Factors affecting aggregate stability and water dispersible clay of recently cultivated semiarid soils of Argentina

摘要

The aggregate stability and water dispersible clay of 18 surface soils ranging from 0 to 32 years of soybean monoculture after clearance from alarm of approximately 5000 ha in the semiarid Chacopampeana plain (Argentina) was studied. Both stabilityvariables were correlated with soil properties influencing aggregate stability. Aggregate stability and water dispersible clay were correlated with the length of agricultural use, organic carbon (OC) content, cation exchange capacity, free Al oxides andhydroxides to clay ratio, exchangeable Ca~(2+) content and exchangeable Na~+ percentage. A synergistic effect was observed between OC and free Al oxides and hydroxides. Clay content and electrolyte concentration of the saturation extract had no effect onaggregate stability and on water dispersible clay. From the results of this study it was concluded that the changing factors along agricultural use that affect water aggregate stability and water dispersible clay were exchangeable Ca~(2+) content and OCcontent.