977 resultados para Soil analysis
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ABSTRACT Swine wastewater (SW) application in agricultural soils may affect its microbial community in a long term. The objective of this study was to evaluate prospective changes in soil bacterial community after eight years continuous application of swine wastewater. The wastewater doses tested were 0; 100; 200 and 300 m3 ha-1, being applied from the beginning of the experiment and with or without recommended fertilization. Three soil samples were taken from each plot for determinations of basal respiration, microbial biomass and metabolic quotient. We also performed DGGE analysis and made a correlation between soil chemical conditions and microbial activity. Microbial community underwent significant structural changes from swine wastewater applications. Higher SW doses (200 and 300 m3 ha-1) influenced significantly (p <0.05) and benefitted certain bacteria groups.
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By coupling the Boundary Element Method (BEM) and the Finite Element Method (FEM) an algorithm that combines the advantages of both numerical processes is developed. The main aim of the work concerns the time domain analysis of general three-dimensional wave propagation problems in elastic media. In addition, mathematical and numerical aspects of the related BE-, FE- and BE/FE-formulations are discussed. The coupling algorithm allows investigations of elastodynamic problems with a BE- and a FE-subdomain. In order to observe the performance of the coupling algorithm two problems are solved and their results compared to other numerical solutions.
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This study aimed at assessing the level of weed infestation indifferent areas that were submitted to different soil management for 16 years. Four management systems were studied: (1) agriculture only under conventional tillage system; (2) agriculture only under no-till system; (3) crop-livestock integrationcrop-livestock integration; (4) livestock only. These areas were sampled at three soil depths (0-5, 5-10 and 10-15 cm), and soil was stored in plastic pots and taken to a greenhouse, where soil moisture and weight were standardized. Soil was kept near 70% moisture field capacity, being revolved every 20 days when all seedling emerged from soil were counted, identified and collected for dry mass assessment. The soil coverage by weeds, number of weed seedlings and dry mass of the weedy community were assessed. A phytoecological analysis was conducted. Weed composition is differentdifferent among management systems after 16 years. Areas with livestock showed much smaller number of weed species in comparison to systems where only grain crops are grown. The presence of livestock affects the potential of germination of soil seed bank. Agriculture systems are similar in terms of weed composition along soil profile, while systems involving livestock show little relation in what regards such sampled depths. Conservationist models of land exploration contribute to reduce severity of weed species occurrence in the long term.
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Soil properties can influence weed community composition and weed density agricultural area. Knowing this relationship would allow to choose the best strategy for the control of such plants. This study aimed to investigate the correlation between weed density and chemical and physical attributes of soil in three areas (UCO, USC, and UPA) for commercial sugarcane cultivation in Campos dos Goytacazes, RJ. Grids of 40 m x 40 m were established in the areas, and soil samples were collected at the intersection points for physical and chemical analysis and evaluation of the soil seed bank (SSB), followed by a phyto-sociological survey of the weeds present. Samples were collected during two periods: February/March and June/July, 2010. SSB presented the greatest number of species per vegetation evaluated in the two sampling periods. Clay content had a positive effect leading to greater weed density in all areas (UCO, USC and UPA) in at least one of the densities (0-10 and 10-20 cm). On the other hand, sand content, when significant, presented a negative correlation with plant density in all the SSB areas analyzed. The pH negatively influenced the density of the species found through the phyto-sociological survey at USC and UPA. Cyperus rotundus, dominant in all areas, correlated positively with phosphorus, potassium, and clay content and negatively with pH and high sand content.
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The objective of this study was to evaluate the weed community in a raw sugarcane renovation area with three soil managements and peanut sowing in succession. The experiment was conducted during the 2007/08 season on a raw sugarcane area harvested without prior burning in the last five cuts. A randomized block design with treatments arranged in a split plot and arranged in four replications was used. The main treatments consisted of three cropping systems: conventional tillage, minimum tillage and direct planting, and subplots consisted in the absence (resting) or presence of crop rotation with peanuts. After 135 days from planting peanuts and 180 days of sugarcane harvest, the number of weeds m-2 was counted and the shoot dry biomass of the weeds collected was determined. The data were interpreted by analysis of variance and the means were compared by Tukey's test at 5% probability so that phytosociological indices a, b, c e d were calculated. The use of soil conservation tillage and peanut in rotation with sugarcane in the renovation areas is effective in controlling weeds and suppression of weed species difficult to control like Cyperus rotundus, Commelina bengalensis, Urochloa plantaginea, and Digitaria nuda.
