Caracterização físico-hídrica de solos numa toposseqüência da zona semiárida da Paraíba.

Abstract

The objectives of the present work were to identify and characterize physichydrically the soils of a hydrological microbasin toposcquence located at the "Paus Brancos" rural community at the |Oriental Borborema physiographyc region of the Cariri homogenous microregion, Campina Grande - Paraiba, Brazil. The study had esscncially two parts: first a pedological description and classification of the soils and second their physic-hydrical characterization. Alluvial, Planosols and Eutrophic Cambisols were identified on the toposcquence. The pedological variation found among the soils, without doubt, is due mainly to the topographic aspects. The identified soils were, in general, medium textured (clay loams, sandy-clay loams and sandy loams). The Cambisols presented a high global density and therefore a very low porosity, due to compaction problems. These facts contributed to obtain low water retention capacity soils with low water content available for plants. Compare with the Cambisols , the alluvial and Planosols showed lower global densities and higher total porosities, inside the expected intervals, conducting to soils with higher water retention capacity and available water for plants. The basic infiltration velocity for all the soils was very slow and the saturated hydraulic conductivity slow to moderately slow . Analyzed the characteristics of the toposcquence soils, it was concluded that , in general, all the soils have an agricultural and husbandry utilization interest needing however more precise studies to attain its integrated management in order to optimize their utilization.