不同形态秸秆还田下乌栅土耕层土壤有机质含量与组成变化  

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

作　　者：陈硕桐 夏鑫 丁元君 冯潇 刘晓雨[2] Marios Drosos 李恋卿[2] 潘根兴[2] CHEN ShuoTong;XIA Xin;DING YuanJun;FENG Xiao;LIU XiaoYu;Marios Drosos;LI LianQing;PAN GenXing(College of Environmental Science and Engineering,Yangzhou University,Yangzhou 225127,Jiangsu;Institute of Resource,Ecosystem and Environment of Agriculture,Nanjing Agricultural University,Nanjing 210095)

机构地区：[1]扬州大学环境科学与工程学院,江苏扬州225127 [2]南京农业大学农业资源与生态环境研究所,南京210095

出　　处：《中国农业科学》2023年第13期2518-2529,共12页Scientia Agricultura Sinica

基　　金：国家自然科学基金基(42077082、41771332)。

摘　　要：【目的】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的乌栅土稻田,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2015年6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2015、2017和2019年水稻收获时采集耕层(0—15 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】与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,CS和CM处理土壤有机质中木质素酚丰度达到峰值,分别比CK增加了115%和66%;还田4年后,所有还田处理的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质量的变化;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,提升了土壤有机质的分子多样性。【Objective】This 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 the useful information for crop residue utilization and paddy soil carbon sequestration.【Method】In June,2015,compared with no straw amendment(CK),untreated(CS),manured(CM)and pyrolyzed(CB)maize residue were returned at 10 t C·hm^(-2) 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.【Result】Compared with 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 115%and 66%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.【Conclusion】Compared with untreated and manured residue,pyrolyzed residue returning enhanced SOC sequestration and the molecular diversity of organic matter,through the retention of plant-derived components in the paddy soil.

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 

分 类 号：S153.621[农业科学—土壤学]