Iêde de Brito Chaves

Propriedades químicas do solo aluvial da Ilha de Assunção - Cabrobó (Pernambuco)

The alluvial soil of the Assuncao Island, in the Sao Francisco River, Cabrobo, State of Pernambuco, Brazil, has been intensively cultivated with annual crops under irrigation. The present yields are unsatisfactory due to the use of inadequate agricultural practices that are not sustainable. This study aimed to survey the soil chemical properties in an area of 1,131 ha by collecting 1,053 samples in the 0-0.30 m surface soil layer. The samples were analyzed for chemical properties and the data were analyzed using descriptive statistics. The obtained results indicated that there was higher variability for aluminum, potassium and phosphorus concentration and for the percentage of sodium saturation. The lowest variability was observed for soil pH. The data did not present a normal distribution. Most soil samples presented low aluminum, organic matter, and phosphorus concentrations. The soil pH, CEC, calcium, magnesium, and potassium concentration were interpreted as appropriate for most crops and were classified as normal regarding the percentage of sodium saturation.

Dinâmica da cobertura vegetal para a Bacia de São João do Rio do Peixe, PB, utilizando-se sensoriamento remoto

ABSTRACT In general, the semiarid region of Paraiba (northeastern Brazil) the vegetation has changed due to human activities, for example, Peixe River basin, that has suffered over the years by human occupation. In this context, this paper aims to conduct a multi-temporal analysis of biophysical variables derived from images of the Landsat 5 satellite and digital image processing techniques and GIS for 23 years. The results indicated increase of vegetation specially in the high slope areas of the basin. That fact may be related to the exodus of rural population occurred during the observed period .It was also observed that the surface albedo was best correlated parameter with changes in vegetal biomass. However, the isolated variations in vegetation cover were not enough to explain the variations in surface temperature and net radiation over the analyzed years.

Estimativa da acidez potencial pelo método do pH SMP em solos da Microrregião Homogênea Brejo Paraibano

The use of the pH SMP to estimate the potential acidity has advantages in relation to the 0.5 mol L-1, pH 7, calcium acetate method, but requires previous edaphic regionalization to estimate the potential acidity. The objectives of this study were to evaluate the soil-water-buffer ratio more adapted to soils from the homogeneous micro-region of Brejo Paraibano and to establish an equation to estimate the potential acidity of these soils by determination of the equilibrium pH of the soil suspension with the SMP solution. One hundred and twenty representative soils samples of the region were analyzed by the conventional calcium acetate method. Also determined was the pH SMP in the equilibrium suspensions soil-water-buffer 10:10:5, 10:20:10 and 10:25:5. The results have demonstrated that the best correlation between H + Al values and pH SMP was obtained with the 10:10:5 suspension and that the equation y = 164.31 - 47.26 x + 3.4717 x2, expressing H + Al (y) values in cmolc dm2, can be used to estimate H + Al values of the studied soils.

Detecção de Mudança da Vegetação de Caatinga (Change Detection of Vegetation Caatinga)

