Alterações ambientais em Parelhas, Rio Grande do Norte: metais pesados em sedimentos de drenagens e percepção de comunidades rurais em relação a mudanças na paisagem

The conservation of natural resources is essential and constitutes the main subject of many researches, which characterize important aspects concerning the environmental alterations in the ground, water, landscape and socioeconomic information. This study aimed to investigate the anthropogenic input of heavy metals in the environment, in the area of the Parelhas dump site and in part of the Seridó River and to determine the concentration of heavy metals in the sediments. This can result in risk to the environment and human health. In addition, we sought to establish the socioeconomic profile of rural communities adjacent to Seridó River and to comprehend the perception of these dwellers about the changes in the places they live. The area of this study is located in the city of Parelhas/RN, in the centralsouthern part of the State, in the micro-region of the Oriental Seridó. This area comprehends the place where the dump site is located, next to RN 086, the Caldeirão dam, the Quintos river called by local citizens Caldeirão creek and part of Seridó river, perpetuated by the Boqueirão dam, which crosses the city and it includes the rural communities of Almas, Domingas, Sussuarana II and Colonos. Regarding the study with bottom sediments, the samples were collected and taken to the laboratory of geochemistry, where they were dried, sieved, weighted and submitted to weak acid attack. The analysis of heavy metals was held by Atomic Absorption Spectrophotometer - Flame AAS. We applied 23 closed questionnaires constituted by 38 questions to collect informations in the rural communities, oriented to establish the socioeconomic profile and the environmental perception of the participants. The participants were distributed in the communities of Almas (1), Domingas (2), Sussuarana II (10) and Colonos (10). Most of them presented similar socioeconomic profiles. They are from 45 to 60 years old and live in these localities for 20 to 30 years or more. The families are composed by 3 or 4 people; the agriculture is the main activity, livestock is the secondary and 48% of them earn the minimal wage. Regarding the environmental perception, the participants can realize some changes in vegetation, soil, water and landscape. People living longer in the community, and with more years of experience on the local reality can perceive the depletion of the soil, pastures and changes in the landscape. These changes portray how the place was previously and what it represents today. The perception of these changes, besides the environmental ones, includes others concerning the increasing number of dwellers in the last years, as well as the number of houses. The changes happened through activities developed by the dwellers over the years, including agricultural practices, livestock, grass planting and even the cultivation of cotton. The study provided the acquisition of new data about the environmental reality of this region. It can subsidize the definition of public policies that can be implemented from the perspective of conservation of water resources and of the coexistence and survival of man in the semi-arid

Horticultura no baixo curso do Rio Doce, zona norte do Natal/RN: avaliação da qualidade da água por meio de ensaios ecotoxicológicos

The research is developed in areas of horticulture in the city of Natal, in the neighborhoods of Lagoa Azul, Pajuçara and Redinha, along the Doce River, border area with Extremoz city, Rio Grande do Norte State. The region of the fluvial plain of Doce River is located in an Environmental Protection Zone (ZPA-9). This is one of the ZPA which is not under the regulatory marks and there are several environmental problems caused by use and land occupation, featuring an evident disregard of environmental laws and whose protection is hindered by the lack of specific legal mechanisms. This study aims to provide an overview of the use of pesticides in the lower course of the Doce River, in Natal, Rio Grande do Norte, and to assess environmental degradation in the area through chronic toxicity tests using the microcrustaceous Ceriodaphnia dubia Richard 1894 (Cladocera, Crustacea) as test organism. Visits were made to the area in 2009 and 2010. To obtain information a diagnosis of the local situation was accomplished based on personal observation and non-participatory photographic record, with the aim of assessing the environmental characteristics, population diversity and work processes of horticulturists. During the visits four different points of the Doce River were chosen to collect water for ecotoxicological tests and survey of physico-chemical parameters (dissolved oxygen, pH, chloride, turbidity, conductivity and temperature), which were measured in the field using Multiparameter Probe (TROLL 9500). The adverse effects of pesticide use in the lower course of the Doce River is a major problem for both the environmental and human health, since many of the substances and active principles that enter in the composition of the products are synthesized molecules whose effects can only be evaluated through different studies on their actions and behavior at short, medium or long term

Degradação ambiental no município de Cerro Corá RN por técnicas de geoprocessamento

