, the soils tested shared most of the taxonomic unities and only a proportion of the community suffers changes caused by human interference.
A mudança do uso da terra e o tipo de solo podem exercer impactos significantes sobre a comunidade microbiana do solo. O bioma Pampa Brasileiro, nas últimas décadas, tem sofrido severas mudanças na paisagem devido à mudança no uso da terra, principalmente pela introdução de plantações de árvores exóticas e pelos cultivos agrícolas. Diferentes usos do solo no bioma Pampa foram avaliados para determinar o efeito sobre a estrutura das comunidades microbianas do solo. Além disso, devido à presença de vários tipos de solo presentes neste bioma, foi investigado se diferentes tipos de solos abrigam diferentes comunidades microbianas. Amostras de solo foram coletadas em duas áreas com diferentes usos do solo (pastagem nativa, mata nativa, plantações de árvores exóticas e cultivo agrícola) e em uma topossequência típica no bioma Pampa formado por Argissolo, Planossolo e solos aluviais. A estrutura das comunidades microbianas do solo (arqueas e fungos) foi avaliada por RISA e capacidades funcionais do solo foram mensuradas através de carbono da biomassa microbiana e quociente metabólico. Diferentes padrões foram detectados nas comunidades de fungos e arqueas influenciados pela mudança no uso da terra e pelo tipo de solo, mostrando que ambos são importantes fatores da estrutura e atividade da comunidade microbiana. Florestamentos de acácia e eucalipto apresentaram as comunidades mais diferentes quando comparados com a vegetação natural. Embora diferenças nas comunidades foram detectadas, os diferentes usos e tipos de solos avaliados compartilham grande parte das unidades taxonômicas e mostram que apenas uma parte da comunidade sofre alterações causadas pela interferência humana.