高级检索

    晋西黄土区退耕年限对土壤孔隙度等物理性质的影响

    Effects of the conversion time of cropland into forestry on soil physical properties in loess area of western Shanxi Province of northern China

      摘要
    • 摘要:
      目的通过分析不同退耕年限林地土壤物理性质的变化，探讨退耕还林工程对土壤物理性质的改良作用。
      方法以晋西黄土区不同退耕年限的荒草地、纯林地、混交林地为研究对象、以农地为对照，通过野外调查，研究了退耕年限对土壤密度、孔隙度、毛管孔隙度等土壤物理性质的影响。
      结果退耕地土壤密度随土层深度的加深显著增加，0 ~ 60 cm土层平均密度分别为：农地（1.38 g/cm3） > 荒草地（1.27 g/cm3） > 纯林地（1.20 g/cm3） > 混交林地（1.18 g/cm3），退耕还林后纯林地、混交林地与农地、草地的土壤密度差异显著（P < 0.05）；土壤密度随退耕年限的增加逐渐减小，退耕23年后基本稳定在1.16 g/cm3，退耕还林对表层土壤密度的改良效果最好，且随着土层深度的增加，这种改良效果逐渐减弱。土壤总孔隙度随退耕年限的增加呈波动性增加，并逐渐趋于稳定。表层（0 ~ 20 cm）孔隙度最大（50.8% ~ 57.6%），且在退耕5 ~ 10年内孔隙度变化最大，退耕25年后孔隙度基本稳定在55.61%左右。0 ~ 60 cm土层的孔隙度为混交林地（53.67%） > 林地（52.87%） > 农地（47.82%） > 荒草地（45.97%）。退耕后形成的纯林地、混交林地与农地、草地的孔隙度差异显著（P < 0.05），纯林地与混交林地孔隙度差异不显著（P ＞ 0.05）。土壤毛管孔隙度随退耕年限的增加呈显著增加趋势。混交林地、纯林地毛管孔隙度分别为51.21%和50.37%，与农地的毛管孔隙度(45.62%)显著差异。
      结论退耕还林工程能明显改善土壤物理性质，且混交林对土壤改良效果好于纯林。

       

      Abstract:
      ObjectiveIn order to discuss the “Grain for Green Project” on improving the soil physical property, we did an analysis about the change of soil physical property in different ages.
      MethodThe paper selects three kinds of land use (grass, pure plantation, mixed plantation) in the loess area of western Shanxi Province, contrasting with farmland, to discuss the effects of various ages in the Grain for Green Project on soil physical properties such as soil bulk density, soil total porosity and capillary porosity.
      ResultThe soil bulk density increased significantly with soil depth. The mean soil bulk density of 0−60 cm soil layer was farmland (1.38 g/cm3) > grassland (1.27 g/cm3) > pure plantation (1.20 g/cm3）> mixed plantation (1.18 g/cm3). There were significant differences in the soil bulk density of woodland and grass, farmland (P < 0.05). Besides, the soil bulk density decreased as the increasing year since abandoned. The value of it had been stable in 1.16 g/cm3 after 23 years old. The best improvement effect was the topsoil, but faded away with the increasing soil depth. The total porosity was inversely proportional to the age and tended to vary gently with increasing age of stand. The value of total porosity of topsoil was the biggest, which was 50.8%−57.6%, and the periods of greatest change was 5−10 years old. The value of it had been stable in 55.61% after 25 years old. The mean in the layers of 0−60 cm was mixed plantation (53.67%) > pure plantation (52.87%) > farmland (47.82%) > grassland (45.97%). There were significant differences between the grassland, farmland and woodland in the total porosity (P < 0.05), and the pure plantation was significantly different from the mixed plantation. With the growth of forest age, the capillary porosity also increased. The value of the mixed plantation and the pure plantation was 52.21% and 50.37%, which was significantly different from the farmland (45.62%).
      ConclusionThe project of the Grain for Green can obviously improve soil physical properties, and the effect of mixed plantation on soil improvement is better than pure plantation.

       

      • HTML全文
      • 参考文献(27)
      • 相关文章
      • 施引文献
    • 资源附件(0)

    /

    返回文章
    返回