Straw is a material used in compost, clothes and more. It can be picked up from threshed wheat which is obtained by using a straight branch or small curved branch on a wheat sheaf. Combining with clay makes adobe. Combining two straw makes a Basket. Sewing with Needle and Thread makes a Straw Hat. And most importantly, adding a Bowl of Mashed Berries and Carrot will start a Dry Compost Pile.
Note: Once removed from the threshed wheat, Straw will decay after 4 minutes.