The processes of occupation and evolution of natural environments as a result of a disorderly process of implementing economic practices agrosilvopastoris play today an important role in the degradation process of changing the landscape and natural resources of the semiarid Northeast. The Serra de Santana has natural elements important to the state of Rio Grande do Norte as the source of the Potengi. Therefore, this study aimed to analyze the degree of degradation in the municipality of Cerro Cora - RN. We used satellite images Landsat-5 and census data for the year 2008. The method made use of geotechnology which includes land use, NDVI, rainfall, livestock and erodibility in the evaluation of environmental degradation, as well as satellite images of Landsat TM-5, in the years 1984, 1995 and 2008, letters of NDVI, census data regarding the socioeconomic obtained from IBGE. The results showed that the absolute majority in the municipality of Cerro Cora has a low to medium susceptibility, which together represent 63.92% of the municipality, with a regression of disturbed areas and the areas of agriculture, and a recovery of the areas of Caatinga , coming to occupy currently 92% of the municipal territory. A Geographic Information System is indispensable to environmental monitoring of Cerro Cora / RN

Diagnóstico da degradação ambiental no município de Areia Branca-RN por geotecnologias

The municipality of Areia Branca is within the mesoregion of West Potiguar and within the microregion of Mossoró, covering an area of 357,58 km2. Covering an area of weakness in terms of environmental, housing, together with the municipality of Grossos-RN, the estuary of River Apodi-Mossoró. The municipality of Areia Branca has historically suffered from a lack of planning regarding the use and occupation of land as some economic activities, attracted by the extremely favorable natural conditions, have exploited their natural resources improperly. The aim of this study is to quantify and analyze the environmental degradation in the municipality. Thus initially was performed a characterization of land use using remote sensing, geoprocessing and geographic information system GIS in order to generate data and information on the municipal scale, which may serve as input to the environmental planning and land use planning in the region. From this perspective, were used a Landsat 5 image TM sensor for the year 2010. In the processing of this image was used SPRING 5.2 and applied a supervised classification using the classifier regions, which was employed Bhattacharya Distance method with a threshold at 30%. Thus was obtained the land use map that was analyzed the spatial distribution of different types of the use that is occurring in the city, identifying areas that are being used incorrectly and the main types of environmental degradation. And further, were applied the methodology proposed by Beltrame (1994), Physical Diagnosis Conservationist under some adaptations for quantifying the level of degradation or conservation study area. As results, the indexes were obtained for the parameters in the proposed methodology, allowing quantitatively analyze the degradation potential of each sector. From this perspective, considering a scale of 0 to 100, sector A and sector B had value 31.20 units of risk of physical deterioration. And the C sector, has shown its value - 34.64 units degradation risk and should be considered a priority in relation to the achievement of conservation actions

Estudo do comportamento mecânico de estruturas de solo-cimento reforçado com fibras de coco e hastes de bambu

In this work the use of coconut fiber (coir) and bamboo shafts as reinforcement of soil-cement was studied, in order to obtain an alternative material to make stakes for fences in rural properties. The main objective was to study the effect of the addition of reinforcement to the soil-cement matrix. The effect of humidity on the mechanical properties was also analyzed. The soil-cement mortar was composed by a mixture, in equal parts, of soil and river sand, 14% in weight of cement and 10 % in weight of water. As reinforcement, different combinations of (a) coconut fiber with 15 mm mean length (0,3 %, 0,6 % and 1,2 % in weight) and (b) bamboo shafts, also in crescent quantities (2, 4 and 8 shafts per specimen) were used. For each combination 6 specimens were made and these were submitted to three point flexural test after 28 days of cure. In order to evaluate the effect of humidity, 1 specimen from each of the coconut fiber reinforced combination was immersed in water 24 hours prior to flexural test. The results of the tests carried out indicated that the addition of the reinforcement affected negatively the mechanical resistance and, on the other hand, increased the tenacity and the ductility of the material.

