ABSTRACT
SOIL POROSITY DIAGRAMS

Elías Letelier A.1
 

A soil porosity diagram is proposed which, in addition to the values of total, capillar and non capillar porosities and available water capacity, also include imbibition capacity and the "structural" and "textural" porosities. Examples are shown, which indicate that theproposed diagram improves the practical information about soil characteristics dealing with water economy, airation, penetrability by roots and thermal conductivity. It is recognized, however, that the reproducibility of the method followed has not been adequately studied. In addition, the sóil dispersion, consisting in the simple mechanical destruction of the aggregates with a spatula, as is done to determine the sticky point, is not complete and may be imprecise. However, as the purpose is mainly to destroy the non capilIar or macropores, probably this objection is not too important. What de diagram indicates as textural porosity includes, undoubtedly, structural micropores that have resisted the mechanical treatment, but in practice these micropores probably do not differ from the textural ones, since they have resisted the treatment.
The relationship faund between the agronomic properties of the soils sampled and the respective porosity diagrams is considered satisfactory.

Keywords:
1Ing. Agr., Estación Experimental La Platina, Instituto de Investigaciones Agropecuarias, Casilla 5427, Santiago, Chile. Actualmente: Especialista FAO, en Argentina