+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Modeling post-tillage soil structural dynamics: A review

Soil & Tillage Research 64(1-2): 41-59, February
Modeling post-tillage soil structural dynamics: A review
Tillage modifies the soil structure to create conditions favorable for plant growth. However, the resulting loose structure is susceptible to collapse by internal capillary forces and external compactive stresses with concurrent changes in soil hydraulic properties. Presently, limited understanding of these complex processes often leads to consideration of the soil plow-layer as a static porous medium. Our objective is to provide a review of recent progress in modeling soil structural dynamics at the porescale, based on soil mechanical and rheological properties. The basic geometrical framework of the models was a cubic arrangement of monosized spherical aggregates (other arrangements are discussed). The process of soil aggregate rejoining by capillary forces was modeled by considering the rate of energy dissipation due to viscous deformation of wet soil, and corresponding energy release due to reconfiguration of water capillary menisci. The model was complemented by independent rheological characterization of soil that provides control on the rate as well as the onset and termination of aggregate coalescence. The model was also adapted for consideration of steady stress (such as overburden) acting upon the unit cells. Unlike steady stress, transient stress (such as traffic) is applied for too short of a period to allow for total energy dissipation by viscous deformation. Hence, a portion of the deformation is elastic (with a recoverable portion of the applied energy). Rheological characterization under transient (oscillatory) stress provided coupled elastic and viscous properties under several loading frequencies. Effects of transient stresses on the geometrical model were modeled by considering a combination of (i) Hertzian-type elastic strain and (ii) viscous flow of soil at the contacts. Application of the models is demonstrated using illustrative examples and rheological measurements of Millville silt loam soil. Finally, we provide and outlook for upscaling the unit cell results to an aggregate bed scale.

(PDF same-day service: $19.90)

Accession: 010994478

DOI: 10.1016/s0167-1987(01)00256-2

Related references

Modeling and methodological strategy of discrete element method simulation for tillage soil dynamics. Transactions of the Chinese Society of Agricultural Engineering 19(2): 34-38, II, 2003

Modeling soil carbon and nitrogen dynamics in no-till and conventional tillage using PASTIS model. Soil Science Society of America Journal 71(2): 336-346, 2007

Modeling the effects of complex topography and patterns of tillage on soil translocation by tillage with mouldboard plough. Journal of Soil and Water Conservation Ankeny 56(4): 335-345, 2001

Modeling slit tillage under various soil and tillage configurations. Paper American Society of Agricultural Engineers ( 90-2624): 31 pp., 1990

Structural improvement of a diluvial meadow soil by combining minimum tillage with zero tillage. Pochvoznanie Agrokhimiya i Rastitelna Zashtita 20(3): 69-77, 1985

C and N mineralization of undisrupted and disrupted soil from different structural zones of conventional tillage and no-tillage systems in northern France. Soil biology and biochemistry 38(9): 2576-2586, 2006

Soil behaviour under tillage: structural evolution during tillage. Agronomie 13(6): 457-465, 1993

Tillage practices for soil and water conservation in the semi-arid zone. III. Runoff modeling as a tool for conservation tillage design. Soil and Tillage Research 4(3): 215-224, 1984

The effect of different soil tillage methods on the stability of structural aggregates in a brown Mediterranean soil and in a volcanic soil. Agricoltura Mediterranea 126(1): 13-21, 1996

Effects of tillage systems on soil organic carbon dynamics, structural stability and crop yields in irrigated wheat ( Triticum aestivum L.) “cotton ( Gossypium hirsutum L.) rotation in semi-arid Zimbabwe. 2008