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Ferruginous "campos rupestres" are a particular type of vegetation growing on iron-rich primary soils. We investigated the influence of soil properties on plant species abundance at two sites of ferruginous "campos rupestres" and one site of quartzitic "campo rupestre", all of them in "Quadrilátero Ferrífero", in Minas Gerais State, southeastern Brazil. In each site, 30 quadrats were sampled to assess plant species composition and abundance, and soil samples were taken to perform chemical and physical analyses. The analyzed soils are strongly acidic and presented low fertility and high levels of metallic cations; a principal component analysis of soil data showed a clear segregation among sites due mainly to fertility and heavy metals content, especially Cu, Zn, and Pb. The canonical correspondence analysis indicated a strong correlation between plant species abundance and soil properties, also segregating the sites.
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The aim of this study is to investigate the floristic composition of an Atlantic rain forest fragment located in Cananéia, São Paulo, Brazil, and to contribute to the knowledge on Atlantic forest through the comparative analysis of this and other floristic surveys both on the southern and southeastern Brazil, in different soil and relief types. We surveyed 215 species in 132 genera and 51 families. Classification and ordination analysis were applied to a binary matrix in order to analyze the similarity among 24 surveys, including the present one, of Atlantic forest from the south and southeast coast of Brazil. Higher floristic similarity was observed among this area and the ones where there was marine influence and more rugged relief. The surveys in areas with greater marine influence (sandy soil) were separated from those in other conditions, possibly indicating a species replacement gradient from the steep slopes towards the lowland and were probably related to different edaphic conditions. A latitudinal gradient was found among the surveys apparently confirming a continuous species replacement along the Atlantic forest, related to a restricted distribution of the species. This suggests that it is essential to preserve areas from the whole Atlantic coast. Atlantic forest distribution is quite complex and its composition cannot be adequately represented by small localized areas.
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Coffee is one of the most appreciated drinks in the world. Coffee ground is obtained from the fruit of a small plant that belongs to the genus Coffea. Coffea arabica and Coffea canephora robusta are the two most commercially important species. They are more commonly known as arabica and robusta, respectively. Two-thirds of Coffea arabica plants are grown in South and Central America, and Eastern Africa - the place of origin for this coffee species. Contamination by microorganisms has been a major matter affecting coffee quality in Brazil, mainly due to the harvesting method adopted. Brazilian harvests are based on fruits collected from the ground mixed with those that fall on collection cloths. As the Bacillus cereus bacterium frequently uses the soil as its environmental reservoir, it is easily capable of becoming a contaminant. This study aimed to evaluate the contamination and potential of B. cereus enterotoxin genes encoding the HBL and NHE complexes, which were observed in strains of ground and roasted coffee samples sold in Rio de Janeiro. The PCR (Polymerase Chain Reaction) results revealed high potential of enterotoxin production in the samples. The method described by Speck (1984) was used for the isolation of contaminants. The investigation of the potential production of enterotoxins through isolates of the microorganism was performed using the B. cereus enterotoxin Reverse Passive Latex Agglutination test-kit (BCET-RPLA, Oxoid), according to the manufacturer's instructions. The potential of enterotoxin production was investigated using polymerase chain reaction (PCR) methods for hblA, hblD and hblC genes (encoding hemolysin HBL) and for nheA, nheB and nheC genes (encoding non-hemolytic enterotoxin - NHE). Of all the 17 strains, 100% were positive for at least 1 enterotoxin gene; 52.9% (9/17) were positive for the 3 genes encoding the HBL complex; 35.3% (6/17) were positive for the three NHE encoding genes; and 29.4% (5/17) were positive for all enterotoxic genes.
