Precrop root system determines root diameter of subsequent crop
Precrop root system determines root diameter of subsequent crop
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DOI：
10.1007/s00374-015-1049-5
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发表时间：
2016-01-01
影响因子：
6.5
通讯作者：
Koepke, Ulrich
中科院分区：
文献类型：
--
作者：
Han, Eusun;Kautz, Timo;Koepke, Ulrich
不同根径级受作物序列影响的根系分布规律知之甚少。连续两年种植直根菊苣和须根高羊茅，在开花时(BBCH=61)用整体法采集45~155 cm土层的大麦根系。使用WinRHIZO Pro软件对4种根径等级，即极细(<；0.1 mm)、细(0.1-0.2 mm)、中等(0.2-0.5 mm)和粗根(>；0.5 mm)的根长密度(RLD，cm(-3))进行了基于图像的分析。极细根、细根、中等根和粗根在土壤深度的比例分别为4.4%、33.6%、50.4%和11.6%。在根很细和很细的情况下，大麦在高羊茅后生长(0.35 cm(-3))的RLD显著高于菊苣(0.53 cm(-3))。与这些结果相反的是，直根菊苣后取样的大麦根导致两个上部根直径级别(中根和粗根；0.38 cm(-3))的RLD高于高羊茅(0.23 cm(-3))。我们的数据表明，前茬作物的根构型首先导致土壤生物孔的不同模式，其次导致后茬作物根系的不同形态。孔道内外更精确的根系取样可能有助于直接比较根系的形态特征。此外，功能结构植物模型将有助于理解根系设计的土壤结构、根系发育可塑性和养分吸收过程之间的相互关系。
Little is known about the root distribution pattern of different root diameter classes as affected by crop sequence. Barley roots were sampled using the monolith method from 45 to 155 cm soil depth at the time of anthesis (BBCH = 61) after growing taprooted chicory and fibrous-rooted tall fescue precrops for two consecutive years. Image-based analysis of the root-length density (RLD, cm cm(-3)) of four root diameter classes, viz., very fine (< 0.1 mm), fine (0.1-0.2 mm), medium (0.2-0.5 mm), and coarse roots (> 0.5 mm), was done by using the WinRHIZO Pro software. Proportional distribution of very fine, fine, medium, and coarse roots across the soil depth was 4.4, 33.6, 50.4, and 11.6 %, respectively. In case of very fine and fine roots, the RLD of barley was significantly higher when grown after tall fescue (0.35 cm cm(-3)) than chicory (0.53 cm cm(-3)). In contrast to these results, barley roots sampled after the taprooted chicory resulted in a higher RLD of two upper root diameter classes (medium and coarse roots; 0.38 cm cm(-3)) in comparison to tall fescue (0.23 cm cm(-3)). Our data suggest the root architecture of precrops resulted first in different patterns of soil biopores and second in a different morphology of the root system of the subsequent crop. More precise root sampling inside and outside the pore channels might be helpful for direct comparisons of root morphological traits. Additionally, functional-structural plant models allowing the modeling of root growth in three dimensions will be helpful tools for understanding the interrelations between root-designed soil structure, root development plasticity, and nutrient uptake processes.