The manuscript should be revised accoording to the comments of the reviewers and the reply by the authors. Particular points of attention are: - the background of the data sets, - the differences between the study areas, - the representativeness of the study areas and the results, - clearification and motivation of the used statistical methods.

The comments of the reviewers are satisfactory processed in the revised manuscript and the reply.
1. Before accepting the paper I like to see a justification of the calculated loads. In 2.4 it is stated: 'DOC and DON concentrations were linearly interpolated between sampling occasions' (line 220 in the revised manuscript). This seems illogical because the concentration data don't show autocorrelation (lines 230-232). If concentrations are really uncorrelated, it might be better to use the mean value. However, I guess that although you didn't find autocorrelation in the data (fortnightly), autocorrelation does exists at a smaller time scale. At a small time scale the concentrations is expected to be continuous. This might justify the interpolation. If concentrations and the discharge are correlated (lines 309 - 310) the interpolation might induce bias.
2. Technical correction: Maj should be May (line 122)