Process and characterization of aggregate stabilization in degraded inceptisols by earthworms

Earthworms are widely recognized as a means of enhancing soil quality. However, less is known about their role in aggregate formation, especially their interaction with organic materials and soil aggregate size, as well as the output of this process. The objectives of this research are to assess the process and characterization of aggregate formation on degraded inceptisols by earthworms. Experiments were conducted in a random block design with factorial pattern using a combination of soil aggregate size, presence and absence of earthworms, presence and absence of compost. Sixteen treatments and 6 replication were used. A total of 96 pots were prepared, and 32 pots were examined every month during three months. The changes of mmorphological and elemental composition were observed using a scanning electron microscopy coupled with an energy-dispersive X-ray spectrometer (SEM-EDS). Aggregate stability was measured using the water aggregate stability method. The results showed that micro- and macro-aggregates were formed in less than two months, the aggregate surface became coarser and more porous. The interaction of aggregate size, earthworms and compost could improve degraded inceptisol quality through aggregate stabilization. This process started after the first month and increased after the second month. During the third month, 76.61% stable aggregates (without compost), 80.56% (without earthworms) and 91.74% (with both earthworms and compost) were formed. This finding suggests that stable aggregates are influenced more by a combination of earthworm and compost, however aggregates formation is strongly influenced by earthworm which is faster than compost.