The researchers used satellite images and field data to predict total phosphorus levels in wetland soils. They compared two models, block kriging and regression kriging, to see which was more accurate. The block kriging model had an R2 of 0.59, while the regression kriging model had an R2 of 0.49. Both models showed similar spatial patterns, but the block kriging model performed slightly better. The regression kriging model using Landsat ETM+ images helped capture unique landscape features in the study area.