Fig. 5. Comparison of NO3–N concentration in runoff in relation to time of application for watersheds with different fertilization strategies. Dates of N applications are indicated by arrows. Watershed W12 was chosen to represent the five watersheds with similar fertilization for comparison with the control watershed, Y6. (a) W12 with split litter and supplemental N application. (b) Y6 with a single annual inorganic N application.