Sustainable Crop Production for Better Human Health
Sustainable agriculture is proven to be one of the most demanding jobs in the present day. The need to increase agricultural production to meet the food requirements of the ever-increasing world population makes consistent maintenance of soil fertility essential. However, bio-fertilizers are a contribution of modern agricultural sciences which retards the nitrification for a sufficiently longer time and increases the soil fertility. Bio-fertilizers are important components of integrated nutrient management. They play a key role in the productivity and sustainability of soil, while protecting the environment, being cost-effective, eco-friendly and a renewable source of plant nutrients to supplement chemical fertilizers in a sustainable agricultural system. Unlike inorganic fertilizers, bio-fertilizers do not supply nutrients directly to plants. These are the microbial inoculants containing the living or latent cells of efficient strains used for application to seeds, soil or composting areas with the purpose of accelerating the microbial process. This procedure is used to augment the availability of nutrients that can easily be assimilated by plants, consequently colonizing the rhizosphere or the interior of the plant and promoting growth by converting nutritionally important elements into an available form. This is achieved through a biological process such as nitrogen fixation and solubilization of rock phosphate. Beneficial microorganisms in bio-fertilizers improve the plant growth, maintain the soil fertility and protect the plants from pests and diseases. Bio-fertilizers are promoted to harvest the naturally available, biological system of nutrient mobilization.
The substantial contribution of bio-fertilizer to the sustainable maintenance of human health has been reported. Bio-fertilizers improve the nutritious properties of fresh vegetables by increasing the antioxidant activity, the total phenolic compounds and chlorophyll (Khalid et al. 2017). Spinach inoculated with different bio-fertilizers was found to have 58.72 and 51.43% higher total phenolic content than the uninoculated control (Khalid et al. 2017). These secondary metabolites play preventive roles in cancer, neurodegenerative and cardiovascular disorders (Rodnguez-Morato et al.
2015). Inoculation of lettuce with Azotobacter chroococcum and Glomus fascicu- latum also increased the total phenolic compounds, anthocyanins and carotenoids content of the vegetable (Baslam et al. 2011). Higher (48.02 and 40.46%) flavonoid content (antioxidant) was observed in lettuce co-inoculated with G. fasciculatum and Glomus mosseae (Baslam et al. 2011). Antioxidant biosynthesis by Arbuscular Mycorrhizal Fungi (AMF) has been reported (Carlsen et al. 2008; Nisha and Rajesh Kumar 2010; Eftekhari et al. 2012). Taie et al. (2008) documented a 75% increase of phenolic acid biosynthesis in soybean seedlings inoculated with Rhizobacteria. Karthikeyan et al. (2010) found that inoculating Pseudomonas fluorescens and Bacillus megaterium into Catharanthus roseus significantly increased the alkaloid content of the crop. Other reports suggest that the combination of PGPR and AMF is beneficial for growth promotion and secondary metabolite production of medicinal and aromatic plants under salt-affected soil and/or normal soil (Pankaj et al. 2019a, b, c, 2017; Trivedi et al. 2017; Verma et al. 2016; Khan et al. 2015; Singh et al. 2018, 2017a, b, c, 2019; Tiwari et al. 2018, 2019a, b; Kour et al. 2019).
Conclusion and Future Prospects
From the conclusion of this chapter, government bodies, NGOs and scientific societies are highly encouraged to both educate and increase awareness in farmers about the ill-effects of agrochemical overuse. Bio-fertilizers have undoubtedly huge potential for future agriculture production in a sustainable manner. However, it is important to ensure that they are successfully applied in order to fulfill their role in a more sustainable agriculture. Food production by the use of bio-fertilizer is a viable alternative to the destructive health effects caused by the consumption of food produce by the use of agrochemicals such as pesticides, inorganic fertilizers, herbicides, etc. The knowledge of the mechanisms of actions employed by microbial inoculants will play a vital role in their use in sustainable agriculture. Excessive use of chemicals, as is often given as the recommended dose in agriculture, can be avoided and thus, can be removed from the human diet. It is confirmed from reviewing the research thus far that the use of bio-fertilizers will ensure healthy food safety for the future population.