Soil organic and inorganic carbon in the loess profiles of Lanzhou area: implications of deep soils
Soil organic and inorganic carbon in the loess profiles of Lanzhou area: implications of deep soils
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DOI：
10.1016/j.catena.2014.10.031
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发表时间：
2015-03
期刊：
影响因子：
6.2
通讯作者：
Fang Zhang;Xiujun Wang;Tian-wen Guo;Ping-liang Zhang;Jiaping Wang
中科院分区：
文献类型：
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作者：
Fang Zhang;Xiujun Wang;Tian-wen Guo;Ping-liang Zhang;Jiaping Wang
土壤有机碳和无机碳是干旱半干旱地区重要的碳库。一直缺乏定量土壤深层SOC和SIC的实地数据。以兰州黄土区为研究对象，对黄土区土壤碳储量进行了研究。土壤样品主要采集于灌溉和非灌溉农田土壤剖面上2 m处。我们的数据表明，有机碳含量随深度的增加而减少，从0-0.2 m的7.0 ± 2.0 g kg− 1减少到1 m以下的3.0 ± 2.0 g kg− 1。表土（0-0.2 m）的SOC变化很大（3-11 g kg-1），但1.0 m以下的范围很窄，为1-5 g kg-1。土壤无机碳含量垂直变化不大，0-2 m土层平均值为16.0 ± 2.5 g kg− 1，而表层土壤无机碳含量的空间变异较大，为10 ~ 21 g kg− 1。灌溉使整个土壤剖面SIC储量略有增加，0-30 cm增加约10%。我们估计，0-2 m的SOC存量约为10 kg C m-2，SIC存量约为SOC存量的4倍。1-2 m土层的有机碳和无机碳储量分别约占0-2 m土层的40%和50%。在0-1 m的范围内，估计的总碳储存量为26.8 kg C m− 2，而在0-2 m的范围内，则为50.0 kg C m− 2。我们的研究表明，忽略深层土壤可能会导致土壤碳储量低估约50%的黄土。
Soil organic carbon (SOC) and inorganic carbon (SIC) are important carbon reservoirs in arid and semi-arid regions. Field data for quantifying both SOC and SIC in deep soils have been lacking. A study was carried out to evaluate soil carbon stocks in the loess of Lanzhou, a typical semiarid area of northwestern China. Soil samples were mainly collected from profiles of upper 2 meters in irrigated and non-irrigated agricultural land. Our data showed that SOC content decreased with depth, from 7.0 ± 2.0 g kg− 1in the 0–0.2 m to less than 3.0 ± 2.0 g kg− 1below 1 m. There was a large variation (3–11 g kg− 1) in SOC of the topsoil (0–0.2 m) but a narrow range of 1–5 g kg− 1below 1.0 m. Soil inorganic carbon content showed little vertical changes with mean value of 16.0 ± 2.5 g kg− 1in the 0–2 m, but a considerable spatial variation of 10 ~ 21 g kg− 1in the topsoil. Irrigation slightly enhanced SIC stock in the whole soil profile, with ~ 10% increase in the 0–30 cm. We estimated that SOC stock was approximately 10 kg C m− 2for the 0–2 m, and the SIC stock was about four times of the SOC stock. The SOC and SIC stocks in the subsoil (1–2 m) were ~ 40% and 50% of the stocks over the 0–2 m, respectively. The estimated total carbon stock was 26.8 kg C m− 2over the 0–1 m, but 50.0 kg C m− 2over the 0–2 m. Our study implies that neglecting deep soil may lead to underestimation of soil carbon stock by ~ 50% in the loess.