ARS | Publication request: Towards a better understanding of the cracking behavior in soils

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 12, 2008
Publication Date: N/A

Technical Abstract: Understanding and modeling shrinkage-induced cracks helps bridge the gap between flow problem in the laboratory and at the field. Modeling flow at the field scale with Darcian fluxes developed at the laboratory scales is challenged with preferential flows attributed to the cracking behavior of soils. Understanding and characterizing the cracking behavior of soils present a much-needed area of research the outcome of which will contribute towards filling major knowledge gaps in understanding soil behavior at the field scale, as well as shedding more light on the physical understanding of the shrinkage-induced preferential flow problem. In this study, we aim at providing a functional definition of the cracking behavior of soils through continuous monitoring of soils at the field scale. Series of field digital images were captured along with multi-layer water content and temperature measurements. In our methodology, we followed an upscaling approach in an attempt to understand the cracking behavior of soils starting with the micro scale constituting the primary soil particles. A functional approach assessing the soil's structure through its functional characteristics (shrinkage-swelling and stress-strain relationships) is adopted building on current novel approaches and tools including the pedostructure concept and the restrained ring method. Cracking dynamics are characterized as function of soil water content using the extracted cracking areas and water content profiles. An optimized methodology to quantify cracking area in soils through digital imagery analysis will be proposed. This study contributes towards filling a major knowledge gap in the understanding of the flow problem at the field scale. The field experiments were conducted on the Savage soil in the Northern Planes Agricultural Research Lab, Sidney, Montana.