Mixed papermill residues affect yield, nutritive value and nutrient use ofa grass-alfalfa sward

Mixed papermill residues (MPR) can improve soil quality, but their impact o n forage yield and quality is not well documented. Three MPR were applied t o mixed grass-alfalfa (Medicago sativa L.) sward in 1997 and 1998 at near 1 00, 200 and 400 kg N ha(-1) and were compared to calcic ammonium nitrate (C AN) at 0, 50, 100 and 200 kg N ha(-1) on a Bedford clay loam (Humic Gleysol ). The MPR and CAN induced a significant linear increase in forage DM yield and relative yield (RY). The award response to MPR addition in 1997 was re lated to the MPR C:NH4+ ratio. MPR and CAN increased the forage NDF concent ration in 1998, but there was no effect in 1997. Nitrogen concentration in forage tissues was increased by MPR and CAN inputs in 1997, but was decreas ed in 1998. In all treatments, NO, tended to accumulate in forage tissues w hen the N nutrition index (INN) exceeded the optimum level. Forage nutritiv e value from the MPR was comparable to CAN. The results of this study sugge st that MPR can be an efficient N source for grass-alfalfa swards on fine-t extured soils.