中国水稻土碳循环研究进展

The Progress in the carbon cycle researches in paddy soil in China

文章首先分析了水稻土在碳循环研究中的地位和重要性,进而对我国水稻土碳循环的研究现状作了较为详尽的阐述,对其主要研究结论进行了深入的剖析。中国大面积的水稻土自1980年以来显示出有机碳库增加现象,说明水稻田对大气CO2可能产生汇效应。水耕熟化过程是有机碳的积累过程,水稻土的碳密度是旱作土碳密度的2～3倍。水稻土的固碳能力与土壤的微团聚体的粒径有关。但对于水稻土中有机碳的分布和结合状态与农业管理措施、水稻土质量变化、农业生态环境变化的关系仍不清楚。因而建议就这一问题从土壤物理学、化学和生物学的相互作用与土壤微团聚体中矿物质、有机质和微生物的相互结合关系的层面上进行多学科研究。同时提出了今后我国水稻土碳循环的重点研究方向和领域,即从整体和系统的角度来研究碳循环和平衡,从不同的时空区域来研究碳循环的过程和强度。

In this paper, the importance of the carbon cycle in paddy soil ecosystem was discussed. Research results of carbon cycle in the paddy soil ecosystem in China were summarized and analyzed. An increasing trend of SOC in paddy soils has been demonstrated by many pilot experiments and state soil survey data since 1980＇s in China. Fertility improved through tillage in the water is the process of accumulation of organic carbon. Carbon density of paddy soil is two or three times of that of dry soil. The ability of storage carbon in paddy soil is related to the size of micro-aggregates. Nevertheless, less is understood on SOC distribution, binding mechanism in paddy soils of China and their changes in response to agricultural practices. Interaction of physical, chemical and biological features in paddy soils, association of SOC with mineral and bioorganic materials in aggregates deserve urgent research. As one of the important parts of terrestrial ecosystem, paddy soil ecosystem occupies particular eco-geographical place and has special biogeochemical cycling process, which make it important in the study of the terrestrial ecosystem carbon cycle and the sustainable development of eco-environment. Additionally, some issues unsettled in paddy soil carbon cycle and the related research emphases in the future were put forward.