Variabilidade Espacial Da Condutividade Hidráulica Do Solo Saturado Em Latossolo Amarelo Distrocoeso, No Município De Cruz Das Almas

Abstract

VARIABILIDADE ESPACIAL DA CONDUTIVIDADE HIDRÁULICA DO SOLO SATURADO EM LATOSSOLO AMARELO DISTROCOESO, NO MUNICÍPIO DE CRUZ DAS ALMAS KARLA SILVA SANTOS ALVARES DE ALMEIDA1; LUCIANO DA SILVA SOUZA1; VITAL PEDRO DA SILVA PAZ1; FAGNER TAIANO DOS SANTOS SILVA2; DAVI NEY SANTOS1 E JULIANA DA SILVA LOPES PEREIRA1 1Universidade Federal do Recôncavo da Bahia – UFRB, Rua Rui Barbosa, 710 – Campus Universitário – CEP 44380-000 – Cruz das Almas – BA, e-mail: karlasilvasantos@yahoo.com.br; lsouza@ufrb.edu.br; vitalpaz@ufrb.edu.br; davineysantos@gmail.com; jslpereira@hotmail.com2Universidade do Estado de Santa Catarina – UDESC, Centro de Ciências Agroveterinárias – CAV, Av. Luiz de Camões, 2090 – CEP 88520-000 - Lages – SC, e-mail: ftssilva.ufrb@gmail.com 1 RESUMO O objetivo desse trabalho foi caracterizar a variabilidade espacial da condutividade hidráulica do solo saturado (K0) utilizando dois métodos de laboratório e amostras com diferentes volumes em Latossolo Amarelo Distrocoeso localizado no Município de Cruz das Almas. Foram coletadas amostras com estrutura indeformada em dois tipos de anéis volumétricos com 0,081 m de altura e 0,070 m de diâmetro (≈312 cm3) e com 0,05 m de altura e de diâmetro (98 cm3). Nos mesmos pontos de amostragem da K0 foram coletadas amostras deformadas para quantificação de areia, silte, argila, porosidade total, macro e microporosidade, densidade do solo em uma malha amostral de 7 x 7 pontos espaçados em 2,0 x 2,0 m, totalizando uma área de 196,0 m². Os resultados foram submetidos à análise estatística exploratória e teste de normalidade de Shapiro-Wilk; posteriormente, verificou-se a dependência espacial pela análise geoestatística. Os resultados revelaram que para a profundidade de 0-0,15 m a condutividade hidráulica determinada no permeâmetro de carga constante no cilindro de volume maior apresentou menor coeficiente de variação, indicando uma melhor representatividade das amostras; a densidade do solo apresentou índice de dependência espacial moderada, com alcance de 1,22 m e semivariograma tipo esférico para a profundidade de 0-0,15m; para a profundidade de 0,15-0,30 o índice de dependência espacial foi forte, com alcance de 1,54 m e semivariograma tipo exponencial. Palavras-chave: condutividade hidráulica saturada, Tabuleiro Costeiro, geoestatística. ALMEIDA, K. S. S. A.; SOUZA, L. S.; PAZ, V. P. S.; SILVA, F. T. S.; SANTOS, D. N.; PEREIRA, J. S. L.SPATIAL VARIABILITY OF HYDRAULIC CONDUCTIVITY OF SATURATED SOIL USING TWO LABORATORY METHODS AND SAMPLES WITH DIFFERENTS VOLUMES 2 ABSTRACT The objective of this work was to characterize the spatial variability of saturated hydraulic conductivity (K0) using two laboratory methods and samples with different volumes in Oxisoil Distrocoeso located in the city of Cruz das Almas. Deformed structural samples were collected in two types of volumetric rings with 0.081 m long and 0.070 m in diameter (312 cm3) and 0.05 m in height and diameter (98 cm3). In the same sampling points of K0 deformed samples were collected for quantification of sand, silt, clay, total porosity, macro and microporosity, bulk density in a sample grid of 7 x 7 points spaced at 2.0 x 2.0 m totaling an area of 196.0 m². The results were submitted to exploratory statistical analysis and Shapiro-Wilk normality test; later, the spatial dependence was verified by geostatistical analysis. The results showed that for the depth of 0-0.15 m the hydraulic conductivity determined in the constant load permeameter in the higest volume cylinder showed a lower coefficient of variation, indicating a better representativeness of the samples; soil bulk density showed moderate spatial dependence index, with a range of 1.22 m and pherical-type semivariogram to the depth of 0-0.15m; to the depth of 0.15-0.30 the spatial dependence index was strong, reaching 1.54 m and exponential semivariogram. Keywords: Saturated hydraulic conductivity, coastal plain, geostatistics

Spatial Variability of the Saturated Hydraulic Conductivity of Soil in Cocoa Farming in Recôncavo Baiano

“…(3) (4) (5) The observed results are in agreement with Almeida et al (2017), who characterized the spatial variability of a saturated hydraulic conductivity soil Distrocoeso Oxisoilin the Municipality of Cruz das Almas, Bahia. They are also in agreement with Guimarães et al (2016) who evaluated the spatial variability of soil physical attributes for Oxisoil areas, and Ultisol Inceptisols used for pasture.…”

“…The results obtained were in accordance with Marques et al (2008), who by analyzing the saturated hydraulic conductivity in a topo sequence with different vegetation types the Lower Amazon, found higher values of this attribute at the surface, citing that K 0 is more sensitive to changes in the physical properties of the soil and the relief position than to changes in vegetation. Almeida et al (2017) also obtained the same behavior for the soil water physical attributes of the soil for the superficial and subsurface layers, confirming the relationship between the saturated hydraulic conductivity and the other attributes of the soil.…”

“…Although the degree of spatial dependence for K 0 classified according Cambardella et al (1994) as strong for the of 0.15-0.30 and 0.30-0.45 m layers in the last layer can be viewed in spatial maps, a more significant distribution of spatial dependence of the attribute. The results show that the estimated K 0 to the surface considered for the delimitation of areas for homogeneous differential management purposes in the field, since the area has variation in nearby locations being observed a range of 5.33 m in the last layer and which is inside the sampling grid that was 8.0 to 8.0 m. Almeida et al (2017), characterizing the spatial variability of K 0 in a neighboring area with the same soil type, were also unable to detect spatial dependence of K 0 in the first layer of soil evaluated. It is therefore recommended to reduce the spacing in the next sampling or use an irregular mesh with varying distances to detect the spatial variability.…”

“…Under agricultural cultivation, soils undergo many disturbances, mainly due to management practices, such as excavation and leveling, that cause soil disturbance, reduce pore size, increase the density, and consequently modify the K 0 (MESQUITA; MORAES, 2004;ALMEIDA et al, 2017). Since the K 0 represents the ease with which the soil transmits water, it is influenced by the physical properties of the soil (GONÇALVES; LIBARDI, 2013).…”

Sample arrangements and spatial variability characterization of dendometrics parameters of Eucalyptus camaldulensis and physical soil attributes

“…The use of this methodology of analysis has been consolidated for some time in the agrarian sciences and has been increasingly applied in the study of the spatial variability of soil attributes (Almeida et al, 2017;Lemos Filho et al, 2017), as well as in the evaluation of the spatial interactions between soil attributes and plant productivity (Lima et al, 2016;Silva et al, 2017) allowing the interpretation of results based on the natural structure of the attribute (Grego et al, 2014;Landim, 2015).…”