INVESTIGADORES
FERNANDEZ HONAINE Mariana
congresos y reuniones científicas
Título:
The influence of plant silica biomineralizations (silicophytoliths) in the soil matrix construction, in Pampean plain soils affected by agricultural practices.
Autor/es:
OSTERRIETH, MARGARITA; ALVAREZ, M FERNANDA; BORRELLI, NATALIA; FERNÁNDEZ HONAINE, MARIANA
Reunión:
Congreso; 4th International Congress Eurosoil; 2012
Resumen:
ln Argentine, the soiis of the pampean piain are one of the most fertile of the worid ano they nave
been used for agricultura! activities formore than 150 years. These human activities have modifíed
the physical, chemicai and biological properties of the soils. The aim of the study is to define and
quantífy the presence of silicophytoliths in soils, and in the matrix of the aggregates in the typical
Argiudolls affected by agricultura! practicas. The presence of silicophytoliths in the soils ranges
between 3% (parental material) and more than 50% (superficial horizons). In the epipedons (A)
the stock of phytolith is about 59-72x103 Kg/ha, and the stock of Si from phytolith is 25-30x103
Kg/ha; the contribution of amorphous silica is relevant. These valúes are higher in the cultivated
plots due to buming activities and the presence of crop residues. The matrix of the aggregates of
strong pedal, is made up in turn by microaggregates with a recuning elemental composition,
mainly consisting of carbón and Silicon. A higher land use leads to lower carbón content and to an
increment of amorphous silica, along with calcium, ¡ron, aluminum subordinaies. Ths weatheringof
silicophytoliths is an ongoing process in these soils and contribute to the fbrmation of amorphous
silica-rich matrix of the aggregates and thus to maintain stabílity. Despite the intensity of tillage in
cultivated soils, the negativo effect woutd be mitigated by the high contribution of the same
silicophytoliths.