The carbon count of 2000years of rice cultivation
The carbon count of 2000years of rice cultivation
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DOI：
10.1111/gcb.12080
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发表时间：
2013-04-01
影响因子：
11.6
通讯作者：
Koegel-Knabner, Ingrid
中科院分区：
文献类型：
--
作者：
Kalbitz, Karsten;Kaiser, Klaus;Koegel-Knabner, Ingrid
世界上超过50%的人口以大米为食。用于水稻生产的土壤大多在浸水条件下管理（水稻土）。这种有利于固碳的管理，可能会使地表和地下的碳循环相互干扰。本研究的目的是阐明长期的碳积累率在表层和亚表层土壤相对于那些在非稻田管理的土壤。我们评估了中国长江三角洲稻田和邻近非稻田管理下的土壤总有机碳和无机碳储量沿着2000年的时间序列的变化。最初的有机碳积累阶段比以前假设的持续时间更长，强度更大，例如，政府间气候变化专门委员会（IPCC）。前300年水稻土表层积累了170178 kg有机碳ha ~（1a）~ 1，下层流失了2984 kg有机碳ha ~（1a）~ 1。由于无机碳酸盐风化和缺乏有机碳补充，在土地筑堤后的前50年，底土碳损失最大，在700年的耕作后，底土碳损失也最大。因此，底土中的碳损失可以抵消表层土壤中的碳增加或损失。我们强烈建议将底土纳入全球碳核算计划，特别是稻田。
More than 50% of the world's population feeds on rice. Soils used for rice production are mostly managed under submerged conditions (paddy soils). This management, which favors carbon sequestration, potentially decouples surface from subsurface carbon cycling. The objective of this study was to elucidate the long-term rates of carbon accrual in surface and subsurface soil horizons relative to those of soils under nonpaddy management. We assessed changes in total soil organic as well as of inorganic carbon stocks along a 2000-year chronosequence of soils under paddy and adjacent nonpaddy management in the Yangtze delta, China. The initial organic carbon accumulation phase lasts much longer and is more intensive than previously assumed, e.g., by the Intergovernmental Panel on Climate Change (IPCC). Paddy topsoils accumulated 170178kg organic carbon ha1a1 in the first 300years; subsoils lost 2984kg organic carbon ha1a1 during this period of time. Subsoil carbon losses were largest during the first 50years after land embankment and again large beyond 700years of cultivation, due to inorganic carbonate weathering and the lack of organic carbon replenishment. Carbon losses in subsoils may therefore offset soil carbon gains or losses in the surface soils. We strongly recommend including subsoils into global carbon accounting schemes, particularly for paddy fields.