Steve. FYI
https://fullfact.org/economy/farming-subsidies-uk/

I see that Rachel Carson's SILENT SPRING is available as a pdf.
I highly recommend reading it. Over 55 yers old but still relevant. It made a deep impression on me back in 1964 when I first read it.
How many lessons are still to be learnt?

An interesting study vaguely related to the thread
http://www.sciencedirect.com/science/article/pii/S2095809917301583 '