Remember, soil is like a bucket with limited capacity for holding water. To make sure it has the right amount of water in it we need to somehow determine how much water is left.
There are three common ways to measure / estimate and manage soil water content:
- We can monitor soil (soil-based approach).
- We can monitor micro-climate (weather-based approach).
- We can monitor plants (crop-based approach).
We can also monitor our irrigation system’s output with flow meters, but this will not account for evaporation. Applied water to the soil is a percent of the total water applied through the irrigation system.
Soil moisture readings are useful to determine how much water is available for the crop, when to start irrigating, and how much water to apply.
In weather-based approaches, we estimate how much water is left in the soil. In crop-based methods, basically plants themselves tell us how they’re doing! The core of any plant-based method relies on monitoring canopy surface temperature.
So far, I have primarily focused on the first approach, but I will get into other ways over time.