Most simple automatic watering systems either use no sensing or just a rain sensor to control to the hose valve. While this will suit most simple cases, our garden has two requirements which need a more complicated system!

1. Manual watering. The garden society members must be able to manually water the garden if required. One of the benefits of the student garden is that it can be a mental health asset, and watering can be a tranquil and calming task so it is important to still allow students to pick up a watering can or hose and tend to the plants. If the automatic system did not detect this then there is a good chance that the plants could become waterlogged and damaged. Because of this, we will need soil moisture sensors. These sensors are the ideal solution anyway, as they more directly measure the water present at the plant root.
2. Technology expectations. This is an 'Internet of Things' garden and so must meet expectations of being pretty wow in the tech department! Also, as we hope the project will be handy for others, we want to try and implement a range of sensors which may be more useful in other gardens or crops. Therefore, we will try and incorporate thermometers, soil moisture sensors, wind sensors, rainfall sensors, light sensors, humidity sensors and probably CO2 sensors for the polytunnel.

Stay tuned for more information on our choice of soil moisture sensor coming soon!