[1]LI Yingxue,ZANG Zhenfeng,ZHANG Yu,et al.Changes in Soil Carbon Pool Activity and Distribution of Labile Organic Carbon Composition in Soil Aggregates Following Conversion of Farmland to Grassland on the Loess Plateau[J].Research of Soil and Water Conservation,2023,30(05):241-249.[doi:10.13869/j.cnki.rswc.2023.05.007.]
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Research of Soil and Water Conservation[ISSN 1005-3409/CN 61-1272/P] Volume:
30
Number of periods:
2023 05
Page number:
241-249
Column:
Public date:
2023-08-10
- Title:
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Changes in Soil Carbon Pool Activity and Distribution of Labile Organic Carbon Composition in Soil Aggregates Following Conversion of Farmland to Grassland on the Loess Plateau
- Author(s):
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LI Yingxue1,2, ZANG Zhenfeng1,2, ZHANG Yu1,2, WANG Yinan1,2, ZHAO Wei1,2,3
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(1.College of Grassland Agriculture, Northwest A&F University, Yangling, Shaanxi 712100, China; 2.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China; 3.Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, China)
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- Keywords:
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soil aggregate; labile organic carbon; returning farmland to grassland; Loess Plateau
- CLC:
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S153.6
- DOI:
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10.13869/j.cnki.rswc.2023.05.007.
- Abstract:
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[Objective] The aims of this study are to examine the impact of conversion of farmland to grassland in the region of the Loess Plateau on labile organic carbon(high, moderate, and low level)in soil aggregates, clarify the regulatory factors for soil carbon pool quality and stability during vegetation restoration, and provide theoretical reference for evaluating soil carbon sequestration potential and organic carbon accumulation mechanism. [Methods] Soil samples in four grassland restoration years(7 years, 18 years, 35 years and 45 years)and one sample from farmland in the 0—10 cm soil layer in Zhifanggou watershed in the hilly and gully region of the Loess Plateau were collected. The distribution and stability of aggregates, the organic carbon(SOC)and labile organic carbon(LOC)contents in soil aggregates(5~2 mm, 2~0.25 mm, 0.25~0.053 mm and<0.053 mm), and the correlations between labile organic carbon(high, moderate, and low level)and soil properties were analyzed. [Results] The stability of soil aggregates increased significantly with returning farmland to grassland. The quality of soil carbon pool in grasslands was higher than that in farmland. The soil carbon pool activity changed little, but the moderate-labile organic carbon(LOC-M)transformed into low-labile organic carbon(LOC-L)and the proportion of non-labile organic carbon increased. It was found that grassland restoration leaded to the redistribution of soil aggregates and labile organic carbon fractions. SOC, high-labile organic carbon(LOC-H), and LOC-M distributed mainly in macroaggregates(>0.25 mm), LOC-L in microaggregates(<0.25 mm). The soil total organic carbon, dissolved organic carbon, total nitrogen, and total phosphorus drove mainly the LOC accumulations in soil aggregates. [Conclusion] In the process of vegetation restoration on the Loess Plateau, the distribution of soil labile organic carbon in aggregates is jointly determined by the comprehensive effects of soil structure and nutrient elements.