Hello amigo!
This is exactly quoted from Claude Money: "For me, a landscape does not exist in its own right, since its appearance changes at every moment; but the surrounding atmosphere brings it to life - the light and the air which vary continually. For me, it is only the surrounding atmosphere which gives subjects their true value."
So to me in my own words, painting in a field instead of the studio gave him more inspiration for his work.
Happy to help and let me know if you have further questions!
~Brooke❤️