Biofertilizer Technology and Integrated Plant Nutrient Management

Keywords

Beneficial microorganisms, rhizosphere, biofertilizers, soil fertility, crop production, sustainable agriculture, integrated plant production, evaluation, crops, inorganic fertilizers, soil fertility, organic fertilizers, fertilizer application, nutrients, organic matter, plant nutrition, cropping systems.

Introduction

Biofertilizer is a substance which contains living micro-organisms which, when applied to seeds, plant surfaces, or soil, colonize the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant.

Biofertilizers add nutrients through the natural processes of nitrogen fixation, solubilizing phosphorus, and stimulating plant growth through the synthesis of growth-promoting substances producing healthy plants.

Biofertilizers can be expected to reduce the use of synthetic fertilizers and pesticides, but they are not yet able to replace their use. The preferred scientific term for such beneficial bacteria is "plant-growth promoting rhizobacteria". They accelerate certain microbial processes in the soil which augment the extent of availability of nutrients in a form easily assimilated by plants.

Types of Biofertilizers

Acetobacter, Azotobacter, Bacillus, Pseudomonas, Rhizobium, or Plant Growth Promoting Bacteria (PGPB) and Arbuscular Mycorrhiza (AM).

Groups of Biofertilizers

• Azolla-Anabena symbiosis: Azolla is a small, eukaryotic, aquatic fern having global distribution. In Prokaryotic blue green algae, Anabena azolla resides in its leaves as a symbiont. Azolla is an alternative nitrogen source. This association has gained wide interest because of its potential use as an alternative to chemical fertilizers.

• Rhizobium: Symbiotic nitrogen fixation by Rhizobium with legumes contribute substantially to total nitrogen fixation. Rhizobium inoculation is a well-known agronomic practice to ensure adequate nitrogen.

• Streptomyces grisoflavus

• Unigrow (UniGrow): Commercial bio fertilizer that is currently in use having promising results in studies. It is made with a by-product of palm oil production, and it contains a microbial element.

Advantages

A few advantages are as follows:

• Biofertilizers are a means of fixing the nutrient availability in the soil and leading to greater farming sustainability.

• They advance shoot and root growth of many crops versus control groups. This can be important when implementing new seed growth.

• It has also been shown that to produce a larger quantity of crops, biofertilizers with the ability of nitrogen fixation and phosphorus solubilizing would lead to the greatest possible effect.

• It increases crop yield by 20-30%, replaces chemical nitrogen and phosphorus by 30%, and stimulates plant growth. It can also provide protection against drought and some soil-borne diseases.

Limitations

The practical aspects that currently limit the applicability of biofertilizers in agriculture are they have been showing varying effects in different environments, and even within the same environment. They have shown the most profound effects in drier climates.

In the future, it is hoped that biofertilizers effects will be better controlled and regulated in all environments. The main concern is the lab-to-field transition, where it is common for a microbial strain with good performance in vitro to perform poorly in greenhouse or field trials.

The inoculation outcome is especially hard to predict because we generally consider and control for a limited number of variables, usually not considering their intricate.

Integrated Plant Nutrient Management

Integrated plant nutrient management (IPNM) is a holistic, integrated approach that considers all the available farm resources that can be used as plant nutrients. The main principles of IPNM are to maximize the use of organic inputs while minimizing nutrient losses and to make only supplementary use of chemical fertilizers. IPNM contributes to better farm waste management, minimizing environmental pollution, improving soil productivity, and the production of safe food and feed.

IPNM is the intelligent and combined use of inorganic, organic and biological resources to sustain optimum yields, improve or maintain the soil chemical and physical properties and provide crop nutrition packages which are technically sound, economically attractive, practically feasible and environmentally safe. Integrated nutrient management (INM) is a low-to-no-cost-effective technology for restoring soil health if they can be produced and used within the same place.

Concept of IPNMS

• Regulated nutrient supply for optimum crop growth and higher productivity.

• Improvement and maintenance of soil fertility.

• Zero adverse impact on agro-ecosystem quality by balanced fertilization of organic manures, inorganic fertilizers, and bio-inoculant.

Advantages

A few advantages are as follows:

• Enhances the availability of applied as well as native soil nutrients.

• Synchronizes the nutrient demand of the crop with nutrient supply from native and applied sources.

• Provides balanced nutrition to crops and minimizes the antagonistic effects resulting from hidden deficiencies and nutrient imbalance.

• Improves and sustains the physical, chemical, and biological functioning of soil.

• Minimizes the deterioration of soil, water, and ecosystem by promoting carbon sequestration, reducing nutrient losses to ground and surface water bodies and to atmosphere.

Limitations

Limitations include:

• Social acceptability.

• Ecological considerations.

• Impact on the environment.

• Nutrient requirement of cropping system.

• Local availability of nutrients resources.

• Soil fertility status and soil problems.

• Economic conditions of farmers and expected profitability.

Conclusion

Biofertilizer inoculation of individual or consortium of beneficial microorganisms have been found to improve plant biomass and crop yield under greenhouse and field conditions. The technological developments such as the advent of next-generation sequencing, gene editing and bioengineering of microbial communities, in silico modeling of proteins and synthetic biology may allow the manipulation of plants and microbes to deliver short and long terms solutions for improving crop productivity to feed the world in a more sustainable manner.

The interest of agriculture specialists and farmers must be turned toward a simple technique of integrated nutrient management, which is an acceptable option, a cost-effective practice, can be easily followed by farmers, and an eco-friendly approach, reducing the claim of fertilizers and could produce greater yield production with better quality traits and maintain satisfactory profit.