Matéria seca e absorção de nutrientes em função do espaçamento e da densidade de semeadura em arroz de terra alta

Foi instalado um experimento em condições de campo, em um Latossolo Vermelho escuro, epi-eutrófico, textura argilosa, em Selvíria-MS, com arroz de sequeiro cv. IAC 201, estudando-se três espaçamentos entre fileiras (30, 40 e 50 cm) e três densidades de semeadura (100, 150 e 200 sementes viáveis/m2). Foram avaliadas a produção de matéria seca da parte aérea no momento do florescimento e determinados os teores e quantidades de N, P, K, Ca, Mg e S absorvidos, assim como a eficiência de utilização de nutrientes. A redução do espaçamento entre fileiras aumentou a produção de matéria seca da parte aérea e a quantidade de nutrientes absorvidos. A variação da densidade de semeadura não afetou os parâmetros estudados. A redução do espaçamento entre fileiras proporcionou maior eficiência de utilização do Ca e diminuiu a do N e Mg. Os teores de nutrientes na matéria seca da parte aérea não foram afetados pela variação do espaçamento entre fileiras.

Hidrocarbonetos policíclicos aromáticos no meio ambiente: diferenciação de fontes em sedimentos e metabólitos em bile de peixes

Many studies on environmental ecosystems quality related to polycyclic aromatic hydrocarbons (PAH) have been carried out routinely due to their ubiquotus presence worldwide and to their potential toxicity after its biotransformation. PAH may be introduced into the environmet by natural and anthropogenic processes from direct runoff and discharges and indirect atmospheric deposition. Sources of naturally occurring PAHs include natural fires, natural oil seepage and recent biological or diagenetic processes. Anthropogenic sources of PAHs, acute or chronic, are combustion of organic matter (petroleum, coal, wood), waste and releases/spills of petroleum and derivatives (river runoff, sewage outfalls, maritime transport, pipelines). Besides the co-existence of multiples sources of PAH in the environmental samples, these compounds are subject to many processes that lead to geochemical fates (physical-chemical transformation, biodegradation and photo-oxidation), which leads to an alteration of their composition. All these facts make the identification of the hydrocarbons sources, if petrogenic, pyrolytic or natural, a challenge. One of the objectives of this study is to establish tools to identify the origin of hydrocarbons in environmental samples. PAH diagnostic ratios and PAH principal component analysis were tested on a critical area: Guanabara Bay sediments. Guanabara Bay is located in a complex urban area of Rio de Janeiro with a high anthropogenic influence, being an endpoint of chronic pollution from the Greater Rio and it was the scenario of an acute event of oil release in January 2000. It were quantified 38 compounds, parental and alkylated PAH, in 21 sediment samples collected in two surveys: 2000 and 2003. The PAH levels varied from 400 to 58439 ng g-1. Both tested techniques for origin identification of hydrocarbons have shown their applicability, being able to discriminate the PAH sources for the majority of the samples analysed. The bay sediments were separated into two big clusters: sediments with a clear pattern of petrogenic introduction of hydrocarbons (from intertidal area) and sediments with combustion characteristics (from subtidal region). Only a minority of the samples could not display a clear contribution of petrogenic or pyrolytic input. The diagnostic ratios that have exhibited high ability to distinguish combustion- and petroleum-derived PAH inputs for Guanabara Bay sediments were Phenanthrene+Anthracene/(Phenanthrene+Anthracene+C1Phenanthrene); Fluorantene/(Fluorantene+Pyrene); Σ (other 3-6 ring PAHs)/ Σ (5 alkylated PAH series). The PCA results prooved to be a useful tool for PAH source identification in the environment, corroborating the diagnostic indexes. In relation to the temporal evaluation carried out in this study, it was not verified significant changes on the class of predominant source of the samples. This result indicates that the hydrocarbons present in the Guanabara Bay sediments are mainly related to the long-term anthropogenic input and not directly related to acute events such as the oil spill of January 2000. This findings were similar to various international estuarine sites. Finally, this work had a complementary objective of evaluating the level of hydrocarbons exposure of the aquatic organisms of Guanabara Bay. It was a preliminary study in which a quantification of 12 individual biliar metabolites of PAH was performed in four demersal fish representing three different families. The analysed metabolites were 1-hydroxynaphtalene, 2-hidroxinaphtalene, 1hydroxyphenanthrene, 9-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1hydroxypyrene, 3-hidroxibiphenil, 3- hydroxyphenanthrene, 1-hydroxychrysene, 9hydroxyfluorene, 4-hydroxyphenanthrene, 3-hydroxybenz(a)pyrene. The metabolites concentrations were found to be high, ranging from 13 to 177 µg g-1, however they were similar to worldwide regions under high anthropogenic input. Besides the metabolites established by the used protocol, it was possible to verified high concentrations of three other compounds not yet reported in the literature. They were related to pyrolytic PAH contribution to Guanabara Bay aquatic biota: 1-hydroxypyrine and 3-hydroxybenz(a)pyrine isomers

