【摘要】 【目的】对比分析广西金光农场蔗地与林地土壤团聚体组成及有机碳分布状况,探讨长期种植甘蔗对土壤质量的影响。【方法】采集蔗地及对应林地土壤,分别用干筛法和湿筛法测定其土壤团聚体组成,分析土壤基本理化性质、平均质量直径(MWD)、平均几何直径(GMD)及分形维数(D)等指标。【结果】蔗地与林地土壤>5 mm粒级的团聚体含量差异显著,其它粒级的差异不显著;种植甘蔗有利于增加大粒径团聚体的有机碳含量;蔗地土壤的破坏率显著高于林地土壤,导致蔗地土壤1～0.5 mm、0.5～0.25 mm和<0.25 mm粒级团聚体累积有机碳占比高于林地土壤。干筛法测定的蔗地土壤的MWD和GMD高于林地土壤,D值则低于林地土壤,但两者之间的差异均不显著;湿筛法的结果与之相反。【结论】长期种植甘蔗不会在较大程度上改变土壤团聚体组成特征,且团聚体机械稳定性显著增加、水稳性显著降低;甘蔗种植有增加大团聚体有机碳含量的趋势,并加速了土壤有机碳的运转。更多还原

【Abstract】 【Objective】To discuss the effect of long-term sugarcane planting on soil quality, the difference in composition of soil aggregates and distribution of soil organic carbon between sugarcane field and woodland soils in Jin-guang Farm of Guangxi Province were analyzed.【Method】The sugarcane field and the corresponding woodland soil were collected, soil aggregates composition was determined by dry sieving and wet sieving respectively, the basic physical and chemical properties, mean weight diameter(MWD), geometric mean diameter(GMD) and fractal dimension(D) were all analyzed.【Result】The content of >5 mm size aggregates between in sugarcane field and woodland was significant difference, but the other size was not. Sugarcane planting was beneficial to increase the content of soil organic carbon in large particle size aggregates, however, the percentage of aggregate destruction(PAD) in sugarcane field soil was significantly higher than that in woodland soil, which led to the higher proportion of soil organic carbon accumulated in the soil group of 1-0.5 mm, 0.5-0.25 mm and < 0.25 mm in sugarcane field than that in woodland soil. Dry sieving results showed that the MWD and GMD of sugarcane field soil were higher than those of woodland soil, and the D value of sugarcane land soil was lower than that of woodland soil, but there were no significant differences. Wet sieving presented opposite trends, and there was no significant difference either.【Conclusion】Long-term sugarcane planting did not change the composition of soil aggregates, the aggregate mechanical stability was significantly increased, and the water stability was significantly reduced. Sugarcane planting also increased the content of organic carbon in large aggregates, and accelerated the transport of soil organic carbon in soil.更多还原