481 research outputs found
Caracterização e ocorrência do distúrbio do amolecimento precoce em mamões 'Golden'
The occurrence of green skin and soft pulp in 'Golden' papaya fruit during certain seasons has been reported by farmers in the northern of the state of Espirito Santo, Brazil. The objective of this study was to characterize and determine the occurrence of this disorder, which was referred as "early softening disorder". Fruits were harvested weekly for 11 months (from September to July). The fruits were stored at 10°C, and then fruit flesh firmness and skin color were analyzed. The results of the firmness test were submitted to regression analysis assuming a linear trendline. The slope of the curve was called the 'softening index' (SI). Fruits with early softening are characterized by a loss of firmness in less than 10 days, even when stored under refrigeration. Although softened, the skin of the fruit remains partially green. Fruits with the disorder occurred more frequently from mid-summer to mid-autumn (February to May). It is not possible to distinguish early softening disorder fruits from those without the disorder by skin color and flesh firmness analysis at the time of the harvest.Tem sido relatado por produtores da região norte do Espírito Santo a ocorrência de mamões 'Golden' com casca verde e polpa mole, em determinadas épocas do ano. O objetivo deste trabalho foi caracterizar e determinar a ocorrência deste distúrbio denominado de amolecimento precoce. Foram realizadas coletas semanais durante 11 meses (período de setembro a julho). Os frutos foram armazenados a 10°C e analisados quanto à firmeza da polpa e à cor da casca. Os resultados de firmeza da polpa foram submetidos à análise de regressão, assumindo-se que a equação é do tipo linear, e o ângulo de inclinação da curva foi chamado Índice de Amolecimento (IA). Frutos com o distúrbio caracterizaram-se pela perda da firmeza em menos de 10 dias, mesmo quando armazenados sob refrigeração. Embora amolecidos, a coloração da casca manteve-se parcialmente verde. A maior frequência de frutos com o distúrbio ocorreu de meados de verão a meados de outono (fevereiro a maio). Não é possível distinguir frutos com o distúrbio do amolecimento precoce daqueles normais pela análise da cor da casca e da firmeza da polpa, no momento da colheita
Measurement of the Bottom contribution to non-photonic electron production in collisions at =200 GeV
The contribution of meson decays to non-photonic electrons, which are
mainly produced by the semi-leptonic decays of heavy flavor mesons, in
collisions at 200 GeV has been measured using azimuthal
correlations between non-photonic electrons and hadrons. The extracted
decay contribution is approximately 50% at a transverse momentum of GeV/. These measurements constrain the nuclear modification factor for
electrons from and meson decays. The result indicates that meson
production in heavy ion collisions is also suppressed at high .Comment: 6 pages, 4 figures, accepted by PR
Pressões De Contato E O Impacto De Conjuntos Motomecanizados Em Latossolo Com Presença E Ausência De Palhada De Cana-de-açúcar
High contact pressures applied to soil result in a greater degree of compaction, in addition to promoting other negative effects. The objective of this study was to quantify contact areas by using different methodologies, and pressures of farm equipment employed in production activity and evaluate structural changes caused in a Red Latosol with the presence and absence of straw cover. The design was completely randomized in a factorial scheme of type 4 (tire on front axle, tire on rear axle, tire on a sugarcane wagon and metallic track of sugar cane Harvester) x 2 (presence and absence of straw). The contact area (CA) of the run was obtained by three procedures: analytical measure of the area of an ellipse (CA1); digital measurement of area of an ellipse (CA2); and measurement of real contact area (RCA), with digital resources. The contact pressure was calculated from the ratio of mass of each machine’s axle and the contact area of the run. The contact area obtained according to the procedure of the ellipse (CA1 and CA2) is overrated when compared to actual area obtained digitally (RCA). The straw reduces the contact pressure in the soil, due to the deep tire treads and consequently, increased contact area. Areas where the traffic of the machines occurred with soil covered with the presence of straw showed reduced soil resistance to penetration, cone index and pre-consolidation pressure, confirming that the increased contact area produced by straw reduced the pressure applied and the compression power dissipated in the soil. © 2016, Federal University of Lavras. All rights reserved.40326527
Inter-relation between soybean yield and soil compaction under degraded pasture in Brazilian Savannah
The Cerrado (Brazilian Savannah) plays an important economic and financial role in the nation, since the pastures of this biome feed cattle for half of the domestic bovine meat productivity, and its agricultural fields produce a third of the country's grain. The variability and spatial dependence between the soil physical attributes and soybean yield were evaluated in a crop rotation planted on a degraded brachiaria pasture, on a dystroferric Red Latosol of an experimental farm of the State University of São Paulo (UNESP), in the 2005/2006 growing season. The linear and spatial correlations between these attributes were also studied, to determine conditions that would allow increased agricultural productivity. In the above pasture area, a grid was installed with 124 plots, spaced 10.0 x 10.0 m and 5.0 x 5.0 m apart, in a total area of 7,500 m². From the linear and spatial point of view, the high grain yield can be explained by the number of grains per plant and soil macroporosity. The high variability observed for most soil properties indicated that the crop - livestock integration system results in environmental heterogeneity of the soil
Search for electroweak production of single top quarks in collisions.
