| 周期性变温对紫色土有机碳矿化的影响 |
| 摘要点击 2238 全文点击 786 投稿时间：2018-09-19 修订日期：2018-11-21 |
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| 中文关键词 土壤有机碳 周期性变温 水分 紫色土 矿化动力学参数 |
| 英文关键词 soil organic carbon cyclical temperature fluctuations soil moisture purple soil mineralization kinetic parameters |
| 作者 | 单位 | E-mail | | 曾蔓漫 | 1. 西南大学资源环境学院, 重庆 400715
2. 农业农村部西南耕地保育重点实验室, 重庆 400715 | zmanman551@163.com | | 慈恩 | 1. 西南大学资源环境学院, 重庆 400715
2. 农业农村部西南耕地保育重点实验室, 重庆 400715 | cien777@163.com | | 樊晶晶 | 1. 西南大学资源环境学院, 重庆 400715
2. 农业农村部西南耕地保育重点实验室, 重庆 400715 | | | 李江文 | 1. 西南大学资源环境学院, 重庆 400715
2. 农业农村部西南耕地保育重点实验室, 重庆 400715 | | | 翁昊璐 | 1. 西南大学资源环境学院, 重庆 400715
2. 农业农村部西南耕地保育重点实验室, 重庆 400715 | | | 李松 | 1. 西南大学资源环境学院, 重庆 400715
2. 农业农村部西南耕地保育重点实验室, 重庆 400715 | |
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| 中文摘要 |
| 在自然状态下，土壤外界的环境温度日变化明显，并呈周期性波动，然而目前有关这种周期性变温如何影响土壤有机碳（SOC）矿化尚无统一观点.为此，以西南地区广泛分布的紫色土为供试对象，采用室内模拟培养的方法，开展周期性变温对其有机碳矿化的影响.培养试验涉及温度和水分两个因子，其中，温度设有4个模式，分别为3个恒温（15、20和25℃）、1个周期性变温（15/25℃变温）；水分设有2个梯度，分别为70% WHC和淹水.在66 d培养期内，好气和淹水条件下，变温（15/25℃变温）培养的紫色土SOC累积矿化量和矿化强度与恒温20℃无明显差异，这表明可用20℃恒温来评估变温（15/25℃）SOC矿化的影响效应.此外，除恒温15℃，各温度处理均表现为淹水培养的紫色土有机碳累积矿化量显著高于好气（70% WHC）培养（P<0.05）.在变温条件下，土壤微生物量碳含量与紫色土有机碳矿化速率之间无显著相关.结合矿化动力学分析可知，淹水条件能有效增加紫色土的易分解碳库大小，但变温不能有效影响紫色土的易分解碳库大小. |
| 英文摘要 |
| In the natural state, the soil temperature changes periodically throughout the day, but there is no unified opinion on whether the daily variation of soil temperature affects the mineralization of soil organic carbon. Therefore, the effect of cyclical temperature fluctuations on organic carbon mineralization of purple soil, widely distributed in southwest China, was studied by an incubation experiment in the laboratory. These soils were incubated at three constant temperatures (15, 20, and 25℃) with cyclically fluctuating temperatures (the range was within 15/25℃) and two moisture levels (70% water holding capacity (WHC) and submerged condition). In the entire incubation period (66 d), aerobic and submerged condition, variable temperature (15/25℃) cultivation of purple soil, SOC cumulative mineralization and the mineralization intensity had no obvious differences with constant temperature of 20℃. This indicated that the periodic variable temperature treatment (15/25℃) of SOC mineralization of purple soil with the same accumulated temperature of constant temperature processing (20℃). In addition, except for constant temperature of 15℃, the temperature processing of submerged condition of purple soil SOC cumulative mineralization was significantly higher than 70% WHC treatment (P<0.05). During the entire incubation period, soil microorganism carbon content could not reflect the SOC mineralization differences under constant temperature and cyclically fluctuating temperature. According to two-pool first-order model, the submerged condition can effectively increase the labile SOC pool size of purple soil, but the cyclically fluctuating temperature cannot effectively affect the labile SOC pool size of purple soil. |
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