Azospirillum brasilense Can Impressively Improve Growth and Development of Urochloa brizantha under Irrigation

Abstract

Development of strategies to ensure grazing systems are sustainably produced in harsh environments, while not fertilizing them conventionally, is challenging. Figuring out the extent to which dose of inoculation and period of watering can positively influence the establishment of an effective symbiosis between U. brizantha cv. Marandu and Azospirillum brasilense is the point of this research. The treatment consisted of mixing 1 kg seeds with the inoculant of the strains Ab-V5 and Ab-V6 at 5, 10, 20, and 40 mL kg−1, 2 × 108 CFU mL−1. The plants grew in pots watered 2, 4, 8, and 16 days after sowing over thirty-days, twice. The bioagent at 5–10 mL kg−1 enabled the plants watered up to 4 days after sowing to peak the production of dry mass of shoots (28.50 g) and roots (12.55 g). The efficiency of the symbiosis goes down quickly with increasing dose and delay of watering. Hence, if the dose of inoculant is higher than 10 mL kg−1, it cannot successfully act in plants watered at least 8 days after sowing anymore. In conclusion, A. brasilense can assist in U. brizantha cv. Marandu growth and healthy development unless a lack of water in the substrate and an overdose collectively deter its potential.

Technological options for establishing pastures and increasing yield and nutrient value forage

“…Faced with this situation, mycorrhizae and nitrogen-fixing bacteria have been proposed as an alternative, as they have been shown to significantly increase the growth and development of Urochloa brizantha grass, which reduces the use of chemical fertilizers (Moreira et al, 2020). Microbial inoculants, also called biofertilizers, have received increasing attention in some countries, gaining prominence and market scale in the agricultural sector (Sánches et al, 2019).…”

Nicotinamida, Azospirillum brasilense e mistura de fitohormônios como bioestimulantes em milho

“…Another biostimulant with potential application in agriculture is bacteria from the genus Azospirillum. These bacteria, classified as diazotrophs, act directly in biological nitrogen fixation and, when associated with the plant rhizosphere, can contribute to nitrogen nutrition (Martins et al, 2012, Moreira et al, 2020, Barbosa et al, 2023. Among the bacteria belonging to this genus, the one with the greatest potential is Azospirillum brasilense, which is present in several inoculants marketed in the country (Mumbach et al, 2017).…”