Wouldnt be much different than running a dripper on a timer unless you have some really innovative method of detecting a perfect watering, itd require more components and probably not be as reliable. If doing anything with maybe log humidity/temp stats, and arduinos are kinda outdated and limited. Id look into raspberry pi. SmartPlantPi - Raspberry Pi Plant Watering and Environmental Kit - SwitchDoc Labs
Wow! Thats a lot of moving parts for auto watering. Personally, I love my blumats....gravity fed watering as the soil dries at a certain depth to maintain consistent level of moisture. They take a little bit to get used to and a bit more expensive depending how you set it up though totally worth it as the system uses no electric