The management of plant wastes and the development of soil quality characteristics have a key role in ensuring the harmony of the agriculture cycle with the environment. By adding the straw of plants directly to the soil as a source of organic matter, time poor soil quality characteristics can be improved. In the study, which was planned as a pot experiment, the effects of increasing the addition of sunflowers straw and maize straw by the increased proportions to clay soil. For this purpose, sunflower and maize harvest residue was added to the soil in 0% control (C), 0.5% (SS0.5 and MS0.5), 1% (SS1 and MS1), 2% (SS2 and MS2), and 4% (SS4 and MS4). Compared to the C, the water stable aggregate value increased by approximately 2.2 and 2.5 times in SS4 and MS4 implementations, mean weight diameter values increased approximately 2.7 and 3.3 times, respectively. In SS4 and MS4 implementations, the available water capacity increased by 80% and 102% compared to the control, respectively, and the modulus of rupture values were decreased by approximately 4.1–4.7 times. The 0.5% and 1% doses of straw implementations did not have great effects on the mechanical properties of the soils. According to the results of this study, 4% straw implementations it has been proven that the addition of SS and MS to the soil that by breaking them into small particles have great importance in rapidly increasing the physical quality of the soils and it can be used as an effective agricultural method.