Analysis Of Down To Earth Magazine: Microbes To Improve Crop Yield
Relevance
”GS 3: Biotechnology, Achievements of Indians in Science & Technology”
Context
- The current estimated demand for bio fertilisers in India is 18,500 tonnes per year, while production is 10,000 tonnes.
- Soil contains several natural microbes that help plants absorb nutrients. These can be cultured and modified into bio-fertilisers. They increase the availability of nutrients and boost yield by 10-25 per cent.
Why should we focus on microorganisms?
- Chemical-free organic farming improves soil fertility, but there are conflicting views about their impact on yield.
- To overcome this and boost productivity, the agriculture sector can tap into microorganisms.
- Scientific research shows constructive and cost-effective use of bacterial, fungal and algal microbes can also have positive results on crop yields.
- Microbes can be used as bio-fertilisers, biostimulants and biopesticides, cultured in the laboratory.
How do Bio fertilisers Works?
- They promote root growth and decompose organic matter.
- They do this by helping fix atmospheric nitrogen in the soil and the root nodules of crops, and by producing hormones and antimetabolites.
- They also scavenge and solubilise phosphates from soil layers and help in soil mineralisation.
- There are three bacteria used as nitrogen-fixing bio-fertilisers. The most common is rhizobium, which works best with legume crops.
- Azospirillum, on the other hand, is used with higher plants or cereals like sorghum, maize, millets and fodder grasses.
- Another common soil bacterium is Azotobacter.
- The species A chrococcum is widely present in Indian soil and grows using soil organic matter.
What are Rice Organisms?
- Blue-green algae such as Tolypothrix, Nostic, Schizothrix, Calothrix, Anoboenosois and Plectonema are also used as bio-fertilisers.
- They are called rice organisms as they are found in these fields.
What are biostimulants?
- Some microbes being cultured as biofertilisers can also be used as biostimulants.
- They are defined as products designed to enhance plant’s nutrition efficiency, improve tolerance to abiotic stress and boost crop quality.
- They may have organic and chemical matter, or mixture of these and microbes. Microbial biostimulants can consist of a single or multiple species of azotobacter, rhizobium and azospirillum bacteria, and even of Mycorrhizal fungi.
Safety Concerns
- The development and use of biostimulants through the years has shown that some can have negative impacts.
- So, countries like India and those in the EU have developed lists of “positive” and “negative” microbial biostimulants.
- In India, the lists are made by the Central Insecticide Board and Registration Committee (CIBRC) and the Directorate of Plant Protection, Quarantine & Storage (DPPQS).
India is the largest consumer of pesticides
- India is not only among the world’s largest consumers of pesticides but also ranks 12th in their production. Their demand is also rising.
- According to a 2017 report by the Centre’s Department of Agriculture Cooperation and Farmers Welfare, consumption of biopesticides increased from 219 tonnes in 1996-97 to 683 tonnes in 2000-01 and to around 3,000 tonnes in 2015-16.
- In 2016, the market was $70.45 million, growing at a compounded annual rate of 17.08 per cent.
Way Forward
- Biopesticide research is at an early stage but evolving.
- Investment in fermentation technology, improved delivery systems and promotion of biological control will help.
- While the agriculture sector has found multiple uses for microbes, their promotion is hindered as they show varying effects in different climate and soil conditions.
- Researchers in recent years have made synthetic communities of beneficial microbes to improve yields.
- We can explore strategies to select synthetic inoculants that are better suited to different conditions.
- In addition, existing national schemes to promote organic and natural farming can also include measures to boost use of microbial inoculants.