Decoded: What is a PUSA decomposer? How can it discourage stubble burning?

Every year, over 5.7 million acres of paddy stubble is burned on farms in Punjab and Haryana, leading to severe environmental issues

The newly formed Commission for Air Quality Management (CAQM) said on Wednesday that the northern Indian states of Punjab, Haryana and Uttar Pradesh have prepared detailed action plans to tackle stubble burning in the coming winter season with likely increased use of the bio-decomposer solution developed by the Indian Agriculture Research Institute (IARI) in Pusa.

The Commission said the plans lay down that bio-decomposer solutions will be used in over 6 lakh acres in UP, 1 lakh acre in Haryana and 7413 acres in Punjab, while the national capital of Delhi will spray over 4000 acres of land.

So how big is the problem of stubble burning during winters in North India and how can bio-decomposers, also called PUSA decomposers because of the name of the research institute that developed it, solve it.

The Problem

Every year, according to some estimates, over 5.7 million acres of paddy stubble is burned on farms in Punjab and Haryana alone, leading to severe environmental issues, depletion of soil quality, and loss of flora and fauna.

The stubble smog engulfs Delhi and its surrounding areas during the months of October-December.

The toxins turn the city's air into an obnoxious concoction of pollutants, resulting in irritations of the eye, skin and in breathing troubles-making Delhi inhospitable.

It ranks as one of the most polluted cities in the world, and inhaling all this toxicity reduces the average life expectancy of Delhites by 9 years, according to WHO reports.

A sizable chunk of this pollution comes from the crop stubble burning exercise carried out by farmers from the adjacent states of Punjab and Haryana.

These farmers don't engage in this act for being mean or nasty, rather, in the absence of more viable choices, they are forced to burn stubble. Burning is cheaper and doesn't erode their already minimal income further.

What is PUSA bio-decomposer, and how does it help?

PUSA bio-decomposer is a bio-enzyme developed by IARI. It decomposes the stubble, turning it into manure, thus improving the soil health and reducing farmers' input costs in terms of fertilisers for the next cropping cycle. 300 grams of PUSA spray is enough to decompose 1 acre of stubble.

What does PUSA stand for? Is it an abbreviation?

The first agriculture institute of Asia was set up in a village called Pusa, in the Samastipur district of Bihar; it was called Imperial Agriculture Research Institute. The initial donations for its setup came from Henry Phipps from the US, and to commemorate his contributions, it is said that the name of the place Pusa is the abbreviated form of Phipps of USA. (Pusa). To date, several initiatives by IARI continue using the abbreviation PUSA.

How does the PUSA bio-decomposer work?

PUSA bio-decomposer is a bio-enzyme that decomposes the stubble. The farmers are required to maintain 50% - 60% of moisture in the soil, there should be no seeds sown already in the field (along with stubble) and the straw should be removed from the field for the spray solution to work.

All these have been communicated to the farmer, and he/she is again asked to provide the right field condition while booking the PUSA bio-decomposer spray post harvesting.

In simple terms, to decompose the stubble effectively, the following steps need to be followed:

1. Post-harvest, spray PUSA bio-decomposer onto the stubble.

2. Since it is a biological material, there shouldn't be any exposure to sunlight, and the moisture content should be adequate. And hence, the soil needs to be rotated by a rotavator, and the field needs to be adequately irrigated for the next 3-4 days.

3. If all the safeguards are followed, the land is ready to be sown with the next cycle of seeds in just 8 days. Since the fungi consortia decompose only the dead mass, the living plant seed does not get affected by its activity.

So the basic steps are easy to be followed - Spray (PUSA) +Turn (the soil) + Irrigate

Does this actually work? Have any pilots been carried out?

IARI has developed the PUSA bio-decomposer and the institute carries multi-location, multi-year trials before coming up with agricultural innovations. Several start-ups like nurture.farm have also conducted pilots for PUSA bio-decomposer in Andhra Pradesh.

Why PUSA? Why not use a Happy Seeder or some other method to combat stubble burning?

For any intervention to gain mass approval, it must be cost-effective, even more so when we are dealing with farmers who have a precarious bottom line to take care of. Despite being subsidised by the government, a Happy Seeder is a heavy investment and requires high HP tractors for their deployment. Such tractors amount to only 15% of the entire tractor population of the country. This makes it a non-viable option for the farmers who prefer burning their fields to deploying heavy machinery. The same is the case with balers.

Why is stubble burning such a big issue? What's the root cause?

A lot of farmers use modern harvesters to harvest their crops as these are faster and do not affect the grain's quality. But the downside of this is the huge amounts of stubble generated, which are as high as 5-6inches in the case of paddy crops. Deploying manual labour or other machines to weed them out is both time-consuming and investment-heavy for the farmer who resorts to a cheaper and quicker way of dealing with the waste - by burning it. This is also necessary for the farmer to sow his next crop in time. If he doesn't, then his yield for the next harvest reduces or gets delayed - affecting his earning capacity.

But stubble burning has a lot of negative effects -

1.  It pollutes the skies - Delhi smog has brought much public and policymaker ire

2.  It kills the soil's microbes and other flora and fauna that come in the fire's way

3.  Adds significantly to the carbon footprint of agricultural activities

4.  Causes economic and ecological damage.

Are there any downsides of PUSA decomposers or bio-decomposers?

Several experts and farmers say that the time taken for the stubble to decompose in the fields after using the decomposer is unusually high and farmers have a very short window to harvest their standing paddy before sowing of the next wheat crop starts. 

In some cases, the solution takes more than 40 days to decompose paddy stubble fully, while the window between paddy harvest and wheat sowing is much less.

However, Dhruv Sawhney, COO and Business Head of nurture. farm, which has joined hands with IARI to develop the latest version of decomposers said that newer decomposer varieties take 20-25 days to completely decompose the stubble as against the older ones which took sometimes 60 days.

“The new varieties of decomposers are in powder form which are water soluble and have a consortium of more than seven different fungi unlike the previous ones which were in capsule forms and had fewer numbers of fungi which took more time to decompose the stubble,” Sawhney told Business Standard.

He said in new ones, crops can be sown after 8 days of spraying the decomposer and turning the soil as the microbes continue to work in the background while the new plant germinates.