Nascent aggregates in the rhizosphere of perennial ryegrass (Lolium perenne L.)

Abstract

To supplement information on compound particles in the size range 2-20 μm, the genesis of soil aggregation was examined by transmission electron microscopy on ultrathin sections of the rhizospheres of ryegrass grown in attapulgite. Microorganisms were added as a soil suspension and the organic matter was supplied by the ryegrass roots. Clusters were formed by accumulation of attapulgite particles on root gel, on root cell fragments, and on microbial extracellular polysaccharides. Microaggregates were formed by the fusion of attapulgite-coated bacteria, colonies and cell remnants, and persisted after the death of the microorganisms. -from Authors