Structure investigation of soil aggregates treated with different organic matter using X-ray micro tomography*

Abstract Soil aggregation which is favorable for plant growth, can be modified by the presence of organic matter and farmers apply different materials to promote soil aggregation and enhance its stability. However, the relationship between the type of organic matter and the resulting properties of the aggregate structure is unclear. Using micro X-ray tomography, intra-aggregate pore formation in soils from fields in Southwestern Japan fed with different organic fertilizers was compared. Organic matter, especially manure-based matter, increased porosity of the intra-aggregate, which is considered to increase growth conditions. Pores that connected the core of the aggregates with the surface were observed in organic matter-applied fields and sponge-like pores were observed in manure-fed fields.