Method for improving tobacco planting soil by returning straw stalks to field

The invention discloses a method for improving tobacco planting soil by returning straw stalks to the field. The method comprises the following steps that obtained straw stalk powder is added into a charging barrel along a feeding hopper, the straw stalk powder is spirally extruded from a discharge port of the charging barrel, so that the straw stalk powder extruded from the discharge port is granulated, and the straw stalk powder is changed into straw stalk granules; a granulating mechanism is mounted on a partition plate, so that the granulated straw stalk particles uniformly fall into fertilization bins on the two sides of a fertilization box; a front wheel shaft and a second gear on the front wheel shaft are driven to rotate, the second gear drives a third gear to rotate through a transmission gear and a first chain, and the third gear drives a material stirring shaft and a fertilizing wheel on the material stirring shaft to rotate; and when the fertilizing wheel rotates, the fertilizer located in an arc-