Hi, my name is Leo Rivera. I’m the Director of Scientific Outreach here at METER Group. In this course, we’re going to talk about soil moisture release curves. And what we’re going to focus on in this lesson is why they are important. Why do we even want to make these measurements?
What do soil moisture release curves tell us?
As it turns out, they tell us a lot of things. They help us understand a lot of different fundamental properties about our soil that can help us make a lot of decisions.
One they tell us how water is stored in the soil, which is important when it comes to availability of water for plant productivity and when it comes to trying to grow things well. It helps us understand how that property changes with different soil types, because that changes a lot with different soil types.
It can also help us understand things like water and solute movement in soils, which can be really important for understanding the potential for contaminant transport, but also just how water redistributes in the soil as it’s being used or moved due to various things.
So, soil moisture release curves are really key when it comes to optimizing water use for crops, and when it comes to modeling soil hydrology and things like contaminant fate and transport.
When we’re thinking about the importance of moisure release curves and how they help us, especially when it comes to irrigation decisions, we’re looking at things like water content. Water content is nice because it’s really easy to measure, but the soil moisture release curve will help us take that water content measurement and then identify what that means in terms of water potentials, which is what the plant is actually feeling.
You can see here a graph that shows different ideal water potential ranges for different plants and different types of crops. The soil moisture release curve really helps us identify what that will mean in terms of water potential for the plant, so we can optimize our irrigation to keep our water potential within the correct ranges for these different types of crops, which optimizes our production to get the best yields possible.
Another really interesting thing that a soil moisture at least can help us understand is some of the fundamental physical properties about soil. So it turns out that we can actually use the soil moisture release curve to understand things like shrink–swell capacity of soil, which tells us how much it can potentially expand and contract, which can be important when it comes to building roads and foundations, and how the soils can potentially impact those structures. It also can help us make what are typically complex measurements, things like cation exchange capacity and soil specific surface area.
These are things that can actually be modeled through the dry end of the soil moisture release curve. So it turns out there are a lot of really unique and interesting things we can learn about soil just through the soil moisture release curve. And in the next video, we’re going to talk about some of the fundamentals behind making those measurements, and then we’ll hit on some of the tools and the best practices for making those measurements.
