276 resultados para Atributos de Dios
Resumo:
Pós-graduação em Ciências Biológicas (Zoologia) - IBB
Resumo:
Pós-graduação em Agronomia (Energia na Agricultura) - FCA
Resumo:
Pós-graduação em Agronomia (Agricultura) - FCA
Resumo:
A utilização de ecossistemas naturais como meta a ser atingida e a seleção de indicadores para monitoramento dos projetos são temas controversos na ciência e na prática da restauração. Analisamos a vegetação ripária em quatro remanescentes de Floresta Estacional Semidecidual, para verificar se alguns atributos dessas comunidades se repetem em diferentes locais, podendo ser referência para esta região fitogeográfica. Instalamos dez parcelas de 100 m² em cada local, amostramos plantas lenhosas com altura ≥ 0,5 m, divididas em estrato regenerante (DAP < 5 cm) e estrato arbóreo (DAP ≥ 5 cm) e classificamos as espécies com base em atributos funcionais, raridade e status de ameaça. Contabilizamos lianas, pteridófitas e árvores com epífitas. As variáveis estruturais de densidade (estrato arbóreo e regenerante e árvores com epífitas), área basal e cobertura de copas não diferiram entre locais. Foram pouco variáveis entre as áreas a riqueza rarefeita para 100 indivíduos no estrato arbóreo, a riqueza total estimada por Jackknife e as proporções de espécies raras, tolerantes à sombra, de crescimento lento e zoocóricas. Porém, analisando-se a proporção de indivíduos na comunidade, somente a tolerância à sombra foi pouco variável. Para as outras variáveis analisadas não existem padrões que possam ser considerados referência para esta região fitogeográfica. No entanto, ainda que para algumas variáveis existam padrões, sua utilização como meta da restauração depende de: 1) prazos longos para monitoramento de projetos e, sobretudo, 2) estudos que demonstrem que os ecossistemas restaurados podem, um dia, igualar aos ecossistemas pré-existentes.
Resumo:
In Brazil, common bean is in one of the most representative economic crops, not only because of its growing area but also because of the economic value of its production. In the crop year 2006/07, in Selvíria (MS), we analyzed the common bean yield as a function of some physical attributes of a Typic Acrustox in minimum tillage and center pivot irrigation system. The aim of this work was to evaluate among the soil physical attributes, under minimum tillage, those that better explain the variability of bean yield using the Pearson and spatial correlations,. A geostatistical grid was installed to collect data from soil and plants, with 117 sampling points in an area of 2025 m² and homogeneous slope of 0.055 m m-1. The results showed a low yield of bean, which occurred probably due to a lower density of plants that the system provided. Thus, for the minimum tillage system, the bean yield could be explained as a function of total porosity and bulk density.
Resumo:
Research has investigated the best nitrogen rate for maize under the most diverse types of soil management. The aim of this study was to evaluate the influence of cover crops, soil management and topdressed N rates on the dry matter production, nutritional status, plant lodging, plant height and first-ear insertion of maize. Field experiments were carried out in Selvíria, Mato Grosso do Sul State, Brazil, in the growing seasons of 2009/2010 and 2010/2011, on a clayey Rhodic Haplustox (20º 20' S and 51º 24' W, at 340 m asl). Thirty-six treatments were established with four replications, in a randomized blocks design, to test combinations of cover crops (millet, Crotalaria juncea and millet + Crotalaria juncea), soil management (tillage with chisel plow + lightweight disking, heavy disking + lightweight disking, and no-tillage system) and N rates (0, 60, 90 e 120 kg ha-1 - urea as source). The maize hybrid DKB 350 YG® was used and topdressing N applied at stage V5 (fifth expanded leaf). Previously grown sunn hemp and millet + sunn hemp resulted in a higher shoot dry matter, P leaf content and total N, P and K uptake. In the no-tillage system, the initial and final population and shoot dry were highest, and first-ear insertion and plant height lower. The application of 120 kg ha-1 topdressed N increased the P leaf content, N and P in the entire plant, shoot dry matter, total N, P and K uptake, plant height, and the first-ear insertion of maize.
Resumo:
The knowledge on spatial distribution of soil properties by means of geostatistics is important as an indicator for a better soil use and management. This study aimed at evaluating the spatial distribution of soil chemical properties, in a forest and pasture area in Manicoré, Amazonas State, Brazil. Grids with 70.00 m x 70.00 m, with regular spacing of 10.00 m x 10.00 m, totaling 64 points, were established, and then soil samples were collected at the depths of 0.0-0.20 m and 0.40-0.60 m and had their chemical properties determined. Data were analyzed by using descriptive statistics and geostatistics, and the sampling density analysis was based on the coefficient of variation and semivariograms range. The mean and median values were adjusted to the closest values, indicating normal distribution, while the spherical, exponential and gaussian models were adjusted to the soil chemical properties. It was concluded that the geostatistics provided adequate information for understanding the spatial distribution. The forest area showed a higher spatial continuity and the pasture area a lower sampling density. The chemical properties showed differences in the spatial variability, while the range represented better the estimates for sampling density and spacing, in the forest and pasture area.
