Determination of Agricultural Sulfur Effects on the Soil Structure Using Fractal Geometery and Aggregate Stability Indices

Due to unsuitable soil physical conditions, calcareous soils, and the existence of a huge amount of sulfur in the country, the study of sulfur effects on the soil structure and other soil properties is necessary. Therefore, the effects of different rates of sulfur including: 0, 750, 1500 and 3000 kg/ha, when accompanied by Halothiobacillus neapolitanus bacteria, on the soil properties in the corn-wheat rotation in two years were investigated. Parameters of soil pH, EC, sulphate, organic carbon, soil structure and wheat yield were measured. For the quantification of soil structure and quantity evaluation of sulfur effect on the soil structure, with measuring the aggregate size distribution, the mean weight diameter (MWD) and geometric mean diameter (GMD) of the aggregate indices, and the amounts of fractal dimension were determined. The r results indicated that with the progress of the experiment and further application of sulfur along with thiobacillus bacteria, aggregation and aggregate stability were increased. The effect of sulfur treatments on MWD and GMD was significant; based on quantification indices, it had 28 percent positive effect on the soil structure. Sulfur with 3 percent reduction of fractal dimension had a significantly positive effect on the soil structure. Application of sulfur decreased a small amount of soil pH and increased 12 percent of the soil EC and 40 percent of the soil sulphate. So soil structure improvement and reclamation of soil physical condition can be very effective on the soil conservation and sustainability of the production resources and the conservation of environment.