Rice straw is very tenacious when it comes to rotting down, it takes it years to turn to
compost, as Jan mentioned Fukuoka san used what he had on hand and he alternated not only the "mulch" material but also the field for planting, that allowed for multiple layers of mulch materials that alternated.
He used chicken manure because those were the animals he grew that allowed him to gather up the manure easily.
As far as using the straw from the same plant, Nature would not alternate planting spots, the wheat seeds would drop to the soil and the straws would fold over and lay on top of the seeds waiting for the germination conditions.
Redhawk