Submitted to: Soil Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/26/2011
Publication Date: 4/15/2011
Citation: He, Z., Honeycutt, C.W., Zhang, H. 2011. Elemental and fourier transform infrared spectroscopic analysis of water and pyrophosphate extracted soil organic matter. Soil Science. 176:183-189. Interpretive Summary: Soil organic matter plays an important role in soil fertility and thus sustainable crop production. Crop rotation and water management have the potential to influence the different components of soil organic matter. To investigate the impact of crop rotation and water management on soil organic matter composition, we evaluated different components of organic matter from soils under different potato crop rotations with and without irrigation. Our data indicated that the inorganic elemental contents in soil organic matter from irrigated fields were consistently lower than those from the corresponding rainfed fields. This research improves our understanding of how the properties of soil organic matter are impacted by crop management.
Technical Abstract: Soil organic matter (SOM) plays an important role in soil fertility, and thus in sustaining potato production. To investigate the impact of crop rotation on SOM composition, we sequentially extracted SOM by water (WEOM) and sodium pyrophosphate solution (PEOM) from different three-year potato crop rotations with or without irrigation and quantified their elemental compositions. Different contents of P, Ca, Al, and Fe were observed among the PEOM fractions from fields with different crop rotations. Elemental contents in PEOM from irrigated treatments were consistently lower than those from the corresponding rainfed treatments. The structural features of these WEOM and PEOM samples were further characterized by Fourier transform infrared (FT–IR) spectroscopy. Generally, the impacts of rotation and irrigation practices reflected on the changes of FT-IR band intensities in 3020-2800 cm-1 (aliphatic groups), and 1640-1600 cm-1 (aromatic compounds) of WEOM samples. FT-IR spectroscopic analysis indicated that PEOM was more enriched in aliphatic, carboxyl and aromatic compounds than WEOM. However, neither crop rotation nor irrigation changed the relative abundance of these functional groups in PEOM. This research improves our understanding of how the properties of SOM may be impacted by crop management.