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Coarse and fine root plants affect pore size distributions differently.

Bodner G, Leitner D, Kaul HP - Plant Soil (2014)

Bottom Line: 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.Scaling between these effective hydraulic impacts and processes at the root-pore interface is essential for plant based management of soil structure.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop Sciences, Division of Agronomy, University of Natural Resources and Life Sciences, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria.

ABSTRACT

Aims: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

No MeSH data available.


Related in: MedlinePlus

Measured and predicted PSD of soil under coarse and fine rooted species using a pore evolution model. a Evolution from an unplanted soil to a rooted soil, and (b) evolution driven by root volume allocation between a soil planted with high and low rm,root-species. Statistical indicators compare measured and predicted pore volume in different radius ranges given in Table 7
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Fig6: Measured and predicted PSD of soil under coarse and fine rooted species using a pore evolution model. a Evolution from an unplanted soil to a rooted soil, and (b) evolution driven by root volume allocation between a soil planted with high and low rm,root-species. Statistical indicators compare measured and predicted pore volume in different radius ranges given in Table 7

Mentions: According to the model of Or et al. (2000) pore dynamics follow a diffusion like process. Volumetric pore frequency tends to a more even distribution with time upon shifting of the median from larger to smaller radii and simultaneously widening of the pore range (increase of ςKosugi). Figure 6 shows measured and simulated PSDs according to this model for the cases of root driven pore evolution identified in Figs. 4 and 5. The corresponding pore volumes in different pore classes are given in Table 7.Fig. 6


Coarse and fine root plants affect pore size distributions differently.

Bodner G, Leitner D, Kaul HP - Plant Soil (2014)

Measured and predicted PSD of soil under coarse and fine rooted species using a pore evolution model. a Evolution from an unplanted soil to a rooted soil, and (b) evolution driven by root volume allocation between a soil planted with high and low rm,root-species. Statistical indicators compare measured and predicted pore volume in different radius ranges given in Table 7
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4372837&req=5

Fig6: Measured and predicted PSD of soil under coarse and fine rooted species using a pore evolution model. a Evolution from an unplanted soil to a rooted soil, and (b) evolution driven by root volume allocation between a soil planted with high and low rm,root-species. Statistical indicators compare measured and predicted pore volume in different radius ranges given in Table 7
Mentions: According to the model of Or et al. (2000) pore dynamics follow a diffusion like process. Volumetric pore frequency tends to a more even distribution with time upon shifting of the median from larger to smaller radii and simultaneously widening of the pore range (increase of ςKosugi). Figure 6 shows measured and simulated PSDs according to this model for the cases of root driven pore evolution identified in Figs. 4 and 5. The corresponding pore volumes in different pore classes are given in Table 7.Fig. 6

Bottom Line: 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.Scaling between these effective hydraulic impacts and processes at the root-pore interface is essential for plant based management of soil structure.

View Article: PubMed Central - PubMed

Affiliation: Department of Crop Sciences, Division of Agronomy, University of Natural Resources and Life Sciences, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria.

ABSTRACT

Aims: 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.

Methods: 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.

Results: 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.

Conclusions: 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.

No MeSH data available.


Related in: MedlinePlus