Figure 4.4 (a) A field experiment investigating the effectiveness with which a grass buffer strip prevents nutrients applied
to the arable field beyond from reaching the stream. In the foreground the V-notch weir is being used to monitor flow, and
the small shed houses automatic equipment to sample and assess water quality at regular intervals. (b) Results from such experiments
indicate that the majority of the dissolved nitrogen entering the buffer strip is either retained or volatilized, with little
reaching the stream even at relatively high loading rates.