Thèses sur le sujet « Biological soil quality »

El biochar es un producto resultante de la descomposición térmica mediante pirolisis de biomasa y aplicado al suelo para mejorar sus propiedades. Este area de investigación está auge actualmente por su papel en mejorar la práctica agrícola y como estrategia de secuestro de carbono en suelo. Aún siendo un campo joven, poco se sabe sobre su idoneidad a largo plazo, y aún no se ha estudiado suficientemente sus posibles efectos negativos sobre la calidad del suelo, incluyendo la biología del suelo. Esta tesis toma como enfoque métodos biológicos para evaluar el impacto de biochar sobre la calidad del suelo. Una parte importante de la tesis se basa en bioensayos de laboratorio, complementados por un estudio de campo para evaluar de manera realista los efectos de biochar en un agroecosistema. Los bioensayos realizados a seis biochars demostraron que el método de producción tiene un impacto importante sobre las propiedades químicas del suelo, y a su vez la respuesta de las plantas. Los biochars de gasificación y pirólisis rápida indujeron inhibición vegetal a concentraciones realistas, mientras biochars de pirólisis lenta generalmente no afectaron a las plantas. La inhibición fue interpretada como consecuencia de efectos a corto plazo sobre la disponibilidad de nutrientes en algunos biochars, debido a sus elevados contenidos de materia volátil, que estimularían el crecimiento de microorganismos y la inmobilización de N, mientras que en los biochar más alcalinos se sospechó que fueron debidos a una reducción de la disponibilidad de P. En tests con invertebrados, las respuestas de colémbolos y enquitreidos han sido muy similares, con estimulación en el biochar de lodos de depuradora y de inhibición en el de astilla de pino producido por gasificación. Los resultados señalan el papel de la alcalinización como causándote de los efectos directos en mortalidad y de reproducción. No se pudo demostrar que el estímulo de la comunidad microbiana causado por el biochar explicara la estimulación de la reproducción de la mesofauna observada en algunos biochars. Se desarrolló un nuevo parámetro de medida del impacto para los colémbolos basado en la biomasa de juveniles y su estructura de tamaños mediante el ajuste a modelos multi-Gaussianos. Los incrementos en el número de clases de edad, acompañados por incrementos en la biomasa y longitud de individuos, han sido interpretados como efectos estimulatorios, mientras, a su vez, su diminución ha se interpretó como efectos inhibitorios. Finalmente, en un experimento de campo simulando un cultivo de cebada enmendado con un biochar de pino producido por gasificación, se han demostrado efectos positivos sobre propiedades físicas del evaluadas. Los efectos sobre las propiedades químicas fueron menos marcados, pero son destacables los incrementos en las concentraciones K+, y la reducción de las de NO3-. El cultivo fue generalmente estimulado a 12 t ha-1, y generalmente inhibido a 50 t ha-1. La actividad de mesofauna fue impactada negativamente a 50 t ha-1 biochar. La adición de biochar permitió aumentos significativos en la abundancia microbiana pero no en su actividad, indicando un aumento de su eficiencia. Ensayos de laboratorio de mineralización de material vegetal indicaron que el biochar reducía la liberación de NO3-. Globalmente, el estudio de campo ha demostrado que biochar puede mejorar la fertilidad del suelo a aplicaciones moderadas, pero puede disminuir la calidad del suelo a aplicaciones altas. Los resultados de esta tesis contribuyen a la escasa información disponible sobre los efectos del biochar sobre la biota del suelo, así como los beneficios y riesgos en suelos alcalinos bajo clima mediterréneos.
Biochar is thermally-decomposed biomass deliberately applied to soil to improve its properties. In recent years, biochar research has grown immensely for its potential role in improving agricultural practices and as a strategy to sequester carbon in the soil. However, as a young scientific field of study, little is proven about biochar’s long-term compatibility with modern agriculture, and there is still major uncertainty about its potential negative impacts on soil quality, information on biochar’s effects on soil biology is quite limited. Biochar’s effects on soil quality is the topic of the thesis, with an emphasis on biological methods for its evaluation. A substantial portion of this thesis is based on ecotoxicological approaches of evaluation. Laboratory bioassay studies were undertaken, and complementary studies were undertaken in the field for a broader evaluation of effects in a more realistic setting. Plant growth tests with six biochars showed that pyrolysis method had a strong influence on chemical properties affecting plant responses. Gasification and fast-pyrolysis chars were strongly inhibitory at realistic application rates, while slow-pyrolysis chars generally did not affect plant growth. Inhibition was interpreted to be due to short-term effects on nutrient plant availability, due to biochar’s volatile matter content which increases competition with microorganisms, and P content and/or effects on P availability. In tests with soil invertebrates, performance of the Collembolan and enchytraeid were analogous for both the sewage sludge and pine gasification char, which were slightly stimulatory and inhibitory, respectively. Our results suggest alkalization-related increases in mortality and inhibition of reproduction. We hypothesized that increased microbial abundance would explain stimulation of fauna performance, but this showed no clear trend with biochar concentration, providing no evidence for a trophic effect. Also, Collembolan juvenile biomass and size class structure endpoints were developed using a multi-Gaussian fitting approach. Increases in number of size classes, accompanied by greater relative allocation of biomass to individuals of larger somatic length, were interpreted as stimulatory conditions, and reduction in the number of classes and proportional representation of larger classes were associated with inhibitory effects. Finally, in the field study, simulating barley cultivation with amendment of a gasification biochar, effects on soil physical properties were generally positive. Measured soil chemical parameters were not strongly affected, with the exception of increased K+ ¬ and decreased NO3-. The barley crop was generally stimulated at 12 t ha-1, and generally inhibited at 50 t ha-1. Mineralization tests showed that biochar also reduced NO3- transformation. Overall, the field study that the biochar can enhance soil quality at moderate application rates, but can decrease soil quality at higher rates. Also, fauna activity was negatively impacted at the high, 50 t ha-1 application rate. The addition of biochar permitted increases in microbial abundance, but not activity, indicating an increase in efficiency. These results all have served to provide basic information on effects of biochar on soil quality, whereas to date little information has been available either for soil biota or in mediterranean or alkaline soils.

