Reed canarygrass forage yield and nutrient uptake on a year-round wastewater application site

Reed canarygrass (Phalaris arundinacea L.) is often planted at wastewater treatment sites to provide ground cover and remove nutrients. Our overall objective was to determine the forage yield and nutrient uptake under year-round potato wastewater application in northern latitudes. Specifically, we determined the effect of N fertilization rate on forage dry matter yield and N and P uptake by reed canarygrass, and compared the forage yield, persistence and nutrient uptake of reed canarygrass relative to those of orchardgrass (Dactylis glomerata L.), smooth bromegrass (Bromis inermis Leyss), timothy (Phleum pratense L.) and quackgrass [Elytrigia repens (L.) Nevski]. With only wastewater application, reed canarygrass had a forage yield of 5.8 Mg ha^-1, with N and P uptake of 113 and 30 kg ha^-1, respectively. Forage dry matter yield, N uptake and P uptake increased to 14.5 Mg ha^-1, 383 kg ha^-1 and 64 kg ha^-1, respectively, with an N fertilization rate of 224 kg ha^-1. Forage yield and N uptake of reed canarygrass, orchardgrass, timothy and smooth bromegrass were similar and exceeded those of quackgrass. Reed canarygrass P uptake exceeded that of the other grasses. Reed canarygrass was less persistent than quackgrass or smooth bromegrass.