This study investigated the effect of rate and type of organic matter, and consecutive application of sodium on secondary particle size distribution. At first, a cropland soil was treated with two organic matter (manure and straw stubble) at different rates of 0%, 1% and 5%, with three types replicates during 4 months. Subsequently, four levels of SAR (0, 1, 10 and 30) were added to the pretrea...