Soils formed from ultramafic rocks are normally by pH values close to neutrality, a high base status and are usually rich in Mg, Fe and heavy metals. The low Ca/Mg ratio and the high heavy metal content could cause toxic effects in the biological communities. Plant communities, in particular, are usually different from nearby areas with different substrates and rich in endemisms and adapted species and subspecies. Despite their great environmental and ecological interest, pedological and ecological properties of mountain or boreal soils developed on similar substrates have seldom been studied worldwide. 198 soil pits (associated with phytosociological surveys) have been opened and analyzed in the ophiolitic area of Mont Avic Natural Park (Val d’Aosta, Western Alps, Italy), beween 900 and 2900 m above see level. Soils formed from ultramafic, mafic rocks and calcschists have been observed, in order to recognize the most ecologically important soil factors. The results show that soil properties are related with altitude and slope aspect in forest habitats, while the effect of substrate becomes important above timberline. Strong leaching in forest soils, related to high acidity and to the podzolization process, decrease the total and bioavailable heavy metal contents, above the treeline pedogenic and geomorphic processes release and accumulate large quantities of potentially hazardous trace elements. The plant communities strictly depend on the edaphic properties above the treeline, while in the forest habitats the differences caused by substrate are less discernible. Microbial and microarthropodal communities suffer stress caused by heavy metals in forest soils, while at the alpine level non significant statistical or ecological correlation are visible. Heavy metals (Ni, in particular) are the most important edaphic properties in differentiating plant communities on different substrata, while the Ca/Mg ratio (usually considered the most influencing soil properties on ultramafic soils) has no particular ecological effect.

The objective of this research was to determine the effects of conventional inputs on soil chemical and biological properties compared to organic systems in a four year vegetable rotation. Tillage and cover crops were the same in all treatments to avoid confounding factors often present in similar research. Additional experiments investigated plant gene expression in organic and conventional management systems and in soils with decreased microbial diversity. Experimental plots were prepared in the spring of 2004; four replications of three management treatments, organic, low-input and conventional, were arranged in a randomized complete block design. The rotation consisted of edamame soybean, sweet corn, fallow (pastured poultry in organic plots), and potatoes. Soil samples were taken in the spring and fall of each year, along with data for pest damage, weed control, yield and quality. Soil samples were analyzed for enzyme activity (maximum activity under substrate saturation) and basic soil chemical properties. Treatments were compared over time using 2-Way ANOVA. Multiplex terminal-restriction fragment length polymorphism (M-TRFLP) profiles of the soil microbial community were compared using Multiple Response Permutation Procedures (MRPP). Multi-way ANOVA detected significant treatment effects over time in total carbon, nitrogen, Mehlich III K, Exchangeable K and exchangeable Na (p=0.05). Many significant changes in soil properties over time could not be attributed to treatment effects. All treatments produced similar yields, indicating that successful organic production of these vegetables is possible in Kentucky. Input costs for organic were 37% higher than conventional, due to the cost of organic fertilizer. The organic system required nearly 50% more labor hours than conventional or low-input. The low-input system was the most cost effective, with 58% less input expenses than the conventional system. Microarray analysis of approximately 37,500 Glycine max transcripts did not show significant differences in the gene expression between plants grown organically and conventionally, in plots with significant soil chemical and microbial differences. An experiment in progress is investigating changes in plant gene expression using real time RT-PCR in tomatoes grown in autoclaved soil and native field soil.

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O sistema de integração Lavoura-Pecuária (iLP), é uma alternativa de conservação dos recursos naturais. Sua característica principal é incluir culturas anuais e pastagens em uma mesma área, com objetivos de aumentar os lucros, manter e ou melhorar os atributos químicos, físicos e biológicos do solo. O objetivo deste trabalho foi avaliar os atributos microbiológicos do solo e sua resiliência, como indicadores de qualidade, em sistemas de iLP, no Ecótono Cerrado-Amazônia no estado de Mato Grosso. Amostras de solo, foram coletadas em 5 conformações de iLP, uma mata nativa e uma sucessão de culturas (soja/milho), no período de chuva, em duas épocas (2012 e 2013). Por meio da análise univariada dos dados, observou-se que as variáveis microbiológicas (carbono da biomassa microbiana = CBM; respiração basal; quociente metabólico; atividade das enzimas β-glicosidase, fosfatase alcalina e ácida, urease; enumeração de micro-organismos celulolíticos, actinomicetos, bactérias e fungos do solo) foram influenciadas pelos sistemas e épocas de coletas. A segunda época de coleta (2013), em geral resultou-se em maiores resultados nos atributos microbiológicos. Os maiores teores de CBM foram observados nos sistemas com maior diversificação da matéria orgânica, como na mata nativa e na iLP A (sistema que de 2005-2009 se manteve com 3 culturas anuais e de 2009-2011 com Brachiaria brizantha ). Os sistemas modificaram a atividade das enzimas. Sendo que, dois sistemas de iLP se assemelharam com a mata nativa, esta por sua vez, apresentou-se mais estável na produção de enzimas que os demais sistemas. As populações de micro-organismos foram afetadas pelos sistemas, mas diferentemente das enzimas, os resultados foram maiores nas iLP do que no sistema referencial. Na análise multivariada, os sistemas apresentaram resultados homogêneos e se agruparam formando um grupo em 2012. Houve uma segregação destes sistemas em 2013, onde formaram 2 grupos com funções similares sobre as variáveis. A partir de um desses grupos foi possível identificar que a iLP C e iLP A foram os sistemas que mais assemelharam com a mata nativa, tal fato comprova que a iLP corrobora para com a melhoria e/ou manutenção dos atributos microbiológicos. Os fatores climáticos tiveram alta influência sobre os resultados. A enzima β-glicosidade apresentou forte correlação sobre as demais enzimas. As variáveis microbiológicas analisadas isoladamente são sensíveis às alterações em função do uso do solo e do tempo, e são bons indicadores de qualidade do solo. A época de coleta influenciou os resultados microbiológicos. O sistema integrado de produção proporciona resiliência na estrutura e função da microbiota do solo, sendo uma ferramenta de manejo menos impactante e com maior capacidade de sustentabilidade do componente microbiológico do solo.
The Crop-Livestock (iLP) system integration is an alternative for the conservation of natural resources. Its main feature is to include annual crops and pastures in the same area, with goals to increase profits maintain and or improve the chemical, physical and biological soil properties. The objective of this study was to evaluate the microbiological soil properties and their resilience, as indicators of soil quality in iLP systems, in the Cerrado-Amazon Ecotone of Mato Grosso state. Soil samples were collected in 5 conformations of iLP, a native forest and a succession of crops (soybean/maize) during the rainy season, in two seasons (2012 and 2013). Through univariate analysis, it was observed that the microbiological variables (microbial biomass carbon = MBC; basal respiration; metabolic quotient; activity of the enzymes β-glucosidase, alkaline and acid phosphatase, urease; enumeration of cellulolytic micro-organisms, actinomycetes, bacteria and soil fungi) were influenced by systems and collection times. The second collection time (2013) generally resulted in higher results in microbiological attributes. The highest levels of the MBC were observed in systems with greater diversification and supply of organic matter, as in native forest and iLP A (which from 2005-2009 remained with 3 annual crops and 2009-2011 with Brachiaria brizantha). The systems had modified the activity of enzymes. In which, two systems with iLP resembled the native forest, this in turn, presented a more stable production of enzymes than other systems. Populations of micro-organisms were affected by the systems, but unlike enzymes, the results were higher than in the iLP reference system. In the multivariate analysis, the systems showed results homogeneous and were grouped forming a group in 2012. But there was a segregation of these systems in 2013, where they formed two groups with similar functions on the variables. From one of these groups could be identified that iLP C and iLP A were the systems that most resembled to the native forest, this fact proves that iLP corroborates with the maintenance and/or improvement of the microbiological attributes. Climatic factors had a high influence on the results. The enzyme β-glucosidase showed a strong correlation over other enzymes. The microbiological variables are sensitive to changes in function of land use and time, and are good indicators of soil quality. The collection time influenced the microbiological results. The integrated production system provides resilience in the structure and function of soil microbes. And it is a tool of the least impactful soil management and greater ability to sustainability of soil microbiological component.

