Soil Water Potential Sensor Research

The beginning of a new engineered soil research program in Chicago 

The CHSTR team has begun a new research program into the water status in engineered or manufactured soils.   We are looking at the matric potential, or more specifically the plant available water in a manufactured planting media.  This is the first phase in what will be a long term extensive research program to study manufactured or engineered soils and their hydrology.

We want you to think of a sponge.  Soak it with water and that is similar to saturating the soil.  As you start to squeeze the sponge, water comes out until you can't get any more out even though the sponge is damp.  This is how the root system in a plant works as well.  It will pull water out of the soil until it reaches a point where it can't get anymore out.  Simple enough right?

The challenge we run into with manufactured soil environments (a blend of ingredients put in place in a landscape) is that we can estimate total water in a soil, but it is difficult to measure how much is available to the plant.  The measurement of how tightly the water is held to the soil is called matric potential. We are looking at using a combination of in field moisture sensors along with matric potential sensors to measure how much water is available to the plant in the soils we are evaluating.  The key here is that the matric potential sensors are a direct measurement of how tightly held the water regardless of what type of soil we look at.

From this we can look further into how these blends are designed, what materials to use and how to optimize drainage and porosity with plant available water in an urban landscape.

We look forward to providing updates through the summer and posting some of our findings along with some background into the technical side of soil physics and hydrology as it applies to landscape horticulture.

CHSTR Team