We present a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector between 1992 and 1995. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb. (arXiv
Soil Co 2 Emission Of Sugarcane Fields As Affected By Topography
The spatial and temporal variation of soil CO 2 emission is influenced by several soil attributes related to CO 2 production and its diffusion in the soil. However, few studies aiming to understand the effect of topography on the variability of CO 2 emissions exist, especially for cropping areas of tropical regions. The objective of this study was to evaluate the spatial and temporal changes of soil CO 2 emission and its relation to soil attributes in an area currently cropped with sugarcane under different relief forms and slope positions. Mean CO 2 emissions in the studied period (seven months) varied between 0.23 and 0.71, 0.27 and 0.90, and 0.31 and 0.80 g m -2 h -1 of CO 2 for concave (Cone), backslope (BackS) and footslope (FootS) positions, respectively. The temporal variability of CO 2 emissions in each area was explained by an exponential relation between the CO 2 emission and soil temperature and a linear relation between CO 2 emission and soil water content. The Q 10 values were 1.98 (± 0.34), 1.81 (± 0.49) and 1.71 (± 0.31) for Conc, BackS and FootS, respectively. Bulk density, macroporosity, penetration resistance, aggregation and oxidizable organic carbon content explain the changes in soil CO 2 emission observed, especially when the Cone position was compared to BackS. The effect of relief form and topographic position on soil CO 2 emission variation was dependent on the time of measurement.6617783ALVENÄS, G., JANSSON, P.E., Model for evaporation, moisture and temperature of bare soil: Calibration and sensitivity analysis (1997) Agricultural and Forest Meteorology, 88, pp. 47-56BERNOUX, M., CARVALHO, M.C.S., VOLKOFF, B., CERRI, C.C., CO 2 emission from mineral soils following land-cover change in Brazil (2001) Global Change Biology, 7, pp. 779-787BERNOUX, M., CARVALHO, M.C.S., VOLKOFF, B., CERRI, C.C., Brazil's soil carbon stocks (2002) Soil Science Society of America Journal, 66, pp. 888-896CAMPOS, D.C., (2003) Potencialidade do sistema de colheita sem queima da cana-de-açúcar para o seqüestro de carbono, , Piracicaba: USP/ESALQ, 103p, Doutorado(2007) Acompanhamento da safra brasileira de cana-de-açúcar, , http://www.conab.gov.br/conabweb/download/safra/3-levantamento0708-nov2007.pdf, COMPANHIA NACIONAL DE ABASTECIMENTO, CONAB, safra, terceiro levantamento, novembro/. Available at:, Accessed 21 Jan. 2008. 2008DANIELS, R.B., HAMMER, R.D., Soil geomorphology (1992) New York: Jonh Wiley, , 236pDAVIDSON, E.A., JANSSENS, I.A., Temperature sensitivity of soil carbon decomposition and feedbacks to climate change (2006) Nature, 440, pp. 165-173DeJONG, E., Soil aeration as affected by slope position and vegetative cover (1981) Soil Science, 131, pp. 34-43Manual de métodos de análise de solo (1997) Rio de Janeiro: Embrapa/CNPS, , EMPRESA BRASILEIRA DE PESQUISA AGROPECUÁRIA, 2 ed, 212pManual de métodos de análise do solo (1979) Rio de Janeiro: Embrapa-SNLCS, , EMPRESA BRASILEIRA DE PESQUISA AGROPECUÁRIA, 247pEPRON, D., BOSC, A., BONAL, D., FREYCON, V., Spatial variation of soil respiration across a topographic gradient in a tropical rain forest in French Guiana (2006) Journal of Tropical Ecology, 22, pp. 565-574FANG, C., MONCRIEFF, J.B., GHOLZ, H.X., CLARK, K.L., Soil CO 2 efflux and its spatial variation in a Florida slash pine plantation (1998) Plant Soil, 205, pp. 135-146FANG, C., MONCRIEFF, J.B., The dependence of soil CO 2 efflux on temperature (2001) Soil Biology and Biochemistry, 33, pp. 155-165FANG, C., MONCRIEFF, J.B., A model for soil CO 2 production and transport. 