O estudo de indicadores biológicos da qualidade do solo em áreas com araucária é muito importante para entender os processos ecológicos que ocorrem nestes sistemas, já que a fauna edáfica atua na decomposição e mineralização da matéria orgânica e, também, nas propriedades e processos físicos, químicos e biológicos do solo. O objetivo deste estudo foi verificar a possibilidade de utilizar alguns grupos da fauna edáfica e das variáveis ambientais como indicadores da qualidade do solo em áreas com araucária natural e reflorestada, impactadas ou não pela queima acidental, por meio de técnicas de análise multivariada. As áreas estudadas incluem: 1. floresta nativa com araucária (NF); 2. reflorestamento de araucária (R); 3. reflorestamento de araucária submetido a incêndio acidental (RF); e 4. pastagem natural com araucárias nativas e ocorrência de incêndio (NPF). Em cada área, amostras de solo para avaliação da comunidade da fauna edáfica e das variáveis ambientais foram coletadas em 0,3 ha, perto de dez árvores de araucária selecionadas ao acaso, em três épocas contrastantes, usando diferentes métodos de coleta (monólitos e armadilhas). As análises de componentes principais (ACP), canônica discriminante (ACD) e de correlação canônica (ACC) foram aplicadas às variáveis ambientais [carbono da biomassa microbiana (CBM), respiração basal (C-CO2) e quociente metabólico (qCO2), estoques de serapilheira, umidade do solo, pH (CaCl2), matéria orgânica (MO) e teores de P, K, Ca, Mg, H+Al] e atributos da fauna edáfica. Foram encontradas cinco espécies de minhocas (2 famílias), 20 famílias de aranhas e oito famílias de colêmbolos nestas áreas. A diversidade da fauna, CBM, C-CO2, estoques de serapilheira e MO foram sempre superiores na área NF e inferiores na NPF. A comunidade de fauna do solo e as variáveis ambientais apresentaram potencial para serem usadas como indicadores da qualidade do solo. Houve alta correlação canônica entre as variáveis ambientais e a fauna edáfica. Os grupos Collembola, Diplopoda, Chilopoda, Isoptera, Araneae, Oligochaeta, biomassa da macrofauna, índice de diversidade de Shannon (H), estoques de serapilheira, P, CBM e C-CO2 foram responsáveis por praticamente toda a separação entre as áreas, sendo bons indicadores das modificações que ocorrem nos ecossistemas com araucária. A ACD demonstrou que a contribuição de cada atributo para separar as áreas sofreu efeito de sazonalidade. As técnicas de análise multivariada (especialmente ACC e ACD) são importantes ferramentas no estudo de indicadores biológicos de qualidade do solo.
The study of biological soil quality indicators in areas with Araucaria is very important to understand ecological processes in these systems, since groups of the soil fauna are major factors in the decomposition and mineralization of organic matter, as well as modifiers of soil physical, chemical and biological properties and processes. The objective of this study was to evaluate the use of soil fauna and environmental variables as quality indicators in natural and reforested Araucaria areas, impacted or not by fire, by means of multivariate analysis techniques. Four study areas included: native forest with Araucaria (NF); Araucaria reforestation (R); Araucaria reforestation submitted to an accidental fire (RF); and native grass pasture with native Araucaria , submitted to an intense accidental fire (NPF). Soil samples containing the soil fauna community and environmental variables were taken in a 0.3 ha area in each area, close to ten Araucaria trees selected at random, in three contrasting seasons, using different collection methods (soil monolith, Pitfall traps). Canonical discriminant analysis (CDA) and canonical correlation analysis (CCA) were applied to the environmental variables [(carbon of the microbial biomass (CMB), basal respiration (C-CO2) and metabolic quotient (qCO2), litter stocks, soil humidity, pH (CaCl2), organic matter (OM), P, K, Ca, Mg, H+Al] and soil fauna attributes. Five earthworm species (two families), 20 spider families and eight springtail families were found in these areas. Soil fauna diversity, CMB, C-CO2, litter stocks and OM were always higher for the NF area and lower for the NPF. The canonical correlation between environmental variables and soil fauna was highly significant. Soil fauna and environmental variables have a great potential as indicators of soil quality. The groups Collembola, Diplopoda, Chilopoda, Isoptera, Araneae, Oligochaeta, biomass of macrofauna, Shannon's diversity index (H), litter stocks, P, CMB and C-CO2 were mostly responsible for the separation between areas, and are therefore good indicators of the changes that occur in the Araucaria ecosystems. CDA identified that the contribution of each attribute for the separation of the areas varied according to the seasonal variation. Multivariate analyses (such as CDA and CCA) are important auxiliary tools in the study of soil quality indicators.

