Fourier transform infrared
spectroscopy (FTIR) was directly applied to study
thedecomposition process of corn straw
residue (CSR). The result showed that FTIRspectra could indicate the dynamic changes of
organic components during
thedecomposition process of CSR With the progress of CSR
decomposition, hydroxyl,ketonic carbonyl, methyl, methylene, methine and aliphatic
compounds decreased, butaromatic compounds increased. This meant that the carbohydrates
and aliphaticcompounds decomposed quickly and lignin decomposed slowly. The inorganic
elements,especially silicon, were reduced from the CSR and accumulated as oxides and
someother inorganic elements were reacted with carboxyls to form carboxylates. In theprocess
of decomposition, carboxyl existed as carboxylic ions, most carbohydrates andaliphatic
compounds were oxidized to CO2 and H2O, the proteins and amino acidswere decomposed to
CO2, NH+4 NO-3 and amides, and the lignin were decomposedto hydroquinones. As far as the
differences between the leaf and the stem during thedecomposition process of CSR, methoxy
increased in the leaf, however, no significantchanges were observed in the stem; the organic
silicon compounds and lignindecomposed significantly in the leaf, but the change was little in
the stem;undecomposed leaf didn' t contain carboxylic ions, on the contrary, carboxylic
ionsexisted in undecomposed stem. During the decomposition process of CSR, addition ofN
fertilizer promoted the decomposition progress of CSR The chemical analysesshowed that the
humification index when the leaf and stem were mixed anddecomposed was higher than that
when the leaf and stem were decomposed separately.