1. Model development (1999) Agricultural and Forest Meteorology, 95, pp. 225-236GARDNER, W.H., Water content (1986) Agronomy Monograph, 9, pp. 493-541. , KLUTE, A, Ed, Methods of soil analysis. 2 ed. Madison: ASAHANSON, P.J., WULLSCHLEGER, S.D., BOHMAN, S.A., TODD, D.E., Seasonal and topographic patterns of forest floor CO 2 efflux from an upland oak forest (1993) Tree Physiology, 13, pp. 1-15HEALY, R.W., STRIEGL, R.G., RUSSELL, T.F., HUTCHINSON, G.L., LIVINGSTON, G.P., Numerical evaluation of static-chamber measurements of soil-atmosphere gas exchange: Identification of physical processes (1996) Soil Science Society of America Journal, 60, pp. 740-747JIA, S.AKIYAMA, T.MO, WINATOMI, M.KOIZUMI, H. Temporal and spatial variability of soil respiration in a cool temperate broad-leaved forest. 1. Measurement of spatial variance and factor analysis. Japanese Journal of Ecology, v.53, p.13-22, 2003KANG, S., LEE, D., LEE, J., RUNNING, S.W., Topographic and climatic controls on soil environments and net primary in a rugged temperate hardwood forest in Korea (2006) Ecological Research, 21, pp. 64-74KANG, S., DOH, S., LEE, D., LEE, D., JIN, V.L., KIMBALL, J., Topographic and climatic controls on soil respiration in six temperate mixed-hardwood forest slopes, Korea (2003) Global Change Biology, 9, pp. 1427-1437KANG, S., KIM, S., DOH, S., LEE, D., Predicting spatial and temporal patterns of soil temperature based on topography, surface cover and air temperature (2000) Forest Ecology and Management, 136, pp. 173-184KEMPER, W.D.ROSENAU, R.C. Aggregate stability and size distribution. In: KLUTE, A. (Ed.) Methods of soil analysis. 2 ed. Madison: ASA, 1986. p.425-441. (Agronomy Monography, 9)KOSUGI, Y., MITANI, T., ITOH, M., NOGUCHI, S., TANI, M., MATSUO, N., TAKANASHI, S., NIK, A.R., Spatial and temporal variation in soil respiration in a Southeast Asian tropical rainforest (2007) Agricultural and Forest Meteorology, 147, pp. 35-47LA SCALA JÚNIOR, N.MARQUES JÚNIOR, J.PEREIRA, G.T.CORÁ, J.E. Carbon dioxide emission related to chemical properties of a tropical bare soil. Soil Biology and Biochemistry, v.32, p.1469-1473, 2000LI, H., YAN, J., YUE, X., WANG, M., Significance of soil temperature and moisture for soil respiration in a Chinese mountain area (2008) Agriculture and Forest Meteorology, 148, pp. 490-503LLOYD, J., TAYLOR, J.A., On the temperature-dependence of soil respiration (1994) Functional Ecology, 8, pp. 315-323OADES, J.M., Soil organic matter and structural stability: Mechanisms and implications for management (1984) Plant and Soil, 76, pp. 319-337PARKIN, T.B., KASPAR, T.C., SENWO, Z., PRUEGER, J.H., HATFIELD, J.L., Relationship of soil respiration to crop and landscape in the walnut creek watershed (2005) Journal of Hydrometeorology, 6, pp. 812-824PENG, Y., THOMAS, S.C., Soil CO 2 efflux in uneven-aged managed forests: Temporal patterns following harvest and effects of edaphic Heterogeneity (2006) Plant and Soil, 289, pp. 253-264RAIJ, B., van, QUAGGIO, J.A., CANTARELLA, H., FERREIRA, M.E., LOPES, A.S., BATAGLIA, C.O., (1987) Análise química do solo para fins de fertilidade, , Campinas: Fundação Cargill, 170pRAICH, J.W., SCHLESINGER, W.H., The global carbon dioxide flux in soil respiration and its relationship to climate (1992) Tellus, 44 B, pp. 81-99RETH, S., MARKUS, R., FALGE, E., The effect of soil water content, soil temperature, soil pH-value and the root mass on soil CO 2 efflux: A modified model (2005) Plant and Soil, 268, pp. 21-33RISCH, A.C., FRANK, D.A., Carbon dioxide fluxes in a spatially and temporally heterogeneous temperate grassland (2006) Oecologia, 147, pp. 291-302(1998) SAS/STAT: User's guide, , SAS INSTITUTE, Cary: SAS InstituteSCHWERTMANN, U., TAYLOR, R.M., Iron oxides (1989) Minerals in soil environments, pp. 379-438. , DIXON, J. B, WEED, S. B, Ed, Madison: SSSASILVA, A.C.TORRADO, P.V.MARTIN-NETO, L.VASQUEZ, F.M.PÉREZ, M.G. Soil organic matter and geomorphic surface stability relationship in an oxisol toposequence (SE-Brazil). In: INTERNATIONAL MEETING OF THE INTERNATIONAL HUMIC SUBSTANCES SOCIETY, 12., São Pedro, 2004. Proceedings. São Carlos: Embrapa Instrumentação Agropecuária, 2004. v.1, p.623-626SOTTA, E.D., VELDKAMP, E., GUIMARÃES, B.R., PAIXÃO, R.K., RUIVO, M.L.P., ALMEIDA, S.S., Landscape and climatic controls on spatial and temporal variation in soil CO 2 efflux in an Eastern Amazonian Rainforest, Caxiuanã, Brazil (2006) Forest Ecology and Management, 237, pp. 57-64SOUZA, C.K., MARQUES JÚNIOR, J., MARTINS FILHO, M.V., PEREIRA, G.T., Influência do relevo e erosão na variabilidade espacial de um latossolo em Jaboticabal (SP). (2003) Revista Brasileira de Ciência do Solo, 27, pp. 1067-1074SOUZA, Z.M., MARQUES JÚNIOR, J., PEREIRA, G.T., MOREIRA, L.F., Influência da pedoforma na variabilidade espacial de alguns atributos físicos e hídricos de um Latossolo sob cultivo de cana-de-açúcar. (2004) Irriga, 9, pp. 1-11SOUZA, Z.M., MARQUES JÚNIOR, J., PEREIRA, G.T., BARBIERI, D.M., Small relief shape variations influence spatial varaibility of soil chemival attributes (2006) Scientia agricola, 63, pp. 161-168SOUZA, Z.M., MARQUES JÚNIOR, J., PEREIRA, G.T., Variabilidade espacial da estabilidade de agregados e matéria orgânica em solos de relevos diferentes. (2004) Pesquisa Agropecuária Brasileira, 39, pp. 491-499SOUZA, Z.M., MARQUES JÚNIOR, J., PEREIRA, G.T., BENTO, M.J.C., Variabilidade espacial de atributos físicos de um Latossolo Vermelho sob cultivo de cana-de-açúcar. (2004) Revista Brasileira de Engenharia Agrícola e Ambiental, 8, pp. 51-58STOLF, R., Teoria e teste experimental de fórmulas de transformação dos dados de penetrômetro de impacto em resistência do solo. (1991) Revista Brasileira de Ciência do Solo, 15, pp. 229-235XU, M., QI, Y., Soil-surface CO 2 efflux and its spatial and temporal variations in a young ponderosa pine plantation in northern California (2001) Global Change Biology, 7, pp. 667-677YOO, G., SPOMIER, L.A., WANDER, M.M., Regulation of carbon mineralization rates by soil structure and water in an agricultural field and a prairie-like soil (2006) Geoderma, 135, pp. 16-25ZAR, J.H., (1999) Biostatistical analysis, , 4 ed. Upper Saddle River: Prentice Hall, 718
Sugarcane trash management assessed by the interaction of yield with soil properties
Currently, sugarcane plays an important global role, particularly with a view to alternative energy sources. Thus, in a sugarcane field of the mill Vale do Paraná S/A Álcool e Açúcar, Rubineia, São Paulo State, managed under two green cane harvest systems (cane trash left on and cane trash removed from the soil), Pearson and spatial correlations between the sugarcane yield (variety RB855035 in the third cut) and soil physical and chemical properties were studied to identify the property best correlated with stalk yield and the best harvest method. For this purpose, two geostatistical grids (121 sampling points on 1.30 ha) were installed on a eutrophic Red Argisol (homogeneous slope of 0.065 m m-1), in 2011, to determine the properties: stalk yield and sugarcane plant population, and soil resistance to penetration, gravimetric moisture, bulk density, and carbon stock, in the layers 0-0.20 and 0.20-0.40 m. The data were analyzed by descriptive, linear correlation and geostatistical analysis. In