模拟玉米秸秆及其生物炭还田...质数量及化学结构特征的影响_刘瑞雪.pdf

吉林农业大学学报 2023，45（1）：51-60http:/Email:jlndxb Journal of Jilin Agricultural University模拟玉米秸秆及其生物炭还田对黑土有机质数量及化学结构特征的影响*刘瑞雪，耿明昕，窦森，关松*，李阳吉林农业大学资源与环境学院，长春 130118摘 要：通过365 d田间原位模拟试验，以典型黑土为研究对象，采用土壤腐殖质化学分组以及固态13C-核磁共振技术研究了全量（12 t/hm2）玉米秸秆还田至015 cm土层以模拟秸秆浅旋还田（SI15）、035 cm土层以模拟秸秆深混还田（SI35）、玉米秸秆覆盖（SM）、全量玉米秸秆制备的生物炭（BC4）以及与全量玉米秸秆相等碳量的生物炭施入量还田（BC12）至015 cm土层处理对土壤有机碳含量、土壤腐殖物质形成以及土壤有机质的化学结构特征的影响。结果表明：与 ck 相比，SI15 与 BC12 处理分别显著提高土壤总有机碳（SOC）含量 21.83%和20.34%，对SOC数量提升作用最大，其次为BC4处理。于活性有机碳而言，SI15、BC4和BC12均显著提高土壤水溶性有机碳、易氧化有机碳和微生物量碳含量。对于相对稳定的土壤腐殖物质而言，不同秸秆还田方式均显著增加胡敏素（HM）和胡敏酸（HA）含量（SI35处理 HA除外），不同秸秆还田方式之间相比，SI15、BC4和BC12处理对提高HM的作用最大。玉米秸秆及其制备的生物炭还田对土壤有机质（SOM）的化学结构特征影响不同，SM、SI15和SI35的玉米秸秆还田处理增强了SOM脂族性，对改善SOM品质，提升土壤肥力具有重要作用；而BC4和BC12玉米秸秆生物炭还田处理明显增强SOM的芳香性和疏水性，对于提升SOM的稳定性和固碳具有重要作用。因此，相比较而言，SI15、BC12和BC4处理更有利于提升黑土SOM数量，改善SOM品质，发挥土壤肥力提升和固碳的协同作用。因此秸秆资源需要有效利用，秸秆还田既是改善土壤有机质、保持土壤肥力，又是一种环境友好、高效、低成本的重要措施之一。关键词：黑土；秸秆还田；生物炭；土壤有机碳；腐殖质组成；13C核磁共振中图分类号：S153.6 文献标志码：A 文章编号：1000-5684（2023）01-0051-10DOI：10.13327/j.jjlau.2021.1268引用格式：刘瑞雪，耿明昕，窦森，等.模拟玉米秸秆及其生物炭还田对黑土有机质数量及化学结构特征的影响 J.吉林农业大学学报，2023，45（1）：51-60.Effects of Simulated Maize Straw and Its Biochar Returning on Quantity and Chemical Structure of Organic Matter in Black Soil*LIU Ruixue，GENG Mingxin，DOU Sen，GUAN Song*，LI YangCollege of Resources and Environment，Jilin Agricultural University，Changchun，130118，ChinaAbstract：Straw resources are effectively utilized,and returning straw to the field is not only an important measure to improve soil organic matter(SOM)and maintain soil fertility,but also one of the most environmentally friendly,efficient and low-cost measures.Through the field in-situ simulation experiment for 365 d,taking the typical black soil as the research object,chemical grouping of soil humus and solid-state 13C-NMR technique was used to study the effects of total amount of corn straw*基金项目：国家重点研发计划项目(2017YFD0200801)，国家自然科学基金项目（42077022），吉林农业大学本科生科技创新基金项目（202010193079）作者简介：刘瑞雪，女，硕士研究生，研究方向：土壤环境与生物化学研究。收稿日期：2021-05-11*通信作者：关松，E-mail：吉林农业大学学报 2023 年 2 月Journal of Jilin Agricultural University 2023，February(12 t/hm2)returning to 0-15 cm soil layer(SI15)to simulate straw shallow rotation returning,returning to the field in 0-35 cm soil layer by simulating straw deep mixing(SI35),corn straw mulching(SM),total corn straw biochar(BC4)and biochar application equal to total corn straw to 0-15 cm soil layer(BC12)treatments on soil organic carbon,soil humic matter formation and chemical structure characteristics of SOM.The