A inserção das mulheres na luta pela terra: movimento de participação e/ou submissão

The following dissertation studies the insertion of peasant women in the conflict for land since the occupation process, dispossession and construction of the settlement New Horizon II, in the municipal district of Maxaranguape. It analyses their participation in the conflict Valley of the Hope", that resulted in the settlements New Life II and New Horizon II in the municipal district of Maxaranguape. The analysis exposes the reasons which took the peasant women, after the land conquest, to go back into domestic space and/or to assume positions of lesser relevance in the political organizations of the settlement. In the conflict Valley of the Hope, the women had a fundamental role, facing the police violence, being front line of the conflicts against the repression forces, risking their lives and the life of their families. After the conquest of the land, transformed into the New Horizon II Settlement, there are a lot of changes in the participation of the women. We can observe that, despite the protagonism of the families, in special of the women in the Valley of the Hope conflict, these female workers still experiment unequal social, economic, political and cultural conditions in relation to the men, expressing the gender inequalities which are found in the daily life of the settlement: in the community, in the domestic and agricultural task. The conflict for the land in the Valley of the Hope and the conquest of the settlement did not necessarily mean the incorporation of the emancipation of the peasant women. However, the political participation in the development of the conflicts allowed to the women the self discovering and the beginning of an emancipation process as gender. There are signals of continuities and ruptures of the present culture, almost always stimulated by the organization of the agricultural female workers

Um estudo das condições de percolação e estabilidade em barragens de terra mediante métodos geofísicos: caso do dique de Sant Llorenç de Montgai - Espanha

The monitoring of Earth dam makes use of visual inspection and instrumentation to identify and characterize the deterioration that compromises the security of earth dams and associated structures. The visual inspection is subjective and can lead to misinterpretation or omission of important information and, some problems are detected too late. The instrumentation are efficient but certain technical or operational issues can cause restrictions. Thereby, visual inspections and instrumentation can lead to a lack of information. Geophysics offers consolidated, low-cost methods that are non-invasive, non-destructive and low cost. They have a strong potential and can be used assisting instrumentation. In the case that a visual inspection and strumentation does not provide all the necessary information, geophysical methods would provide more complete and relevant information. In order to test these theories, geophysical acquisitions were performed using Georadar (GPR), Electric resistivity, Seismic refraction, and Refraction Microtremor (ReMi) on the dike of the dam in Sant Llorenç de Montgai, located in the province of Lleida, 145 km from Barcelona, Catalonia. The results confirmed that the geophysical methods used each responded satisfactorily to the conditions of the earth dike, the anomalies present and the geological features found, such as alluvium and carbonate and evaporite rocks. It has also been confirmed that these methods, when used in an integrated manner, are able to reduce the ambiguities in individual interpretations. They facilitate improved imaging of the interior dikes and of major geological features, thus inspecting the massif and its foundation. Consequently, the results obtained in this study demonstrated that these geophysical methods are sufficiently effective for inspecting earth dams and they are an important tool in the instrumentation and visual inspection of the security of the dams