both treatments, the property stand density was best correlated with sugarcane yield (r = 0.725 in the trash mulching treatment - TM and r = 0.769 in the trash removal treatment - TR). However, in relation to the soil properties, bulk density (0-0.20 m) was best correlated (r = 0.305 in TM, r = 0.211 in TR). Similarly, from the spatial point of view, stand density was the property that best explained the sugarcane yield. However, in the TM treatment the density (0.20-0.40 m) was the only soil property spatially correlated with stalk yield. The carbon stock in the soil of the TM was 11.5 % higher than in the TR treatment. Results of the TM treatment were best, also with regard to soil management and conservation.Atualmente, a cultura da cana-de-açúcar desempenha importante papel no cenário mundial, sobretudo ao aspecto relacionado às fontes energéticas alternativas. Assim, em um talhão de cana-de-açúcar na Usina Vale do Paraná S/A Álcool e Açúcar, Rubineia, SP, manejado sob duas formas de colheita da cana crua, com palhada (COP) e sem palhada (SEP) sobre o solo, foram estudadas as correlações Pearson e espacial entre a produtividade da cana-de-açúcar (variedade RB855035, em seu terceiro corte) e as propriedades físico-químicas do solo, objetivando verificar aquele que possui a melhor correlação com essa produtividade, assim como o melhor método de colheita. Para tanto, foram instaladas duas malhas geoestatísticas (1,30 ha e 121 pontos amostrais cada) em um Argissolo Vermelho eutrófico (declive homogêneo de 0,065 m m-1), no ano de 2011. Os atributos avaliados foram: produtividade de colmos de cana-de-açúcar, população de plantas, resistência do solo à penetração, umidade gravimétrica, densidade e estoque de carbono do solo, nas profundidades de 0-0,20 e 0,20-0,40 m. Realizaram-se as análises descritiva, correlações lineares e geoestatística dos dados. Em ambos os tratamentos, a população de plantas apresentou a melhor correlação de Pearson (r = 0,725** em COP; r = 0,769** em SEP), com a produtividade da cana-de-açúcar. Entretanto, em relação ao solo, a densidade (0-0,20 m) teve a melhor correlação (r = 0,305** em COP; r = 0,211* em SEP). Da mesma forma, do ponto de vista espacial, a população de plantas melhor explicou a produtividade da cana-de-açúcar. Contudo, a densidade (0,20-0,40 m) do tratamento com palhada foi a única propriedade do solo que apresentou correlação espacial com a produtividade de colmos. O estoque de carbono do solo para o tratamento com palhada foi 11,5 % superior ao sem palhada. O tratamento com palhada foi o que possibilitou os melhores resultados, inclusive no que se refere ao manejo e à conservação do solo.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)sugar mill Usina Vale do Parana S/A Alcool e AcucarInstituto Federal do Mato GrossoUNESP DEFERSUNESP DEFER
Geoestatística na avaliação dos atributos físicos em latossolo sob floresta nativa e pastagem na Região de Manicoré, Amazonas
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.A utilização das técnicas geoestatísticas permite detectar a existência da dependência e distribuição espacial dos atributos do solo, constituindo importante ferramenta na análise e descrição detalhada do comportamento dos atributos físicos do solo. Este trabalho teve como objetivo o uso da geoestatística na avaliação dos atributos físicos em Latossolo sob floresta nativa e pastagem na região de Manicoré no Amazonas. Nas áreas de floresta nativa e pastagem, foram estabelecidas malhas com dimensão 70 × 70 m e demarcados pontos nessas malhas espaçados a cada 10 m, totalizando 64 pontos. Esses pontos foram georreferenciados e, em seguida, foram feitas as