Nature's Gift: Unlocking the Power of Local Microbes to Boost Peanut Yields Dr Amrita Sengupta

Introduction: Peanut is a crucial food and oilseed crop in India, occupying around 54.2 lakh hectares annually. It significantly contributes to India's economy and food security by providing essential nutrients. Peanut's ability to fix nitrogen enhances soil fertility, making it a valuable soil-enriching crop. However, the overuse of synthetic fertilizers in modern agriculture has led to environmental and health issues. To address this, there is growing interest in sustainable practices like using beneficial rhizobacteria to promote plant growth and reduce reliance on chemical inputs. (Losacco et al., 2021) (Wilson, 2000) (Sandhu, 2021) (Mabrouk et al., 2018) (Zambrano-Mendoza et al., 2021)

Importance of Rhizobacteria for Peanut Productivity:
Rhizobacteria are a group of bacteria that colonize the root zone of plants and confer numerous benefits, such as enhancing nutrient availability, producing plant growth hormones, and protecting against pathogens. In the case of peanut, these rhizobacteria play a vital role in facilitating biological nitrogen fixation, a process that converts atmospheric nitrogen into plant-available forms. Rhizobacteria can enhance plant nutrition, yield, and soil fertility as bio fertilizers, making them a promising alternative to synthetic fertilizers. (Nosheen et al., 2021) Research has demonstrated the benefits of rhizobacteria on groundnut, highlighting their potential for sustainable peanut cultivation. However, the capabilities of newly isolated rhizobium strains as groundnut bio fertilizers are not well understood. Investigating these novel strains could provide insights for developing effective bio fertilizer solutions.

Challenges and Findings: My research endeavor was focused on identifying and characterizing highly efficient rhizobacteria strains that could significantly boost peanut yields, a critical challenge in addressing the growing demand for this essential crop. In a research study, I investigated the potential of native rhizobacteria isolated from peanut-growing regions of West Bengal to improve peanut yields.

Isolation and Evaluation of Rhizobial Strains for Peanut:
My research journey began with the isolation and characterization of rhizobial strains from the root nodules of peanut plants in the fields of West Bengal from varied agro-climatic regions, a major peanut-producing region in India. The goal was to identify rhizobial isolates with superior nitrogen-fixing ability, that could potentially enhance peanut productivity in a sustainable manner.
Through extensive fieldwork and laboratory analyses, we successfully isolated and identified several rhizobial strains with promising characteristics.

Greenhouse and Field Trials: Evaluating the Potential of Rhizobial Inoculants:
To validate the effectiveness of the isolated rhizobial strains, we conducted a series of greenhouse and field trials. In the greenhouse experiments, peanut plants inoculated with the selected rhizobial strains displayed significantly enhanced growth parameters, such as shoot length, root length, and biomass, compared to uninoculated control plants grown under pot culture experiments.

The field trials were carried out in government research farms, where we compared the performance of peanut crops inoculated with our rhizobial strains to those receiving conventional chemical fertilizers. The results were extremely encouraging, with the rhizobial inoculation treatments consistently outperforming the chemical fertilizer plots in terms of peanut pod yield, quality, and overall plant vigour. (Weselowski et al., 2016) (Nor, 2020) (C. et al., 2019)

Discussion:
The research extensively characterized native Rhizobium isolates through biochemical, morphological, and genetic analyses. The isolates displayed remarkable metabolic versatility, enabling them to thrive in the rhizosphere. Molecular identification confirmed their classification within the Rhizobium genus. Pot culture experiments demonstrated the positive effects of the Rhizobium isolates on peanut growth and nitrogen fixation. (Dey et al., 2004) (Sinharoy et al., 2024)

The newly isolated rhizobia strains were as effective as commercial strains in providing nitrogen to peanut plants. The pot culture experiment showed the superior performance of novel rhizobium NRA1, which exhibited the highest nodulation, nitrogen fixation, and plant growth. (Rhijn & Vanderleyden, 1995) (Sinharoy et al., 2024) (2024) The native rhizobium NRA1 displayed enhanced rhizosphere competence compared to known Rhizobium strains. Field trials further validated the effectiveness of rhizobial inoculation in enhancing peanut yields.

Impact and Implications:
The findings of my research have far-reaching implications for sustainable peanut production in India. By harnessing the power of native rhizobial strains, we can significantly enhance peanut yields in a cost-effective and environmentally friendly manner, reducing reliance on synthetic fertilizers.
The successful development and deployment of these rhizobial biofertilizers can lead to several benefits:

1. Improved Peanut Productivity: The use of elite rhizobial inoculants can boost peanut yields by up to 20-25%, ensuring better food and nutritional security.
2. Enhanced Soil Health: The nitrogen-fixing ability of the rhizobia can enrich soil fertility, reducing the need for chemical inputs and promoting long-term soil sustainability. (Gopalakrishnan et al., 2014)
3. Reduced Environmental Footprint: By minimizing the use of synthetic fertilizers, we can mitigate the negative environmental impacts associated with their overuse, such as water pollution, greenhouse gas emissions, and disruption of soil ecosystems.
4. Economic Benefits for Farmers: The adoption of rhizobial biofertilizers can lower the input costs for farmers, improving their profitability and livelihoods.
5. Scalable and Adaptable Technology: The rhizobial strains isolated in this study are native to the local peanut-growing regions, making them well-suited for widespread deployment across the state and potentially other parts of the country.

Conclusion:
This research has demonstrated the significant potential of native rhizobial strains to enhance sustainable peanut production in India. The successful development and deployment of these rhizobial biofertilizers can lead to improved peanut productivity, enhanced soil health, reduced environmental impact, economic benefits for farmers, and a scalable and adaptable technology that can be widely adopted across the peanut-growing regions of the country. The findings of this study have far-reaching implications for the future of sustainable agriculture, showcasing the power of harnessing the capabilities of native microorganisms to revolutionize crop cultivation practices.

Dr Amrita Sengupta
Deputy Director of Agriculture (Personal), Department of Agriculture, Government of West Bengal, overseeing extension services and policy implementation to enhance Agricultural Productivity and Farmer Welfare.
PhD in Agronomy with expertise in microbial intervention or bio fertilizer related research.



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