In conservation plowing why are dead weeds and stalks of the previous year's crop left in the ground?

In conservation plowing, dead weeds and stalks from the previous year's crop are left in the ground to enhance soil health and reduce erosion. These residues act as a protective layer, minimizing water runoff and wind erosion while improving soil structure and moisture retention. Additionally, they provide habitat for beneficial organisms and contribute organic matter as they decompose, enriching the soil with nutrients for future crops.