Root growth and soil water utilization of winter wheat in the North China Plain
Root growth and soil water utilization of winter wheat in the North China Plain
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DOI：
10.1002/hyp.5533
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发表时间：
2004-08
影响因子：
3.2
通讯作者：
Xiying Zhang;D. Pei;Suying Chen
中科院分区：
文献类型：
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作者：
Xiying Zhang;D. Pei;Suying Chen
冬小麦（Triticum aestivum L.）是华北平原的主要农作物。该地区的季风气候导致夏季降雨量最多，但在冬小麦生长季节（12月至5月），降雨量远远低于作物的水分需求。需要提高冬小麦对土壤水分的利用效率，以减少对灌溉的需求。在本文中，我们报告了两个季节的工作结果，土壤水分利用，根系生长和分布，根系吸水的作物在不同的灌溉处理，以及可能的途径，以提高土壤水分利用效率。1996 ~ 1997年和1998 ~ 1999年冬小麦两个生长季在栾城站（37° 53′N，114° 41′E）进行了田间试验。在随机小区设计中，每个季节设置五个处理：雨养和灌溉冬小麦，灌溉次数从1到4不等。在实验地点，土壤有效持水量约为454 mm，顶部2 m土壤剖面。根系取样结果表明，冬小麦根系发达，平均最大生根深度为2 m。大部分根系集中在40 cm以上的土壤中。土壤顶层（0-20 cm）的根长密度非常高，超过5 cm cm−3。在高土壤水分条件下，根系吸水量在土壤剖面上的分布与根长密度的分布基本一致。土壤表层根系对土壤水分的吸收起着重要作用。当根长密度小于0.8cm cm−3时，根系是限制作物充分利用土壤水分的主要因素。深层根系的缺乏限制了作物对土壤水分的充分利用。因此，在成熟时，超过100毫米的可用水仍然在根区的雨养处理，虽然上层已经进入水分亏缺。在旱季不灌溉的处理中，作物吸收了土壤总有效水分的80%。对于灌溉小麦，从40%到50%的作物水分吸收来自土壤储存水。土壤有效贮水对华北平原小麦高产起着重要作用。在有限供水条件下，采取有效措施提高土壤贮水利用率，可以改善作物生产性能。结果表明，深耕打破土壤盘有利于作物根系在土壤深层的生长，均匀播种也有利于作物从土壤表层吸收水分，与土壤蒸发竞争。版权所有© 2004年约翰威利父子有限公司。
Winter wheat (Triticum aestivum L.) is the major crop in the North China Plain (NCP). The monsoon climate in this region causes most rain to fall in the summer season, but during the winter‐wheat growing season (October–May) the rainfall is far less than the water requirements for the crop. The efficiency of soil water use by winter wheat needs to be improved to reduce the need for irrigation. In this paper, we report the results of two seasons' work on soil water utilization, root growth and distribution, root water uptake by the crop under different irrigation treatments, and possible ways to improve soil water‐use efficiency. The field experiments were carried out at Luancheng Station (37° 53′N, 114° 41′E) from 1996 to 1997 and 1998 to 1999, two growing seasons of winter wheat. Five treatments for each season: rain‐fed and irrigated winter wheat with different irrigation numbers from 1 up to 4, were set up in a randomized plot design. Soil available water‐holding capacity at the experimental site was about 454 mm for the top 2 m soil profile. Root sampling results showed that winter wheat had a prolific root system with an average maximum rooting depth of 2 m. Most of the root system was concentrated in the upper 40 cm of soil. Root length density in the top layer of soil (0–20 cm) was very high, with values over 5 cm cm−3. The distribution of water uptake from the soil profile under high soil moisture conditions was the same as the distribution of root length density. The roots in the top layer of soil played an important role in soil water uptake. When root length density was less than 0 · 8 cm cm−3, the root was the main factor limiting the complete utilization of soil water by crops. The scarcity of roots in the deep soil layers restricted the full utilization of soil water by the crops. Thus, at maturity, over 100 mm of available water remained in the root zone for the rain‐fed treatment, although the upper layers had already entered water deficit. The crop took up 80% of the total available soil water in the treatment without irrigation in a dry season. For irrigated wheat, from 40 to 50% of crop water uptake was from the stored soil water. Available stored soil water played an important role in the higher production of wheat crops in the NCP. Effective measures to increase the utilization of stored soil water could improve crop performance under conditions of limited water supply. Results showed that deep tillage to break the soil pan improved root growth in the deeper soil layers, and sowing the crop evenly also enhanced water uptake from the top soil layer to compete with soil evaporation. Copyright © 2004 John Wiley & Sons, Ltd.