Utilização de Azospirillum brasilense e doses de nitrogênio no cultivo do azevém

Abstract

In order to reduce the environmental impacts caused by the excess of synthetic products in agriculture, the use of biological inputs has become essential to combine productivity and sustainability in agricultural practice. The objective was to evaluate the effects of treating ryegrass seeds with Azospirillum brasilense cultivated with different doses of nitrogen on the growth of plants with and without cuts during cultivation. The treatments were: T1 - Treatment without inoculation, but with the recommended dose of urea; T2 - the seeds were inoculated with Azospirillum brasilense and the recommended dose of urea was applied; T3 - the seeds were inoculated with Azospirillum brasilense and the dose of urea was doubled in relation to the recommended dose. The ryegrass seeds were treated with A. brasilense and sown according to the treatments, as well as the urea doses. In the plots where no cuts were made, the experimental design used was completely randomized, with three treatments and four replications. The evaluation carried out was the length of the aerial part of the plants 90 days after sowing. The plants were cut close to the ground, in an area measuring 1m long x 0.5m wide. In the other half of the plots, ryegrass plants were cut every 20 days, which characterized a completely randomized experimental design in subdivided plots: 3 (treatments with A. brasilense and urea) x 4 (cuts over time). The aerial part of the plants was measured before each cut in an area of 1m long x 0.5m wide. In the results obtained regarding the cuts carried out, it can be seen that in treatments with the recommended dose of urea with or without the application of A. brasilense (T1 and T2), in cut 4 the ryegrass plants showed greater height. For the treatment with double dose of urea and application of A. brasilense (T3), cuts 2 and 3 are those with the highest plant height. Treatments containing A. brasilense, with the recommended dose and double the recommended dose of urea, stimulate the growth of the aerial part of ryegrass plants, in 75% of the cuts, under the conditions of this experiment. Treatments containing A. brasilense, with the recommended dose and double the recommended dose of urea, do not stimulate the growth of the aerial part of ryegrass plants, grown without cutting, under the conditions of this experiment.