Sediment delivery is a major problem in the Green River, Kentucky, home of 71 of the state’s 103 known mussel species and 151 fish species. The river also provides water for many of its surrounding counties. This research focuses on how suspended sediment loads, grain size, and sediment concentration during runoff events are related to watershed characteristics. The research characterized suspended sediment loads, grain size, and sediment concentration during runoff events and how they were related to watershed characteristics such as hydro-climatic regime, watershed size, geology and soils, topography and landuse conditions and land cover conditions. The study focused on Brush Creek and Pitman Creek watersheds in the Upper Green River Basin. This research can help in the planning and development of effective environmental strategies by screening out mitigation measures that would not be effective for implementation to minimize sediment load and suspended sediment concentration in the Green River, thereby improving the water quality of the river. Water quality was monitored using data sondes positioned at selected sites in the two watersheds. Water samples were collected during turbidity thresholds of 100 NTU and analyzed for suspended sediment concentrations. Regression models between ‘discharge and stage’ and also between ‘average turbidity and suspended sediment concentration’ were formulated and load estimates were made and compared. Four sets of samples were collected, two at Brush Creek on 11 April (Brush Creek’s event 1) and 3 May (Brush Creek’s event 2) and the other two at Pitman Creek on the 12 February (Pitman Creek’s event 1) and 3 March (Pitman Creek’s event 2) all in the year 2008. The suspended sediment samples collected for all four events were well graded but had relatively more silt than clay and sand. This could be due to the fact that more time and energy was needed to break the bonds in clay minerals or particles and also to the fact that more energy was also needed to transport sand compared to silt. Brush Creek watershed’s particles had smaller grain sizes than Pitman Creek watershed’s particles. All four events showed clockwise hysteresis indicating that most of the sediments from both watersheds during the events were derived from the bed and banks of the channel or area adjacent to the channel. The 11 April event (Brush Creek’s event 1) produced an estimated load of 1.1 x 105 kg and a sediment yield of 5.3 x 102 kg/km2. The 3 May event (Brush Creek’s event 2) produced an estimated load of 3.8 x 104 kg and a sediment yield of 1.8 x 102 kg/km2. Brush Creek watershed’s estimated load for the period compared was 4.9 x 105 kg and a sediment yield of 2.3 x 103 kg/km2 (53 kg/km2/day). The 12 February event (Pitman Creek’s event 1) produced an estimated load of 2.9 x 105 kg and a sediment yield of 8.4 x 102 kg/km2. The 3 March event (Pitman Creek’s event 2) produced an estimated load of 5.7 x 105 kg and a sediment yield of 1.6 x 103 kg/km2. Pitman Creek watershed’s estimated load for the period compared was 1.1 x 106 kg and a sediment yield of 3.1 x 103 kg/km2 (71 kg/km2/day). Pitman Creek watershed’s higher number of stream network per unit area, its high elevation and relief, its high percentage of erodible soil per unit area, its lesser area of protection of erodible soil by its vegetation compared to Brush Creek watershed’s are responsible for its higher sediment load and yield.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
Este trabalho se propÃs a avaliar as alteraÃÃes nas atividades microbiana, quÃmica e fÃsica em solo sob sistemas agrÃcolas anuais e perenes na regiÃo da Chapada do Apodi - CE. Procurou-se testar a hipÃtese de que o uso agrÃcola de Ãreas sob sistemas anuais e perenes causam alteraÃÃes ambientais que influenciam a biomassa e a atividade microbiana do solo, reduzindo-a em relaÃÃo a Ãreas sob vegetaÃÃo natural. Foram selecionadas duas Ãreas com respectivas testemunhas (vegetaÃÃo natural); a primeira sob cultivo de bananeiras (Fazenda Frutacor) e a outra sob cultivo de rotaÃÃo milho e soja (Fazenda Faedo). Coletaram-se amostras compostas de solo em trÃs profundidades (0-5, 5-15 e 15-25 cm) com quatro repetiÃÃes. Nas amostras coletadas foram realizadas anÃlises fÃsicas, quÃmicas e microbiolÃgicas. Fisicamente, observou-se uma elevaÃÃo no teor de argila, com o aumento da profundidade na Ãrea cultivada com banana e na mata natural pivot. Em relaÃÃo aos atributos quÃmicos do solo, os riscos potenciais de salinidade e de saturaÃÃo por sÃdio aparentemente sÃo desprezÃveis. As prÃticas de manejo reduziram o N e o carbono orgÃnico total nos solos das Ãreas sob cultivo. Quanto à microbiologia dos solos, o carbono da biomassa microbiana e a populaÃÃo de fungos micorrÃzicos arbusculares foram mais elevados na profundidade de 0-5cm do solo. A respiraÃÃo basal do solo mostrou que os solos das Ãreas avaliadas tÃm baixa atividade microbiana quando comparados a solos do Cerrado. A atividade e produÃÃo da arilsulfatase e da fosfatase Ãcida foram estimuladas possivelmente, pela competiÃÃo dos Ãnions H2PO4 - e SO4 - pelos mesmos sÃtios de adsorÃÃo nos colÃides do solo, nas Ãreas de banana e rotaÃÃo milho e soja. A maior atividade da enzima β-glucosidase ocorreu nas Ãreas cultivadas, influenciada pela quantidade e qualidade do resÃduo vegetal retornado ao solo.
This work had the proposed to evaluate the alterations in the microbial activities, chemistry and physics in soil under annual and perennial agricultural systems in the area of the Chapada do Apodi - CE. It tried to test the hypothesis that the agricultural use of areas under annual and perennial systems causes environmental alterations that they influence the biomass and the microbial activity of the soil, reducing it in relation to areas under natural vegetation. Two areas were selected with respective witness (natural vegetation); the first under cultivation of banana trees (Fazenda Frutacor) and the other under cultivation of rotation corn and soy (Fazenda Faedo). Samples composed of soil were collected in three depths (0-5, 5-15 and 15-25 cm) with four repetitions. In the collected samples physical analyses, chemistries and microbiological were accomplished. Physically, an elevation was observed in the clay text, with the increase of the depth in the area cultivated with banana and in the forest natural pivot. In relation to the chemical attributes of the soil, the potential risks of salinity and of saturation for sodium seemingly are worthless. The handling practices reduced N and the total organic carbon in the soils of the areas under cultivation. With relationship to the microbiology of the soils, the carbon of the microbial biomass and the population of arbuscular mycorrhizal fungi were more elevated in the depth of 0-5cm of the soil. The basal breathing of the soil identified that the soils of the appraised areas have microbial when compared low activity the soils of the Cerrado. The activity and production of the arylsulphatase and of the acid phosphatase were stimulated possibly, for the competition of the anions H2PO4- and SO4- for the same ranches of adsorption in the coloides of the soil, in the banana areas and rotation corn and soy. The largest activity of the enzyme β-glucosidase happened in the cultivated areas, influenced by the amount and quality of the vegetable residue come back to the soil.

Scopo del progetto era valutare lo stato di salute e la qualità dei suoli agricoli lombardi e di alcune sue aree caratterizzate da specifiche criticità ambientali, attraverso un monitoraggio multidisciplinare. L’uso di indicatori biologici accoppiato alle classiche tecniche analitiche ha consentito di implementare le informazioni ottenute dal punto di vista chimico-fisico. Contrariamente al passato infatti, la componente vivente del suolo è diventata fondamentale alla comprensione delle sue condizioni, in quanto esso è stato riconosciuto come sistema strettamente connesso agli altri comparti ambientali, influenzato e caratterizzato da tutti gli organismi che lo compongono. Sulla base di ciò sono state indagate la struttura e le caratteristiche delle comunità microbiche, dei lombrichi e dei protozoi ciliati, le attività enzimatiche del suolo, e la genotossicità delle sostanze inquinanti utilizzando il trifoglio come pianta indicatrice. Abbiamo inoltre avuto modo di applicare alcune tecniche che esulano dal classico monitoraggio, ma che forniscono informazioni preziose circa il comportamento di una sostanza o di un elemento. Si tratta dell’applicazione della diluizione isotopica per determinare la presenza del cromo esavalente in suoli potenzialmente contaminati, e di biosaggi con batteri bioluminescenti per valutare la biodisponibilità di arsenico e mercurio in un Sito di Interesse Nazionale.
The aim of the project was to assess health status and quality of agricultural soils of the Lombardia region, and some areas with critical environmental situations, through a multidisciplinary monitoring. The use of biological indicators coupled to classic analytical techniques, has allowed the implementation of the information obtained from the chemical-physical point of view. Contrary to the past, the living component of the soil has become crucial to better understand its condition, as it has been recognized as a system closely related to other environmental media, influenced and characterized by all organisms that compose it. Basing on this it was investigated the structure and characteristics of microbial communities, earthworms and ciliated protozoa, the enzymatic activities of the soil, and the genotoxicity of pollutants using clover plants as indicator. We also had the opportunity to apply some of the techniques that are outside the classic monitoring, but that can provide valuable information about the behavior of a substance or an element. These techniques are: the application of isotope dilution to determine the presence of hexavalent chromium in potentially contaminated soils, and bioassays with bioluminescent bacteria to assess the bioavailability of arsenic and mercury in a Site of National Interest.

