N-USE EFFICIENCY, YIELD AND QUALITY IN MAIZE-WINTER BARLEY ROTATION

Abstract

The aim of this work was to evaluate the effects of three nitrogen fertiliser levels (0, 100, 200 kg N ha - 1 ), supplied only to maize crop, on N uptake, N retranslocation and productive performances of maize and the following winter barley crop, as residual effects. The nitrogen applied to maize significantly influenced grain protein and N uptake in maize; yield, grain protein and N uptake in winter barley, whereas no significant difference between N fertilised plots in both species were found. Postanthesis N uptake were significantly higher in N treatments for maize and winter barley, whereas no significant difference between N fertilised plots and control for N retranslocation were observed. Soil mineral N deficit at the end of cropping system was higher in the intermediate N fertilization level then in the highest one, indicating that only the 100 kg N ha - 1 treatment utilised all applied and mineralised N. Therefore, the intermediate N level seems to ensure a good balance among yield, quality and N utilisation of maize and barley, with smaller risks of nitrogen leaching.