Wetting and drying induce stresses in soil which changes the physical structure of the soil. For this reason, the effect of this process on evaluating the methods for estimating the threshold of compactibility (load-bearing capacity, pre-compaction stress) of a coarse textured soil (sandy loam) collected from the fields of the Sugarecane and By-product Development Co. in Ahvaz province was studied. In this research, the plate sinkage test (PST) and confined compression test (CCT) methods were evaluated. Large air-dry disturbed soil samples were prepared and some of them were exposed to five wetting and drying cycles. After that, the large soil samples with/without wetting and drying cycles were compressed under three loads (0, 100 or 200 kPa) and then the centre section of the preloaded soil samples was firstly submitted to PST. Then immediately one cylindrical sample was cored for CCT. The results showed that for the soil samples without wetting and drying process, there was no significant difference between the applied load and the estimated values using PST method. However, for the soil samples under wetting and drying process, the obtained values were significantly greater than the applied loads. Therefore, for tilled soil, PST can be used as a quick method to determine the compression parameters of the soil in laboratory or in the field.