Bodner G, Leitner D, Kaul H-P
Department of Crop Sciences, Division of Agronomy, University of Natural Resources and Life Sciences, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria.
Computational Science Center, University of Vienna, Oskar Morgenstern-Platz 1, 1090 Vienna, Austria.
Plant Soil. 2014;380(1-2):133-151. doi: 10.1007/s11104-014-2079-8. Epub 2014 Mar 14.
Small scale root-pore interactions require validation of their impact on effective hydraulic processes at the field scale. Our objective was to develop an interpretative framework linking root effects on macroscopic pore parameters with knowledge at the rhizosphere scale.
A field experiment with twelve species from different families was conducted. Parameters of Kosugi's pore size distribution (PSD) model were determined inversely from tension infiltrometer data. Measured root traits were related to pore variables by regression analysis. A pore evolution model was used to analyze if observed pore dynamics followed a diffusion like process.
Roots essentially conditioned soil properties at the field scale. Rooting densities higher than 0.5 % of pore space stabilized soil structure against pore loss. Coarse root systems increased macroporosity by 30 %. Species with dense fine root systems induced heterogenization of the pore space and higher micropore volume. We suggested particle re-orientation and aggregate coalescence as main underlying processes. The diffusion type pore evolution model could only partially capture the observed PSD dynamics.
Root systems differing in axes morphology induced distinctive pore dynamics. Scaling between these effective hydraulic impacts and processes at the root-pore interface is essential for plant based management of soil structure.
小规模的根-孔隙相互作用对田间尺度有效水力过程的影响需要得到验证。我们的目标是建立一个解释框架，将根系对宏观孔隙参数的影响与根际尺度的知识联系起来。
对来自不同科的12个物种进行了田间试验。根据张力入渗仪数据反演确定小杉孔径分布（PSD）模型的参数。通过回归分析将测得的根系性状与孔隙变量相关联。使用孔隙演化模型分析观察到的孔隙动态是否遵循类似扩散的过程。
根系基本上在田间尺度上调节了土壤性质。高于孔隙空间0.5%的生根密度可稳定土壤结构，防止孔隙流失。粗根系使大孔隙度增加了30%。具有密集细根系的物种导致孔隙空间的非均质化和更高的微孔隙体积。我们认为颗粒重新定向和团聚体聚结是主要的潜在过程。扩散型孔隙演化模型只能部分捕捉观察到的PSD动态。
轴形态不同的根系诱导出独特的孔隙动态。这些有效水力影响与根-孔隙界面过程之间的尺度转换对于基于植物的土壤结构管理至关重要。
