秸秆隔层还田及水氮管理对土壤无机氮量及酶活性的影响  

The Effects of Straw Incorporation Depth on Nitrogen Dynamics and Enzymatic Activities in Soil

作　　者：陈盛 黄达 章二子[4] 朱建彬 郭相平 CHEN Sheng;HUANG Da;ZHANG Erzi;ZHU Jianbin;GUO Xiangping(College of Agricultural Engineering,Hohai University,Nanjing 210098,China;College of Civil and Architecture Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of New Energy and Building Energy Saving,Guilin 541004,China;Nanjing Jiangning Water Authority,Nanjing 210098,China)

机构地区：[1]河海大学农业科学与工程学院,南京210098 [2]桂林理工大学土木与建筑工程学院,广西桂林541004 [3]广西建筑新能源与节能重点实验室,广西桂林541004 [4]南京市江宁区水务局,南京210098

出　　处：《灌溉排水学报》2022年第5期45-54,共10页Journal of Irrigation and Drainage

基　　金：国家重点研发计划项目(2020YFD0900703);国家自然科学基金项目(52109052);中国博士后科学基金资助项目(2021M690873);广西建筑新能源与节能重点实验室(桂科能22-J-21-8)。

摘　　要：【目的】秸秆是农业生态系统中宝贵的生物质资源,资源总量丰富,利用潜力巨大,其中秸秆还田为最主要利用方式。研究确定秸秆隔层埋深以及最优的水氮组合,为秸秆还田资源化高效利用提供理论支撑和应用依据。【方法】通过小区试验,研究不同秸秆埋深(表面覆盖、埋深20 cm、埋深30 cm)配合不同灌水量(80%Iw、Iw、120%Iw,其中Iw为灌水定额)和不同施氮量(180、225、270 kg/hm^(2))下,在番茄不同生育期土壤无机氮量及和酶活性受到的影响,对比分析秸秆埋深、灌水量和施氮量耦合作用下对土壤中铵态氮、硝态氮量和脲酶、蔗糖酶及过氧化氢酶活性变化规律和影响效果。【结果】上层土壤铵态氮和硝态氮量随时间呈显著下降趋势(P<0.05),下层土壤铵态氮和硝态氮量随时间呈显著上升趋势(P<0.05);上层土壤脲酶活性随时间呈先显著下降后显著上升的趋势(P<0.05),下层土壤脲酶活性呈先不变后显著上升的趋势(P<0.05);上、下层土壤蔗糖酶活性均呈显著下降的趋势(P<0.05);上、下层土壤过氧化氢酶活性变化不显著(P>0.05);施氮量和秸秆埋深显著影响上层土壤铵态氮和硝态氮量(P<0.05),高施氮量和秸秆埋深20 cm可显著提升上层土壤铵态氮和硝态氮量(P<0.05);灌水量对下层土壤的铵态氮和硝态氮量影响显著(P<0.05),增加灌水量有利于上层土壤铵态氮和硝态氮向下层土壤运移;秸秆埋深对上、下层土壤脲酶、蔗糖酶和过氧化氢酶活性均影响显著(P<0.05),秸秆埋深20 cm可有效提升上、下层土壤脲酶、蔗糖酶和过氧化氢酶活性。【结论】秸秆埋深20cm具有较优保水保肥作用。综合考虑土壤无机氮量、酶活性、作物生长特点和节水需求,当前水肥管理模式下,秸秆埋深20cm,灌水量80%Iw,施氮量270 kg/hm^(2)为最优组合。【Objective】It has been a consensus that adding organic matter such as crop straws to soil not only improves soil fertility and soil structure but also boosts enzymatic activity and nutrient cycling.However,what is the optimal way of amending soil with straws is poorly understood.The purpose of this paper is to fill this knowledge gap by systematically studying the effects of incorporating straws into different soil depths on nitrogen mineralization and enzymatic activity at different growth stages of tomato.【Method】The plot experiment was conducted in a tomato field,with the straw incorporated over the soil surface,at the depth 20 cm and 30 cm,respectively.For each straw incorporation,there were three irrigation treatments – irrigating 80%,100% and 120%of water measured from an evaporation pan,and three nitrogen fertilizations:180 kg/hm^(2),225 kg/hm^(2),270 kg/hm^(2).During the experiment,we measured the content of NH_(4)^(+)-N and NO_(3)^(-)-N,as well as the activities of urease,sucrase and catalase in the soil at different growing stages.【Result】The contents of NH_(4)^(+)-N and NO_(3)^(-)-N in the upper soil decreased with time(P<0.05),while in the subsoil they increased with time(P<0.05).As time elapsed,the activity of urease in the upper soil declined first followed by an increase,both significantly(P<0.05),while in the subsoil it remained unchanged initially followed by an increase(P<0.05).In contrast,the activity of sucrase in the soil profile decreased with time(P<0.05),and the activity of catalase remained the same(P>0.05).Nitrogen fertilization and straw incorporation depth combined to affect the contents of ammonium and nitrate in the upper soil(P<0.05),with high nitrogen application combined with straw burial depth of 20 cm increased the contents of ammonium and nitrate nitrogen in the upper soil most(P<0.05).Irrigation amount affected the contents of NH_(4)^(+)-N and NO_(3)^(-)-N in the lower soil(P<0.05),and increasing irrigation amount benefited the downward movement of NH_(4)^(+)-N a

关 键 词：秸秆隔层还田 铵态氮 硝态氮 脲酶 蔗糖酶 过氧化氢酶 

分 类 号：S156.4[农业科学—土壤学]