Earlier this week, we went outside on a cold and windy day to tested a soil moisture sensor one of our volunteers, Brandon Miranda, has been designing. The equipment and some of the coding needed to build the sensor came from the Philadelphia Water Department. Brandon has been edited the code for the soil moisture sensor to customize the device for our garden.
Brandon ran a test to see if the soil moisture sensor is able to measure the amount of water in the soil. Brandon then took a container full of soil to continue running tests with. It was difficult to run tests at this point because the soil was frozen due to the cold weather we have been having.
Once the soil has thawed, Brandon plans to plant some seeds in the container, and keep the soil moisture sensor in the container as the plant grows. He will water the plant whenever the sensor data shows the moisture level is low. If the plant grows and remains healthy, we will start to use the sensor in our soil beds outside.
Brandon’s goal is to use the monitor to help us know when we need to water the plants when they start to grow again in the spring. Sometimes, the topsoil may seem wet enough while the soil where the plants’ roots are need water. The soil moisture sensor will measure the amount of water at that deeper level of soil, and save data onto either an SD card or directly to a laptop if the laptop via an arduino is connected to it. An arduino allows you to program and code sensors.
Eventually, we hope to use the soil moisture sensor as a way to test whether the soil is too dry for the plants or not. That way, we will not underwater the plants when the topsoil is wet or overwater when the topsoil is dry, but the deeper soil is wet.