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This research aimed to determine the soil seed bank and its relationship with environmental factors that have an influence in the distribution of the vegetation above the ground in an excluded area of natural grassland in the South of Brazil. Most of the 122 identified species in the seed bank were perennials. Data analysis indicated three distinct community groups, according to the size and composition of the soil seed bank in lowlands with permanent wet soils, in lowlands and in other areas. In general, lowlands were characterized by low-fertility soils, high moisture and aluminum contents, being spatially homogeneous habitats and, therefore, more restricted to vegetation heterogeneity than other parts of the relief. Environmental factors most associated with soil seed bank size and composition were relief position and their co-related soil variables such as: soil moisture content, potassium content, organic matter, basic saturation of cation exchange soil capacity, exchangeable basics sum of the soil and clay soil content. According to that, relief position, associated with combined effects of soil chemical properties related to it, determines the observed variation pattern of the soil seed bank, as a reflection of the vegetation above the area.
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The correlation of soil fertility x seed physiological potential is very important in the area of seed technology but results published with that theme are contradictory. For this reason, this study to evaluate the correlations between soil chemical properties and physiological potential of soybean seeds. On georeferenced points, both soil and seeds were sampled for analysis of soil fertility and seed physiological potential. Data were assessed by the following analyses: descriptive statistics; Pearson's linear correlation; and geostatistics. The adjusted parameters of the semivariograms were used to produce maps of spatial distribution for each variable. Organic matter content, Mn and Cu showed significant effects on seed germination. Most variables studied presented moderate to high spatial dependence. Germination and accelerated aging of seeds, and P, Ca, Mg, Mn, Cu and Zn showed a better fit to spherical semivariogram: organic matter, pH and K had a better fit to Gaussian model; and V% and Fe showed a better fit to the linear model. The values for range of spatial dependence varied from 89.9 m for P until 651.4 m for Fe. These values should be considered when new samples are collected for assessing soil fertility in this production area.
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A simple method was developed for treating corn seeds with oxamyl. It involved soaking the seeds to ensure oxamyl uptake, centrifugation to draw off excess solution, and drying under a stream of air to prevent the formation of fungus. The seeds were found to have an even distribution of oxamyl. Seeds remained fungus-free even 12 months after treatment. The highest nonphytotoxic treatment level was obtained by using a 4.00 mg/mL oxamyl solution. Extraction methods for the determination of oxamyl (methyl-N'N'-dimethyl-N-[(methylcarbamoyl)oxy]-l-thiooxamimidate), its oxime (methyl-N',N'-dimethyl-N-hydroxy-1-thiooxamimidate), and DMCF (N,N-dimethyl-1-cyanoformanade) in seed" root, and soil were developed. Seeds were processed by homogenizing, then shaking in methanol. Significantly more oxamyl was extracted from hydrated seeds as opposed to dry seeds. Soils were extracted by tumbling in methanol; recoveries range~ from 86 - 87% for oxamyl. Root was extracted to 93% efficiency for oxamyl by homogenizing the tissue in methanol. NucharAttaclay column cleanup afforded suitable extracts for analysis by RP-HPLC on a C18 column and UV detection at 254 nm. In the degradation study, oxamyl was found to dissipate from the seed down into the soil. It was also detected in the root. Oxime was detected in both the seed and soil, but not in the root. DMCF was detected in small amounts only in the seed.
