It is the same where I am, a bit south of you, what I have noticed it is the Chow Bann, villagers, that burn the roadsides not the authorities, and if you notice it is done early evening time, all the local government staff would have gone home by then.
Also in our area, our sugar mill has been open for 1 month not seen a load of burnt cane go to the mill yet. and last year our local mill received 1.5 million ton of cane, very little was burnt.
But ,no such thing as a free lunch, our cane is now cut by machine, secondhand ones imported from Australia and Brazil, a local guy we know has 500 rie of cane ,he showed me his diesel bill, for the most of last season was 100 000 baht ,most of that was fuel for his cane cutter ,he rest was haulage costs for trucks and trailers hauling cane to the mill ,hardly Enviornmental friendly, for the cane cutter, I now see a procession ,cane cutter going down the road ,followed by a truck and trailer ,then a tractor towing a large diesel cart,.............before it would have been the cost a box of matches.