中国农业科学

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最新录用:不同形态秸秆还田下乌栅土耕层土壤有机质含量及其组成变化

陈硕桐1, 2,夏鑫1, 2,丁元君1, 2,冯潇1, 2,刘晓雨1, 2Marios Drosos1, 2,李恋卿1, 2,潘根兴1, 2   

  1. 1南京农业大学农业资源与生态环境研究所,南京 210095;2南京农业大学资源环境科学学院土壤学系,南京210095
  • 出版日期:2022-07-27 发布日期:2022-07-27

Changes in Topsoil Organic Matter Content and Composition of a Gleyic Stagnic Anthrosol Amended with Maize Residue in Different Forms from the Tai Lake Plain, China

CHEN ShuoTong1,2XIA Xin1,2DING YuanJun1,2FENG Xiao1,2LIU XiaoYu1,2, DROSOS Marios1,2, LI LianQing1,2, PAN GenXing1,2   

  1. 1Institute of Resource, Ecosystem and Environment of Agriculture, Nanjing Agricultural University, Nanjing  210095;  2Department of Soil Science, College of Resources and Environment Sciences, Nanjing Agricultural University, Nanjing 210095, China 
  • Published:2022-07-27 Online:2022-07-27

摘要:

【目的】研究基于田间试验,探讨不同形态秸秆还于稻田后耕层土壤有机质含量及其分子组成的动态变化,为秸秆资源化利用和稻田土壤固碳提供依据。【方法】选择江苏省常熟市某村乌栅土稻田,选用新鲜未处理(CS)、过腹处理(CM)和炭化处理(CB)的玉米秸秆,于20156月以等碳量(10 t C·hm-2)一次性还田,并以未还田处理作为对照(CK),分别于201520172019年水稻收获时采集耕层(015 cm)土样测定有机碳含量,并采用13C同位素丰度和生物标志物提取-GC/MS鉴定探析有机质组成变化。【结果】CK相比,还田当年和2年后所有还田处理都显著提高了耕层土壤有机碳含量(8%36%),但还田4年后,仅CB处理下有机碳含量显著增加(24%),且增加的碳来源于施入的生物质炭。还田2年后,CSCM处理下土壤有机质中木质素酚丰度达到峰值,分别比CK增加了66%115%;还田4年后,所有还田处理下植物源脂类的丰度均显著提高,相应地,植物源与微生物源脂类的丰度比(PL/ML)和生物标志物组分的多样性指数(H’)也显著提升。【结论】分子组成的变化可以用来判明不同形式秸秆还田下土壤有机质含量和组成的变化;秸秆炭化还田比直接还田和过腹还田有利于稻田土壤固碳,且增强了植物源有机组分在土壤中的持留并提升土壤有机质的分子多样性。

关键词: 稻田土壤, 秸秆还田, 土壤有机质, 生物标志物, 分子组成, 太湖地区

Abstract: 【ObjectiveThis study was to explore the changes in topsoil organic matter content and composition of a rice paddy with crop residue return in different forms, in order to provide sound information for crop residue utilization and paddy soil carbon sequestration.MethodIn June, 2015, untreated (CS), manured (CM) and pyrolyzed (CB) maize residue were returned at 10 t C hm-2, compared with no straw amendment (CK), to a paddy topsoil in Tai Lake plain, China. Topsoil (0-15 cm) samples were collected at rice harvest in November respectively of 2015, 2017 and 2019, and the changes in soil organic carbon (SOC) content and molecular composition were analyzed using 13C isotope and biomarker assays. 【ResultCompared to CK, topsoil OC was significantly increased by 8%-36% in 2015 and 2017 with all the residue amendment treatments, but increased by 24% only under CB in 2019,  with the SOC increases mainly from the input biochar. The abundance of lignin phenols in the topsoil under CS and CM peaked after 2-year amendment, and increased by 66% and 115% relative to CK, respectively. After 4 years, molecular abundance of plant-derived lipids increased significantly under all the amendments and the abundance ratio of plant- to microbe-derived lipids (PL/ML) and Shannon diversity of biomarkers (H’) were significantly enhanced. 【ConclusionCompared to untreated and manured residue, pyrolyzed residue return enhanced SOC sequestration and the molecular diversity of organic matter, through the retention of plant-derived components in the paddy soil.


Key words: paddy soil, crop residue return, soil organic matter, biomarkers, molecular composition, Tai Lake Plain