Previous research at the site indicated that the occurrence of
surface runoff was rare (McDowell and Monaghan, 2014). Indeed,
none has been measured in the 2 years prior to the present work.
Subsurface drainage was intercepted at 35-cm by 60 Teflon suction
cups (MacroRhizon, Rhizosphere Research Products, Wageningen,
The Netherlands) installed in May 2012 at a 45
angle to a depth of 35-cm and arranged in 5 replicate (5 m2) plots of each treatment.
Each replicate contained 4 cups each spaced 1-m apart. The cups
were confirmed as not sorbing orthophosphate prior to installation
and were located above the water table.