Improving Sustainable Field-Grown Wheat Production With Azospirillum brasilense Under Tropical Conditions: A Potential Tool for Improving Nitrogen Management

Abstract

Sustainable intensification of cropping systems requires to increase productivity and nutrients use efficiency while reducing negative impacts of agricultural management practices on ecosystem and environment. Plant growth-promoting rhizobacteria (PGPR) inoculations are considered one of the most promising and safe strategy to alleviate environmental alterations in context of climatic extremes to improve plant nutrition while reducing dependency of nitrogen (N) fertilizer application. This study investigated the interactive effects of N levels and inoculation with A. brasilense on plant biomass, grain yield, agronomic efficiency (AE) of applied N, apparent N-fertilizer recovery (AFR) and N content in plant targeting economic feasibility of wheat production system. The field trial tested 4 N application levels applied in side-dressing (control, low, average and high; named 0, 50, 100 and 200 kg N ha−1) and two inoculations (without and with A. brasilense seed inoculation). The results exhibited that inoculation with A. brasilense enhanced AE, AFR and N uptake in wheat plants with increased root and shoot N accumulation and grain N accumulation under average and high N application levels. In addition, inoculation increased root and shoot biomass, leading to a yield increase of 10.3% compared with non-inoculated plants. Wheat plant inoculation associated with application of the average N level provided the greatest profitability. Furthermore, results showed that reducing N fertilization from 100 to 50 kg N ha−1 along A. brasilense inoculation led to an increase in operating profit of 10.5%. In view of low economic cost, ease of application, and high probability of a positive response by wheat crops, even associated with different N application levels, the inoculation with A. brasilense prone to be a key sustainable management practice to improve wheat production under tropical conditions. This practice has the potential to increase wheat grain yield, N use and uptake, and overall farm profitability.

Overview of biofertilizers in crop production and stress management for sustainable agriculture

“…significantly enhanced the growth of Arachis hypogea plant, protects plants from stress, and exhibits the production of ammonia and IAA (Gohil et al, 2022). Azospirillum brasilense reduces N fertilization, improves plant nutrition, and increases plant biomass and wheat grain yield as reported by Galindo et al (2022).…”

Isolation and characterization of local Azospirillum and yeast strains to be used for wheat grains inoculation to improve plant growth and yield under field cultivation

“…Backer et al, (2018) show that inoculation with PGPR is considered one of the most promising and safe strategy and it has quite significant role in alleviation of environmental changes under the context of climate extremes and excessive use of fertilizer in agricultural soils. As well as Galindo et al, (2022) said that the inoculation of these microbes is recognized as one of the best and alternative strategy for ecofriendly crop-management techniques as it could improve plant nutrition on other hand reducing the dependence of N 2 fertilizer application.…”

“…Azospirillum brasilense has been reported to promote plant growth by increasing the production of phytohormones like gibberellins, auxins and cytokinins (Fukami et al, 2018, andGalindo et al, 2022). Santi et al, (2013) showed that phytohormones produced by bacteria thus enhance root branching and root elongation, which in turn favour the uptake of soil water and minerals and has a positive effect on plant growth, and Gibberellin produced by Azospirillum was found to play an important role in the early stages of plant growth in Graminae by enhancing shoot and root growth and increasing root-hair density.…”

Regulatory Mechanisms of Plant Growth-Promoting Rhizobacteria and Plant Nutrition against Abiotic Stresses in Brassicaceae Family

“…Plants and microbial communities are the components of similar limited resources with a different relationship. However, plants assist microbial communities with available nutrients from the soil rhizosphere [ 18 ] and improve nitrogen mineralization, which can enhance the uptake of other nutrients for a higher performance and yield of plants [ 19 ]. The positive association (symbiosis) and negative association (pathogenesis) of the plant rhizosphere microbial community can affect nutrient availability and resource partition, thus increasing or reducing crop production, respectively [ 18 , 20 ].…”