Similarities in chemical composition of soil organic matter across a millennia-old paddy soil chronosequence as revealed by advanced solid-state NMR spectroscopy
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This study examined the chemical composition of soil organic matter (SOM) along a 2,000-year paddy soil chronosequence in eastern China by use of advanced solid-state nuclear magnetic resonance (NMR) spectroscopy as well as Fourier transform infrared spectroscopy (FTIR), aiming to identify changes in the chemical composition of SOM over a millennium timescale. The results showed that soil organic carbon concentration in the surface soil reached a steady state after 100 years of rice (Oryza sativa L.)–wheat (Triticum sp.) cropping on coastal tidal flats. The 13C NMR spectra and fractions of structural groups or components of the whole SOM samples differed little along the chronosequence, suggesting a similar chemical composition in SOM samples regardless of the duration of rice cultivation. The FTIR spectral pattern and relative intensities of some resolved functional groups or components of whole SOM were also similar along the soil chronosequence. The similarities in chemical composition of SOM can be attributed to the rice–wheat cropping system, in which SOM has undergone ongoing turnover under periodical fresh plant material input and wet–dry cropping alternation, leading to a similar chemical composition of bulk SOM.
KeywordsSoil organic matter Chemical composition Paddy soil chronosequence NMR FTIR
We would like to thank the National Science Foundation (EAR-1226323) for partial support.
- Ci E, Yang L, Cheng Y, Shi L, Yin S (2008) Effect of cultivation history on distribution of organic carbon and structure of humus in paddy soils (In Chinese). Acta Pedologica Sin 45:950–956Google Scholar
- Lehmann J, Solomon D (2010) Organic carbon chemistry in soils observed by synchrotron-based spectroscopy. In: Singh B, Grafe M (eds) Development in Soil Science, vol 34. Elsevier, The Netherlands, pp 289–312Google Scholar
- Li Z, Zhang T, Li D, Velde B, Han F (2005) Changes in soil properties of paddy fields across a cultivation chronosequence in subtropical China. Pedosphere 15:110–119Google Scholar
- Nelson DW, Sommers LE (1996) Total carbon, organic carbon, and organic matter. In: Sparks DL et al. Ed. Methods of soil analysis: part 3, chemical methods. SSSA Book Series, vol. 5. Soil Sci. Soc. Am, Madison, pp. 961–1010Google Scholar
- Stevenson F (1994) Humus chemistry: genesis, composition, reactions. Wiley, New YorkGoogle Scholar
- Zhang M, He Z (2004) Long-term changes in organic carbon and nutrients of an Ultisol under rice cropping in southeast China. Geoderma 118:167–179Google Scholar