Ability of seedling roots of Lolium perenne L. to penetrate soil from artificial biopores is modified by soil bulk density, biopore angle and biopore relief
Ability of seedling roots of Lolium perenne L. to penetrate soil from artificial biopores is modified by soil bulk density, biopore angle and biopore relief
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DOI：
10.1007/s11104-004-5764-1
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发表时间：
2005-05-01
期刊：
影响因子：
4.9
通讯作者：
Tisdall, JM
中科院分区：
文献类型：
--
作者：
Hirth, JR;McKenzie, BM;Tisdall, JM
为了预测异质土壤中的根生长，我们需要了解根何时会生长到连续的生物孔中，沿着连续的生物孔和从连续的生物孔中出来。在这项研究中，我们确定了生物孔角和壁面粗糙度对不同容重的根向周围土壤渗透的影响。在堆积密度为1.25、1.38或1.50 mg m(-3)的土壤中，形成了直径3 mm、长34分钟的直形人工生物孔，没有径向压缩。生物孔与水平线成40度或90度倾斜，其壁起皱或变光滑。黑麦草(Lolium Perenne)种子根在生物孔中生长7天，并检测其对周围土壤的渗透性。从垂直生物孔进入土壤的根很少(13%)，而大多数(78%)在距水平40度的生物孔中只在短距离(4~24 mm)内生长。随着土壤容重的增加，留在与水平生物孔成40度角的根的长度增加，尽管耕作通过减少根在穿透土壤之前的生长距离来改变这种影响。与光滑的人工生物孔相比，蚯蚓(Aporrectodea RoSea)挖掘的土壤表面的显微照片显示它们相对不平坦。该研究为建立含有生物孔的非均质土壤中的根系生长模拟模型奠定了基础。
To predict root growth in heterogeneous soil, we need to understand when roots will grow into, along and out from continuous biopores. In this study we determined the effect of biopore angle and wall roughness on root penetration into surrounding soil of different bulk densities. Straight 'artificial biopores', 3-mm diameter and 34-min long, were formed without radial compression in soil compacted to bulk densities of 1.25, 1.38 or 1.50 Mg m(-3). Biopores were inclined at 40 degrees or 90 degrees from the horizontal and their walls scarified or left smooth. Seminal roots of ryegrass (Lolium perenne) were grown for 7 days in the biopores and their penetration of the surrounding soil examined. Few roots (13%) penetrated soil from vertical biopores while most roots (78%) in 40 degrees-from-horizontal biopores grew for only short distances (4-24 mm) before penetrating soil. As soil bulk density increased, the length of roots remaining in 40 degrees-from-horizontal biopores increased, although scarification modified this effect by decreasing the distances roots grew before penetrating soil. Compared with smooth artificial biopores, micrographs of soil surfaces excavated by earthworms (Aporrectodea rosea) showed they were relatively uneven. This study provides a basis for developing simulation models of root growth in heterogeneous soil containing biopores.