文献类型： 外文期刊

作者： Kang, Longfei ¹ ; Wu, Jiamei ³ ; Zhang, Chunfeng ⁴ ; Zhu, Baoguo ⁴ ; Chu, Guixin ¹ ;

作者机构： 1.Shaoxing Univ, Coll Life Sci, Shaoxing 312000, Peoples R China

2.Shihezi Univ, Agron Coll, Dept Resources & Environm Sci, Key Lab Oasis Ecoagr,Xinjiang Prod & Construct Grp, Shihezi 832000, Peoples R China

3.Hunan Inst Agr Environm & Ecol, Changsha 410000, Peoples R China

4.Heilongjiang Acad Agr Sci, Jiamusi Branch, Jiamusi 154007, Peoples R China

关键词： decay constant; easily oxidized organic C; macro-aggregate; meso-aggregate; micro-aggregate; mineral-bound organic C; particulate organic C; potentially mineralizable C

期刊名称：PEDOSPHERE （ 影响因子：5.7； 五年影响因子：5.7 ）

ISSN： 1002-0160

年卷期： 2024 年 34 卷 1 期

页码：

收录情况： SCI

摘要： Investigating the impacts of soil conversion on soil organic carbon (OC) content and its fractions within soil aggregates is essential for defining better strategies to improve soil structure and OC sequestration in terrestrial ecosystems. However, the consequences of soil conversion from paddy soil to upland soil for soil aggregates and intra-aggregate OC pools are poorly understood. Therefore, the objective of this study was to quantify the effects of soil conversion on soil aggregate and intra-aggregate OC pool distributions. Four typical rice-producing areas were chosen in North and South China, paired soil samples (upland soil converted from paddy soil more than ten years ago vs. adjacent paddy soil) were collected (0-20 cm) with three replicates in each area. A set of core parameters (OC preservation capacity, aggregate carbon (C) turnover, and biological activity index) were evaluated to assess the responses of intra-aggregate OC turnover to soil conversion. Results showed that soil conversion from paddy soil to upland soil significantly improved the formation of macro-aggregates and increased aggregate stability. It also notably decreased soil intra-aggregate OC pools, including easily oxidized OCa (EOCa), particulate OCa (POCa), and mineral-bound (MOCa) OC, and the sensitivity of aggregate-associated OC pools to soil conversion followed the order: EOCa (average reduction of 21.1%) > MOCa (average reduction of 15.4%) > POCa (average reduction of 14.8%). The potentially mineralizable C (C0) was significantly higher in upland soil than in paddy soil, but the corresponding decay constant (k) was lower in upland soil than in paddy soil. Random forest model and partial correlation analysis showed that EOCa and pH were the important nutrient and physicochemical factors impacting k of C mineralization in paddy soil, while MOCa and C-related enzyme (beta-D-cellobiohydrolase) were identified as the key factors in upland soil. In conclusion, this study evidenced that soil conversion from paddy soil to upland soil increased the percentage of macro-aggregates and aggregate stability, while decreased soil aggregate-associated C stock and k of soil C mineralization on a scale of ten years. Our findings provided some new insights into the alterations of soil aggregates and potential C sequestration under soil conversion system in rice-producing areas.