Atividade cromosférica induzida por planetas extrasolares gigantes

In the present work, we have analyzed the behavior of the chromospheric activity of stars with planets, as a function of different planetary parameters, searching for possible effects of planets on the chromosphere of the hosting star. For this study we have selected a sample of 73 main sequence stars with planets, of spectral types F, G and K. Our analysis shows that among stars with planets presenting semi-major axis smaller than 0.15 AU, a few ones present enhanced CaII emission flux, paralleling recent results found in the literature for coronal X-ray flux. Nevertheless, in contrast to Kashyap et al. (2008), who claim that enhanced X-ray flux in stars with planets is associated to massive close-in planetary companions, we suggest that such an aspect, at least in the context of CaII emission flux, is rather an effect of stellar sample selection. We have also studied the behavior of the CaII emission as a function of orbital parameters such as orbital period and eccentricity, and no clear trend was found, reinforcing our present suggestion that enhanced chromospheric activity in stars with planets is an intrinsic stellar phenomenon

Interpretando direitos e incorporando novas agências: o reconhecimento da Terra Indígena Las Casas, PA, e as perspectivas caiapó sobre esse processo

O artigo trata do processo de retomada e reconhecimento da Terra Indígena Las Casas, PA, de ocupação tradicional dos índios caiapó. O intuito é mostrar que os Caiapó interpretam esse evento, que é também jurídico e administrativo, a partir de suas próprias ló- gicas culturais, a ele incorporando novas agências e visões de mundo

Reforma agrária de mercado e territorialização: um estudo a partir do Programa Cédula da Terra em Canindé-CE

The research Reforma Agrária de Mercado e Territorialização: um estudo a partir do Programa Cédula da Terra em Canindé-Ce , has an objective to discuss until whas time denominated agrarium refom has capacity of territory the of families in Five from the seven settlements cmated by resourles from the prgramme cell of earth em Canindé-Ce. In this context, the present work analysis the relation sitip between power and kind of identity, in special in those settlements, trying to learn the dialetic relationship. That passes by the process and appropriation in these spaces by these families gave the beginning of buying the land. The procedure methologic used by us gave privilege to realize the interview included in this process, wita the leaders of rural associations (STR); commission clero of earth (CPT); rural workers movement without land (MST); wita agricolas tecnics, and so the local coordinators of cell of earth in Fortaleza. The analysis of agrarium reform in Canindé, infects that the families giving entrance in buying the land, they could creatieg a hope in quality of life for getting the land. Nevertheless, it did not happen, in the rost of the parts of the areas in study. The territories present in general focus, the worse process of poomest besides the amount of debiths of these families, putting in risk the territorialization of themselves

Terra e trabalho: permanência de uma política pública na Fazenda Mundo Novo, em Caicó-RN

This is study about the Project Vazantes, as a case of stay policy on access to land upstream of the weir humid New World, in Caicó-RN. It includes social and economic aspects of vazanteiros, that in their experiences with the land, recreate structures, forms and functions. Theoretically, the work is based on the ideas miltonianas (1986, 1988, 1996, 1997) on the production and reproduction of space, as seen this system of actions that is articulated to the public policies and the achievements solidarity, to the extent that production, in vazantes there is virtually no technology investment, technical assistance and rural credit. Regarding the search procedures, we conducted interviews and questionnaires with vazanteiros applied but did photographic records and research into documentary sources Agricultural Research Company's Rio Grande do Norte S / A (EMPARN), the Union of Rural Workers of Caicó (STRC ), In newspapers and magazines, as well as other sources of information related to the object of study.Such procedures, coupled with theoretical and methodological benchmarks, helped in the understanding of the relationship that takes place in the New World Farm, in order that space produced by actors (EMPARN and vazanteiros) comprises a structure of power that involves multiple interests in extent that land and labor are appropriate mechanisms as dialetizantes

Detecção de áreas degradadas na sub-bacia hidrográfica do rio taperoá/pb, utilizando parâmetros físicos dos sensores modis/terra e tm/landsat

