Efectos del calentamiento sobre la agregación de los suelos

Resumo

Two soils rich in organic matter but with different texture (sandy loam and siltloam respectively) were heated under controlled laboratory conditions with a view tostudying the heating effect on soil aggregation. The heating temperatures selected were 25º,170º, 220º, 380º y 460ºC. Determinations included the aggregate size distribution, the wateraggregate stability (using the test of Le Bissonnais and Gaillard, 1997 and the drop test ofLow, 1954) and the organic carbon content in the soils.No significant changes in aggregate size distribution or aggregate stability as determinedby the wet sieving test were observed below 220ºC. By contrast the drop test revealed anincrease proportion of water-stable aggregates at 170º and 220ºC with respect to the controlsoils. Between 220º and 460ºC strong desaggregation and a marked decrease in the wateraggregate stability was relationed to the combustion of organic matter.