EFECTO DEL APORTE DE ENMIENDAS ORGÁNICAS SOBRE PROPIEDADES FÍSICAS E HIDROLÓGICAS DE UN SUELO URBANO DEGRADADO.

The soils of urban and suburban areas are very often subjected to the A horizon removal, which cause a strong hydraulical and physical properties degradation. To remediate this problem, the addition of large quantities of organic matter, usually organic residues, is needed. It is still not clear whether or not the surface application of those residues is more efficient than its mix within the topsoils, to improve soil properties. The effects of different mixes based on biosolids on the so called "Preferential flow paths" (PFP) and other hydraulical and physical properties of underlying soil was studied. An experiment was performed in columns, filled with the Bt horizon of a Typic Argiudoll, Biosolid mixed with sawdust or sand or composted were applied on surface or mixed within topsoil. PIP, bulk density, water content, and water infiltration rate were measured and total porosity and the Shrink-Swelling Index were calculated. The lower PFP percentage was found in the control (Bt horizon). Treatments receiving compost and biosolid mixes showed significant higher PIP percentage. Bulk density decreased and water infiltration increased after organic materials were applied. The hydraulical and physical properties of underlying soil improved both when organic materials were applied on surface or mixed within the control topsoils. [ABSTRACT FROM AUTHOR]