8 billion would buy a lot of cane cutting machines and maintenance support to assign to the growing areas for common use.
As to 'burning', I think human cutters will only cut fields where the standing cane has been flash burned to remove the sharp leaves. Machines will cut as is but what is cut will be heavier and larger in volume due to the redundant foiliage. Paying the grower by weight is a loser for the miller?
Then there remains the stubble which, presumably, the grower burns again before ploughing in.
Is that the process?