I'm not sure if anyone actually polices it really - there always seems to be loads on the roadsides and I don't think the councils ever get in trouble.
IMHO, prisoners should be chained together to go and pick the dam stuff - I don't pay taxes so they can watch TV!!!
I'm not sure about in the fields but the councils by law have to remove Ragwort from roadsides, we had loads growing around us (on the roadside) We spoke to Citizens Advice and they told us the counil have to remove it, we wrote them a letter and they did. It keeps coming back but they come and spray it each year before it seeds. Sorry can't be more help, maybe call Citizens Advice they were great with us.
This Defra guidance document from which the following is taken may be helpful.
[ QUOTE ]
The Natural Environment and Rural Communities Act 2006 delegates the
functions available to the Secretary of State under the Weeds Act to Natural
England, a Defra agency. This delegation of functions enables Natural England
to investigate complaints where there is a risk that injurious weeds might spread
to neighbouring land. Natural England gives priority to investigating complaints
where there is a risk of weeds spreading to land used for grazing horses or
livestock, land used for forage production and other agricultural activities.
Last year I reported a local land owner to Natural England but they did not do anything because I had not spoken to the land owner myself. I did not actually know where he lived as it was a building plot so couldn't contact him.
I would suggest you put your concerns in writing to the land owner giving a deadline for the ragwort to be removed, if it isn't done, then report it.
I did it again this year to a different land owner (developer bought land and sold it to various people as plots, all left to go to ruin) this time it was cleared within a week.