Análise de uso e cobertura do solo no município de Parelhas/RN

The human interference in the semiarid region of Seridó Potiguar has promoted the increase of degraded areas. The economic dynamic that was established in the Seridó territory, especially after the fall of the trinomial cattle-cotton-mining in the 70s and 80s of the 20th century as pillars of the regional economy, resulted in an accelerated process of erosion of natural resources. The municipalities of the Seridó region have been spatially reordered by this new economic dynamic, marked by the growth of existing enterprises, and the development of new agricultural practices. One of the municipalities in the region that restructured its territorial space with the emergence of new agro-industrial activities was the town of Parelhas. With the demise of the trinomial cattle-cotton-mining in the 1980s, other productive activities were intensified from the 1990s, amongst them, pottery, responsible for the vegetal extraction for use as energy source. This recent economic and spatial restructuring in the region, reflected in the Parelhense municipal territory, required new productive ingredients responsible for the modification of past production relations that were based on cattle, cotton and mining. By that a process of exploring the environment was unleashed, especially the native vegetation, in an uncontrolled manner. In this context, the objective of this study was to survey and detect deforestation in the areas of Caatinga vegetation, used indiscriminately as energy supply for new agricultural practices, using remote sensing techniques based on the quantification of the Normalized Difference Vegetation Index / NDVI, Soil-Adjusted Vegetation Index / SAVI, surface temperature and rainfall data in the years 1990 and 2010. The results indicated that SAVI values above 0.2 in 1990 and 2010 represent the areas with the highest density of vegetation that occur exclusively along the major drainages in the town and areas of higher elevations. The areas between the ranges of values from 0.5 to 0.15 SAVI are areas with poor vegetation. On the other hand the highest values of temperature are distributed in the western and southeastern parts of the township, usually in places where the soil is exposed or there is sparse vegetation. The areas of bare soil decreased in extension in 2010 at 11, 6% when related to 1990, this was caused by a higher rainfall intensity in the first half of 2010, but no regeneration of vegetation occurred in some places in the western and southeastern areas of the municipality today, due to the extraction of firewood to fuel the furnaces of industries in town

Dinâmica do uso e ocupação do solo no litoral de Macau-RN no período de 1978 a 2008

This study was developed in the northern coast of the city of Macau, a total area of 88,52 km², located in the State of Rio Grande do Norte. It presents relatively plain surface, with interlaced of streams and gamboas, characterized by contributions of oceanic water, flooding areas of swamps. Altogether, the climatic and topographical conditions provide an ideal environment for the development of saline activity. Inserted in the geologic context of the Potiguar Basin, the region presents favorable conditions for the production of hydro-carbons. It still presents natural conditions for shrimp breeding and artisanal fishing. This work analyzes the transformations occurred in the land use, using air photographs of 1978, Landsat 5 ETM Images of 1988, 1998 and 2008. A secular analyzes was carried through the dynamics of the use of the territory and the transformations occurred in the landscape due to the increment of the productive activities. In the survey of the data for study of the area, it was verified that little alteration occurred in the 30 years. The saline activity that was present since the year of 1978 having an increase of about 5% in thirty years; the shrimp breeding activity that had its presence in the decade of 1990, presented a high growth in the land use, therefore in 1998 it presented 0.45% and currently it presents 6.59%. In the field it was observed that great areas used previously for the saline activity, today it is prepared for shrimp breeding and that the areas of petroleum exploration occupy salt mines, beaches and trays. In 1988 it presented a percentage of 0, 07% and currently it occupies 0.46%, having grown 50% in the last 10 years. Although the variation of the occupation of the area has been little expressive, shrimp breeding showed a growth of 1,200% in only 10 years. In regards to petroleum activity, there wasn t any demonstration of an increasing impact in the land use in the area of study in 26 years of exploration

Poda apical, densidade de plantas e cobertura plástica do solo na produtividade do tomateiro em cultivo protegido

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

Solarização em microcosmo: efeito de materiais vegetais na sobrevivência de fitopatógenos de solo e na produção de voláteis

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

Efeitos da simulação da solarização do solo com materiais vegetais sobre o crescimento micelial de fungos fitopatogênicos habitantes do solo

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

Controle de fitopatógenos do solo com materiais vegetais associados à solarização

