Optimizing plant growth, nutrient uptake, and yield of onion through the application of phosphorus solubilizing bacteria and endophytic fungi

• Published in: Frontiers in microbiology Vol. 15; p. 1442912
• Main Authors: Arunachalam, Thangasamy, Gade, Komal, Mahadule, Payal Arun, Soumia, P S, Govindasamy, Venkadasamy, Gawande, Suresh Janardhan, Mahajan, Vijay
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 25-07-2024
• Subjects: Microbiology; nutrient use efficiency; onion yield; phosphate solubilizing bacteria; Serendipita indica; soil fertility; vesicular arbuscular mycorrhiza; nutrient use efficiency; onion yield; soil fertility; vesicular arbuscular mycorrhiza; Serendipita indica; phosphate solubilizing bacteria
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2024.1442912

The application of mineral fertilizers deteriorates soil properties and affects crop yield and nutritional properties. However, plant growth-promoting microorganisms (PGPM-
, phosphorus solubilizing bacteria (PSB), and vesicular arbuscular mycorrhizae (VAM)) have great potential to reduce fertilizers and improve soil fertility, crop yield, and nutrient uptake and mitigate the environmental effect of mineral fertilizers.
Hence, a field experiment was conducted involving nine treatments to evaluate the effects of PGPM along with 50% or 100% of the recommended dose of fertilizers on plant growth, soil fertility, nutrient uptake, and onion productivity.
Results indicated that 100% RDF combined with
or PSB led to improved plant growth, and higher nutrient concentrations in both leaves and bulbs of onions compared to RDF alone. Moreover, the application of 100% RDF with
increased total dry matter yield by 11.5% and 7.6% in the 2018-2019 and 2019-2020 seasons, respectively, compared to 100% RDF alone. This treatment also resulted in the highest nutrient uptake, with N uptake increasing by 6.9%-29.9%, P by 13.7%-21.7%, K by 20.0%-23.7%, and S by 18.1%-23.4%. Additionally, the combination of 100% RDF with
inoculation led to a notable increase in bulb yield, with increments of 16.2% and 13.9% observed in 2018-2019 and 2019-2020, respectively, compared to 100% RDF alone. Similarly, the application of 100% RDF along with PSB inoculation resulted in an increase in bulb yield by 7.2% and 9.4% in the respective years. However, VAM did not exhibit satisfactory performance or improvements in the onion crop.
Overall, the study suggests that combining 100% RDF with
or PSB can enhance onion productivity and nutrient use efficiency. The present study may open a new avenue of PGPM application in enhancing onion yield and improving the bulb quality as well as soil health. However, field trials across different regions and soil types are necessary to validate these findings for practical adoption by farmers.