Management-induced organic carbon accumulation in paddy soils: The role of organo-mineral associations
Management-induced organic carbon accumulation in paddy soils: The role of organo-mineral associations
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DOI：
10.1016/j.still.2012.08.004
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发表时间：
2013
影响因子：
6.5
通讯作者：
L. Wissing;A. Kölbl;W. Häusler;P. Schad;Z. Cao;I. Kögel‐Knabner
中科院分区：
文献类型：
--
作者：
L. Wissing;A. Kölbl;W. Häusler;P. Schad;Z. Cao;I. Kögel‐Knabner
铁氧化物与土壤有机质之间存在着强烈的相互作用，对有机质的稳定起着重要作用。这些过程往往受到土壤耕作的影响，包括耕作、轮作和灌溉。我们评估了铁氧化物对有机碳（OC）积累的影响，在发展过程中用于水稻生产的土壤相比，非灌溉种植系统。土壤样品取自浙江省（中国）统一母质的两个年代序列。散装土壤和土壤组分进行了分析，有机碳浓度，土壤矿物学和土壤有机质（SOM）组成的测定，固态13 C NMR光谱。在2000年的水稻种植过程中，水稻土的有机碳浓度从18 mgg-1增加到30 mgg-1，而非水稻土的有机碳浓度在所有年龄段都很低（11 mgg-1）。SOM组成固态13 C NMR光谱显示，在成壤过程中没有改变，无论是时序。长期水稻管理导致的木质素衍生化合物的选择性富集，目前的研究无法证实。水稻土的管理创造了一个与非水稻土不同的氧化铁形成环境。水稻土主要由结晶性差的铁氧化物（FeO）和含量明显较低的结晶铁氧化物（Fed-FeO）组成。这与非水稻土相反，非水稻土的特征在于高比例的结晶氧化铁。水稻特有的氧化铁组成是有效的，经过50年的土壤发育和比例的氧化铁没有改变在进一步的成土作用。这一时序研究表明，有机碳积累的潜力是较高的水稻土与非水稻土，并已达到水稻土发育的最早阶段。与氧化还原循环变化相关的水稻土管理的变化不仅会影响水稻土的氧化铁组成，而且很可能也会影响有机碳的储存潜力。
Iron (Fe) oxides strongly interact with organic matter in soil and play an important role in the stabilization of organic matter. These processes are often influenced by soil cultivation, including tillage, crop rotation and irrigation. We assessed the effect of Fe oxides on organic carbon (OC) accumulation during the development of soils used for paddy rice production in comparison to non-irrigated cropping systems. Soil samples were taken from two chronosequences derived from uniform parent material in the Zhejiang Province (PR China). Bulk soils and soil fractions were analyzed for OC concentrations, soil mineralogy and soil organic matter (SOM) composition was determined by solid-state13C NMR spectroscopy. Paddy soils were characterized by increasing OC concentrations, from 18mgg−1to 30mgg−1, during 2000years of rice cultivation, but OC concentrations of non-paddy soils were low in all age classes (11mgg−1). SOM composition revealed from Solid-state13C NMR spectroscopy did not change during pedogenesis in either chronosequence. Selective enrichment of lignin-derived compounds, caused by long-term paddy rice management, could not be confirmed by the present study. The management of paddy soils creates an environment of Fe oxide formation which was different to those in non-paddy soils. Paddy soils are dominated by poorly crystalline Fe oxides (Feo) and significantly lower content of crystalline Fe oxides (Fed−Feo). This was in contrast to non-paddy soils, which are characterized by high proportions of crystalline Fe oxides. The paddy-specific Fe oxide composition was effective after only 50years of soil development and the proportion Fe oxides did not alter during further pedogenesis. This chronosequence study revealed that the potential for OC accumulation was higher in paddy versus non-paddy soils and was already reached at earliest stages of paddy soil development. Changes in paddy soil management associated with redox cycle changes will not only affect Fe oxide composition of paddy soils but most probably also OC storage potential.