Three spring-sown species of lupins (Bora, Prima and Wodjil) and peas were compared in terms of N fixation and subsequent leaching under a following winter cereal crop. Although peas out-yielded lupins (5.4 t compared with ca 3.5 t grain, respectively), the yellow lupin (Wodjil) fixed more N than peas (180 compared with 120 kg N ha-1) and all three lupins contained more protein (> 30%) than the peas (22%). Wodjil was the most effective at suppressing weeds, carrying only 12% of the weed burden found in fallow plots, followed by peas (19%). Winter leaching amounted to > 50 kg nitrate-N ha-1 from under the winter cereal, regardless of whether the previous treatment was a legume crop or was left fallow. There were no significant differences in leaching... |