A caatinga e um bioma de grande diversidade que cobre a maior parte da area de clima semiarido brasileiro. Varias tecnicas ja foram utilizadas com o objetivo de determinar quantitativamente e qualitativamente o estado da vegetacao a partir de imagens de satelite e indices de vegetacao foram desenvolvidos para auxiliar no mapeamento da vegetacao e otimizar os parâmetros presentes nas medidas multiespectrais utilizadas com esse fim. Este trabalho teve como objetivo mapear a vegetacao da caatinga, e selecionar um indice de vegetacao usando o IBVL para validacao dos resultados e detectar mudancas ocorridas. Concluiu-se que o melhor indice que se correlaciona com a cobertura vegetal da caatinga foi o Normalized Difference Vegetation Index, do periodo seco, e que a metodologia utilizada mostrou-se eficiente para caracterizacao, classificacao e separacao em 9 classes. A maior recuperacao ocorreu em areas de drenagem e em declividade mais acentuada. A classe detectada de nao mudanca ocorreu em areas de menor cobertura vegetal e de solos propensos a erosao. Estimou-se que 38,71% da area da bacia do rio Taperoa esteja em processo de desertificacao. Palavras-chave: Semiarido, Geoprocessamento, Degradacao. Change Detection of Vegetation Caatinga ABSTRACT The caatinga biome is a large diversity that covers most of the area of Brazilian semi-arid climate. Several techniques have been used in order to determine quantitatively and qualitatively the state of vegetation from satellite images and vegetation indices were developed to assist in vegetation mapping and optimizing the parameters present in the multispectral measurements used for this purpose. This study aimed to map the vegetation of the caatinga, and select a vegetation index using IBVL to validate the results and detect changes. It was concluded that the best index that correlates with the vegetation of the caatinga was the Normalized Difference Vegetation Index, the dry period, and that the methodology used was efficient for characterization, classification and separation into nine classes. The best recovery occurred in areas of drainage and steeper slope. The class detected no change occurred in areas with less vegetation cover and soils prone to erosion. It was estimated that 20.21% of the area of the river basin Taperoa is in an advanced process of desertification. Keywords: Semiarid, Geoprocessing, Degradation.

Soil Chemical Amendments and the Macronutrients Mobility Evaluation in Oxisol Treated With Biochar

Biochar is material produced during a process called pyrolysis. This material can be used as fertilizer to increase the agronomic productivity of low fertility soils. The objective of this study was to evaluate the soil chemical amendments and the macronutrients leaching following biochar application, produced from poultry litter, in Yellow Red Latosol in laboratory experiments. Soil columns (height 20 cm) containing 0; 10; 15; 20; 25 and 30 t ha-1 of biochar with four replications totaled 24 experimental units. For 30 days, water was applied daily to each column, and the leachates were collected and chemically characterized. After this period, soil samples were taken from the 0-10 and 10-20 cm layer depth and chemically characterized. Biochar reduced exchangeable acidity values. Biochar improved soil fertility. Leachates contained increasing EC, K, Na, Ca and Mg, however the concentration of these elements were small in relation to the biochar doses.

Mapeamento da Caatinga com Uso de Geotecnologia e Análise da Umidade Antecedente em Bacia Hidrográfica (Mapping of Caatinga with Use of Geotechnology and Analysis of Antecedent Humidity in Hydrographic Basin)

A B S T R A C T The state of Paraiba is characterized by striking climatic irregularities, both its spatial and temporal rainfall, since 86.6% of its territory is part of the Brazilian semiarid region. The vegetation of caatinga, enough already impacted by human activity, has different features related to soil and climatic factors, among these, the precipitation, which influenced by the relief, tends to increase with altitude within the different spaces hidrogeografic. The lower rainfall, increased aridity and the irregularity of rainfall distribution. In the dry season, most plants of the caatinga lose foliage, recovering quickly, as soon as you start a new period of rain. Generally, the quantity and persistence of hardwood biomass from caatinga vegetation is related to soil water availability. This study aimed to analyze the influence of antecedent moisture on multispectral image captured by the sensor and medium resolution satellite used for mapping of

SENSORIAMENTO REMOTO E GEOPROCESSAMENTO APLICADOS AO ZONEAMENTO GEOAMBIENTAL: Bacia Hidrográfica do Açude Camará - PB

The diversity of landscapes at the Camara dam hydrographic basin, especially in terms of landforms, soils and production systems, has lead to the elaboration of this geoenvironmental zoning. Its importance is res ected in concerns about environmental conservation, socioeconomic development, and preservation of the area’s natural resources in pursuit of sustainable development. This work aimed at creating an updated database and at carrying out a simpliÞ ed analysis of physiographic attributes, soil, climate, topography and land use by means of geoenvironmental zoning for separating and describing landscape units, their potential and their limitations. This research used a CBERS satellite image and geoprocessing (GIS) techniques from the SPRING program, which formed the groundwork for the descriptive Þ eld studies. The information obtained for soil, topography and land use was used for the description of areas prone to environmental degradation. The results obtained for the hydrographic basin led to its division into 19 geoenvironmental units.