Resumo:
The use of geostatistical techniques allows detection of the existence of dependence and the spatial distribution of soil properties, thus constituting an important tool in the analysis and detailed description of the behavior of soil physical properties. The aim of the present study was to use geostatistics in assessment of physical properties in a Latossolo (Oxisol) dystrophic under native forest and pasture in the Amazon region of Manicore. Grids with of 70 x 70 m were established in native forest and pasture, and points were marked in these grids spaced at every 10 m, for a total of 64 points. These points were then georeferenced and in each one, soil samples (128) were collected at the depths of 0.00-0.20 and 0.40-0.60 m for a survey of their physical properties. These grids are parallel at a distance of 100 m from one another. The following determinations were made: texture, bulk density and particle density, macroporosity, microporosity, total porosity and aggregate stability in water. After tabulating the data, descriptive statistical analysis and geostatistical analysis were performed. The pasture had a slight variation in its physical properties in relation to native forest, with a high coefficient of variation and weak spatial dependence. The scaled semivariograms were able to satisfactorily reproduce the spatial behavior of the properties in the same pattern as the individual semivariograms, and the use of the parameter range of the semivariogram was efficient for determining the optimal sampling density for the environments under study. The geostatistical results indicate that the removal of native forest for establishing pasture altered the natural variability of the physical properties.
Resumo:
Pós-graduação em Agronomia (Ciência do Solo) - FCAV
Resumo:
Pós-graduação em Agronomia (Agricultura) - FCA
Resumo:
Pós-graduação em Agronomia - FEIS
Resumo:
This study aimed to evaluate and characterize the chemical properties of soil organic matter under two periodically flooded forest formations on the island of Marambaia, Rio de Janeiro. These formations differ on the degree of soil water saturation, caused by the influence of water table, and in the (F1) formation presents the water table nearer the surface compared to the (F2) formation. Samples were collected in layers from 0.00 to 0.05, 0.05-0.10 and 0.10-0.20 m. The soil properties evaluated were: pH, H+ + Al+ 3, Ca+2, Mg+2, Na+, K+, P, N, total organic carbon (TOC) and base saturation (V%), humin carbon fraction (C-HUM), carbon of humic acid fraction (HAF-C) and fulvic acid fraction carbon (FAF-C). Statistically higher pH values were observed for F1. In F2 there are higher values of Mg+2, P, N and V% value. Correlation was found between the concentrations of Mg+2, N, humic acid and fulvic acid with water table in F1, and water table in F2 with Na+ and K+. Fraction C-HUM was more representative of the total organic carbon, followed by C-HAF and C-FAF. The TOC levels were higher in F1. The C /N ratio was lower in F2, with values ranging between 9 and 12, and F1 were found higher values of this relationship, ranging from 9 to 15. Among the pathways of formation of organic soils in both areas it appears that the major route for organic matter accumulation is the inheritance route.
Resumo:
Better knowledge of the anthropogenic soils can help create future scenarios for the Amazon region through information that supports the sustainable planning. The aim of this study was to evaluate the spatial variability of soil physical anthropogenic and not anthropogenic in the region of Manipur, AM. In the study area we selected two, one with no anthropogenic soils (native forest) and another with anthropogenic soils (black earth archaeological). In each area, we established a grid measuring 70 x 70 m and the soils were sampled at the points of intersection of the grid with regular spacing of 10 by 10 feet, making a total of 64 sampling points in each landscape. Soil samples were collected at a depth from 0.0 to 0.10 I did the analyzes physical (texture, bulk density, macroporosity, microporososidade, porosity and aggregate stability). Then, the data were subjected to descriptive statistics and geostatistics. It was found that the anthropogenic and non-anthropogenic soils showed different behaviors in relation ace their spatial structures. The spatial variability that prevailed in anthropogenic and non-anthropogenic soil was moderate and weak indicating that these soils are strongly linked to changes in the soil by extrinsic factors. The soil was observed anthropogenic best results for total porosity, microporosity and bulk density, showing superior characteristics compared for agronomic soil not anthropogenic. And the range of values found in the above two areas were used in the mesh, showing greater spatial continuity in these environments.
Resumo:
The objective of this study was to analyze different intensities of soil sampling for accuracy in geostatistical analysis and interpolation maps for precision agriculture in the sugarcane area. Soil samples were collected at two regular grids at a depth of 0.00 to 0.20m for granulometric analysis (area 1) and soil fertility (area 2). We compared soil sampling intensities: 208, 105, 58 and 24 points in Area 1 and 206, 102 and 53 points in Area 2. The data were submitted to descriptive analysis and geostatistics. The variograms constructed with 105 points didn't differ from variograms with 208 points, which doesn't occur for 58 and 24 points. The increase of sampling interval and reducing the number of points promote greater error in kriging. Samples with more than 100 points per area did not result in significant improvements in the error of kriging, or differed in the amount of fertilizer applied to the field.
Resumo:
The tillage comprises on average 25% of the cost of deploying a reed, so this cost reduction measures are desirable since they do not compromise the quality of the operation and longevity of sugarcane. The objective was to evaluate the effect of different tillage systems in Acrustox, correlating soil physical properties and characteristics of sugarcane agroindustrial plant cane and ratoon cane. We used five types of soil tillage, over experimental design in blocks with five replications. The particle size was measured every 0.1 m to 0.4 m depth, through deformed soil samples collected at the end of the first growth cycle of the culture. For other soil physical properties: bulk density, total porosity and water content, assessments were performed at the end of each cycle, collecting soil samples in layers of 0-0.20 to 0.21-0.40 m, in addition to performing the penetration resistance, using a penetrometer impact. The response of sugarcane depending on the types of tillage was determined from the evaluation of productivity per hectare of stem (TCH), sugar (TPH), the values of pol % cane (AP), sugar total recoverable (ATR) and fiber samples collected at harvest stalk of sugarcane plant and ratoon cane. In the tillage studied, there was a change of the physical attributes of the soil, causing reduced productivity in 2009/2010 crop, compared with the 2008/2009 season. In tillage system of furrowing direct lowest result was observed for TCH, especially in 2009/2010 crop, when the difference with conventional tillage was 20.53 Mg ha(-1).