Wheat yields grain and straw. Is zakat permissible on straw?

Zakat is due on grains at the time of their harvest if they reach the prescribed threshold, based on the Almighty's saying: "And give its due on the day of its harvest." And based on the Prophet's (peace be upon him) saying: "On what is watered by the sky and springs, or what is 'athari' (rain-fed), a tenth is due; and on what is watered by irrigation, half a tenth is due." As for straw, there is no zakat on it because there is no text concerning it, and because its cultivation is not intended for the growth of the land, nor is it commonly utilized. It is a byproduct of the grain and is neither consumed nor stored for eating.