Effective management of agricultural residues is crucial for enhancing soil properties, providing essential nutrients to plants, and sequestering organic carbon in the soil. With the increasing acreage of maize and sunflowers, which produce significant biomass, effective straw management becomes particularly important. In arid and semi-arid regions, improper incorporation of crop residues into the soil can create challenges in seedbed preparation and increase the need for chemical fertilizers. In this study, maize straw (MS) and sunflower straw (SS) were mechanically shredded to increase surface area and applied to the soil at doses of 0, 0.5, 1, 2, and 4%. The treated soils were incubated for 180 days, after which maize plants were grown in them. At the end of incubation, maize plants were grown in the treated soils. To meet the nutrient requirements during the maize growth period, straw and control fertilization alone were studied with the full dose of 300–80 mg kg⁻¹ Nitrogen-Phosphorus (N-P) (100%) and the half dose of 150–40 mg kg⁻¹ N-P (50%). Accordingly, the effects of the applications on some soil properties and physiological, morphological, and chemical characteristics of the maize plant were determined. At the end of incubation, a significant increase in the nutrient content of the soils, especially P, K, and Mn. Significant differences occurred in the morphological and physiological characteristics of the maize plant, and preliminary results indicated that the dosage of chemical fertilizers could be reduced by 50% when NP is applied together with straw.