长期垄作免耕对稻田土壤有机碳剖面分布的影响  

Effect of Long Term Ridge-cultivation Without Tillage on Distribution of Organic Carbon in Soil Profiles of Paddy Fields

作　　者：慈恩[1,2] 朱洁[1,2] 彭娟[1,2] 符卓旺[1,2] 高明[1,2] 魏朝富[1,2] 谢德体[1,2] 

机构地区：[1]西南大学资源环境学院,重庆400716 [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400716

出　　处：《水土保持学报》2012年第1期170-173,共4页Journal of Soil and Water Conservation

基　　金：重庆市自然科学基金项目(CSTC;2009BB1108);中国博士后科学基金(20090460716;201003306);中央高校基本科研业务费专项(XDJK2009C060);重庆高校优秀成果转化资助项目;中国科学院战略性先导科技专项(XDA05050506);重庆市环境保护局环保科技项目(环科字2010第26号)

摘　　要：以稻田免耕长期定位试验为平台,研究长期垄作免耕对稻田土壤有机碳剖面分布的影响。结果表明,垄作免耕(中稻)、垄作免耕(稻油)、常规平作(中稻)和水旱轮作(稻油)4种耕作处理实施20年后,稻田0-60cm土体中各土层有机碳含量最高值和最低值分别出现在垄作免耕(稻油)和水旱轮作(稻油)中,且水旱轮作(稻油)中各土层有机碳含量均显著低于其他耕作处理;垄作免耕(稻油)中0-10cm和40-60cm土层有机碳含量与垄作免耕(中稻)、常规平作(中稻)之间差异不显著,但20-40cm土层有机碳含量则显著高于其他耕作处理(P<0.05),可见同传统耕作相比,长期垄作免耕(稻油)稻田的增碳优势主要体现在20-40cm土层。不同耕作处理连续实施20年后,稻田0-60cm土体有机碳密度的高低顺序为垄作免耕(稻油)>垄作免耕(中稻)>常规平作(中稻)>水旱轮作(稻油),且处理间差异显著(P<0.05)。垄作免耕15～20年期间,稻田0-10cm表层土壤有机碳储量基本稳定,但20-40cm土层有机碳储量仍有增加,其中垄作免耕(稻油)增加最为明显,表明20-40cm土层碳累积是长期垄作免耕下稻田发挥增碳功能的重要机制。A filed experiment was conducted to investigate effect of long term ridge-cultivation without tillage on distribution of soil organic carbon（SOC） in profiles of paddy fields.The experiment included four cultivation treatments： Ridge-cultivation without tillage（rice）,ridge-cultivation without tillage（rice-rape）,plain-cultivation（rice） and plain-cultivation（rice-rape）.The results showed that the highest and lowest SOC concentrations in different layers（0-10 cm,10-20 cm,20-40 cm and 40-60 cm） of paddy fields were respectively found in ridge-cultivation without tillage（rice-rape） and plain-cultivation（rice-rape） after different cultivation treatments were conducted for 20 years.SOC concentrations in different soil layers were significantly lower in plain-cultivation（rice-rape） treatment,as compared with other cultivation treatments.SOC concentrations in the 0-10 cm and 40-60 cm layers had no significantly difference among ridge-cultivation without tillage（rice）,ridge-cultivation without tillage（rice-rape） and plain-cultivation（rice）.SOC concentration in the 20-40 cm layer was significantly higher in paddy fields under ridge-cultivation without tillage（rice-rape） when compared to paddy fields under other cultivation treatments（P0.05）.The results showed that accumulation of organic carbon in the 20-40 cm layer was much more obvious in paddy fields under ridge-cultivation without tillage（rice-rape） when compared to paddy fields under traditional cultivation treatment.After different cultivation treatments were conducted for 20 years,SOC densities in the 0-60 cm layer of paddy fields decreased in the order of ridge-cultivation without tillage（rice-rape） ridge-cultivation without tillage（rice） plain-cultivation（rice） plain-cultivation（rice-rape）,and there was significantly difference among all the treatments（P0.05）.During ridge-cultivation without tillage was conducted in paddy fields for 15～20 years,organic carbon storage was kept stable

关 键 词：垄作免耕 稻田 有机碳 土壤剖面 

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