Effect of Nitrogen Topdressing Fertilization and Inoculation of Seeds with Azospirillum brasilense on Corn Yield and Agronomic Characteristics

Abstract

Biological nitrogen fixation and plant hormone synthesis promoted by Azospirillum spp. bacteria play a role in enhancing crop productivity and reducing losses. This may constitute a strategy to enhance crop productivity and reducing losses, thereby increasing nitrogen fertilization efficiency. This research aimed to evaluate the effects of Azospirillum brasilense Ab-V5 and Ab-V6 strain inoculation and nitrogen fertilization on the agronomic characteristics and productivity of two maize hybrids (Zea mays L.) AS 1572 and AG 9030. Experiments were carried out at Santa Maria, RS, Brazil in the 2013/2014 and 2014/2015 growing seasons using a 2 × 2 × 5 factorial arrangement to distribute two maize hybrids, inoculated, or not, with Azospirillum brasilense, and five nitrogen doses (0, 60, 120, 240, and 480 kg ha−1). Kernel yield, mass, and dimensions, as well as kernel number on the cobs, stalk diameter, plant height, ear insertion height, prolificacy, nitrogen use efficiency (NUE), and their correlations were measured. Compared to uninoculated plants, higher kernel yield (p < 0.05) was observed for AS 1572 hybrid when inoculated with A. brasilense, with an increase of 0.978 Mg ha−1 or 10.95%. This effect was primarily due to the higher NUE rate and the increase (p < 0.05) in the number of kernels per cob. The AG 9030 hybrid showed no response to inoculation. A. brasilense inoculation increased the NUE rate of the AS 1572 hybrid in the condition N zero dose at N 60 kg ha−1 dose. Nitrogen fertilization increased crop productivity, notably by raising kernel mass and other productivity components, but reduced the NUE rate. The maximum technical efficiency obtained for the AS 1572 hybrid was of 10.705 Mg ha−1 with a N dose of 342 kg ha−1, whereas the AG 9030 hybrid produced a maximum grain yield of 10.089 Mg ha−1 with a dose of 350 kg ha−1 of N. We conclude that the inoculation with A. brasilense increases NUE, maize grain yield, and agronomic characteristic in the AS 1572 hybrid.

Corn seed inoculation with Azospirillum brasilense in different nitrogen fertilization management

“…Similar results were obtained by Skonieski et al (2019), as they observed that only part of the nitrogen required by the maize crop is supplied by the Azospirillum ssp bacterium . In this case, it was necessary to complement the mineral fertilization of nitrogen.…”

Effects of growth‐promoting rhizobacteria on maize growth and rhizosphere microbial community under conservation tillage in Northeast China

“…Previous studies have shown that PGPR inoculation may enhance crop yields to different degrees, improve soil fertility, and increase absorption and utilization of soil nutrients (Cassán et al ., 2009; Díaz‐Zorita and Fernández‐Canigia, 2009; Singh et al ., 2011). In the warm humid region of Argentina and Brazil, inoculation with different Azospirillum brasilense strains isolated from the maize rhizosphere increased maize grain yields by 5%–11% under no‐tillage irrespective of soil type (Salvo et al ., 2018; Skonieski et al ., 2019). However, it remains unknown whether PGPR inoculation under conservation tillage is beneficial in cold‐climate areas.…”

Inoculation effect of Azospirillum sp. and two levels of nitrogen on the performance of the hybrid corn ‘Insignia 800

“…and nitrogen fertilization in corn. The inoculation with A. brasilense increased Nitrogen Use Efficiency (NUE), maize grain yield and agronomic characteristic in the AS1572 hybrid (Skonieski et al, 2019) but there was no response in another hybrid; the use of this diazotrophic bacterium is viable even when high rates of nitrogen in the form of urea applied to the soil (Galindo et al, 2016). However, Schaefer et al (2019) consider that Azospirillum brasilense helps plant growth and yield but does not replace the effect of N fertilization.…”