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. The influence of vine water status was studied in commercial vineyard blocks of Vilis vinifera L. cv. Cabernet Franc in Niagara Peninsula, Ontario from 2005 to 2007. Vine performance, fruit composition and vine size of non-irrigated grapevines were compared within ten vineyard blocks containing different soil and vine water status. Results showed that within each vineyard block water status zones could be identified on GIS-generated maps using leaf water potential and soil moisture measurements. Some yield and fruit composition variables correlated with the intensity of vine water status. Chemical and descriptive sensory analysis was performed on nine (2005) and eight (2006) pairs of experimental wines to illustrate differences between wines made from high and low water status winegrapes at each vineyard block. Twelve trained judges evaluated six aroma and flavor (red fruit, black cherry, black current, black pepper, bell pepper, and green bean), thr~e mouthfeel (astringency, bitterness and acidity) sensory attributes as well as color intensity. Each pair of high and low water status wine was compared using t-test. In 2005, low water status (L WS) wines from Buis, Harbour Estate, Henry of Pelham (HOP), and Vieni had higher color intensity; those form Chateau des Charmes (CDC) had high black cherry flavor; those at RiefEstates were high in red fruit flavor and at those from George site was high in red fruit aroma. In 2006, low water status (L WS) wines from George, Cave Spring and Morrison sites were high in color intensity. L WS wines from CDC, George and Morrison were more intense in black cherry aroma; LWS wines from Hernder site were high in red fruit aroma and flavor. No significant differences were found from one year to the next between the wines produced from the same vineyard, indicating that the attributes of these wines were maintained almost constant despite markedly different conditions in 2005 and 2006 vintages. Partial ii Least Square (PLS) analysis showed that leaf \}' was associated with red fruit aroma and flavor, berry and wine color intensity, total phenols, Brix and anthocyanins while soil moisture was explained with acidity, green bean aroma and flavor as well as bell pepper aroma and flavor. In another study chemical and descriptive sensory analysis was conducted on nine (2005) and eight (2006) medium water status (MWS) experimental wines to illustrate differences that might support the sub-appellation system in Niagara. The judges evaluated the same aroma, flavor, and mouthfeel sensory attributes as well as color intensity. Data were analyzed using analysis of variance (ANOVA), principal component analysis (PCA) and discriminate analysis (DA). ANOV A of sensory data showed regional differences for all sensory attributes. In 2005, wines from CDC, HOP, and Hemder sites showed highest. r ed fruit aroma and flavor. Lakeshore and Niagara River sites (Harbour, Reif, George, and Buis) wines showed higher bell pepper and green bean aroma and flavor due to proximity to the large bodies of water and less heat unit accumulation. In 2006, all sensory attributes except black pepper aroma were different. PCA revealed that wines from HOP and CDC sites were higher in red fruit, black currant and black cherry aroma and flavor as well as black pepper flavor, while wines from Hemder, Morrison and George sites were high in green bean aroma and flavor. ANOV A of chemical data in 2005 indicated that hue, color intensity, and titratable acidity (TA) were different across the sites, while in 2006, hue, color intensity and ethanol were different across the sites. These data indicate that there is the likelihood of substantial chemical and sensory differences between clusters of sub-appellations within the Niagara Peninsula iii
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The major focus of this dissertation was to explain terroir effects that impact wine varietal character and to elucidate potential determinants of terroir by testing vine water status (VWS) as the major factor of the terroir effect. It was hypothesized that consistent water status zones could be identified within vineyard sites, and, that differences in vine performance, fruit composition and wine sensory attributes could be related to VWS. To test this hypothesis, ten commercial Riesling vineyards representative of each Vintners Quality Alliance sub-appellation were selected. Vineyards were delineated using global positioning systems and 75 to 80 sentinel vines per vineyard were geo-referenced for data collection. During the 2005 to 2007 growing seasons, VWS measurements [midday leaf water potential ('l')] were collected from a subset of these sentinel vines. Data were collected on soil texture and composition, soil moisture, vine performance (yield components, vine size) and fruit composition. These variables were mapped using global information system (GIS) software and relationships between them were elucidated. Vines were categorized into "low" and "high" water status regions within each vineyard block and replicate wines were made from each. Many geospatial patterns and relationships were spatially and temporally stable within vineyards. Leaf'l' was temporally stable within vineyards despite different weather conditions during each growing season. Generally, spatial relationships between 'l', soil moisture, vine size, berry weight and yield were stable from year to year. Leaf", impacted fruit composition in several vineyards. Through sorting tasks and multidimensional scaling, wines of similar VWS had similar sensory properties. Descriptive analysis further indicated that VWS impacted wine sensory profiles, with similar attributes being different for wines from different water status zones. Vineyard designation had an effect on wine profiles, with certain sensory and chemical attributes being associated from different subappellations. However, wines were generally grouped in terms of their regional designation ('Lakeshore', 'Bench', 'Plains') within the Niagara Peninsula. Through multivariate analyses, specific sensory attributes, viticulture and chemical variables were associated with wines of different VWS. Vine water status was a major contributor to the terroir effect, as it had a major impact on vine size, berry weight and wine sensory characteristics.
