A pot experiment in a plastic house proceeded in 2022 at the Karma Ali site of the Agricultural Research Station, College of Agriculture, University of Basrah, Iraq. The experiment aimed to investigate the impact of mineral sulfur and organic matter addition, leaching requirements, and irrigation water salinity on the physical properties of soil cultivated with Zea mays L. (maize) plants. This study administered two organic residues (cow and alfalfa), three levels of mineral sulfur (0%, 0.8%, and 1.6%), three levels of leaching needs (15%, 25%, and 35%) more than the field capacity, and two levels of irrigation water salinity (4 dSm^-1 and 8 dSm^-1). The organic residues and mineral sulfur mixture with the soil incurred incubation for 60 days. Yellow maize (Zea mays L.) planting followed incubation, maintaining the soil moisture at field capacity fertilization, and carrying out irrigation operations according to the above treatments. Soil bulk density and mean weighted diameter measuring ensued at the end of the experiment. The results showed the ability of organic residues to reduce bulk density and increase soil stability (mean weighted diameter). The decrease in bulk density was more evident in the alfalfa residues, which amounted to 1.25 μg m^-3 soil and 0.62 mm, respectively. The leaching requirement level of 35% exceeded in reducing the bulk density of soil compared with the other two levels, which amounted to 1.25 μgm^-3 soil. The 1.6% sulfur and irrigation water salinity of 4 dSm^-1 reduced the soil’s bulk density and increased the mean weighted diameter of the soil (1.31 μgm^-3 soil and 0.79 mm, respectively).

Keywords: Organic residues, leaching requirements, mineral sulfur, soil bulk density, mean weighted diameter, salinity

Key findings: Using organic residues, leaching requirements of 35%, mineral sulfur addition of 1.6%, water salinity of 4 dSm^-1, and the interactions between these factors in improving the soil’s physical properties proved possible. Alfalfa residue and sulfur excelled in reducing soil bulk density and increasing soil stability compared with cow residue. Moreover, mineral sulfur enhanced the physical properties of the soil.