季节性冻土区不同调控模式对土壤水盐迁移协同效应的影响

Effects of different regulatory models on synergistic effects of soil water and salt migration in seasonal frozen soil regions

为了有效揭示季节性冻土区农田土壤水盐空间演变机理,以野外大田试验为研究载体,设置了生物炭调控(CS)、秸秆调控(JS)、生物炭与秸秆联合调控(CJS)和对照组(BL)4种调控处理,分别测试了冻结期与融化期各土层处土壤能量累积效果、水盐空间分布特征,进而探究了冻融条件下土壤水盐迁移协同效应关系。研究结果表明:冻结期,秸秆的覆盖调控作用显著地提升了土壤保温效果,减少土壤热量散失,土壤冻结速率减慢,土壤水分在浅层的富集现象显著,同时,其有效地提升了土壤水分与盐分的协同效应关系,其中,JS处理条件下浅层土壤储盐量分别相对于BL、CS和CJS处理提升了42.4、18.4和18.0 g。融化期,生物炭与秸秆的联合调控作用增加了地表对于光照和热量的吸收,加快了土壤的融解速率,同时,土壤的持水能力增强,盐分淋洗效果显著,土壤水分与盐分的协同作用效果显著高于其他3种处理。为丰富寒区农田土壤水盐调控技术以及科学合理提升农业水土资源利用效率提供理论指导。

In order to reveal the spatial evolution mechanism of soil water and salt in seasonal frozen soil area effectively,the field experiments were carried out and four kinds of control treatments were set up,including biochar control(CS),straw control(JS),combined biochar and straw control(CJS)and control group(BL).The cumulative effect of soil energy and spatial distribution of water and salt in different soil layers during freezing and thawing periods were tested,and the synergistic effect of soil water and salt migration under freezing and thawing conditions was explored.The results show that:During the freezing period,straw mulching significantly improved soil thermal insulation,reduced soil heat loss,slowed down soil freezing rate,and significantly enriched soil moisture in the shallow layer.At the same time,the synergistic effect of soil moisture and salinity was effectively enhanced.The soil salt storage under JS treatment increased by 42.4,18.4 and 18.0 g compared with BL,CS and CJS treatment,respectively.During the melting period,the combined regulation of biochar and straw increased the surface s absorption of light and heat,and accelerated the soil s melting rate.At the same time,the water holding capacity of soil was enhanced,the effect of salt leaching was significant,and the synergistic effect of soil water and salt was significantly higher than that of the other three treatments.This study is expected to provide guidance for enriching the technology of soil water and salt regulation in cold regions and promoting agricultural water and soil resources scientifically and reasonably.