冻融对沼泽湿地土壤水稳性大团聚体的影响

水稳性大团聚体(>0.25 mm)是土壤侵蚀和质量的重要表征指标.通过室内培养,在不同含水量、冻融次数和压实处理条件下,研究冻融过程对三江平原沼泽湿地土壤水稳性大团聚体的影响.结果表明,冻融过程影响土壤水稳性大团聚体含量,但压实和土壤起始含水量对湿地土壤的水稳性大团聚体影响较小,而冻融次数影响显著.4次冻融前,随着冻融次数的增加,不同处理的土壤水稳性大团聚体含量呈增加趋势;4次冻融后,高含水量处理的土壤水稳性大团聚体变化不明显,而低含水量处理的土壤水稳性大团聚含量有微弱增加.

Effects of Freezing2tha wing on Soil Water2stable Aggregates in Fresh Marsh

Soil water-stable macro-aggregates (>0.25mm) are an important characteristic index of soil ero-sion and soil quality. The effects of freezing-thawing on the content of soil water-stable macro-aggregates in Sanjiang Plain wetlands were studied under different soil water contents,numbers of freezing2thaw cycles,and compaction treatments by indoor incubation experiment. Results showed that the content of soil water-stable macro-aggregate was influenced by the freezing2thawing. The effects of freezing-thawing frequency were more significant compared with compaction and initial soil water content. Before the 4th freezing-thaw cycle,the content of soil water-stable macro-aggregates under different treatments increased with the increas-ing of freezing2thawing frequency. After the 4th freezing-thaw cycle,however,the content at high soil water content did not change obviously and increased slightly.