Root water uptake and profile soil water as affected by vertical root distribution
Root water uptake and profile soil water as affected by vertical root distribution
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DOI：
10.1007/s11258-006-9163-y
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发表时间：
2007-02
期刊：
影响因子：
1.7
通讯作者：
Guiping Yu;J. Zhuang;K. Nakayama;Yan Jin
中科院分区：
文献类型：
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作者：
Guiping Yu;J. Zhuang;K. Nakayama;Yan Jin
植物根系吸水是控制田间水分平衡的主要过程，对农业生态系统管理至关重要。基于自然湿土和干土条件下田间玉米植物（Zea mays L.）的液流测量，我们研究了根系垂直分布对根系吸水的影响以及由此引起的土壤剖面水的变化。观察结果表明，对于提高植物应对缺水的能力，最密根土壤层的深度比最大根深更重要。最密根层出现在30厘米土深以下，非常有利于在干燥土壤条件下维持植物水分供应。在根系最密集的土层中，由于局部水分的高效消耗，白天有效土壤水饱和度（Se）总是急剧下降。生根深度的限制显着增加了各个土层之间的 Se 差异，特别是在干燥土壤条件下，这可能是由于各层之间水流的物理不平衡。这项研究强调了根系分布和模式在调节土壤水分利用方面的重要性，从而提高植物对季节性干旱的耐受力，从而实现可持续农业生产力。
Water uptake by plant roots is a main process controlling water balance in field profiles and vital for agro-ecosystem management. Based on the sap flow measurements for maize plants (Zea mays L.) in a field under natural wet- and dry-soil conditions, we studied the effect of vertical root distribution on root water uptake and the resulted changes of profile soil water. The observations indicate that depth of the most densely rooted soil layer was more important than the maximum rooting depth for increasing the ability of plants to cope with the shortage of water. Occurrence of the most densely rooted layer at or below 30-cm soil depth was very conducive to maintaining plant water supply under the dry-soil conditions. In the soil layers colonized most densely by roots, daytime effective soil water saturation (Se) always dropped dramatically due to the high-efficient local water depletion. Restriction of the rooting depth markedly increased the difference ofSebetween the individual soil layers particularly under the dry-soil conditions due likely to the physical non-equilibrium of water flow between the layers. This study highlights the importance of root distribution and pattern in regulating soil water use and thereby improving endurance of plants to seasonal droughts for sustainable agricultural productivity.