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The soil-inhabiting insect-pathogenic fungus Metarhizium robertsii also colonizes plant roots endophytically, thus showing potential as a plant symbiont. M robertsii is not randomly distributed in soils but preferentially associates with the plant rhizosphere when applied in agricultural settings. Root surface and endophytic colonization of switchgrass (Panicum virgatum) and haricot beans (Phaseolus vulgaris) by M robertsii were examined after inoculation with fungal conidia. Light and confocal microscopies were used to ascertain this rhizosphere association. Root lengths, root hair density and emergence of lateral roots were also measured. Initially, M robertsii conidia adhered to, germinated on, and colonized, roots. Furthermore, plant roots treated with Metarhizium grew faster and the density of plant root hairs increased when compared with control plants. The onset of plant root hair proliferation was initiated before germination of M robertsii on the root (within 1-2 days). Plants inoculated with M robertsii AMAD2 (plant adhesin gene) took significantly longer to show root hair proliferation than the wild type. Cell free extracts of M robertsii did not stimulate root hair proliferation. Longer term (60 days) associations showed that M robertsii endophytically colonized individual cortical cells within bean roots. Metarhizium appeared as an amorphous mycelial aggregate within root cortical cells as well as between the intercellular spaces with no apparent damage to the plant. These results suggested that not only is M robertsii rhizosphere competent but displays a beneficial endophytic association with plant roots that results in the proliferation of root hairs. The biocontrol of bean (Phaseolis vulgaris) root rot fungus Fusarium solani f. sp. phaseolis by Metarhizium robertsii was investigated in vitro and in vivo. Dual cultures on Petri dishes showed antagonism of M robertsii against F. solani. A relative inhibition of ca. 60% of F. solani growth was observed in these assays. Cell free culture filtrates of M robertsii inhibited the germination of F. solani conidia by 83% and the inhibitory metabolite was heat stable. Beans plants colonized by M robertsii then exposed to F. solani showed healthier plant profiles and lower disease indices compared to plants not colonized by M robertsii. These results suggested that the insect pathogenic/endophytic fungus M robertsii could also be utilized as a biocontrol agent against certain plant pathogens occurring in the rhizosphere.
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Frames are the most widely used structural system for multistorey buildings. A building frame is a three dimensional discrete structure consisting of a number of high rise bays in two directions at right angles to each other in the vertical plane. Multistorey frames are a three dimensional lattice structure which are statically indeterminate. Frames sustain gravity loads and resist lateral forces acting on it. India lies at the north westem end of the Indo-Australian tectonic plate and is identified as an active tectonic area. Under horizontal shaking of the ground, horizontal inertial forces are generated at the floor levels of a multistorey frame. These lateral inertia forces are transferred by the floor slab to the beams, subsequently to the columns and finally to the soil through the foundation system. There are many parameters that affect the response of a structure to ground excitations such as, shape, size and geometry of the structure, type of foundation, soil characteristics etc. The Soil Structure Interaction (SS1) effects refer to the influence of the supporting soil medium on the behavior of the structure when it is subjected to different types of loads. Interaction between the structure and its supporting foundation and soil, which is a complete system, has been modeled with finite elements. Numerical investigations have been carried out on a four bay, twelve storeyed regular multistorey frame considering depth of fixity at ground level, at characteristic depth of pile and at full depth. Soil structure interaction effects have been studied by considering two models for soil viz., discrete and continuum. Linear static analysis has been conducted to study the interaction effects under static load. Free vibration analysis and further shock spectrum analysis has been conducted to study the interaction effects under time dependent loads. The study has been extended to four types of soil viz., laterite, sand, alluvium and layered.The structural responses evaluated in the finite element analysis are bending moment, shear force and axial force for columns, and bending moment and shear force for beams. These responses increase with increase in the founding depth; however these responses show minimal increase beyond the characteristic length of pile. When the soil structure interaction effects are incorporated in the analysis, the aforesaid responses of the frame increases upto the characteristic depth and decreases when the frame has been analysed for the full depth. It has been observed that shock spectrum analysis gives wide variation of responses in the frame compared to linear elastic analysis. Both increase and decrease in responses have been observed in the interior storeys. The good congruence shown by the two finite element models viz., discrete and continuum in linear static analysis has been absent in shock spectrum analysis.