中国稻田土壤有机碳汇特征与影响因素的研究进展

稻田是中国面积最大的耕地之一,稻田土壤有机碳（SOC）是重要的农业碳库,被认为在减缓大气二氧化碳（CO2）浓度上升和全球变暖中起着重要作用。明确中国稻田SOC汇特征与影响因素,有助于制定合理的农业管理措施,科学地增强稻田土壤固碳减排潜力。研究发现,在空间分布上,中国稻田SOC含量具有地域性差异,总体表现为华南、西南高于华北、西北,长江中游高于长江下游;且稻田SOC含量沿海拔升高而增加,随土壤深度增加而减少。在组成上,稻田土壤活性碳比例不超过5.3%,惰性碳比例远大于活性碳,高达60%以上,稻田固碳重点在于惰性组分。在影响因素上,人为管理措施是导致稻田碳汇变化的主要原因,并与自然因素密切相关。为充分发挥稻田土壤碳汇功能,未来研究应加强稻田SOC稳定机制研究,制定因地制宜的农业管理推广方案,为中国“双碳”目标的实现提供科学依据。

Characteristics and Influencing Factors of Soil Organic Carbon Sink in Paddy Fields in China: A Review

Paddy field is one of the largest cultivated land in China, and soil organic carbon (SOC) in paddy field is an important agricultural carbon pool, which is considered to play an important role in slowing down the rise of atmospheric carbon dioxide (CO2) concentration and global warming. Defining the characteristics and influencing factors of SOC sink in paddy fields in China is helpful to formulate reasonable agricultural management measures and scientifically enhance the potential of carbon sequestration and emission reduction in paddy soils. It is found that the SOC content of rice fields in China has regional differences in spatial distribution, which is generally higher in South China and Southwest China than in North China and Northwest China, and higher in the middle reaches of the Yangtze River than in the lower reaches of the Yangtze River. Moreover, SOC content in paddy field increased with the elevation of the sea and decreased with the increase of soil depth. In terms of composition, the proportion of activated carbon in paddy soil is less than 5.3%, and the proportion of inert carbon is much higher than that of activated carbon, up to more than 60%. The key point of carbon sequestration in paddy soil lies in inert carbon. In terms of influencing factors, artificial management measures are the main reason for the change of carbon sink in rice fields, and are closely related to natural factors. In order to give full play to the function of paddy soil carbon sink, future research should strengthen the research on SOC stability mechanism in paddy fields, and formulate agricultural management and extension schemes according to local conditions, so as to provide scientific basis for the realization of China''s " peak carbon emissions and carbon neutrality" .