不同年限有机栽培对土壤生物固氮活性的影响  

Soil Biological Nitrogen Fixation under Organic Management in Different Years

作　　者：赵艳利 魏晓梦 吴传发 邓扬悟[1] 廖健利 黄丹枫[3] 吴金水[2] 葛体达[2] ZHAO Yan-li;WEI Xiao-meng;WU Chuan-fa;DENG Yang-wu;LIAO Jian-li;HUANG Dan-feng;WU Jin-shui;GE Ti-da(Jiangxi University of Science and Technology,Ganzhou 341000,China;Institute of Subtropical Agriculture Chinese Academy of Sciences,Changsha 410125,China;Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]江西理工大学,江西赣州341000 [2]中国科学院/亚热带农业生态研究所,湖南长沙410125 [3]上海交通大学,上海200240

出　　处：《土壤通报》2021年第3期602-610,共9页Chinese Journal of Soil Science

基　　金：国家重点研发计划(2019YFC0605004);江西省重点研发计划(20202BBG73007);湖南省国际科技创新合作基地(2018WK4012)资助。

摘　　要：氮是对作物生长和产量维持最重要的元素。有机农业无化学肥料投入,生物固氮是氮素最重要的来源之一。然而到目前为止,有机栽培对农田土壤微生物固氮活性的影响尚不清楚。本文以20年常规栽培花椰菜农田土壤为对照,比较经10年、14年、20年有机栽培后土壤微生物固氮活性的变化,并通过多元统计分析探究了影响土壤生物固氮活性的因素。研究结果表明,在7天的测定周期中,与常规栽培相比,10年和14年有机栽培降低了前期土壤生物固氮速率,但整个周期累积固氮在量各处理间无显著差异。不同年限有机栽培对土壤生物固氮速率和累积固氮量影响显著,整体而言14年有机栽培的最低,10年和20年有机栽培间的差异因培养时间而异。培养结束时,常规栽培土壤固氮速率接近于0,有机栽培的花椰菜土壤则仍保持较高活性。皮尔森相关分析和冗余分析(RDA)表明,NH_(4)^(+)、NO_(3)^(-)及Olsen P含量是影响有机栽培土壤生物固氮活性的关键因素;其中,NO_(3)^(-)对固氮有抑制作用,Olsen P则促进了土壤生物固氮活性的增加。Nitrogen(N)is the most important element for the growth and yield of crops.Biological N fixation plays an essential role in N supply in organic agriculture without chemical fertilizer input.However,the effect of organic management years on biological N fixation activity is still unclear.This study compared the dynamics of N fixation rate and cumulative N fixation in soils under the organic management of cauliflower for 10 years,14 years,20 years and its conventional management for 20 years.And the factors influencing N fixation were explored using multivariate statistical analysis.The results showed that during the 7-day incubation,10-year and 14-year organic managements reduced the N fixation rate compared with conventional management.However,the accumulative N fixation over the incubation showed no significant difference among all treatments.The N fixation rate and cumulative N fixation amount were significantly affected by organic management years and were the lowest in 14-year organic management.At the end of incubation,the soil N fixation rate under conventional management was near zero,whereas N fixation activity remained high under organic managements.Pearson correlation and redundancy analysis showed that the N fixation activity was primarily affected by the contents of NH_(4)^(+),NO_(3)^(-) and Olsen P.NO_(3)^(-) suppressed the N fixation,while Olsen P increased the N fixation activity.

关 键 词：有机农业 耕作年限 固氮活性 矿质态氮 有效磷 

分 类 号：S147.5[农业科学—肥料学]