Root growth dynamics inside and outside of soil biopores as affected by crop sequence determined with the profile wall method
Root growth dynamics inside and outside of soil biopores as affected by crop sequence determined with the profile wall method
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DOI：
10.1007/s00374-015-1032-1
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发表时间：
2015-10-01
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
生根作物由于其较大的根大小和深深的生根习性，能够在底土中产生土壤生物孔(直径2毫米)。本研究的目的是量化作物序列对小麦整个生育期的根系生长动态的影响。在菊苣和高羊茅两种作物序列处理下，采用剖面壁法对小麦分蘖、孕穗、开花和吐乳4个生育期的根长(Kmm-2)进行了时间观测。在垂直剖面墙上测量到的生物化石的出现频率取决于前茬的选择，其中菊苣前茬的出现频率(2.3%)高于高羊茅(1.5%)。在菊苣后生长的小麦根长(0.024 km m(-2))显著高于高羊茅(0.006 km m(-2))。到开花期，菊苣生孔外根长平均比高羊茅高出45.9%。我们的结论是，在所研究的地点，生物孔作为根快速生长到更深土层的途径，允许根重新进入并探索底土。因此，与直根作物轮作的谷物可以受益于在早期生长阶段加强对深层土壤的水分和养分的吸收。各种非生物和生物因素的模型模拟将有助于揭示未来生物孔-根-冠关系的直接证据。
Taprooting crop species are capable of creating soil biopores (> 2 mm in diameter) in the subsoil due to their large root size and deep-rooting habit. The aim of this study was to quantify root growth dynamics of wheat in the subsoil during its complete growth season as affected by crop sequence. Temporal observation on root length (km m(-2)) of wheat inside and outside of biopores at four growth stages (tillering, booting, anthesis, and milk) was conducted by using the profile wall method under the two crop sequence treatments involving two precrops, viz., chicory and tall fescue. Frequency of biopore presence measured on vertical profile walls depended on the choice of precrops in which chicory precrop resulted in higher frequency (2.3 %) compared with tall fescue (1.5 %). Root length of wheat measured inside biopores was significantly higher when grown after chicory (0.024 km m(-2)) in comparison to tall fescue (0.006 km m(-2)). On average, root length outside biopores after growing chicory was 45.9 % higher than tall fescue until the stage of anthesis. We conclude that at the site under study biopores as pathways for rapid root growth into deeper soil layers allow roots to re-enter and explore the subsoil. Thus, cereals cultivated in rotation with taprooted crops can draw benefit from enhanced uptake of water and nutrients from deeper soil layers during early growth stages. Model simulations with various abiotic and biotic factors will be helpful to reveal the direct evidence of biopore-root-shoot relationship in the future.