| 摘要: |
| 为了探明现代长期集约化生产和耕作管理模式下土壤物理状态的变化特征，对关中地区农田0～60 cm剖面范围内的土壤物理特性进行了研究。结果显示：(1) 土壤剖面容重呈现先增大后减小的变化趋势，表层0～10 cm土壤容重最小，为1.34 g·cm-3，20～40 cm土层容重高达1.67 g·cm-3，达到了制约根系延伸的极限容重；(2) 土壤紧实度随着剖面深度增加逐渐增大，0～15 cm、15～25 cm、25～45 cm土层范围内的平均值分别为482 kPa、1 647 kPa、2 268 kPa；(3) 土壤饱和导水率随着土层深度增加而逐渐减小，其中0～10 cm土层的饱和导水率最高，平均为0.968 mm·min-1，且各土层之间的差异达到显著水平。研究表明只有0～10 cm土层土壤结构性较好，而10 cm以下土壤的物理状态具有明显的退化趋势，制约着作物根系的延伸、气体交换和水分的入渗，应予以足够的重视。 |
| 关键词: 容重；紧实度；饱和导水率 关中；农田土壤 |
| DOI： |
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| 基金项目:农业部农村能源综合建设项目（1251005507）；陕西省农业厅项目（k332021312） |
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| Physical properties in soil profile of farmlands in Central Shaanxi |
| ZHU Fei-hua, WANG Yi-quan, HU Wei-guang, ZHANG Run-xia, RAN Yan-ling |
| () |
| Abstract: |
| In order to reveal the effects of intensive production and cultivation model on the variation of soil quality, the physical properties were determined in 0～60 cm soil profile of farmlands in Central Shaanxi. The results showed: (1) The bulk density in 0～60 cm soil profile showed an initial increase followed by a steady decrease with the increase of depth. The bulk density was lowest in 0～10 cm layer (a mean of 1.34 g·cm-3) and highest in 20～40 cm layer (1.67 g·cm-3). (2) The compactness in 0～60 cm soil profile increased with the increase of depth, and the average compactness in 0～15 cm, 15～25 cm and 25～45 cm layers was 482 kPa, 1 647 kPa and 2 268 kPa, respect
ively. (3) The saturated hydraulic conductivity (Ksat) showed a sharp decrease with the increase of soil depth, and the highest Ksat was 0.968 mm·min-1 in 0～10 cm layer. There was a statistically significant difference in Ksat among soil layers. In conclusion, the soil structure was relatively ideal only in 0～10 cm layer, and the subsurface layers were universally degenerated, which limited severely root extension, gas exchange and water infiltration. Therefore, great attentions should be paid to the improvement of soil physical properties. |
| Key words: bulk density compactness saturated hydraulic conductivity Central Shaanxi farmland soil |
