[关键词]
[摘要]
为探究积雪覆盖对东北地区农田黑土水溶性盐分含量的影响,在野外人工除雪后,对雪被去除试验组(B)与自然积雪对照组(N)0~30 cm农田黑土的7种土壤水溶性盐组分(Na+、K+、Ca2+、Mg2+、Cl?、SO42?、HCO3?)的含量变化过程进行试验研究。结果表明:覆雪期B组与N组平均盐分总量(质量分数)相较于试验期初分别增长107.22、129.54 mg/kg。土壤温度对Na+、Ca2+、Mg2+、HCO3?的含量具有显著影响,B组土壤的4种盐组分相比N组分别增加10.47%、?5.79%、?10.29%、?7.60%。融雪期B组与N组土壤盐分总量基本持平,该时期土壤含水率对Na+、Mg2+、HCO3?的含量具有显著影响,B组土壤的3种盐组分相比N组分别增加16.33%、?33.60%、?10.38%。试验期内,雪被去除处理下土壤HCO3?和二价阳离子(Ca2+、Mg2+)含量显著减少,一价阳离子(Na+、K+)与两种酸根离子(Cl?、SO42?)含量显著增加。HCO3?对盐分总量的影响程度最高,雪被去除处理引起的HCO3?含量减少将导致覆雪期与融雪期的土壤pH值分别降低0.04、0.03。总体而言,冬季雪被去除处理使作物生长季前的东北地区农田黑土原有的盐组分含量重新分布,引起土壤碱性的减弱。
[Key word]
[Abstract]
Global warming has profoundly changed the pattern of snow cover in the middle latitudes. In order to explore the effect of snow cover change on the water-soluble salinity of farmland black soil in the northeast black soil region, the method of artificial snow removal was adopted in the field, and the snow removal test group (Bare Ground) and the natural snow control group (Normal Ground) respectively were set up. The content changes of 7 kinds of water-soluble salt components (Na+, K+, Ca2+, Mg2+, Cl?, SO42?, HCO3?) in two groups of 0-30 cm farmland black soil were studied.The test results showed that the total salt content of soil was significantly reduced by snow removal during the snow cover period, and the average salt content of group B and group N increased by 107.22 and 129.54 mg/kg, respectively, compared with the beginning of the test period. The contents of Na+, Ca2+, Mg2+and HCO3? were significantly affected by the temperature during the snow cover period, and the four salt components in group B were increased by 10.47%, ?5.79%, ?10.29% and ?7.60%, respectively, compared with group N. The total amount of soil salt in group B and group N was basically the same during the snowmelt period, and the moisture content in this period had a significant impact on the contents of Na+, Mg2+ and HCO3?. The three salt components in group B soil increased by 16.33%, ?33.60% and ?10.38%, respectively, compared with group N. During the experiment period, the contents of HCO3? and bivalent cations (Ca2+ and Mg2+) in the soil were significantly reduced, while the contents of monovalent cations (Na+, K+) and two acid ions (Cl? and SO42?) were significantly increased under the snow removal treatment. HCO3? has the highest effect on the total salt content, and the decrease of HCO3? content caused by snow removal will lead to the decrease of soil pH value by 0.04 and 0.03 in the snow cover period and the snow melt period, respectively.In general, the removal of snow in winter redistributed the salt content of the farmland black soil before the crop growing season in Northeast China, which caused the decrease of soil alkalinity and adversely affected the flocculation state of soil particles. Through studying the effect of snow removal on the water-soluble salt content of farmland black soil in the northeast black soil region, a scientific basis is provided for exploring the change of black soil salt dynamics and environmental stability under the influence of climate warming.
[中图分类号]
[基金项目]