This study includes the results of the analysis of areas susceptible to degradation by remote sensing in semi-arid region, which is a matter of concern and affects the whole population and the catalyst of this process occurs by the deforestation of the savanna and improper practices by the use of soil. The objective of this research is to use biophysical parameters of the MODIS / Terra and images TM/Landsat-5 to determine areas susceptible to degradation in semi-arid Paraiba. The study area is located in the central interior of Paraíba, in the sub-basin of the River Taperoá, with average annual rainfall below 400 mm and average annual temperature of 28 ° C. To draw up the map of vegetation were used TM/Landsat-5 images, specifically, the composition 5R4G3B colored, commonly used for mapping land use. This map was produced by unsupervised classification by maximum likelihood. The legend corresponds to the following targets: savanna vegetation sparse and dense, riparian vegetation and exposed soil. The biophysical parameters used in the MODIS were emissivity, albedo and vegetation index for NDVI (NDVI). The GIS computer programs used were Modis Reprojections Tools and System Information Processing Georeferenced (SPRING), which was set up and worked the bank of information from sensors MODIS and TM and ArcGIS software for making maps more customizable. Initially, we evaluated the behavior of the vegetation emissivity by adapting equation Bastiaanssen on NDVI for spatialize emissivity and observe changes during the year 2006. The albedo was used to view your percentage of increase in the periods December 2003 and 2004. The image sensor of Landsat TM were used for the month of December 2005, according to the availability of images and in periods of low emissivity. For these applications were made in language programs for GIS Algebraic Space (LEGAL), which is a routine programming SPRING, which allows you to perform various types of algebras of spatial data and maps. For the detection of areas susceptible to environmental degradation took into account the behavior of the emissivity of the savanna that showed seasonal coinciding with the rainy season, reaching a maximum emissivity in the months April to July and in the remaining months of a low emissivity . With the images of the albedo of December 2003 and 2004, it was verified the percentage increase, which allowed the generation of two distinct classes: areas with increased variation percentage of 1 to 11.6% and the percentage change in areas with less than 1 % albedo. It was then possible to generate the map of susceptibility to environmental degradation, with the intersection of the class of exposed soil with varying percentage of the albedo, resulting in classes susceptibility to environmental degradation

Desenvolvimento do açaizeiro de terra firme, cultivar pará, sob atenuação da radiação solar em fase de viveiro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência da secagem, armazenamento e embalagem nos resultados da análise química de terra para fins de fertilidade

Amostras de terra provenientes de uma Terra Roxa Estruturada e um Latossol Vermelho Escuro textura média foram analisados quimicamente para se verificar a influência de embalagem (caixa de papelão saco de polietileno), tempo de armazenamento (1-32 dias) e processo de secagem (ao ar ou estufa a 60°C). A secagem foi o fator que mais influenciou a análise determinando variações nos resultados analíticos principalmente para pH e fósforo. O armazenamento apresentou influência apenas para fósforo trocável enquanto que a embalagem não influiu nos resultados. As variações dos resultados analíticos para pH, em função da secagem, e fósforo, em função da secagem e tempo de armazenamento, foram de ordem a alterar a interpretação da fertilidade quanto aos limites de classes.

Memórias sobre um conflito de terra em relatos de história de vida

Este artigo se propõe a analisar as memórias de pequenos produtores rurais do assentamento Camucim (litoral sul da Paraíba) sobre um conflito de terra ocorrido no final dos anos 70 e início dos anos 80, do século XX. Essas memórias foram obtidas através de entrevistas de história de vida, que foram submetidas à Análise de Discurso. A partir da história oral, pretende-se analisar o sentido subjetivo construído pelos narradores, através de suas memórias. Nesse sentido, o conflito é relembrado como uma luta legítima, abençoada por Deus, o que nos remete para o papel fundamental da Igreja nesse processo, através da Comissão Pastoral da Terra (CPT). Além disso, os narradores constroem uma imagem de lutadores corajosos e vitoriosos.

