耕作制度对紫色水稻土有机碳累积及矿化动态的影响  

Effects of Tillage Systems on Accumulation and Mineralization of Organic Carbon in Purple Paddy Soil

作　　者：彭娟[1] 符卓旺[1] 朱洁[1] 慈恩[1] 高明[1] 谢德体[1] 

机构地区：[1]西南大学三峡库区农业面源污染控制工程技术研究中心,资源环境学院,重庆400716

出　　处：《水土保持学报》2011年第4期175-178,182,共5页Journal of Soil and Water Conservation

基　　金：中国博士后科学基金(20090460716,201003306);重庆市自然科学基金(CSTC,2009BB1108);中央高校基本科研业务费专项(XD-JK2009C060);重庆市环境保护局环保科技项目(环科字2010第26号);中国科学院战略性先导科技专项(XDA05050506);重庆高校优秀成果转化资助项目

摘　　要：以稻田长期定位试验为平台,研究常规平作(中稻-冬水田)、垄作免耕(中稻-冬水田)、垄作免耕(中稻-油菜)和水旱轮作(中稻-油菜)4种耕作制度对紫色水稻土有机碳累积及矿化动态的影响。结果表明:实行不同耕作制度均能提高土壤有机碳密度,以垄作免耕(中稻-油菜)最佳。不同耕作制度实施20年后,农田0-10 cm表层土壤有机碳密度已趋于稳定,垄作免耕会提高10-20 cm和20-40 cm土层有机碳密度,而水旱轮作各土层有机碳密度均低于其他耕作处理。不同耕作制度下水稻土中易氧化有机碳数量和有机碳氧化稳定系数差异较大,其中,垄作免耕(中稻-油菜)下水稻土有机碳氧化稳定系数最大。各耕作处理中,土壤有机碳的最大矿化速率差异显著,有机碳矿化率和pH呈显著正相关;在培养期间,垄作免耕(中稻-油菜)的累积矿化量始终显著低于其他处理;常规平作(中稻-冬水田)的总矿化强度最大,垄作免耕(中稻-油菜)最小。A 20-year experiment was conducted to study the effects of different tillage systems on accumulation and mineralization of organic carbon in purple paddy soil.The experiment included four tillage treatments： Conventional tillage with rotation of rice and winter fallow system,no-tillage and ridge culture with rotation of rice and winter fallow system,no-tillage and ridge culture with rotation of rice and rape system,and conventional tillage with rotation of rice and rape system.The results showed that the organic carbon density of soil surface had been stabilized since the tillage systems were carried out 20 years before,no-tillage and ridge culture increased the organic carbon density in the 10-20 cm and 20-40 cm soil layers,but the organic carbon density of conventional tillage with rotation of rice and rape system was lower than other tillage treatments.There were obvious differences between the amount of labile organic carbon and the oxidation stability coefficient under different tillage systems.The oxidation stability coefficient of organic carbon under long-term no-tillage and ridge culture was higher than that under conventional culture.There was significant difference in the maximum mineralization rate of organic carbon under different systems,mineralization rates of organic carbon and pH were in significantly positive correlation.In the incubation of 62 days,the cumulative mineralization of no-tillage and ridge culture was always lower than the conventional tillage.The total mineralization intensity of no-tillage and ridge culture was the lowest in all tillage systems.

关 键 词：耕作制度 有机碳 累积 矿化 紫色水稻土 

分 类 号：S157.42[农业科学—土壤学] S153.62[农业科学—农业基础科学]