围封对宁夏荒漠草原土壤团聚体组成及其稳定性的影响

发布时间：2018-02-28 07:54

本文关键词： 围封荒漠草原土壤团聚体平均重量直径团聚体破坏率　出处：《草地学报》2017年01期 　论文类型：期刊论文

【摘要】：以空间序列代替时间序列,采用干筛法和湿筛法研究了围封禁牧条件下宁夏荒漠草原恢复演替过程中0~40cm土层土壤团聚体组成、破坏率及平均重量直径(MWD)等指标,以探讨围封对荒漠草原土壤团聚体稳定性的影响。结果表明:围封有利于荒漠草原土壤团聚体的形成,随围封年限的增加,0.25mm土壤微团聚体含量总体呈下降趋势。其中,0.25mm干筛团聚体含量在0~10cm和10~20cm土层变化显著,均以围封10年的草地最低;0.25mm水稳性团聚体含量在0~10cm和20~40cm土层变化显著,其中0~10cm土层以围封7年的草地最低,20~40cm土层以围封10年的草地最低;随围封年限的增加,土壤团聚体平均重量直径呈先降低后增加的趋势,以围封10年的草地最高,团聚破坏率则以围封7年、10年的草地较低,未封育和封育3年的草地较高。从垂直分布看,随剖面深度的增加,大团聚体特别是5mm粒级团聚体含量显著增加。
[Abstract]:Using spatial sequence instead of time series, dry sieve method and wet sieve method were used to study the soil aggregate composition, damage rate and average weight diameter (MWD) of 0 ~ 40cm soil layer during restoration and succession of Ningxia desert steppe under closed grazing condition. The effects of enclosure on the stability of soil aggregates in desert steppe were studied. The results showed that the enclosure was beneficial to the formation of soil aggregates in desert steppe. The content of soil microaggregates in 0.25mm soil decreased with the increase of enclosing time, and the content of 0.25mm dry sieve aggregates changed significantly in the 0 ~ 10cm and 10m ~ 20cm soil layers, and the lowest 0.25mm water-stable aggregates in the 0 ~ 10cm and 200cm soil layers were significantly changed in the enclosed grassland for 10 years, especially in the 0 ~ (10) cm and 20 ~ (40 cm) soil layers. The average weight diameter of soil aggregates decreased first and then increased with the increase of enclosing years, and the highest was in the enclosed grassland for 10 years, and the soil mass diameter was the lowest in the 0 ~ 10cm soil layer, which was the lowest in the enclosed grassland soil layer for 7 years, and the lowest in the enclosed grassland soil layer for 10 years. The failure rate of agglomeration was 7 years, 10 years was lower, and that of unfenced and closed 3 years was higher. From the vertical distribution, the content of large aggregates, especially 5mm agglomerates, increased significantly with the increase of depth of section.
【作者单位】：宁夏大学农学院;宁夏大学西北土地退化与生态恢复国家重点实验室培育基地;宁夏同心县同心中学;
【基金】：国家自然科学基金(31460624) 宁夏自然科学基金项目(NZ14025)资助
【分类号】：S812.2

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