EDAFOLOGÍA, Vol. 10 (3), pp. 175-180, 2003
EFECTOS DEL CALENTAMIENTO SOBRE LA AGREGACIÓN DE LOS SUELOS
R. GARCÍA-CORONA, E. BENITO, E. DE BLAS*
Departamento de Biología Vegetal y Ciencia del Suelo. Universidad de Vigo. 36310 Vigo. e-mail: [email protected].
Two soils rich in organic matter but with different texture (sandy loam and silt loam respectively) were heated under controlled laboratory conditions with a view to studying the heating effect on soil aggregation. The heating temperatures selected were 25o, 170o, 220o, 380o y 460oC. Determinations included the aggregate size distribution, the water aggregate stability (using the test of Le Bissonnais and Gaillard, 1997 and the drop test of Low, 1954) and the organic carbon content in the soils.
No significant changes in aggregate size distribution or aggregate stability as determined by the wet sieving test were observed below 220oC. By contrast the drop test revealed an increase proportion of water-stable aggregates at 170o and 220oC with respect to the control soils. Between 220o and 460oC strong desaggregation and a marked decrease in the water aggregate stability was relationed to the combustion of organic matter.
Key words: soil heating, aggregate size distribution, water aggregate stability, organic matter.