NITROGEN-USE EFFICIENCY OF POPLAR SRC FERTILIZED WITH CATTLE SLURRY

摘要

In Regions characterized by intensive livestock activities, animal slurries are predominantly applied tornmaize and there is the need to identify alternative crops, suitable to receive slurry applications, in areas unsuited tornmaize cultivation. This study addresses the following research questions: i) what is the effect of cattle slurryrnapplication on poplar productivity? (ii) does poplar use efficiently the N applied in the form of cattle slurry? Tornexplore these questions, a field experiment was carried out over 5 years in the low Po Valley, Northern Italy.rnFertilization treatments annually applied were: i) no fertilization (control); ii) cattle slurry 10 mm, i.e., 10 L m~(−2)rn(CS10); and (iii) cattle slurry 20 mm, i.e.,20 L m~(−2) (CS20). The N-use efficiency was assessed by joint evaluation ofrnthree indices: the physiological efficiency of applied N (PEN) was 109 kg yield DM per kg N uptake; the recoveryrnefficiency of applied N (REN) was 0.08 kg N uptake per kg N applied; and the agronomic efficiency of applied Nrn(AEN) was 7 kg yield DM per kg N applied. The low values of AEN and REN indicate that poplar is not a first choicerncrop for cattle slurry fertilization.