Nitrogen fertilization and inoculation with Azospirillum brasilense in barley

The barley is an important crop in Brazil, mainly due to the use of its grain in the production of beers. The objective of this work was to evaluate the effects of nitrogen fertilization and inoculation with Azospirillum brasilense on barley. The experiment was carried out in the field, using a randomized block design in a factorial scheme, with four nitrogen doses (0, 40, 80 and 120 kg ha(-1)) in the presence or absence of seed inoculation with A. brasilense and three replications. Growth characteristics and dry mass of the plant, production components, N content and grain yield were evaluated. The highest grain yield was achieved with 66 kg ha(-1) of N, without application of the bacteria. It was concluded that the use of A. brasilense increases the yield of barley grains in the absence of nitrogen fertilization, but does not supplant the productivity gain only with the use of N in higher doses. The B. sorokidiana severity was favored by the application of A. brasilense in the highest N doses. The inoculation with A. brasilense is a viable alternative to increase the yield of barley grains, in case of cultivation without nitrogen fertilization.