Produtores familiares e estratégias ligadas à terra

A manutenção e/ou a ampliação da terra compõem o eixo central em torno do qual os produtores familiares organizam sua vida e seu trabalho. Este artigo analisa as estratégias desses produtores em relação à divisão de herança e à sucessão, e as formas que utilizam para aquisição de novas áreas. O levantamento das características das famílias e da propriedade foi realizado por meio de um questionário aplicado junto a 89 produtores familiares de três municípios da mesorregião de São José do Rio Preto (SP). Posteriormente foi entrevistado um terço dos produtores de cada município que havia respondido ao questionário. A análise das estratégias fundiárias mostrou uma grande diversidade na forma de partilhar a herança e de conduzir a sucessão, sendo que ambos os processos são apoiados, basicamente, em regras tradicionais, embora mantenham uma fachada de adequação às normas legais. Quanto às estratégias de aquisição de mais terras, observou-se que os produtores são capazes de organizar complexas formas de capitalização, centradas em maiores esforços no trabalho e na contenção de gastos, além da utilização de políticas públicas favoráveis e de práticas costumeiras. Os arranjos intra-familiares e as formas de cooperação ligadas ao parentesco mais amplo também se mostraram importantes para a ampliação da propriedade.

Gestão ambiental: uma súplica do planeta, um desafio para políticas públicas, incubadoras e pequenas empresas

O texto traz uma reflexão sobre o papel das incubadoras de empresas no apoio a práticas ambientais por micro e pequenas empresas. Reconhecendo as debilidades estruturais das empresas de pequeno porte e as dificuldades para a realização de investimentos ambientais, defende o uso de incubadoras como instrumento de política pública para estimular investimentos ambientais. Identifica um número restrito de incubadoras de tecnologias ambientais, em plano internacional. Relata os resultados de uma pesquisa que avaliou a aplicabilidade de um indicador para apurar o desempenho ambiental de incubadoras. Destacaram-se dois resultados: a) a baixa importância atribuída, pelas incubadoras (e pelas empresas abrigadas) ao desempenho ambiental; e b) a ausência de estímulos, pelas incubadoras, aos investimentos ambientais. Desse último resultado deriva importante conclusão: a de que, uma vez apurados os padrões insatisfatórios de desempenho ambiental, de incubadoras e empresas assistidas, ficariam criadas as condições para a formulação e a implementação de medidas indutoras de novas posturas.

Análise do uso da terra na microbacia do Arroio do Meio - Santa Maria - RS, por Sistema de Informações Geográficas e imagem de satélite

O objetivo desse trabalho foi verificar a viabilidade do uso de um Sistema de Informações Geográficas (SIG) e a imagem de satélite para a análise do uso atual da terra e localização de áreas onde possam estar ocorrendo conflitos entre capacidade e uso do solo, na microbacia hidrográfica do Arroio do Meio. Foram utilizadas técnicas de geoprocessamento, como álgebra entre mapas, consulta ao banco de dados e reclassificação de imagens. Uma microbacia foi escolhida como objeto deste estudo, por ser considerada por muitos autores como sendo uma das melhores unidades para o planejamento e desenvolvimento sócioeconômico dos habitantes do meio rural. Na microbacia estudada, foram encontrados 555ha cobertos com florestas, compreendendo 24% da área total. As lavouras com área de 1.314ha ocupam a maior parte da microbacia (56%). Os campos de pastagens cobrem 184ha, ou seja, 8% da área total. As áreas alagadas representam 11% da área da microbacia, tendo respectivamente 265ha. Foram detectados ainda, 31ha sombreados (1%) onde não se determinou com exatidão o uso da terra. Nas áreas com declividade superior a 47%, foram detectados 32ha sem cobertura de florestas, perfazendo 1,4% da área da microbacia. em declives superiores a 30%, existem 71ha (3%) sendo usados para a agricultura. A área ocupada com Chernossolos e Neossolos Litólicos, unidade de mapeamento Ciríaco-Charrua em declividade maior que 30% sem cobertura florestal é de 14ha (0,6%). de acordo com a declividade e o solo, as áreas de conflito alcançam 5% da área total, o que demonstra que, na maior parte da microbacia, a terra está sendo usada de acordo com sua capacidade.