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以东北典型黑土区耕地土壤为研究对象,通过对不同水分补充条件下、不同频度和程度的冻融交替处理后土壤干筛团聚体和水稳性团聚体组成、破坏率(PAD0.25、PAD1.0)、平均质量直径(Dmm)、平均质量比表面积(SAmm)和分形维数(D)等特征指标的测定与分析,研究季节性冻融对典型黑土区表层土壤团聚体特征的影响.结果表明:无水无冻融及无水冻融显著增加了>5mm干筛团聚体和>0.25mm水稳性团聚体的含量,干筛和水稳性团聚体的Dmm分别较冻融前增加了7.98%～29.41%和36.11%～44.44%,SAmm、D的变化规律也表现为促进大团聚体的团聚作用.少水冻融和季节冻融则显著增加了<2mm干筛团聚体和0.25～1mm水稳性团聚体的含量,Dmm、SAmm、D均表现出加剧风干团聚体拆分的趋势,水稳性团聚体的SAmm和D分别降低了10.88%～25.52%和1.02%～3.40%(P<0.05),团聚作用有所增强.季节性冻融后PAD0.25降低了33.45%(P<0.05),PAD1.0无明显变化,典型黑土区季节性冻融增强了土壤团聚体的水稳定性.
Taking the cultivated soils in the typical black soil region of northeast China as the research object, the soil dry-sieved agglomerates and water-stable aggregates formed under different water supplementation conditions with different frequency and degree of alternation, the destruction rate (PAD0.25, PAD1.0), average mass diameter (Dmm), average mass specific surface (SAmm) and fractal dimension (D) were measured and analyzed to study the effect of seasonal freeze-thaw on the characteristics of surface soil aggregates in typical black soil areas The results showed that the freeze-thaw and freeze-thaw without water significantly increased the content of agglomerates> 5 mm dry aggregates and> 0.25 mm water-stable aggregates, respectively Increased by 7.98% -29.41% and 36.11% -44.44%, respectively. The changes of SAmm and D also showed the effect of promoting agglomeration of large aggregates, while less water freezing and thawing and seasonally freezing and thawing significantly increased the contents of <2mm dry sieve aggregates and The contents of water-stable aggregates of 0.25-1 mm, Dmm, SAmm, and D all showed an increasing trend of resolving the air-dried aggregates. The SAmm and D of water-stable aggregates decreased by 10.88% -25.52% and 1.02% -3.40, respectively % (P <0.05), and the agglomeration effect was enhanced.PAD0.25 was decreased by 33.45% (P <0. 05). There was no significant change in PAD1.0. The seasonal freezing and thawing of typical black soil enhanced the water stability of soil aggregates.