Efecto del sistema y uso de la tierra en la distribución de los agregados en suelos de la altillanura colombiana = Effect the land use system in aggregate size distribution of soil from the eastern plains of Colombia

Se encontraron altas correlaciones entre materia orgánica y macroagregados del suelo (>1 mm). Cuando el contenido de MO fue inferior al 3.4% disminuyó notablemente la agregación del suelo haciéndolo susceptible a la degradación y pérdida de estructura. Igualmente se encontró alta correlación entre el contenido de arena y los macroagregados del suelo. Suelos con contenido de arena superiores al 50% reducen significativamente los macroagregado del suelo que los hace altamente susceptibles a la degradación por la alta pérdida de materia orgánica que presentan esta atexturas por efecto de labranza.

This study shows the impact of different land use systems in some physical, chemical and biological of 70 peaces. Three landscapes were evaluated: Altillanura plana (Ap), Altillanura ondulada (Ao) and Altillanura disectada (Ad), and into them different soil use systems: native savanna, improved pastures, improved renovated pastures. Representative soil samples new collected in the top 0-25 min depth and analyzed for aggregate size distribution. Ap showed a- higher proportion of macroaggregates (>1 mm): 81.4%, Ao y Ad showed 68.5% and 58.6% respectively. At the same time Ap showed higher content of aggregates between 1-4 mm. There was found a high correlation between macroaggregates and organic matter. When the O.M. content was less than 3.4% aggregation diminished. Similarly the was good correlation between Sand content and macroaggregates. When Sand content was higher than 50% aggregation diminished.