Elucidating the PGPR and nitrogen fertilization effects on growth and physiology of early and late maturing varieties of Arachis Hypogaea

Abstract

To enhance crop productivity and meet the increasing demand for food, the use of nitrogen fertilizers has become widespread. However, excessive nitrogen application can lead to environmental pollution and also increase the agricultural production cost. To minimize this excessive usage, a strategy is being devised which can limit fertilizer usage and is eco friendly.Through this study usage of PGPR is suggested along with limited nitrogen use to optimize or initiate the natural process of biological nitrogen fixation. This initial small amount of nitrogen will help in starting the BNF while pgprs will help in establishing this symbiotic relationship between plant and bacteria. The ideal choice for this experiment is a plant with the capability to biologically fix nitrogen, making the peanut plant a prime candidate. As a member of the legume family, peanuts exhibit this nitrogen-fixing ability. Moreover, peanuts are globally significant as an oilseed crop. In summary, this study seeks to investigate the impact of Plant Growth-Promoting Rhizobacteria (PGPR) and various nitrogen ratios on peanut plants, both in a controlled greenhouse environment and in actual field conditions. Two peanut varieties, NARC 2019 and BARD 479, were subjected to various treatments combining PGPRs from two different sources and two nitrogen ratios (15 kg N/ha and 30 kg N/ha). The morphophysiological, biochemical and phytochemical traits were measured. Also the effect of treatments on metoabolite were also analyzed through GCMS of root exudates, lastly the best results were also examined in field. All morphophysio traits show improvement after subjecting to nitrogen and pgprs. Amomg the nitrogen ratios all traits show highest performance at 30 kg N/ha. But incase of pgprs, both of them have shown enhancement in triats.Incase of root fresh and dry weight,length and total phenolic and flavonoid content, PGPR 2 outperformed PGPR 1 while in other trait PGPR 1showed better results. The results revealed that both nitrogen ratios did not induce stress in the plants, as evidenced by the absence of significant enzyme production. Moreover, the combination of PGPRs and nitrogen significantly enhanced plant growth across all treatments. A significant change in metabolite profile was observed in root exudates especially of plants treated with PGPRs as compared to control. Almost similar trend of result observed in field data as was found in glasshouse. Overall the treatment using PGPR1 with 30 kg N/ha yielded the most remarkable results, suggesting its potential in promoting substantial plant growth. Our findings highlight the importance of adopting sustainable practices in agriculture to minimize nitrogen pollution. By promoting biological nitrogen fixation and harnessing the beneficial effects of PGPRs, we can optimize plant growth without causing stress. This approach holds promise in ensuring sustainable crop productivity while preserving the ecological balance. Embracing these practices can contribute to a healthier and greener environment, securing food security for future generations.