coletadas de solo em cada ponto da malha nas camadas de 0,00-0,20 e 0,40-0,60 m para determinação dos atributos físicos, totalizando 128 amostras de solo em cada malha. Essas malhas encontram-se paralelas com uma distância uma da outra de 100 m e o solo nessas áreas é classificado como Latossolo. Determinaram-se textura, densidade do solo e de partículas, macroporosidade, microporosidade, porosidade total e estabilidade dos agregados em água. Após a tabulação dos dados, foram realizadas análises estatísticas descritivas e geoestatística. A pastagem apresentou leve variação nos seus atributos físicos em relação à floresta nativa, com coeficiente de variação alto e dependência espacial fraca. Os semivariogramas escalonados conseguiram reproduzir de forma satisfatória o comportamento espacial dos atributos no mesmo padrão dos semivariogramas individuais, e o uso do parâmetro alcance do semivariograma mostrou-se eficiente para determinar a densidade amostral ideal para os ambientes em estudo. Os resultados geoestatísticos indicaram que a retirada da floresta nativa para a implantação da pastagem alterou a variabilidade natural dos atributos físicos.UNESP Faculdade de Ciências Agrárias e VeterináriasUFAM Instituto de Educação, Agricultura e AmbienteUNESP FCAV Departamento de Solos e AdubosUniversidade Federal do Acre Programa de Pós-graduação em Ciência, Inovação e Tecnologia para a AmazôniaUNESP Faculdade de Ciências Agrárias e VeterináriasUNESP FCAV Departamento de Solos e Adubo
Análise multivariada e variabilidade espacial na estimativa da erodibilidade de um argissolo vermelho-amarelo
A erodibilidade é um fator de extrema importância na caracterização da perda de solo, representando os processos que regulam a infiltração de água e sua resistência à desagregação e o transporte de partículas. Assim, por meio da análise de dependência espacial dos componentes principais da erodibilidade (fator K), objetivou-se estimar a erodibilidade do solo em uma área de nascentes da microbacia do Córrego do Tijuco, Monte Alto-SP, e analisar a variabilidade espacial das variáveis granulométricas do solo ao longo do relevo. A erodibilidade média da área foi considerada alta, e a análise de agrupamento k-means apontou para uma formação de cinco grupos: no primeiro, os altos teores de areia grossa (AG) e média (AM) condicionaram sua distribuição nas áreas planas; o segundo, caracterizado pelo alto teor de areia fina (AF), distribui-se nos declives mais convexos; o terceiro, com altos teores de silte e areia muito fina (AMF), concentrou-se nos maiores declives e concavidades; o quarto, com maior teor de argila, seguiu as zonas de escoamento de água; e o quinto, com alto teor de matéria orgânica (MO) e areia grossa (AG), distribui-se nas proximidades da zona urbana. A análise de componentes principais (ACP) mostrou quatro componentes com 87,4 % das informações, sendo o primeiro componente principal (CP1) discriminado pelo transporte seletivo de partículas principalmente em zonas pontuais de maior declividade e acúmulo de sedimentos; o segundo (CP2), discriminado pela baixa coesão entre as partículas, mostra acúmulo da areia fina nas áreas de menor cota em toda a área de concentração de água; o terceiro (CP3), discriminado pela maior agregação do solo, concentra-se principalmente nas bases de grandes declives; e o quarto (CP4), discriminado pela areia muito fina, distribui-se ao longo das declividades nas maiores altitudes. Os resultados sugerem o comportamento granulométrico do solo, que se mostra suscetível ao processo erosivo devido às condições texturais superficiais e à movimentação do relevo
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