One of the problems in gardening systems is how to water our garden or farm. There are pumps that fit boards such as the Arduino and Raspberry Pi. The 350GPH liquid pump (https://www.sparkfun.com/products/10455) could be used on your Arduino or Raspberry Pi:

You can also use a higher-voltage pump. To control it from the Arduino, you can use a relay that is connected between the Arduino and the pump. A relay can be connected to digital pins from Arduino. Using  digitalRead() and digitalWrite() we can communicate with Relay from Arduino.