土壤学报2011，Vol.48Issue(5)：979-987,9.
稻草还田条件下水田和旱地土壤有机碳矿化特征与差异
CHARACTERISTICS OF MINERALIZATION OF SOIL ORGANIC CARBON IN PADDY AND UPLAND WITH RICE STRAW INCORPORATED AND DIFFERENCES BETWEEN THE TWO
摘要
Abstract
To improve the farmland soil fertility and provide suggestions for better field management for more carbon sequestration, effects of land use and rice straw incorporation models on mineralization of soil organic carbon were quantitatively investigated. The CO2-C evolved from the soil was measured during incubation of the undisturbed soil column mulched or incorporated with C labeled rice straw over a 100-day period. Results show that straw carbon participated in carbon mineralization, contributing 34.74% in paddy mulched with straw (SM) , 17. 85% in paddy incorporated with straw ( SI) , 35. 68% in upland ( SM ) and 36. 06% in upland (SI) of the 14C-labelled rice straw carbon applied in either way after 100 d incubation. Meanwhile, 0. 99%~ 1. 17% and 2. 25%~2. 53% of the native soil organic carbon ( SOC) in the paddy and upland soil was mineralized, respectively. Rice straw application model and land use and their interaction all showed significant effects on mineralization rate and accumulative mineralization rate of applied rice straw carbon (p < 0.01). However, only land use (p < 0. 01 ) did on mineralization rate of SOC and accumulative mineralization rate of SOC. Application of rice straw did not affect much the total soil accumulative carbon mineralization rate except in upland (SI) because straw in the soil inhibited decomposition of native SOC, thus reducing the lOOd cumulative mineralization rate by 13. 95% in paddy (SM) , 15. 68% in paddy (SI) , 11. 04% in upland (SM) and 3. 34% in upland (SI). Comparatively, Straw incorporation in paddy fields and straw mulch in upland fields are better straw application models and more favorable to accumulation of SOC. The mineralization rate of either applied rice straw carbon or native SOC in paddy soil is obviously lower in paddy soil than in upland soil, which is one of the main reasons why the content of soil organic carbon is generally higher in paddy soil than in upland soil within the same landscape.关键词
水田/旱地/原状土柱/有机碳矿化/14C示踪技术Key words
Paddy/ Upland/ Undisturbed soil column/ Mineralization of organic carbon/ 14C radioactive tracer technique分类
农业科技引用本文复制引用
王嫒华,苏以荣,李杨,吴金水,郑华,朱捍华,胡乐宁..稻草还田条件下水田和旱地土壤有机碳矿化特征与差异[J].土壤学报,2011,48(5):979-987,9.基金项目
国家自然科学基金面上项目(40671104) （40671104）
中国科学院知识创新重要方向项目(KSCX2-YW-436) （KSCX2-YW-436）
中国科学院战略性先导科技专项(XDA05070403)共同资助 （XDA05070403）