Scopo del progetto era valutare lo stato di salute e la qualità dei suoli agricoli lombardi e di alcune sue aree caratterizzate da specifiche criticità ambientali, attraverso un monitoraggio multidisciplinare. L’uso di indicatori biologici accoppiato alle classiche tecniche analitiche ha consentito di implementare le informazioni ottenute dal punto di vista chimico-fisico. Contrariamente al passato infatti, la componente vivente del suolo è diventata fondamentale alla comprensione delle sue condizioni, in quanto esso è stato riconosciuto come sistema strettamente connesso agli altri comparti ambientali, influenzato e caratterizzato da tutti gli organismi che lo compongono. Sulla base di ciò sono state indagate la struttura e le caratteristiche delle comunità microbiche, dei lombrichi e dei protozoi ciliati, le attività enzimatiche del suolo, e la genotossicità delle sostanze inquinanti utilizzando il trifoglio come pianta indicatrice. Abbiamo inoltre avuto modo di applicare alcune tecniche che esulano dal classico monitoraggio, ma che forniscono informazioni preziose circa il comportamento di una sostanza o di un elemento. Si tratta dell’applicazione della diluizione isotopica per determinare la presenza del cromo esavalente in suoli potenzialmente contaminati, e di biosaggi con batteri bioluminescenti per valutare la biodisponibilità di arsenico e mercurio in un Sito di Interesse Nazionale.
The aim of the project was to assess health status and quality of agricultural soils of the Lombardia region, and some areas with critical environmental situations, through a multidisciplinary monitoring. The use of biological indicators coupled to classic analytical techniques, has allowed the implementation of the information obtained from the chemical-physical point of view. Contrary to the past, the living component of the soil has become crucial to better understand its condition, as it has been recognized as a system closely related to other environmental media, influenced and characterized by all organisms that compose it. Basing on this it was investigated the structure and characteristics of microbial communities, earthworms and ciliated protozoa, the enzymatic activities of the soil, and the genotoxicity of pollutants using clover plants as indicator. We also had the opportunity to apply some of the techniques that are outside the classic monitoring, but that can provide valuable information about the behavior of a substance or an element. These techniques are: the application of isotope dilution to determine the presence of hexavalent chromium in potentially contaminated soils, and bioassays with bioluminescent bacteria to assess the bioavailability of arsenic and mercury in a Site of National Interest.

Aux Antilles, dans les plantations de bananes en monoculture mécanisée, l'un des principaux problèmes à résoudre est le contrôle des populations de nématodes phytoparasites. Dans cette thèse, les effets d'apports de différentes matières organiques (MO), brutes ou compostées, sur la régulation biologique des nématodes ont été étudiés, cet effet suppresseur ayant déjà été montré sur d'autres cultures. L'analyse de la littérature sur le sujet montre que les effets d'un apport de MO sur les populations de nématodes phytoparasites et sur leurs dégâts sont complexes et varient fortement en fonction de la nature biochimique du produit et de l'espèce de nématode. Ainsi, les matières organiques qui libèrent beaucoup d'azote minéral en se décomposant favorisent la croissance des racines, ce qui peut augmenter la ressource alimentaire des nématodes phytoparasites et/ou la tolérance des plantes à leurs attaques. La décomposition des matières apportées peut libérer des composés nématotoxiques. Enfin, l'apport de carbone peut entrainer une diversification des communautés de nématodes, une complexification des réseaux trophiques et, par la suite, favoriser la régulation biologique des nématodes phytoparasites par les espèces appartenant aux niveaux trophiques supérieurs et par la microflore. Nous avons, par une étude fine de la structure des communautés de nématodes et le suivi de la croissance des jeunes plants de bananier, cherché à évaluer l'induction de la régulation biologique des nématodes parasites du bananier dans une sole bananière par un apport de MO, au moyen de deux expérimentations en pots conduites pendant 13 semaines. Les MO testées étaient quatre MO brutes et quatre MO compostées. L'expérience sur les MO brutes a montré que trois des quatre MO (bagasse, écumes de sucrerie et déchets verts) ont entrainé une diminution des populations de nématodes parasites dans les racines du bananier, l'intensité de cette régulation dépendant de l'espèce. En revanche, le quatrième type de MO, des boues de station d'épuration, n'a pas permis de diminuer la pression parasitaire. Les différences de croissance des systèmes racinaires n'ont pas été un facteur explicatif des régulations observées et les meilleures conditions de croissance observées n'ont pas réduit les impacts des nématodes phytoparasites sur les racines. Seules les écumes de sucrerie ont entrainé un impact positif global sur la plante, en diminuant la pression parasitaire tout en augmentant sa croissance. La bagasse et les déchets verts, principalement composés de lignines et de cellulose, ont entrainé une modification significative de la structure des communautés de nématodes, avec un fort accroissement des populations de nématodes fongivores et, avec la bagasse, de nématodes carnivores. L'expérience en pot sur les MO compostées a montré que les trois composts commerciaux produits par SITA VERDE (Biogwa, Ecogwa B, Ecogwa D) et l'amendement organique commercial Vegethumus (de Phallipou-Frayssinet) avaient engendré une diminution du parasitisme et que ce contrôle dépendait de l'espèce de nématodes phytoparasites. Dans cet essai, le contrôle des nématodes parasites du bananier est apparu lié à la biomasse racinaire totale des bananiers. L'apport des composts Ecogwa D et Vegethumus a augmenté la taille des populations de nématodes microbivores, mais seul Vegethumus a accru la voie de décomposition fongique. [...] Suite et fin du résumé dans la thèse.

