Here is some info about startup
wiki on the chemical in start up
link to a publication by Monsanto on startup
A few highlights:
The median half-life of glyphosate in soil ranges between 2 and 197 days; a typical field half-life of 47 days has been suggested. Soil and climate conditions affect glyphosate's persistence in soil. The median half-life of glyphosate in water varies from a few days to 91 days.[24]
ATTENTION: AVOID CONTACT WITH FOLIAGE, GREEN STEMS, OR FRUIT OF CROPS, DESIRABLE PLANTS AND TREES SINCE SEVERE INJURY OR DESTRUCTION MAY RESULT.
I personally would have nothing to do with any organic matter that was sprayed with startup. If the canola was sprayed with startup than it is probably genetically modified to have the 'round up ready gene'. I would think that any non organic straw would be tainted to some degree, and maybe even some organic straw if used while there are still fertilizer residues on it.