冻融作用下土壤容重和含水量变化对黑土全氮垂直分布的影响  

Effects of changes in soil bulk density and moisture on vertical distribution of total nitrogen in black soils under freeze-thaw action

作　　者：张少良[1,2] 庄亚茹[1,2] 闫鹏科 肖梓良 冯兰茜 王曜 ZHANG Shaoliang;ZHUANG Yaru;YAN Pengke;XIAO Ziliang;FENG Lanqian;WANG Yao(School of Resources and Environment,Northeast Agricultural University,Harbin 150030,China;Key Substances Transportation and Regulation in Mollisols,Northeast Agricultural University,Harbin 150030,China)

机构地区：[1]东北农业大学资源与环境学院,哈尔滨150030 [2]黑土关键物质转运与调控研究中心(东北农业大学),哈尔滨150030

出　　处：《东北农业大学学报》2024年第8期91-99,141,共10页Journal of Northeast Agricultural University

基　　金：黑龙江省自然科学基金联合基金重点项目(ZL2024D001);东北农业大学“青年领军人才”支持计划(NEAU2023NLI-016)。

摘　　要：冻融影响下黑土剖面全氮(TN)垂直分异和主控因子是科学管理土壤氮素的重要依据。利用隔热土柱装置,模拟冻融交替影响下土壤容重、初始含水量、冻融循环次数等对黑土剖面(0~30 cm)TN空间分异的影响。结果表明:土壤容重为1.0 g·cm^(-3)时,多数处理经历冻融循环后土壤TN降低;含水量为15%且经历15次冻融循环后的土壤TN降幅最大,含水量为20%和25%的土壤TN降幅随冻融循环次数增加而增加;冻融循环后,含水量为15%的土壤剖面靠近底土(犁底层)位置的TN均升高。土壤容重为1.1 g·cm^(-3)时,经历不同冻融循环次数后,各处理不同土层TN均增加;含水量为15%和25%时,土壤TN增幅随冻融循环次数增加先增后降;含水量为20%时,经历10次冻融循环后土壤TN先略微降低,随冻融循环次数增加TN增幅变大。土壤水分含量与冻融循环次数对剖面土壤TN时空分异有显著交互作用。冻融循环过程中,降低低容重土壤含水量可有效减少耕层氮损失,适当提升高容重土壤含水量有利于增加耕层TN,特别是当冻融循环次数增加时作用效果更强。The vertical differentiation of total nitrogen(TN)in black soil profile under the influence of freezing and thawing and the main controlling factors are important bases for scientific management of soil nitrogen.In this study,the plastic tubes covered by the heat-insulated materials were used to simulate how soil bulk density(BD),initial soil moisture content(SM)and the number of freeze-thaw cycles effect the spatial differentiation of TN in the black soil profile(0-30 cm)under the influence of freezing and thawing alternation.The results indicated that TN tended to decrease after freeze-thaw cycling when the BD was 1.0 g·cm^(-3),and the gap of TN decrease was the biggest after 15 times of freeze-thaw cycling when SM were 15%(W/W),while the gap of TN decrease increased with freeze-thaw cycles frequency increase when SM was 20%and 25%.It was worth mentioning that TN increase was highest in the bottom of soil profile which was close to the plough pan,when SM was 15%.However,TN in most of the treatments increased after freeze-thaw cycling when the BD was higher(1.1 g·cm^(-3)).The mass concentration of TN increase increased firstly and then decreased in treatments of 15%and 25%of SM,while TN slightly decreased in the 10 freeze-thaw cyclies and then increased with freeze-thaw cycling frequency in treatment of 20%of SM.There was a significant interaction between SM and freeze-thaw cycling on TN changes in soil profiles during freeze-thaw cycling process.Generally,during the freeze-thaw cycling process,decreasing SM with a lower BD could effectively reduce the N loss,while a suitable SM with a higher BD was beneficial to increase TN in plough layer,especially when freeze-thaw cycles increased.

关 键 词：冻融 土壤氮转化 土壤氮运移 土壤氮分布 黑土 

分 类 号：S155.27[农业科学—土壤学]