Soil salinity in the Yellow River Delta affects agriculture. Researchers studied soil salt levels in a maize field at different scales. They found that soil salinity varied moderately across the field, plot, and ridge scales. As the sampling scale decreased, soil salinity variability increased. Soil salt content decreased with micro-topography from high to low, and vegetation coverage changed from sparse to dense. The distribution of soil salinity at small scales was different from large scales, showing a clear scale effect. The optimal models for predicting soil salinity were influenced by structural and random factors.