The State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science Chinese Academy of Sciences, Nanjing, People's Republic of China.
PLoS One. 2012;7(8):e43368. doi: 10.1371/journal.pone.0043368. Epub 2012 Aug 17.
Paddy soils are classified as wetlands which play a vital role in climatic change and food production. Soil carbon (C), especially soil organic C (SOC), in paddy soils has been received considerable attention as of recent. However, considerably less attention has been given to soil inorganic carbon (SIC) in paddy soils and the relationship between SOC and SIC at interface between soil and the atmosphere. The objective of this research was to investigate the utility of applying Fourier transform mid-infrared photoacoustic spectroscopy (FTIR-PAS) to explore SOC and SIC present near the surface (0-10 µm) of paddy soils. The FTIR-PAS spectra revealed an unique absorption region in the wavenumber range of 1,350-1,500 cm(-1) that was dominated by C-O (carbonate) and C-H bending vibrations (organic materials), and these vibrations were used to represented SIC and SOC, respectively. A circular distribution between SIC and SOC on the surface of paddy soils was determined using principal component analysis (PCA), and the distribution showed no significant relationship with the age of paddy soil. However, SIC and SOC were negatively correlated, and higher SIC content was observed near the soil surface. This relationship suggests that SIC in soil surface plays important roles in the soil C dynamics.
稻田土壤被归类为湿地，在气候变化和粮食生产中发挥着重要作用。最近，人们对稻田土壤中的土壤碳（C），特别是土壤有机碳（SOC）给予了相当大的关注。然而，对稻田土壤中的土壤无机碳（SIC）以及土壤与大气界面处 SOC 和 SIC 之间的关系的关注则相对较少。本研究的目的是探讨应用傅里叶变换中红外光声光谱（FTIR-PAS）来探索稻田土壤表层（0-10 µm）SOC 和 SIC 的适用性。FTIR-PAS 光谱在 1350-1500 cm(-1) 的波数范围内揭示了一个独特的吸收区域，该区域主要由 C-O（碳酸盐）和 C-H 弯曲振动（有机物质）主导，这些振动分别用于表示 SIC 和 SOC。使用主成分分析（PCA）确定了稻田土壤表面上 SIC 和 SOC 之间的圆形分布，该分布与稻田土壤的年龄没有显著关系。然而，SIC 和 SOC 呈负相关，并且在土壤表面附近观察到较高的 SIC 含量。这种关系表明，土壤表面的 SIC 在土壤 C 动态中起着重要作用。
