Science

A successful solution to the ‘slash and burn’ problem

Core feature: Pusa Decomposer uses eight or so fungi in order to quicken the decomposition of the stubble.   | Photo Credit: Ritu_Raj_Konwar

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Year after year, farmers in Punjab, Haryana and Delhi have been burning agricultural waste, particularly the stubble left after harvesting wheat, leading to environmental hazards, such as smoke and particle-rich air, making the air we breathe extremely poisonous. As the spring season starts, like now, people in the area are hit with ‘smog’, or smoke and fog, making the air unbreathable. The Air Quality Index or AQI rises to severe levels (400 or more in Delhi and its neighbourhood). Incidentally, AQI is estimated based on the amount of particle pollution in the air and the associated generation of ozone, NO2 , SO2 , CO. Breathing all of these is bad for health. AQI is good when it is lower than 50 units (as in Mysuru, Kochi, Kozhikode and Shillong), moderate when it is 51–100, unhealthy between 151–200, (as in Hyderabad these days), very unhealthy between 201–300, hazardous between 301–400 and severe above 400 (as in today’s Delhi region, where stubble burning continues).

Viable solution

The Government of Delhi has recently come up with a viable solution to handle this problem of stubble burning, thanks to its collaboration with the Indian Agricultural Research Institute (IARI) at Pusa, in the city. Called ‘Pusa Decomposer’, they have come up with a set of capsules, which are dissolved in water containing jaggery, chickpea flour and a set of about eight types of microorganisms (fungi), essential to quicken the decomposition of the stubble. This is then fermented for three-to-four days, and the liquid so obtained is ready to be sprayed in the farmers’ field in order to decompose the left over biomass. They state that four such capsules are enough to make 25 litres, which can be used to decompose the crop residue per hectare of the field. Thereby, the stubble gets converted into manure in the field.

The Pusa decomposer has been successful in solving the problem, and appears to pave the way for large scale applications across the country. In his article in the blog: <the wire.in/agriculture/pusa-decomposer-iari-stubble-burning>, Shri Gaurav Vivek Bhatnagar gives a detailed analysis of the issue.

Decomposing stubble

Note here that Pusa Decomposer uses eight or so fungi in order to quicken the decomposition of the stubble. An earlier report by da Costa and others in the journal Applied and Environmental Microbiology, March 2018, 84(5) (DOI:10.1128/AEM.01815-17) titled ‘Enzyme activities at different stages of biomass decomposition in three species of fungus-growing termites’, points out that termites are used in order to generate the necessary fungi to decompose the stubble. Termites themselves attack crop produce in India, causing havoc in an indiscriminate manner. (See, for example the paper by Mahapatro and Chatterji in Proceedings of National Academy of Sciences, India, Section B Biological Sciences 88, 977–994 (2018). https://doi.org/10.1007/s40011-016-0837-5.). Then, why buy extra trouble, but simply isolate the microorganisms which produce the necessary enzymes for decomposing the stubble? It was with this logic that IARI seems to have come up with its Pusa Decomposer formula. As we note, this has worked well.

Incidentally, it is interesting to note that food grains produced using the Pusa Decomposer qualify as organic farming, since it involves no growth hormones, antibiotics, no genetically modified organisms, and no leaching of surface water or ground water.

Jongue’s method

Indeed, if we look at the origin and development of farming itself of plants and foodgrains over millennia, it was organic in nature, until almost the industrial revolution in the eighteenth century, and the developments in chemistry which led to the discovery of fertilizers and related chemicals which were added to increase food farming. In this connection, it is interesting to read what Stephanie Hanes points out in her article in Christian Science Monitor, in 2008 (https:csmonitor.com/Environment/2008/0430/p13s01-sten.html). The traditional method has been ‘slash and burn’ (as we too have been doing in our wheat farming). But a farmer called Jongue in Mozambique in East Africa did not burn his corn farm, but let the corn stalks rot. In one part of his farm, rather than slash and burn, he mixed tomatoes and peanuts in the field to rot. Then he let the mice in the field eat up this stuff – a natural way of removing the rotting material. (If the mouse population became too large, he brought in cats to restrict the mice!) He also tried planting sorghum with success. This was what one may call organic farming. The yield and the quality were good enough to sell the corn or sorghum in the market.

His organic farming was based on the use of mice as the source of the necessary molecular ingredients such as fungi, and no other additives. In a way, the Pusa Decomposer, with its jaggery, chickpea flour and naturally occurring fungi is the modern day Jongue approach!

As field trials in the Delhi, Haryana region have been found successful, Pusa Decomposer should be tried in areas of Northeast India where ‘slash and burn’ (locally called ‘jhum’) is still followed (in Tripura, Arunachal Pradesh and Meghalaya, for instance), IARI might try and introduce it there as well. It will also improve the AQI in the region (Agartala in Tripura is ‘moderate’ to ‘unhealthy’, currently).

dbala@lvpei.org


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Printable version | Oct 17, 2021 6:31:32 AM | https://www.thehindu.com/sci-tech/science/a-successful-solution-to-the-slash-and-burn-problem/article33150542.ece

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