I have ordered the following soil moisture sensors for testing:
-Gravity Soil Moisture sensor
This sensor's surface is gold plated using an immersion electrolysis process. Compared to conventional soil moisture sensors, it should last longer. I'm expecting this to last longer than the Grove sensor.
-Gravity Capacitive Soil Moisture Sensor
This sensor uses capacitive sensing to detect soil mositure. I expect this sensor to work the longest.
- Grove Soil Moisture Sensor
This sensor uses a corrosive surface to detect soil moisture using resistive sensing. I expect this sensor will last the least amount of time before corrosion occurs.

Additionally, I have also ordered several mini submersible water pumps from AliExpress.