Estimation of precompression stress in an Ultisol cultivated with sugarcane/ Estimativa da tensao de preconsolidacao em Argissolo cultivado com cana-de-acucar

• Published in: Revista brasileira de engenharia agrícola e ambiental 2019-05, Vol.23 (5), p.336
• Main Authors: Mendes, Pericles M.B, Rolim, Mario M, de Lima, Renato P, Pedrosa, Elvira M.R, Tavares, Uilka E, Neto, Djalma E. Simoes
• Format: Article
• Language: English
• ISSN: 1415-4366
• DOI: 10.1590/1807-1929/agriambi.v23n5p336-340

Compressive soil properties are typically used for the understanding of compaction process. As an alternative to laboratory tests, pedo-transfer functions have been used to estimate the mechanical behaviour of soil as a function of soil physical parameters. The impact of soil bulk density (BD) and gravimetric water content (w) was examined on soil strength and pedo-transfer functions were proposed to predict the precompression stress ([[sigma].sub.p]) in an Ultisol cultivated with sugarcane. Undisturbed soil cores were sampled at the depths of 0-0.20 and 0.2(p -0.40 m, subjected to different water contents, and subsequently, compression tests were performed to determine [[sigma].sub.p]. The data were subjected to analysis of variance and regression analysis. Bulk density and w affected [[sigma].sub.p] positively and negatively, respectively. Approximately 70% of the variation of the a could be explained as a function of BD and w through an accessible multiple regression model. Comparisons with other pedo-transfer functions showed that estimates of [[sigma].sub.p] may be rather sensitive to soil management and textural classes. Variations imposed by soil management and cohesive character into depth suggest that independent models should be considered to characterise compressive behaviour of soil by horizon or layer. Key words: compaction, soil compressibility, coastal tablelands Propriedades compressivas do solo sao frequentemente utilizadas para entender o processo de compactacao. Alternativamente a ensaios laboratoriais, funcoes de pedo-transferencia tem sido usadas para estimar o comportamento mecanico em funcao de parametros fisicos do solo. Este trabalho objetivou examinar o impacto da densidade (BD) e do conteudo de agua (w) na resistencia do solo a compactacao, bem como propor funcoes de pedo-transferencias para predicao da tensao de preconsolidacao ([[sigma].sub.p]) em um Argissolo cultivado com cana-de-acucar. Amostras indeformadas foram coletadas nas camadas de 0-0,20 e 0,20-0,40 m e submetidas a diferentes conteudos de agua, e entao, ensaios de compressao foram realizados e a [[sigma].sub.p] foi estimada. Os dados foram submetidos a analise de variancia e de regressao. A BD e o w afetaram positiva e negativamente a [[sigma].sub.p], respectivamente. Aproximadamente 70% da variacao da [[sigma].sub.p] foi explicada em funcao da BD e do w atraves de um acessivel modelo de regressao multipla. Comparacoes com outras funcoes de pedo-transferencia mostra