Response of soil C and N transformations to condensed tannins and different organic N-condensed tannin complexes

► Condensed tannins (CT) may decrease C mineralization and nitrification. ► Addition of organic N to soil increase C mineralization and net N mineralization. ► Complexation of organic N compounds with CT decrease N-availability. ► Chitin-CT complexes may act in soil similarly as protein-CT complexes.