Organic mulches and cover crops mulched in situ were assessed for their effects on B. cinerea primary inoculum and disease levels in inflorescences at flowering and/or bunches at harvest. Organic mulches were used to enhance biological degradation of vine debris to reduce levels of B. cinerea primary inoculum the following season. Four mulch types (anaerobically and aerobically fermented marc (grape pressings), inter-row grass clippings and shredded office paper) were applied under ten-year-old Riesling vines in a ten-replicate randomized block design in New Zealand over two consecutive years. Plastic mesh bags, each containing naturally infected vine debris, were placed under vines on bare ground (control) and at the soil-mulch interface, in winter (July) 2003 and 2004. In each year, half the bags were recovered at flowering (December) and the remainder at leaf plucking (February), for assessment of B. cinerea sporulation from the vine debris and debris degradation rate. Bait lamina probes, which measure soil biological activity, were placed in the soil-mulch interface three weeks before each of the two bag-recovery dates in both years and were then removed and assessed at the same times as were the bags. All mulches led to a reduction in B. cinerea sporulation. This reduction was significantly correlated with elevated rates of vine debris decomposition and increased soil biological activity. Over both years, compared with the controls, all treatments gave a 3-20-fold reduction in B. cinerea sporulation, a 1.6-2.6-fold increase in vine debris degradation and in the two marc and the paper treatments, a 1.8-4-fold increase in activity of soil organisms. The mulches also altered vine characteristics and elevated their resistance to B. cinerea through changes to the soil environment. Functional soil biological activity, as measured by Biolog Ecoplates and bait lamina probes, was increased 2-4 times in the two marc and paper treatments, compared with the control, an effect relating to the elevated soil moisture and reduced temperature fluctuations under these mulches. Soil nutrient levels and the C:N ratios were also affected in these treatments. The mulched paper lowered vine canopy density by up to 1.4 times that of the other treatments, an effect which probably led to elevated light penetration into the canopy and consequent increased canopy temperature, photosynthesis and lowered canopy humidity. These changes to soil and vine characteristics increased grape skin strength by up to 10% in the paper treatment and sugar concentrations by 1.2-1.4 °Brix in the two marc and paper treatments. The severity of B. cinerea infections in the anaerobic marc, aerobic marc and paper treatments were reduced to 12%, 3% and 2.2% of the control, respectively, in field assessments averaged over two consecutive harvests. Cover crops mulched in situ had similar effects to those of the organic mulches, increasing soil biological activity and reducing B. cinerea primary inoculum and the severity of B. cinerea infection in grapes at harvest (2006). Inter-row phacelia and ryegrass were mulched in winter 2005 and compared with a bare ground control, under 10-year-old Chardonnay vines in a ten-replicate randomized block design. Functional soil biological activity increased by 1.5-4.5 times in the two cover crop treatments compared with the control, an effect possibly related to elevated soil moisture in these treatments. This increase in soil moisture and soil biological activity increased vine debris degradation, reduced B. cinerea primary inoculum on the debris and decreased B. cinerea severity at flowering (December 2005) and harvest (April 2006). These results show the potential of organic mulches and cover crops mulched in situ to enhance soil ecosystem services and improve the sustainability of viticultural practices.

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The microbial biomass of the soil is of great importance in the increase of crop productivity and its accompaniment reflects possible changes in the soil, being a good indicator of soil quality. The objective of this work was to evaluate the chemical and biological attributes of the soil and soybean yield succeeding coverage plants. The experiment was conducted in the municipality of Presidente Bernardes-SP, in a soil classified as Dystroferric Red Argisoil. The experimental design was completely randomized. The treatments were constituted by the adoption of cover species, being millet, fallow, seeded, sorghum, corn, pigeon pea and fertilized fallow. The cover plants were kept until the 85th day after sowing and were later withdrawn for silage and the entire area of the experiment left for the regeneration of Urochloa brizantha cv. Marandu and maintained for 160 days, afterwards the soybean was sown. The biomass production of cover and brachiaria plants, foliar and bromatological tissue analyzes were evaluated. Soil was also sampled to evaluate the chemical composition and microbiological characteristics, and evaluations of soy production components. Soybean yield increased after the pre-cultivation of pigeon pea. The biological attributes were influenced significantly by the cultivation of coverage crops, and the pre-cultivation with pigeon peas stood out in the improvement of such attributes. The species used as cover plants and green manure did not alter the chemical attributes of the soil, with the exception of sulfur in depth of 10 - 20 cm.
A biomassa microbiana do solo é de suma importância no aumento de produtividade das culturas e seu acompanhamento reflete possíveis mudanças no solo, sendo uma boa indicadora de qualidade dos solos. O objetivo deste trabalho foi avaliar os atributos químicos e biológicos do solo e produtividade da soja sucedendo plantas de cobertura. O experimento foi conduzido no município de Presidente Bernardes-SP, em um solo classificado como Argissolo Vermelho distroférrico. O delineamento experimental foi em faixas inteiramente casualizadas. Os tratamentos foram constituídos pela adoção de espécies de cobertura, sendo o milheto, pousio, braquiária semeada, sorgo, milho, feijão guandu e pousio adubado. As plantas de cobertura foram mantidas até o 85º dia após a semeadura e posteriormente foram retiradas para a realização de silagem e toda a área do experimento deixada para a regeneração do pasto de Urochloa brizantha cv. Marandu e mantida por 160 dias, posteriomente realizada a semeadura da soja. Foram avaliados a produção de biomassa das plantas de cobertura e da braquiária, análises do tecido foliar e bromatológica. Também foi amostrado o solo para avaliar a composição química e características microbiológicas, e avaliações dos componentes de produção da soja. A produtividade da soja apresentou incremento após o pré-cultivo de feijão guandu. Os atributos biológicos foram influenciados significativamente pelo cultivo de plantas de cobertura, sendo que o pré-cultivo com feijão guandu destacou-se na melhoria de tais atributos. As espécies utilizadas como plantas de cobertura e adubo verde não alteraram os atributos químicos do solo, com exceção do enxofre em profundidade de 10 – 20 cm.

