垄作免耕对稻田垄埂土壤有机碳累积和作物产量的影响  

EFFECTS OF NO-TILLAGE RIDGE-CULTIVATION ON SOIL ORGANIC CARBON ACCUMULATION IN RIDGES AND CROP YIELDS IN PADDY FIELDS

作　　者：慈恩[1,2] 王莲阁[1] 丁长欢[1] 谢德体[1,2] 

机构地区：[1]西南大学资源环境学院,重庆400715 [2]重庆市三峡库区农业面源污染控制工程技术研究中心,重庆400715

出　　处：《土壤学报》2015年第3期576-586,共11页Acta Pedologica Sinica

基　　金：中国科学院战略性先导科技专项(XDA05050506);国家自然科学基金项目(41301245);中央高校基本科研业务费专项(XDJK2013B043);重庆市环境保护局环保科技项目(环科字2010第26号)资助

摘　　要：依托稻田免耕长期定位试验,研究了垄作免耕对稻田垄埂土壤有机碳累积和作物产量的影响。研究主要涉及常规平作(中稻-冬水田,简称中稻)、常规平作(中稻-油菜,简称稻油)、垄作免耕(中稻)和垄作免耕(稻油)等4个耕作处理。针对垄作对田面微地形的影响,将垄作小区中所有垄埂当成一个整体,统计其土壤有机碳的累积指标,再与平作处理中同体积或同质量的表土层(对比土层)作比较。结果表明,在对比土层和小区垄埂体积相同时,垄作免耕(稻油)的垄埂土壤有机碳密度要显著高于2个常规平作处理中对比土层和垄作免耕(中稻)的垄埂(p<0.05);在对比土层与小区垄埂质量相同时,各耕作处理的垄埂或对比土层中单位质量土壤的固碳量依次为:垄作免耕(稻油)>常规平作(中稻)>垄作免耕(中稻)>常规平作(稻油),且处理间差异显著(p<0.05)。这表明,针对垄埂和对比土层而言,垄作免耕(稻油)的土壤有机碳累积效应要优于垄作免耕(中稻)和常规平作处理。与传统的常规平作相比,垄作免耕的水稻增产效应明显,虽然其会导致油菜减产,但不影响水旱两季作物的经济总产出。总体而言,垄作免耕(稻油)是一种能兼顾环境和经济效益的稻田保护性耕作措施。No-tillage ridge-cultivation is a prominent representative of the conservation tillage systems for paddy fields in South China. It is, therefore of some important practical significance to quantify whether the conservation tillage system is able to contribute to improving soil organic carbon （ SOC ） sequestration and keeping stable and high crop yields as well, in paddy fields. Ridge cultivation changes micro-topography of the surface soil in paddy fields. However, for long, in their studies on organic carbon accumulation in topsoil of cropland under ridge cultivation and under conventional tillage, the difference in micro-topography of the surface soil between the two different cultivation systems has been often neglected, which would inevitably affect accuracy of the comparison. Hence, a long-term field experiment was conducted to investigate effects of no-tillage ridge-cultivation on SOC accumulation in ridge soil and crop yields in paddy fields, taking into full account the effect of ridges on micro-topography of the tested paddy fields. The long-term field experiment, initiated in 1990 and located in the experimental farm of Southwest University in Chongqing city, China （30°26＇ N, 106°26＇ E ） , is designed to have four different cultivation treatments in the field experiment, that is, Treatment CP1 （conventional tillage under the rotation of rice and winter fallow） , Treatment CP2 （ conventional tillage under the rotation of rice and rape ） , Treatment RN1 （ no-tillage ridge-cultivation under the rotation of rice and winter fallow ） , and Treatment RN2 （ no-tillage ridge-cultivation under the rotation of rice and rape ） . In this study, all the ridges in each plot under ridge cultivation were considered as a whole when calculated and compared SOC accumulation with the topsoil layers in Treatments CP1 and CP2 （ the soil layers in the control ） , and the comparison required that the soil layers in the control and the ridges should have the same soil volume or mass in their r

关 键 词：土壤有机碳 水稻 保护性耕作 固碳 垄埂 

分 类 号：S153[农业科学—土壤学]