Spatial variability of soil hydrophysical variables in a Tahiti lime orchard irrigated by micro-sprinkler

• Autor(es):

  Coelho Filho, Mauricio A. (USP. ESALQ);

  Coelho, Rubens D. (USP. ESALQ);

  Gonçalves, Antônio C.A. (UEM).

• Fonte:

  Revista Brasileira de Engenharia Agrícola e Ambiental; volume 5, número 2, páginas 239-246. Maio 2001.

• Assuntos:

  spatial variability;

  available water;

  geostatistics;

  citrus.

• Resumo:

  This study was carried out in a Tahiti lime orchard, in a micro-sprinkler irrigated area, aiming to evaluate the soil hydrophysical characteristic variability related with irrigation management. Soil samples were collected at 0.20 m depth, based on a grid with 126 samples to determine sand, silt and clay contents, bulk density and available water (AW). The upper limit of available water was calculated by values of field capacity (Wfc) and the lower limit by tensiometer working range (Wt) and permanent wilting point (Wpwp). Low variation was observed for Wfc, Wt, Wpwp and clay content, with the variation coefficient increasing in this order. The results showed medium variability for sand, silt, AWt and AWpwp. In the scope of the present work, the spatial independence was verified. By using the semivariograms, it was possible to interpolate by kriging. The spatial distribution of soil water (Wfc, Wt and Wpwp) was similar to the clay content. The spatial correlation between these variables was described by structured cross-semivariograms.

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