Most probably being grown as "an energy crop", pulverised during harvesting and then carted along a totally inadequate road system to an anaerobic digestion plant near Mepal, see http://www.geograph.org.uk/photo/4685713
Uploaded to Geograph by Richard Humphrey on 15 October 2016
Photo © Richard Humphrey, 15 October 2016. Licensed for reuse under this Creative Commons licence