Characterization and genesis of a natrustalf from the central region of Ceara state

Abstract

This study was carried out with the objective of obtaining information on the characteristics and genesis of three pedons of a Typic Natrustalf located in the semi arid region of Brazil. These soils are relatively shallow with an abrupt textural change, have a poor drainase and a very developed natric horizon. The surficial horizons are very sandy originated by a reworked material. The natric horizon has a clay content around 25% characterized by a very strong blocky or colunar structure. The clay fraction of these soils is constituted basically bi 2:1 clay minerals like micas, vermiculite and smectite. Some calcium plagioclase and kaolinite does occur. In the coarser fraction occurs minerals like calcite, calcium plagioclase, hornblend and quartz.