干湿循环对黄棕壤有机碳矿化的影响

论文总字数：16611字

目 录

摘要 ……………………………………………………………………1

Abstract ………………………………………………………………1

1 材料与方法 …………………………………………………………2

• 1. 试验土壤概况 ………………………………………………………………3
  2. 样品准备 ……………………………………………………………………………3
  3. 研究方法 ……………………………………………………………………3
  4. 数据计算与分析……………………………………………………………3

2 结果与分析 …………………………………………………………4

2.1干湿循环对土壤CO₂释放速率的影响 ………………………………4

2.2干湿循环对土壤累积CO₂释放量的影响 ……………………………5

2.3干湿循环对土壤全碳（TOC）的影响………………………………………6

2.4干湿循环对土壤全氮（TN）含量的影响 …………………………………7

2.5干湿循环对土壤碳氮比的影响 …………………………………………7

3 结论 …………………………………………………………………8

3.1干湿循环对呼吸速率的影响…………………………………………………………8

3.2干湿循环对土壤总矿化量的影响……………………………………………………9

3.3培养后土壤全碳、全氮和碳氮比的变化……………………………………………9

4 讨论 …………………………………………………………………9

5 创新与不足 …………………………………………………………10

5.1 创新点 ………………………………………………………………………………10

5.2 不足之处 ……………………………………………………………………………10

6 展望与建议 …………………………………………………………10

参考文献 ………………………………………………………………11

致谢 ……………………………………………………………………11

干湿循环对黄棕壤有机碳矿化的影响

高雅晓玲

,China

Abstract：Dry-wet alternation can cause transient mineralization of soil organic carbon, and CO₂ emissions from farmland are related to the global carbon cycle and global changes. Yellow brown soil is the main soil type in Jiangsu Province, and its organic matter content is high. The yellow-brown soil region in China is characterized by warm and rainy summers and cold, dry winters. Frequent wet and dry cycles have a great influence on the organic carbon turnover in yellow brown soils. However, the effect of wet and dry cycles on the organic carbon mineralization in yellow-brown soil is still unclear. Therefore, yellow brown soil was used as a test soil sample for this test. Incubation experiments were conducted to study the effect of dry-wet cycle treatment on the organic carbon mineralization in yellow-brown soils in order to determine the influence of the number of wet and dry days and frequency on organic carbon mineralization in yellow-brown soil. Soil samples over a 2 mm sieve were subjected to wet and dry cycles of 7d (DW7), 14d (DW14), 21d (DW21), and 28d (DW28), respectively, while being treated with a constant water content (Control) for darkness indoors. Cultured at 25°C. The experimental results show that the wet and dry cycle improves the soil organic carbon mineralization rate, and the soil organic carbon mineralization rate gradually decreases with the incubation time. The general pattern of CO₂ release rate is markedly increased during rehydration, and the respiratory rate is decreased during the dry-wet treatment. Finally, the respiratory rate of each treatment tends to be consistent; from the perspective of cumulative CO₂ emission, CO₂ accumulation of each treatment cycle is different. The law of change is that in the early culture period, the cumulative amount of CO₂ is: 21dgt; 28dgt; 14dgt; 7d. However, on the 35th day of culture, DW28 accumulated more soil CO₂ than DW21 soil. At 49 days, DW7 accumulated more than DW14, and the final CO₂ accumulation was: 28dgt; 7dgt; 21dgt; 14d; The total nitrogen, total carbon, and carbon-to-nitrogen ratio of the post-soil did not show significant differences in this experiment. These results indicate that the duration and frequency of the wet and dry cycle have a significant impact on the soil organic carbon mineralization, which can significantly stimulate the soil organic carbon mineralization. In this experiment, the wet and dry cycle length has a greater impact.

Key words：Soil organic carbon, , mineralization, Drying and wetting cycles

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