SPATIAL VARIABILITY OF DRAINABLE POROSITY OF A HOLM SOIL IN PIRACICABA, SÃO PAULO STATE

Revista Brasileira de Engenharia Agrícola e Ambiental

Queiroz, José Elenildo²  Libardi, Paulo Leonel¹  Cruciani, Décio Eugênio¹ 

[1] USP, Brazil;UFPB, Patos, Brazil

关键词:  underground drainage;    drainable porosity;    spatial variability;   

DOI  :  10.1590/1807-1929/agriambi.v3n2p135-139

学科分类：农业科学（综合）

来源: Universidade Federal de Campina Grande * Centro de Ciencias e Tecnologia

【 摘 要 】

This research was developed with the purpose to study the spatial variability of the drainable porosity of a holm soil, using descriptive statistical techniques and geostatistics in the analysis of the data. Undisturbed soil samples were collected (average depth of 0.30 m) in a grid of 84 points, with regular spacing of 5.00 m between rows and 3.33 m between columns, within a field plot of 10 x 90 m, for determination of the drainable porosity using a tension table. The statistical analyses showed that the data were adjusted to a normal distribution and presented average variability (CV = 43.8%), as well as weak spatial dependence between the observations (nugget effect > 75%), with range medium of 23 m. To the obtained experimental semivariogram a spherical model was adjusted, whose parameters were used in the kriging process, which allowed the elaboration of a map of isovalues of drainable porosity, whose interpretation is important in the planning of the underground drainage system.

【 授权许可】

Unknown