N biochemical diversity as a factor of soil diversity

As lithosphere-biosphere interphases, soils have some characteristics (mainly biochemical characteristics) highly influenced by living organisms and therefore these characteristics vary according to soil biological activity and diversity. The variability of these characteristics could be used for the differentiation of soil types. This potential utility was successfully analysed for N biochemical fractions in temperate-hurnid region soils. The fractions of medium-to-low hydrolytic resistance and among them hydrolysable organic N, α-aminoacid N, hydrolysable unidentified N and, to a lesser extent, hexosamine N, were the main organic N forms to supplement the physical and chemical characteristics in soil classification systems.