With the yearly rise in human population and the resulting increase in demand for food production and supply, a significant threat to food security is growing(Santhosh Kumar et al., 2018). Farmers have been using synthetic chemical fertilisers excessively to achieve high crop production in order to meet the rising food demand. However, excessive use of chemical fertilisers degrades soil quality by turning it excessively salty and biologically inert, which has detrimental effects on both the environment and human health. Additionally, it causes eutrophication, soil acidification, weakens plant roots, and an increase in disease occurrences. Due of all of these detrimental effects, employing chemical fertilisers has become into(Mma & Mfm, 2014). Given the adverse effects associated with chemical fertilizers, it has become crucial to adopt eco-friendly alternatives such as compost, farmyard manure, organic waste, and biofertilizers to boost crop productivity through environmentally sustainable methods(Singh, 2019).Bio-fertilizer, also recognized as "microbial inoculant," represents an innovative advancement in the field of agriculture.This organic formulation comprises live microorganisms extracted from soil or roots, which are then introduced into a compatible carrier substrate. This formulation aids in the conversion of essential plant nutrients in the soil, transforming them from an inaccessible form to a usable one for crop plants through biological processes(Boubekri et al., 2021).A carrier material is a base made from raw materials found locally, capable of holding microbial inoculants viable for a specific duration and easily accessible to farmers. It needs to be cost-effective, simple to handle, mixable, non-harmful to both the bacterial inoculants and plants, suitable for packaging, possessing high water retention capacity, and able to sustain the extended shelf life of microorganisms while being readily obtainable(Ben Rebah et al., 2002).Maize, often hailed as the superior cereal crop, is a demanding plant, needing approximately 120 to 180 kilograms of nitrogen per 10,000 square meters of land to thrive and produce a yield. Similarly, Zea mays convar, belonging to the maize species, has a substantial need for nitrogen fertilizer to support its growth and productivity. These plants thrive best in well-drained, deep loam, and silt loamy soils rich in organic matter, with an ideal pH level ranging from 7.5 to 8.5. They exhibit optimal growth at temperatures around 34°C.Sweetcorn typically requires approximately 90 days to complete its growth and maturation process.
Reports indicate that biofertilizers have the capacity to fix approximately 20–40 kilograms of nitrogen per 4046 square meters of land(Mahato & Kafle, 2018). Within the realm of biofertilizers, nitrogen-fixing bacteria like Azotobacter are recognized for their ability to fix nitrogen as ammonium ions in the soil(Agarwal et al., 2018). Additionally, they generate plant growth hormones such as indole acetic acid (IAA), gibberellins, cytokinin, and auxin, contributing to processes such as plant cell division, flowering, seed germination, seed dormancy, abscission, and offering protection against pathogens(Potdar et al., 2019).
Numerous research studies have been conducted regarding the implementation of biofertilizers on crop plants, resulting in a noteworthy enhancement in vegetative growth, yield, and soil fertility. The application of Azotobacter has shown significant positive effects on the growth and yield of maize, leading to increased plant height, root length, stem diameter, fresh and dry weight of maize, leaf area, number of kernels per row, grain weight, and maize stover yield(Baral& Adhikari, 2014). Moreover, the utilization of biofertilizers has demonstrated improvements in grain yield, stimulation of seed germination, bolstering seedling resistance against both biotic and abiotic stress, nitrogen fixation, and the production of phytohormones, thereby promoting better growth in maize plants(Mirjana Jarak, 2012).Rudolph et al., (2015) findings revealed that the application of plant growth promoting rhizobacteria on maize seeds notably elevated seed germination, biomass, and overall yield (LG, 2015). Similarly,(Lhamo et al., 2022) observed that treating maize seeds with Azotobacter resulted in higher chlorophyll content within the leaves. This biofertilizer also notably improved the growth of Zea mays, thereby advocating its use, especially for enhancing maize production(Mirjana Jarak, 2012).Potdar et al. (2019) discovered that applying Azotobacter derived from lignite to sweet corn seeds resulted in heightened growth and increased yield of sweet corn. In a comparative study conducted by Mahato & Neupane (2018) between Azotobacter and Trichoderma, along with other fertilizers, on maize growth, seeds treated with Azotobacter displayed significant improvements in parameters such as plant height, stem girth, dry shoot weight, root length and width, as well as root weight. Meanwhile, the application of Trichoderma exhibited either negative effects or negligible impact. Similar findings were also noted in two cultivars of Zea mays L., namely HUDAIBA (HD) and MUGTAMA45 (MG).Hence, the current research endeavors to isolate Azotobacter, create biofertilizer utilizing Azotobacter, and conduct trial experiments to assess its effectiveness as a biofertilizer for sweetcorn (Zea mays convar) cultivation.