Nitrogen fertilization and rhizobium inoculation in common bean cultivated after corn intercropped with palisade grass

Abstract

The objective of this work was to evaluate the effect of nitrogen (N) doses and Rhizobium tropici inoculation on common bean grown under no-tillage system, after second-crop winter corn intercropped with Urochloa brizantha (Syn. Brachiaria bryzantha) or Urochloa ruziziensis (Syn. Brachiaria ruziziensis). Two experiments were performed during two agricultural years, on a dystroferric Haplorthox. A randomized block design was used in split plots, with four replicates. The plots were constituted of absence or presence of seed inoculation with R. tropici, and the subplots were constituted of four N doses (0, 35, 70, and 140 kg ha^-1). Evaluations were made for the number of nodules per plant, nodule dry matter, N-leaf content, shoot dry matter, shoot-accumulated N, number of pods per plant, and grain yield. The evaluated variables were not affected by seed inoculation with R. tropici. Increasing doses of N fertilization decreased nodulation, and increased dry matter yield, N content and N accumulation of common bean aerial parts. Common bean grain yield was little influenced by N fertilization.