Fans of the manure system, here is an essential mod. Slurry tanks are very practical for storing on the edges of fields. LucaModding is releasing, on the same principle, a flexible tank from 105.000 to 240.000 L and its transport trailer. The idea is simple, you buy the tank + the trailer. You deploy everything (be careful to level the ground before, see in the video). And you can start filling with the help of slurry tanker or cistern. Storage is important and will allow you to fertilize large plots.
The Manure System is only available on PC, and therefore the flexible tank too. I strongly advise you to watch the overview video before using it. It clearly shows all the steps to follow to put everything in place correctly.