Impactos ambientais podem interferir nas características da biomassa microbiana, no processo de ciclagem de nutrientes, nas características físicoquímicas e também na diversidade da microbiota e da macrofauna. O objetivo desse trabalho foi conhecer as diferentes interações entre estes atributos e identificar os indicadores da qualidade do solo envolvidos com o tempo de recuperação. Três áreas com estágios diferentes de recuperação (5, 10 e 20 anos) foram comparadas com uma floresta Estacional Semidecídua nativa (NT) com intuito de estudar o comportamento da microbiota, da macrofauna e de suas interações com os atributos físico-químicos. Foram coletadas amostras em 15 pontos por áreas, escolhidos aleatoriamente. Dentre os atributos microbiológicos, a maior atividade das enzimas urease, fosfatase ácida e desidrogeanse foi encontrada na área nativa. O mesmo foi constatado para a respiração basal e para o carbono e nitrogênio da biomassa microbiana. A análise da estrutura da comunidade de Bacteria, feita a partir de TRFLP, separou as áreas, nativa e de 20 anos de recuperação, das demais, somente no verão. A densidade do solo, a umidade e a microporosidade afetaram negativamente os indicadores microbiológicos do solo, sendo em conjunto com o carbono total do solo os principais fatores discriminantes das áreas. Ocorreu maior presença das espécies de FMA A. spinosa, A. colossica, A. lacunosa, G. decipiens e Gigaspora sp. na área NT e das espécies G. viscosum, A. mellea, A. scrobiculata e S. heterogama na área R05 e G. rosea nas áreas R10 e R20. As principais variáveis ambientais que explicam a relação com as espécies de FMA foram microporosidade, macroporosidade, atividade da fosfatase ácida e densidade, umidade, CBM, NBM e N-NO3. Efeito sazonal sobre as espécies de FMA também foi observado. Maiores valores de proteína do solo relacionada com glomalina (GRSP) foram encontrados no inverno e somente a proteína do solo relacionada com glomalina facilmente extraível (EE-GRSP) separou a área NT das demais. Observou-se, também, alta correlação dessa glicoproteina com os atributos físico-químicos e microbiológicos. Em relação à fauna edáfica ocorreu efeito da sazonalidade e do método de coleta utilizado (armadilhas e monolito). Houve diferença entre os índices de Shanon, Simpson e Pielou somente na época seca, sendo as maiores diferenças nas áreas mais antigas (NT e R20). Maior riqueza foi encontrada ao se utilizar o método de monolito. De acordo com a análise discriminante, Diplopoda foi o principal grupo para as duas épocas e os dois métodos de coleta. Porosidade, densidade basal, umidade, nitrogênio total do solo e atividade das enzimas desidrogenase e urease foram fatores importantes para a separação dos grupos da fauna no gradiente de recuperação ambiental. Esse trabalho mostrou que os atributos biológicos e físicoquímicos de qualidade do solo interagem e se modificam de acordo com a idade das áreas e com a sazonalidade.
Environmental impactation can affect microbial biomass, nutrient cycling, processes, physical-chemical characteristics and also the diversity of microbes and edaphic fauna. The aim of this study was to understand the different interactions between these attributes and to identify the indicators of soil quality involved in the recovery process. Three areas with different stages of recovery [5 (R05), 10 (R10) and 20 (R20) years] were compared with a native semideciduous forest (NT) in order to study the behavior of microbes, macrofauna and their interactions with the physical and chemical attributes. Samples were collected at 15 points in each area. Greater activity of urease, acid phosphatase and dehydrogenase were found in the native area. The same result was found for basal respiration, microbial biomass carbon (MBC) and nitrogen (MBN). The structure of Bacteria analyzed by T-RFLP discriminated the native and R20 from R05 and R10, only in the summer. Soil bulk density, humidity and microporosity negatively affected soil microbiological indicators and together with total soil carbon they were the main discriminant factors. A. colossica, A. lacunosa, G. decipiens and Gigaspora sp. were more abundant in NT and the species G. viscosum, A. mellea, A. scrobiculata and S. heterogama in R05 and G. rosea in R10 and R20. Porosity, soil bulk density, humidity, acid phosphatase activity, MBC, MBN and N-NO3 - were the principal environmental variables related to AMF species distribution. Seasonal influences on AMF species were also observed. Higher glomalin related soil protein (GRSP) content was found only in the winter and NT had only EE-GRSP (easly extracted glomalin related soil protein) different from the recovery areas. Correlations among glomalin and physical-chemical and microbiological attributes were observed. Edaphic fauna groups were influenced by seasonality and by sampling methodology (pitfall traps and monoliths). Shannons, Simpsons and the evenness index were significant only in the dry season and in the oldest areas. Richness was higher when the monolith method was used. Diplopoda was the principal group that discriminated the recovery gradient for both seasons and methodologies. Porosity, soil bulk density, humidity, total nitrogen, urease and dehydrogenase were important factors to separate faunal groups. This work showed that biological and physico-chemical soil quality attributes interact and changed according to gradient recovery and seasonality.

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Capes
Any inappropriate soil management, cause negative environmental impact on the diversity of soil fauna. This dissertation aimed to evaluate the influence of land use systems (LUS) on the morphological diversity of springtails, as well as its relationship with physical and chemical soil attributes. Were studied five LUS on the Plateau of Santa Catarina, Brazil: native forest (F), Eucalyptus plantation (Reu), perennial pasture (P), integrated crop-livestock (ILP) and no-tillage (PD), in two different seasons (winter and summer). The evaluation was performed by installing traps of type Pitfall traps per sampling grid (3 x 3). The same points were evaluated physical and chemical soil attributes. The morphotyping of the springtails consisted in observing five characteristics and each feature has been assigned a partial value of Eco-morphological index (EMI) for Biological Quality of Soil Index (QBS) modified. The data were subjected to multivariate analysis. In winter, the LUS (F) presented the highest abundance of morphotypes due the best values of Ca/Mg ratio, total organic carbon (TOC), bioporos, micropores and soil moisture in comparison to other LUS. ILP systems and PD already correlated with the Macropores. In the summer, again the F showed the highest abundance of morphotypes, however, the greatest diversity of levels of adaptation was found in PD. In summer, the F presented related to the TOC and micropores, while ILP and PD correlated with pH, bioporos and soil density. In winter, the value of QBS was greater in F, followed by Reu, P, PD and ILP, respectively, being smaller the higher the intensification of the LUS. In the summer, the QBS values were higher in F, followed by ILP, Reu, PD and P, respectively. The separation to the level of morphotypes proved an efficient alternative to indicate the level of intensification of land use, especially in combination with other explanatory environmental variables
Todo e qualquer manejo inadequado do solo, causa impacto ambiental negativo sobre a diversidade da fauna edáfica. A presente dissertação objetivou avaliar a influência de sistemas de uso e manejo do solo (SUS) sobre a diversidade morfológica de colêmbolos, bem como sua relação com atributos físicos e químicos do solo. Foram estudados cinco SUS no Planalto Catarinense, Brasil: floresta nativa (F), reflorestamento de eucalipto (Reu), pastagem perene (P), integração lavoura-pecuária (ILP) e plantio direto (PD), em duas épocas distintas (inverno e verão). A avaliação dos colêmbolos foi realizada instalando-se armadilhas do tipo Pitfall traps em um grid amostral (3 x 3). Nos mesmos pontos foram avaliados atributos físicos e químicos do solo. A morfotipagem dos colêmbolos consistiu na observação de cinco características e para cada característica foi atribuído um valor parcial do índice ecomorfológico (EMI) para a obtenção do Índice de Qualidade do Solo (QBS) modificado. Os dados foram submetidos a análises multivariadas. No inverno, o SUS F apresentou a maior abundância de morfotipos devido a melhores valores de relação Ca/Mg, carbono orgânico total (COT), bioporos, microporos e umidade do solo em comparação aos demais SUS. Já os sistemas ILP e PD se correlacionaram com o atributo macroporos. No verão, novamente a F apresentou maior abundância de morfotipos, porém, a maior diversidade de níveis de adaptação foi encontrada em PD. No verão, a F apresentou relação com o COT e microporos, enquanto ILP e PD se correlacionaram com pH, bioporos e densidade do solo. No inverno, o valor de QBS foi maior em F, seguido por Reu, P, PD e ILP, respectivamente, sendo menor quanto maior a intensificação do SUS. Já no verão, os valores de QBS foram maiores em F, seguido por ILP, Reu, PD e P, respectivamente. A separação ao nível de morfotipos se mostrou uma eficiente alternativa para indicar o nível de intensificação de uso do solo, principalmente em conjunto com outras variáveis ambientais explicativas

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Among 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.

