Index >> Microbes and Lithosphere >> Formation of Soil Aggregate

Formation of Soil Aggregate
Water molecules are dipolar. One side of the water molecule is positively charged while the opposite side is negatively charged. The negative end of water molecule attracts the positive end of the second water molecule thus forming long chains of water molecule. Cations get attracted to the negative end of water chain, the positive end of which are attracted by clay particle thus holding the clay particles by bridges of water molecules.

When soil dries up, the chain of water molecule shortens more and more; ultimately clay particles are united by some organic compounds formed during the decomposition of soil organic matter. Soil microorganisms decompose organic matter to form dark gummy substance which bind the clay, sand and silt particles to form soil aggregate. Fungal hyphae and root hairs also bind the particles of soil to form aggregates.