There is an irritation system inside the barn.

It can be used to spread any chemicals you might need during the night.

It is powered by the generator.

Click on the "overnight mist spray irrigation".

Next, you need to enable all the sprinklers. This is a classic puzzle, where enabling a button will enabled all the adjacent buttons, too.

Imagine the buttons are numbered from left to right, top to bottom:

| 1 | 2 | 3 | 4 | | 5 | 6 | 7 | 8 |

Reset, and then: 2,6,7,3

Check out that heap of leaves. Fix the pipe.