Location:
Golden Jubilee Hall, Civil Engineering Department, IISc
Title: Can we measure soil density with electromagnetic methods? (Poster)
Venue: Offline- GJ Hall, Department of Civil Engineering &
Speaker: Prof. Marco Bittelli, Department of Agricultural and Food Sciences
University of Bologna
Date & Time: 17-05-2022 at 11.30
Venue: Offline- GJ Hall, Department of Civil Engineering &
Online:
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https://sarathygeotech.zoom.us/j/86999104500?pwd=QmtWa2p0QndsRGphaGhpelpDdEtjUT09
Meeting ID: 869 9910 4500
Passcode: 342220
Abstract: Soil density is a very important property both for geo-technical and agricultural applications. For instance, soil compaction increases density, shear strength, bearing capacity and stability of slopes, while in agricultural fields the results of soil compaction from tractors and machinery is often detrimental for root growth requiring tillage. Many techniques are available for measuring soil density, The most common ASTM methods are: the ring and water replacement method, the rubber balloon method, the sand replacement method (ASTM, 2016) and the drive cylinder method. Since these techniques requires sampling or soil disturbance, in many cases only a few data points are collected over the area of interest. Monitoring of bulk density over large areas for geo-statistical analysis requires a fast and effective method allowing for acquisition of many data points. Methods are available in the literature to obtain density from TDR. However, algorithms for simultaneous measurements of density and soil water content are not available. Moreover, the methodologies presented in the literature requires tests and evaluation and uncertainties. In this study we present a new algorithm implemented into a software was developed and the method tested over samples having different textural properties and further analysis of the methodology. It is shown that the method provided a measurement of density with an accuracy between 1 and 3 %. The new algorithm implements an automated methodology combined with a non-linear least square optimization, allowing for analysis of many waveforms at a time. Several equations to derive soil water content from electric permittivity were tested, showing that dielectric mixing models provides more accurate results.
Speaker Bio: Marco Bittelli is Professor of Soil and Environmental Physics at the Department of Agricultural and Food Sciences, of the University of Bologna. Bittelli conducts research in a variety of soil and environmental physics areas, with special focus on the exchange of mass and energy in the soil-plant-atmosphere system, numerical modelling in the earth sciences, non-linear processes and electromagnetic methods in ecosystems. He published 75 papers in peer-reviewed international journals, 9 book chapters, 3 books and he participated in many national and international research projects. He served as associate editor of Vadose Zone Journal and he has been editor of the journals Measurement Science and Technology, Geophysics and Water. Information can be found at: www.marco.bittelli.it
