Nitrogen fertilization and inoculation with diazotrophic bacteria in corn intercropped with xaraés grass

The objective of this work was to evaluate the effect of nitrogen (N) fertilization doses with and without inoculation of seeds with Azospirillum brasilense in fall corn intercropped with Urochloa brizantha cv. Xaraés over the nutrition, the production and yield components of the corn crop, and the dry matter yield and crude protein levels of xaraés grass under irrigation in the Cerrado region. The experiment had a completely randomized block design with four replications in a 2 × 5 factorial scheme. The treatments consisted in inoculating or not the corn seeds with A. brasilense and five N doses (0, 30, 60, 90 and 120 kg ha-1 N). The inoculation of corn seeds with A. brasilense in intercropping with xaraés grass in the fall season increases nutrition, height growth of plants and corn production components, however, without effect on grain yield. Corn plants from seeds inoculated with A. brasilense lead to a lower production of dry mass of xaraés grass in intercropping. Nitrogen fertilization in the cover layer linearly increases the crude protein content of the xaraés grass up to the dose of 120 kg ha-1 N.