I agree, it’s a tricky balance. Higher yielding first wheats are one of the best margins here but they don’t occur without either a break or a fallow.....That's certainly generally true, Flat 10.
But there may be certain business circumstances, one such example being revealed by the question titled in this thread, where margins can be increased by reducing turnover a bit.
Of course, had that ever been an easy option to adopt, even Carillion might have done it.