Self-Care Urban Nursery Concept - 1.0

Actually want a bit of advice before my parts get here. I will edit this later on as i build and improve on The SCUNC. From the breadboard sketch, can anyone see an error in being able to, via RPi2, monitor soil moisure, when it drops below a certain amount turn on a pump motor to run an irrigation system, and turn it off again after a period of time? Any help would be greatly appreciated. I am a bit of a noob as i haven't worked with electronics since high school.