Why should this be the takeaway from the paper, as opposed to the fact that an additive to the silage can reduce N2O emissions by up to 99%?
Unkess there’s something in it for them that they can’t get by just claiming they’re applying the additive, farmers won’t do it.
There is no industry in the world more allergic to regulation than farming, despite the fact that most of themp farmers in the developed world (and much of the developing world) are heavily subsidised by the city dwellers they complain about.
If that doesn’t work, increase fines and/or add criminal charges and prison.