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The soil quality indicators analyses during and after the transition period of conventional to organic production system are very important to evaluated the sustainability of agricultural systems. Soil microbiological and biochemical indicators shall quickly indicate changes occurred on both, soil management and production systems. The objective of this work was to evaluated shifts on microbiological and biochemical soil indicators of a conventional common bean production system in transition to an organic system, under conventional and non-tillage soil management systems after cover crops. Total enzymatic activity (AET), betaglucosidase activity (betaglucosidase), acid fosfatase activity (fosfatase), carbon (CBM) and nitrogen (NBM) of the microbial biomass, the basal soil respiration (RBS) and the metabolic quotient (qCO2) were evaluated on soil samples collected at tillage common bean cycle. The experiment was carried out at Embrapa Rice and Beans, in Santo Antônio de Goiás GO, and it was also collected soil samples in a secondary forest area close to the experiment to be used as a reference. The content of carbon and nitrogen of the soil microbial biomass, as well as, microbial and enzymatic activities in conventional and non-tillage systems were independent of the cover crop specie used. Under the experimental conditions, the soil management systems did not show effect in the enzymatic and microbial soil activities. The total and acid fosfatase enzymatic activities of the cropped soils were lower than in the forest soil. The betaglucosidase enzymatic activity was higher in cropped soil than under forest soil in the raining season and lower in the dry season. The soil tillage performed before common bean sowing promoted shifts on the CO2 efflux from soil to the atmosphere, which was verified by an increase on both, basal soil respiration and metabolic quotient.
A análise da qualidade do solo durante e após o período de transição de um sistema produtivo convencional para um sistema orgânico é importante como indicador de sustentabilidade. Indicadores microbiológicos e bioquímicos da qualidade do solo devem responder rapidamente a mudanças no manejo e alterações nos sistemas de produção. Assim, este experimento teve como objetivo avaliar as alterações nos indicadores microbiológicos e bioquímicos do solo em um sistema de produção em transição para cultivo orgânico do feijoeiro comum (Phaseolus vulgaris L.), sob sistema de preparo convencional (SPC) e direto (SPD) do solo, após o manejo de diferentes plantas de cobertura de solo. Avaliaram-se a atividade enzimática total (AET), a atividade de betaglicosidase (β-glicosidase) e de fosfatase ácida (Fosfatase), o carbono (CBM) e o nitrogênio (NBM) da biomassa microbiana, a respiração basal do solo (RBS) e o quociente metabólico (qCO2) em amostras de solo coletadas durante o ciclo de cultivo do feijoeiro comum. O experimento foi conduzido na Embrapa Arroz e Feijão, em Santo Antônio de Goiás GO e área de mata nativa próxima ao ensaio foi utilizada como referência. O teor de carbono e nitrogênio da biomassa microbiana no solo, assim como de atividades microbianas e enzimáticas avaliadas, tanto sob SPD quanto sob SPC, foi independente da espécie de planta de cobertura de solo utilizada. Nas condições testadas, o sistema de preparo de solo não teve influência na atividade das enzimas do solo e nem na atividade microbiana do solo. No solo agricultável testado, a atividade enzimática total e de fosfatase ácida foi menor do que em solo não agricultável. No período chuvoso, a atividade de betaglicosidase foi maior em solo agricultável do que em solo não agricultável e menor no período seco. O preparo do solo para a semeadura do feijoeiro comum provocou aumento da perda de gás carbônico, verificado em decorrência de aumento na respiração basal do solo e no quociente metabólico.

Aspects scientifiques de la production in vitro en relation avec l'activité "recherche-développement" d'un laboratoire industriel (LBV France). Mise au point d'une technique pour 30 variétés. Détermination d'un milieu de culture optimal pour chacune des phases de développement. Recherche de marqueurs précoces de la conformité et de l'identité variétale. Utilisation de l'électrophorèse, application à 14 systèmes enzymatiques. Proposition d'essai de modélisation appliqués à la planification et à la gestion de la production. Simulation de la généralisation de la cinétique de production sur 200 variétés réparties dans 15 genres différents.

Responses of biological indicators of soil quality to winter cover cropping were measured on soil samples collected from 6 commercial growers' fields and two experiment research stations in the Willamette Valley of Oregon. The research stations were the North Willamette Research and Extension Center (Aurora, OR), and the Oregon State University Vegetable Farm (Corvallis, OR). The research stations and five on-farm sites compared winter cover crops or winter fallow in rotation with a summer vegetable crop. In one on-farm site, minimum tillage or conventional till following winter cover crops was compared. The objectives of this study were to: 1) monitor changes in soil biological properties under field managed with cover crops; 2) test potential of buried cotton strip as indicator of soil biological activity and as a soil quality index; and 3) assess the degree of correlation between tensile strength and cotton strip weight loss. The major findings were: 1) microbial biomass carbon and ��-glucosidase activity were the most sensitive to cover crop management; 2) cotton strip decomposition was correlated to soil biological properties but was not very sensitive to management changes; and 3) that measuring weight loss was nearly as effective as tensile strength in assessing cotton strip decomposition in soils.
Graduation date: 1999

The release of crude oil onto agricultural land has the potential of taking that land out of production. Its return to production is often the principal goal of site remediation. A two-year study was conducted to examine the effects of a crude oil pipeline spill on the productivity of agricultural land. Experimental plots of wheat ('Triticum aestivum' c.v. Pasqua), canola ('Brassica rapa' c.v. Argentine), bromegrass ('Bromus biebersteinii' Rohman and Schult, c.v. meadow) and alfalfa ('Medicago sativa L. c.v. algonquin') were established in 1996 within the area of a spill which occurred in October, 1994, as well as on adjacent uncontaminated land. The study soil was a clay loam Gleyed Rego Black Chernozem developed from predominantly moderately fine lacustrine materials. Surface expression at the site was gently undulating. The annual crop plots were sampled for total oil and grease analysis in the spring of each year while sampling in the forage plots occurred only in the first spring. (Abstract shortened by UMI.)