Fig. 4. Depth profiles of total N and NO₃^––N concentrations in the unsaturated zone and shallow ground water (deepest sample points) for each study site. For total N, bold lines connect the medians, boxes show interquartile range, and whiskers show the total range. For NO₃^––N, fine lines connect the medians, shown as points. The width between the two lines corresponds to the concentration of organic N + NH₄⁺–N + NO₂^––N, which consists primarily of organic N at most locations.