Biofertilizers: Towards sustainable agriculture

Modern agriculture is still increasingly dependent on synthetic inputs to ensure requisite yield and productivity. One of the widely used, in certain cases, abused inputs, are chemical or synthetic fertilisers. While various studies establish the fact that judicious use of synthetic inputs is acceptable, its adverse effects, in the long run, can’t be denied, the key one being the imbalance of the soil ecosystem, which can reduce yield and, in turn, increase the use of chemical inputs, resulting in a vicious cycle.

In recent years, the growing adoption of organic farming has resulted in a more sustainable approach towards agriculture as it emphasises on adopting environmentally benign practices to ensure food security while protecting and nurturing soil biodiversity. Stakeholders are adopting various strategies to make organic and sustainable agriculture mainstream; one of the key ones being the use of bio-based fertilizers or bio-fertilizers to provide optimum nutrients to crop and enhance soil potency.

With interest in sustainability on the rise, there is much effort targeted towards the development of organic and sustainable fertilizers as inputs. While these terms are often used interchangeably, a way of differentiating between them is through the source of origin. Most of the bio-based fertilizer inputs are of plant and microbial origin, while organic fertilizers include those of animal origin too. The term “biofertilizer” itself has been denoted in various ways over the past 10 years. At present, biofertilizers are widely used to denote substances that are incorporated with microbes or other living cells or organisms that can help in nurturing plant growth and promote soil health; it also denotes growth-enhancing substances that are bio-based or bio-derived in origin. Irrespective of the terminology used, the underlying concept remains the same.

Biofertilizers have come a long way from being seen as a supplement to chemical fertilizers to their current position as nutritional aids that can mobilise vital growth elements in an easily assimilated form. They are often regarded as a renewable source of plant nutrients and promote soil health and have become a vital constituent in integrated crop and soil management.

Role of biofertilizers to enhance soil microbiome

A key focus in line with promoting sustainable agriculture in the coming years is to focus on implementing eco-friendly methods to enhance the microbial ecosystem of the soil and to promote a diverse range of naturally occurring microbes to ensure sustained crop production activities. Various research studies have established that a naturally occurring ecosystem will flourish through the careful maintenance of beneficial soil micro-organisms. These microbes are diverse and help in maintaining the physicochemical properties of soil, ensure soil health and promote plant growth and crop yield.

One of the ways where biofertilizers can help in nurturing an optimum soil ecosystem is to provide sufficient organic matter to nurture the soil microbiome. Their ability to increase the population of microbial strains such as Azotobacter, Azospirillum, Phosphobacteria and Rhizobacteria help in providing optimum nitrogen cycling, which is critical to both soil and plant health. Biofertilizers help in enhancing nutrient availability and uptake by aiding nutrient solubilisation. They also help in producing plant hormones such as cytokines, help in stimulating proper root architecture and improving photosynthesis. This aids the plants to become more resistant to stress and pathogen attacks by producing metabolites. Thus, the use of biofertilizers has a twofold effect: enhancing soil health while promoting plant growth.