Effect of different doses of nitrogen and inoculation with Azospirillum brasilense on the productive characteristics of maize

Abstract

This study assessed the effects of different nitrogen doses on maize crops, with and without the inoculation of Azospirillum brasilense. The experiment was carried out during the 2020/2021 harvest season in the administrative department of Concepción, district of Horqueta, Paraguay, at the coordinates of 23°14'31.7" S and 56°53'05.9" W. The experiment followed a randomized complete block design (RCBD) arranged in a factorial design (4 X 2). Factor A included nitrogen doses (0, 40, 80, and 120 kg ha-1), while factor B corresponded to the bacterial inoculation (with and without A. brasilense). The experiment was performed in three replications; each experimental unit (EU) was 22.5 m2. The study evaluated the following characteristics: plant height, cob insertion height, cob length and diameter, weight of 1000 kernels, and kernel yield. The data were analyzed using analysis of variance (ANOVA), and the averages were compared using Tukey's test at a 5% probability of error. Regression analysis was also carried out during the study. The experiment results demonstrated that increased nitrogen levels positively affected the measured characteristics, fitting a quadratic model, except for cob insertion height. Inoculation with A. brasilense significantly increased corn growth and productivity. The interaction of both factors produced a significant increase in cob length. Based on the experiment results, applying 104.30 kg ha-1 of N in combination with A. brasilense inoculation is recommended for improved maize production.