秸秆还田量及破碎程度影响下的农田土壤碳氮淋失特征  

Impact of Straw Return Quantity and Fragmentation Degree on Carbon and Nitrogen Leaching Characteristics in the Farmland Soil

作　　者：吴涵 张志远 贾琳娜 付行 辛佳[1,2,3] Wu Han;Zhang Zhiyuan;Jia Linna;Fu Hang;Xin Jia(College of Environmental Science and Engineering;Key Laboratory of Marine Environmental and Ecology,Ministry of Education;Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering,Ocean University of China,Qingdao 266100,China)

机构地区：[1]中国海洋大学环境科学与工程学院,山东青岛266100 [2]中国海洋大学海洋环境与生态教育部重点实验室,山东青岛266100 [3]中国海洋大学山东省海洋环境地质工程重点实验室,山东青岛266100

出　　处：《中国海洋大学学报(自然科学版)》2025年第4期120-133,共14页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(42177053)资助。

摘　　要：秸秆还田作为一种对农业可持续发展具有积极促进作用的外源碳氮输入方式,因其富含有机质,能为土壤提供碳氮营养,并随着水分渗透过程参与深层土壤以及地下水的碳氮循环过程。本研究针对华北平原集约化农业区,选取代表性土壤样本,通过土柱淋溶实验模拟不同还田量(0、13000及19500 kg/hm ^(2))和破碎程度(细碎与粗碎)下的秸秆还田策略,系统性探究了秸秆还田措施对土壤碳氮淋失特性的影响,并结合三维荧光技术分析淋滤液中DOC的荧光特征及其组分变化。实验研究结果表明:相较于其他秸秆处理组别,采用细破碎超量还田策略能显著提升DOC向深层土壤的迁移效率,累积DOC淋出量增长了16.77%~24.77%;与此同时,还能有效减少16.31%~34.84%的NO^(-)_(3)-N向下淋失。在淋溶周期结束后,所有秸秆处理的土壤样本均呈现出不同程度的固碳能力提升,增幅区间在7.67%~181.9%;而对于溶解性无机氮而言,NO^(-)_(3)-N为主要的存在形式,秸秆还田有助于提高其在土壤中的存储量。此外,三维荧光光谱分析揭示,秸秆还田能够引入易于微生物降解的DOC成分,从而激活土壤微生物活性,进一步影响DOC的化学结构稳定性。综上所述,采用细破碎并适当增大还田量的秸秆还田策略,既能优化DOC的淋溶效能,又能有效抑制NO^(-)_(3)-N向下淋溶,这对于改善土壤健康状况、减少地下水污染风险具有重要意义。Straw return,an exogenous carbon and nitrogen input strategy beneficial for agricultural sustainability,enriches the soil with organic matter,supplying vital carbon and nitrogen nutrients.It also contributes to deep soil and groundwater carbon-nitrogen cycling through water infiltration.This study was conducted in the intensively cultivated North China Plain,where representative soil samples were collected.Using column leaching experiments that simulated different straw return rates(0,13000,and 19500 kg/hm ^(2))and fragmentation levels(fine and coarse),this research systematically explored the effects of straw return on carbon and nitrogen loss characteristics in the soil.Furthermore,three-dimensional fluorescence technology was utilized to analyze the fluorescence characteristics and changes in DOC components within the leachate.Experimental results showed that,relative to other straw treatments,the fine-fragmented excessive straw return strategy significantly improved DOC migration efficiency to deeper soil layers,augmenting cumulative DOC leaching by 16.77%~24.77%.Simultaneously,it effectively reduced the downward leaching of NO^(-)_(3)-N by 16.31%~34.84%.Upon completing the leaching cycles,all soil samples subjected to straw return exhibited enhanced soil carbon sequestration capacity,with increases ranging from 7.67%to 181.9%.Regarding dissolved inorganic nitrogen,NO^(-)_(3)-N was the predominant form,with straw return facilitating its retention in the soil.Furthermore,three-dimensional fluorescence spectroscopy analysis indicated that straw return introduced readily degradable DOC components,thus activating soil microbial activity and affecting the chemical structural stability of DOC.In summary,a straw return strategy that includes fine fragmentation and a moderate increase in return rate optimizes DOC leaching efficiency and effectively suppresses the downward leaching of NO^(-)_(3)-N.This approach is significantly important for enhancing soil health and reducing the risk of groundwater pollution.

关 键 词：秸秆还田 DOC 氮素 三维荧光 淋溶 

分 类 号：S156[农业科学—土壤学]