A incorporação de material orgânico associada à solarização do solo é uma técnica promissora no controle de patógenos de plantas. O trabalho consistiu na prospecção de materiais vegetais promissores na produção de voláteis fungitóxicos capazes de inviabilizar as estruturas de resistência de fitopatógenos do solo. em condição de campo foram incorporados 3 Kg/m² de folhas e ramos de brócolos, eucalipto, mamona e mandioca brava, associada ou não à solarização, visando o controle de Fusarium oxysporum f. sp. lycopersici raça 2; Macrophomina phaseolina; Rhizoctonia solani AG-4 HGI e Sclerotium rolfsii. O controle foi avaliado por meio da sobrevivência das estruturas, em meios semi-seletivo específicos, aos 7, 14, 21 e 28 dias do início do experimento. Foram monitoradas as temperaturas do solo e do ar por um DataLogger Tipo CR23X (Campbell Scientific) e a porcentagem de CO2 e de O2 pelo equipamento analisador de gases (Testo 325-1). A associação da incorporação dos materiais vegetais com a solarização do solo inativou F. oxysporum f. sp. lycopersici raça 2, M. phaseolina e R. solani. O fungo S. rolfsii foi o único que não apresentou 100% de controle com solarização mais mamona durante o período estudado. A incorporação de mandioca seguido de solarização propiciou o controle de todos os fungos estudados com menos de sete dias da instalação do experimento, sendo tão eficiente quanto o brócolos na erradicação dos fitopatógenos veiculados pelo sol.

Modificações químicas em solo solarizado, com e sem incorporação de resíduos orgânicos

The soil solarization is used in small properties as an alternative for control of phytopathogens and weeds, besides it also can affect the availability of some nutrients and phytotoxic elements in the soil. Thus, one experiment was carried out as a three-factor factorial (solarized and not solarized soil x with and without addition of vegetable residue x four collection times) for evaluation of variations of pH, organic matter, phosphorus, total nitrogen, potassium, calcium, magnesium and aluminum in a soil characterized as Distrofic Red Latosoil, in Botucatu county (SP). The incorporated vegetable residue was constituted of crop remains of kale (Brassica oleraceae var. acephala L.) fresh and triturated. Soil samples of each treatment were collected from zero to Urn of depth, at 7, 21, 35, and 49 days after solarization treatment, from January to March of 2001. Soil chemical analyses were done as well as the soil temperature were monitored on the treatments. The solarized soil with kale organic residues addition treatment presented higher values of pH, organic matter, total nitrogen, phosphorus, potassium, calcium, magnesium and minor values of aluminum.

Desenvolvimento de plantas de ervilha (Pisum sativum L.), submetidas à diferentes potenciais da água no solo: índices fisiológicos

A ervilha é cultivada no Brasil Central, durante o inverno seco, exigindo para o pleno êxito da cultura o uso da irrigação. Assim, o presente trabalho se propõe a avaliar os efeitos do potencial da água no solo nos índices fisiológicos da análise quantitativa de crescimento de plantas de ervilha (Pisum sativum L.). O experimento foi montado em casa de vegetação, em solos de textura argilosa, com delineamento experimental inteiramente casualizado, com quatro tratamentos decorrentes de potenciais mínimos da água no solo (-33, -100, -200 e -1500 kPa) em três repetições, cada qual contendo duas plantas de ervilha, cultivar Caprice. Os resultados obtidos evidenciaram que a redução do potencial água no solo, induziu o decréscimo na área foliar, sem interferir no comportamento da razão de massa foliar, razão de área foliar, taxa assimilatória líquida e taxa de crescimento relativo.

Variabilidade espacial da densidade do solo sob manejo da irrigação

Este trabalho foi desenvolvido em um solo aluvial na Estação Experimental da Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Algodão, município de Souza, Estado da Paraíba, Brasil, com o objetivo de estudar a variabilidade espacial da densidade do solo. A área tem uma superfície cultivada de 17 ha e os testes de campo foram feitos em 40 pontos amostrais, locados na linha central longitudinal de cada parcela agrícola, eqüidistante de 50 m. Na determinação da densidade do solo, foi utilizado o método do anel volumétrico, em amostras com estrutura indeformada para as profundidades de 0-30, 30-60 e 60-90 cm. A variabilidade espacial foi determinada pela técnica de estatística clássica e da geoestatística. Na análise estatística clássica, a densidade do solo para as três profundidades apresentou baixos valores de desvio-padrão e coeficiente de variação, indicando pouca variação da densidade do solo com aumento da profundidade. A densidade do solo manifestou estrutura de dependência espacial, modelada por meio de semivariogramas, os quais permitiram a interpolação por Krigagem, apresentando estrutura esférica nas profundidades de 0-30 e 60-90 cm, com alcance de 46 m e estrutura exponencial com alcance de 255,10 m para a profundidade 30-60 cm.

Influência da geometria e umidade de colunas de solo na biodegradação de filmes de PCL

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