Yeah it's Ok for you guys in the huge North American continent.
You have to remember that the Uk is only the size of Centra Park
In the Uk I think you'd be relatively ok on farmland once the corn (that's wheat to you colonials
) has been cut, especially if there is a public right of way. Or on common land.
Of course you need to watch out for people, dogs, sufficent overshoot etc.
To satisfy the legal question of sufficient reason to be there you can show your EWBS or NFAS memebership etc and say you are testing a bow... look officer I've only brought 3 arrows
On the rare occasions I do it, I generally take very few arrows and immediately unbrace and pack up if I see people. I suspect the average policeman would be interested rather than stroppy as long as you approach him in a friendly manner. I find that approaching someone can often defuse the potential confontation.
If you think shooting is tough, try persuading some old biddy that you want a limb off her Yew tree and you are not either a con man or a mad chainsaw weilding psychopath
Del