I read the discussion about output nutrient retention at NDR Output: Conceptual Understanding - #2 by jesseG @jesseG.
the solution was to calculate the raster result “modified_load_n ” MINUS “n_export.tif ” to get the nutrient retention service. My question is about values in water bodies, if it is nutrient retention then it could be zero value in the water, but in my results the water has a value greater than zero.