Study on dynamic change of soil organic matter during corn stalk decomposition by δ13C method

Dou Sen (1) , Zhang Jin-Jing (1) , Eric Lichtfouse (2) , Cao Ya-Cheng (3)

1 College of Natural Resources and Environmental Sciences
2 ASD - Agronomy for Sustainable Development
3 Institute of Soil Science [Beijing]

In an incubation experiment, dynamic change in amounts of soil organic matter (SOM), HA and FA were studied during corn stalk (CS) decomposition in dark-brown soil by δ13C method. The results showed that organic carbon from both new added CS and original soil decreased, but decomposition rate of the latter was slower than that of the former during incubation periods. The residual rate of CS was about 36% at 360th day and 24% at 720th day, whereas that of original SOM was above 90% at 360th day and about 76% at 720th day. In the initial stage of incubation (1hour), the formed rate of FA was faster than that of HA. Then, FA transformed into HA. After 15 th day, HA transformed into FA again. HA and FA from original SOM also transformed each other, and it was still the same trend that FA transformed into HA before 15 th day. But the transformed rate in original SOM was relatively slower than that in new-formed SOM. δ13C method can be used to study decomposition dynamics of SOM in short-term incubation experiment (several months～several years).

Mots clés: dynamics; fulvic acid; humic acid; δ13C; dark-brown soil

Domaines: Science des sols

Dou Sen, Zhang Jin-Jing, Eric Lichtfouse, Cao Ya-Cheng. Study on dynamic change of soil organic matter during corn stalk decomposition by δ13C method. Acta Pedologica Sinica, 2003, 40, pp.328-334. ⟨hal-00264085⟩