秸秆深还不同年限对黑土腐殖质组成和胡敏酸结构特征的影响

发布时间：2018-01-30 13:27

本文关键词： 秸秆深还年限土壤腐殖质组成胡敏酸结构特征　出处：《土壤学报》2017年01期 　论文类型：期刊论文

【摘要】：秸秆深还(Corn stover deep incorporation,CSDI)指将作物秸秆深埋于土壤亚表层20~40 cm深处,用以解决秸秆焚烧和土壤肥力退化的可持续利用模式。本文以吉林农业大学玉米连作耕地试验田未施用秸秆和秸秆深还不同年限的土壤为研究对象,设置CK、CSDI(2014)、CSDI(2013)和CSDI(2012)共4种处理,分别代表未施入秸秆、2014年秸秆深还(深还第1年)、2013年秸秆深还(深还第2年)、2012年秸秆深还(深还第3年),研究秸秆深还不同年限对黑土腐殖质组成和胡敏酸结构特征的影响。通过腐殖质组成修改法提取富里酸(Fulvic acid,FA)、胡敏酸(Humic acid,HA)和胡敏素(Humin,HM),国际腐殖质协会(International Humic Substances Society,IHSS)推荐的方法提取HA样品,通过元素组成、红外光谱和差热分析测定HA结构。结果表明:与CK相比,秸秆深还1年后显著提高了土壤和腐殖质各组分有机碳含量,亚表层累积效果更明显,其土壤有机碳(SOC)、HA、FA和HM有机碳含量分别增加了23.7%、30.5%、27.3%和46.1%,但PQ值(HA在可提取腐殖物质的比例)没有显著变化;HA氧化度和缩合度降低明显,表层和亚表层(O+S)/C比值分别降低14.31%和14.68%,H/C比值分别增加27.74%和28.86%,脂族链烃和芳香碳含量增加,热稳定性降低,HA结构趋于简单化。随着年限增加,深还3年后SOC、FA和HM有机碳含量呈下降趋势,HA有机碳含量呈上升趋势,PQ值变化显著,HA缩合度、氧化度呈上升趋势,脂族性减弱,芳香性增强,HA结构趋于复杂化。说明随着年限增加,秸秆不断矿化分解,秸秆深还对土壤腐殖质组成和结构特征的影响效果减弱。
[Abstract]:Corn stover deep incorporation (CSDI) means to bury crop straw deeply in 2040 cm depth of subsurface layer of soil. In order to solve the sustainable utilization model of straw burning and soil fertility degradation, this paper took the soil of Jilin Agricultural University continuous cropping cultivated land without straw and straw depth of different years as the research object, and set up CK. CSDIX2014 (CSDIX2013) and CSDIX2012), respectively, representing the absence of straw, in 2014, the straw was still deep (deep and the first year). In 2013, the straw depth was returned (the second year), and in 2012, the straw depth was returned (the third year). The effects of different years of straw depth on the composition of humus and the acid structure of Hu Min in black soil were studied. Hu Min and Huminine HM). The method recommended by the International Humus Association International Humic Substances Society HSS was used to extract HA samples. The structure of HA was determined by elemental composition, IR and DTA. The results showed that compared with CK, the organic carbon content of soil and humus components was significantly increased after 1 year of straw depth. The accumulative effect of subsurface layer was more obvious, the contents of organic carbon of soil organic carbon (SOC) and HM increased by 27.3% and 46.1%, respectively. However, there was no significant change of PQ value and HA in the proportion of humic substances extracted. The oxidation degree and condensation degree of HA decreased obviously, and the ratio of O / S / C decreased by 14.31% and 14.68 H / C respectively, and increased by 27.74% and 28.86% respectively. The content of aliphatic chain hydrocarbon and aromatic carbon increased, the thermal stability decreased and the structure of HA tended to simplify. The content of organic carbon of HA is increasing. The change of PQ value is obvious. The degree of oxidation is increasing, the aliphatic property is weakening, the aromaticity is increasing and the structure of HA tends to be complicated. It shows that with the increase of the number of years, the structure of HA tends to be complicated. The effect of straw depth on soil humus composition and structure was weakened.
【作者单位】：吉林农业大学资源与环境学院;吉林省榆树市恩育乡农机管理服务站;
【基金】：国家自然科学基金项目(41571231) 国家重点研发计划项目(2016YFD0200304)资助~~
【分类号】：S153.6
【正文快照】： (2吉林省榆树市恩育乡农机管理服务站,吉林榆树130408)我国作物秸秆产量巨大,农民为节约成本便于耕作,多数选择就地焚烧[1]。不仅污染环境,而且不利于建立可持续的农田生态系统。秸秆还田是最简便、最实用的技术措施,对改善土壤结构和微生物群落,增加农田土壤有机碳库及促进养

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