Fig. 4. Concentration of reduced N in the clippings from perennial ryegrass turf grown with daily N additions (A) or intermittent N additions (B). Arrows indicate intermittent N additions, with long, intermediate, and short arrows representing the 32-d, 16-d, and 8-d additions, respectively. Values are means of three replicates. For clarity, error bars are absent; standard deviation averaged 3%.