results showed that compared with ck,SI15 and BC12 treatments significantly increased the total soil organic carbon(SOC)content by 21.83%and 20.34%,respectively,with the greatest effect on the quantity of SOC,followed by BC4 treatment.As for active organic carbon,SI15,BC4 and BC12 treatments significantly increased water-soluble organic carbon,easily oxidizable organic carbon and microbial biomass carbon content in soil.In the composition of soil humic substances,different straw returning methods significantly increased the content of HM.For relatively stable soil humus,the contents of humin(HM)and humic acid(HA)were almost significantly increased by different straw returning methods(except for HA in SI35 treatment).Compared with different straw returning methods,SI15,BC4 and BC12 treatments had the greatest effect on the improvement of HM.The effects of simulated corn straw and its biochar on the chemical structure of SOM were different.The treatments of corn straw returning of SM,SI15 and SI35 enhanced the lipoid property of SOM.Among them,SI15 was more beneficial to improving the hydrophobicity of SOM,SI35 was beneficial to improving the hydrophilicity of SOM,and played an important role in improving SOM quality and soil fertility.BC4 and BC12 corn straw biochar treatments significantly enhanced the aromaticity and hydrophobicity of SOM,which played an important role in improving the stability and carbon sequestration of SOM.Therefore,by comparison,SI15,BC12 and BC4 treatments are more beneficial to increasing the quantity of SOM in black soil,improving the quality of SOM,and exerting the synergistic effect of soil fertility improvement and carbon sequestration.Key words：black soil；straw returning；biochar；soil organic matter；humus composition；13C nuclear magnetic resonance黑土是极其珍贵的自然资源，黑土腐殖质含量高于其他类型的土壤，具有较好的保水保肥性，具有通透性强、容重较低、持水能力强、土壤呼吸能力良好、微生物活性强等优点。但近年来无论是从质量或是数量方面来看，黑土耕地资源都有不同程度的下降。黑土质量下降主要体现在两方面：一方面是耕层结构变差，耕作层（020 cm）变薄，由于长期不合理耕作导致犁底层上移且厚、硬，阻碍水分和养分的运输；另一方面是耕层，尤其是亚表层（2040 cm）有机质含量过低，导致土壤肥力急速下降。东北的黑土地素有“黄金玉米带”和“大豆之乡”之称，土地高产且肥沃，是世界三大黑土区之一。但也面临着土地肥力透支的问题，因此提高黑土资源，保持黑土肥力已是刻不容缓。秸秆含有丰富的氮（N，0.65%1.82%）、磷（P2O5，0.08%0.196%）、钾（K2O，1.02%1.94%）和其他微量元素等1，是理想的作物生长肥料。大量研究表明，秸秆还田可提高土壤物理、化学和生物质量2-3。因此，秸秆还田对“减肥增效”提高生态效益具有重要意义。陈温福等4提出的“秸秆炭化还田”理论中，生物质炭是一种由农业废弃物在高温厌氧条件下热解碳化所得的具有多孔性、强吸附性、多含氧官能团、高芳香性、比表面积大等特性的高碳稳定物质4-6。因此，它在碳封存、农业废弃物管理、提高农业生产力和土壤质量方面具有潜力，是一个有效和有益的中长期土壤管理战略5。生物质炭施入土壤后可有效提高土壤有机碳（SOC）储量，被认为是碳的最终碳汇7而促进C封存8-9，减少温室气体排放10-13；另一方面，还可为土壤与作物提供许多益处，如保持养分14和水，促进种子发芽15、提高作物产量，提高土壤结构的稳定性16-1