Maize yield under Urochloa ruziziensis intercropping and previous crop nitrogen fertilization

Abstract

Maize intercropping with forage crops and N under no-tillage management have led to discrepant results regarding the impact on crop yield. Therefore, understanding various production systems is necessary to assist producers in decision making. The aim of this experiment was to evaluate whether maize (Zea mays L.) intercropping with Urochloa ruziziensis (R. Germ. and C.M. Evrard) Crins promotes differences in the agronomic performance of maize and if split top-dressing N fertilization in the previous crop (common bean [Phaseolus vulgaris L.]) promotes increase in maize agronomic performance. The experiment was conducted during two agricultural years in southeastern Brazil, with treatments arranged as a split-plot fitted in a randomized block design, with four replications. Main plot was cropping systems (two systems - maize sole and maize intercropped with U. ruziziensis) while subplots comprised 10 combinations of split top-dressed N applications, totaling 90 kg ha−1, applied to the previously cultivated common bean crop. Regardless of the agricultural year, intercropping with U. ruziziensis sown simultaneously with maize reduced maize yield by 12% on average. Intercropping maize and U. ruziziensis increased soil coverage from an average of 64–100% over maize as an only crop. The agronomic performance of maize grown in sole crop or intercropped with U. ruziziensis was not influenced by the effect of top-dressing N fertilization applied in common bean under no-tillage as previous crop. Intercropping maize with U. ruziziensis is a viable option for producers seeking improved soil coverage or grazing opportunities, however, caution is needed since maize yields may be reduced.