July 8, 2010 by Dr. Richard Stirzaker, Principal Research Scientist, CSIRO Australia
Monitoring electrical conductivity at different depths in soil can sometimes give more information about an irrigation strategy than monitoring soil moisture at the same depths in soils. Because soluble salts (e.g. nitrate) move with the water, nitrate dynamics can provide a prompt signal of over-irrigation; something that is often missed in the interpretation of water content data. Conversely, the accumulation of unwanted salts in the root-zone points to under-watering. In that instance salt leaves behind a signature for us to decipher. When we decode the salt signature we will find that water and solute monitoring interpret each other. But how can a grower or scientist measure the EC levels in different soils?
In this seminar, Dr. Richard Stirzaker, a researcher at CSIRO in Australia, will address measuring electrical conductivity in different soils. Dr. Stirzaker will compare data sets where only soil moisture is used, where both soil moisture and electrical conductivity are used. He will also discuss how the EC measurements are made, the current limitations of the measurement techniques, and the hopes for future measurement technologies
Want to view more? The video below illustrates how water and salts move through soils.
Dr. Stirzaker studied Agriculture Science at the University of Sydney and after working as a research assistant he also completed his Doctorate at the university. He then joined CSIRO in 1990 and is currently a Principle Research Scientist based in Canberra. His current projects deal with irrigation, water productivity and the ecological footprint of agriculture. He also holds an honorary chair in the Faculty of Natural and Agricultural Sciences at the University of Pretoria, South Africa. Dr. Stirzaker recently published the book "The Scientist's Garden," a book written for a wide audience, exploring how the world turns water, sunlight and nutrients into food to feed itself. The book starts in Dr. Stirzaker's own garden and takes a close look at how and why it grows , then moves to stories about the parts soil, river, aquifers and irrigation play in our quest for food. The book closes comparing past agriculture to today's present practices and offers some solutions to some of the big conundrums of modern food production.
Do you have more questions about electrical conductivity in soils? Post your questions on one of our forums and receive answers from Decagon scientists and other user or you can find answers to some frequently asked questions. You can also speak directly with one of our researchers by calling 1-800-755-2751.
Or you can visit the soil moisture sensors product pages to learn more about measuring moisture content and electrical conductivity in soils.