Scholl P, Leitner D, Kammerer G, Loiskandl W, Kaul H-P, Bodner G
Department of Crop Sciences, Division of Agronomy, University of Natural Resources and Life Sciences, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria ; Institute of Hydraulics and Rural Water Management, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria.
Computational Science Center, University of Vienna, Oskar Morgenstern-Platz 1, 1090 Vienna, Austria.
Plant Soil. 2014;381(1-2):193-213. doi: 10.1007/s11104-014-2121-x. Epub 2014 Apr 28.
Roots are essential drivers of soil structure and pore formation. This study aimed at quantifying root induced changes of the pore size distribution (PSD). The focus was on the extent of clogging vs. formation of pores during active root growth.
Parameters of Kosugi's lognormal PSD model were determined by inverse estimation in a column experiment with two cover crops (mustard, rye) and an unplanted control. Pore dynamics were described using a convection-dispersion like pore evolution model.
Rooted treatments showed a wider range of pore radii with increasing volumes of large macropores >500 μm and micropores <2.5 μm, while fine macropores, mesopores and larger micropores decreased. The non-rooted control showed narrowing of the PSD and reduced porosity over all radius classes. The pore evolution model accurately described root induced changes, while structure degradation in the non-rooted control was not captured properly. Our study demonstrated significant short term root effects with heterogenization of the pore system as dominant process of root induced structure formation.
Pore clogging is suggested as a partial cause for reduced pore volume. The important change in micro- and large macropores however indicates that multiple mechanic and biochemical processes are involved in root-pore interactions.
根系是土壤结构和孔隙形成的重要驱动因素。本研究旨在量化根系诱导的孔径分布（PSD）变化。重点在于活跃根系生长期间孔隙堵塞与形成的程度。
在柱实验中，通过反演估计确定了小杉对数正态PSD模型的参数，该实验设置了两种覆盖作物（芥菜、黑麦）和一个未种植的对照。使用类似对流扩散的孔隙演化模型描述孔隙动态。
有根系处理显示出更宽的孔径范围，其中大于500μm的大孔隙和小于2.5μm的微孔隙体积增加，而细孔隙、中孔隙和较大的微孔隙减少。无根系对照显示PSD变窄，所有半径类别的孔隙度均降低。孔隙演化模型准确描述了根系诱导的变化，而无根系对照中的结构退化未得到恰当描述。我们的研究表明，根系在短期内有显著影响，孔隙系统的异质性是根系诱导结构形成的主要过程。
孔隙堵塞被认为是孔隙体积减少的部分原因。然而，微孔隙和大孔隙的重要变化表明，根系与孔隙的相互作用涉及多种机械和生化过程。
