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Information - SSS9 Quantification of soil structure and soil porosity changes caused by natural and anthropogenic affects (co-listed in HS)
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Event Information |
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Soil structure is a dynamic property and it is subjected to genesis and degradation processes.
The main factors that affect the degradation of soil structure are the long-term intensive cultivations, which deplete the soil organic matter content, soil erosion, soil compaction, the formation of surface crusts and the formation of a compacted layer along the soil profile (e.g. ploughpan).
Organic matter is shown to play a key roles in the formation of soil structure and its stabilization. There may exist critical contents of soil organic matter for different soils which must be maintained if the soil are to be fully functional. Soil structure is shown to be of fundamental importance for all aspects of soil functions. Optimum structure is that which enables the soil to have the widest range of possible uses. That is, when the soil’s “functionality” is at its maximum (or maximal).
Soil structure degradation following intensive agricultural activities, soil compaction, loss of structural stability and the formation of surface crusts give rise to the loss of infiltrability resulting in increasing runoff and soil erosion while a degradation of the continuity of elongated transmission pores may on one hand cause a strong reduction of water movements through the soil porous matrix and on the other hand reduced water exchange between intra- and interaggregate pores may lead to increasing leaching of solutes through preferential pathways.
Furthermore, mining and other activities lead to man-made soil systems of ameliorated or reclaimed sediment mixtures that are in an initial stage of soil development. are often characterized by the absence of soil horizons, by a small-distance spatial variability of geologically different components and by an instable pore structure with complex hydraulic and other soil properties. Up to now, these physical factors have not been adequately taken into consideration.
This session could focalised on the quantification of soil structure and its changing, including the contribution of soil micromorphology, following the agricultural activity and the natural seasonal dynamics, with the aim to propose indicators to characterize the soil structure quality and to quantify the soil degradation aspects (loss of structure stability, compaction, crusting, etc.). The porosity is one of the best indicator of soil structure quality and the quantification of the size, continuity, connectivity, orientation and irregularity of pores is fundamental to understand water flow and allows a more precise modelling of water movement. These knowledge are the basis for recommendation of sustainable soil management systems able to maintain and improve the soil structure quality and to prevent soil degradation and are useful for policymakers to develop future strategies that must be adopted for a real sustainable agriculture that includes productivity as well as environmental protection aspects.
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Preliminary List of Solicited Speakers |
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Helmut Rogasik – ZALF, Institut für Bodenlandschaftsforschung, Müncheberg, Germany
X-ray CT analyses of soil structure changes induced by agricultural machinery or different tillage practices
Milena Cislerova – Czech Technical University, Prague, Czech Republic
Soil structure as a source of preferential flow
Victor Chertkov – Technion, Haifa, Israel
An attempt to connect soil structure, shrinkage, cracking and hydraulic properties without the need for fitted parameters
Olga P. Gate – Institute of Soil Science and Plant Cultivation, Pulawy, Poland
Soil physical quality as affected by management practices
Sergio Pellegrini – Istituto Sperimentale per lo Studio e la Difesa del Suolo, Firenze, Italy
Effect of different organic matter amendments on topsoil structural properties
Xh. Peng – University of Kiel, Germany
Influence of soil structure on the shrinkage behaviour and consequences for modelling approaches
S. Peth – University of Kiel, Germany
The mechanical behaviour of soil under cyclic loading-Implication for soil deformation and stress distribution
Jerzy Liepic – Institute of Agrophysics, Polish Accademy of Sciences, Lublin, Poland
Soil porosity and water infiltration as influenced by tillage method
Jose Doerner – Instituto Sciencias do Suelos, Universidad Austral de Chile, Valdivia, Chile
Anisotropy of permeability and its effect on the water movement in hillslopes
Miroslav Kutilek - Emeritus Professor of Soil Physics, Prague, Czech Republic
The influence of uniaxial compression upon pore size distribution in bi-modal soils
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