PUSA Decomposer

SEP 26

Preliminary   > Environment and Ecology   >   Pollution   >   Air pollution

Why in news?

  • Delhi Chief Minister Arvind Kejriwal announced an innovative technique called  Pusa Decomposer  developed by the scientists at Indian Agriculture Research Institute (IARI).

About the decomposer:

  • It will be used for the speedy decomposition of stubble, left over after rice cultivation, in the national capital and nearby states.
  • Four capsules of Pusa decomposer can be used for one hectare of field and once applied the stubbles would bio-degrade in 20 days.
  • This would reduce the need for Stubble burning which contributes heavily to air pollution in Delhi.

About Stubble Burning:

  • Stubble burning is, quite simply, the act of removing paddy crop residue from the field to sow wheat.
  • It’s usually required in areas that use the ‘combine harvesting’ method which leaves crop residue behind.

What is combine harvesting?

  • Combines are machines that harvest, thresh i.e. separate the grain, and clean the separated grain, all at once.
  • The problem, however, is that the machine doesn’t cut close enough to the ground, leaving stubble behind that the farmer has no use for.
  • There is pressure on the farmer to sow the next crop in time for it to achieve a full yield.
  • The quickest and cheapest solution, therefore, is to clear the field by burning the stubble.

But Is Burning the Only Solution?

  • Not really, but it is the easiest and cheapest method available to farmers as of now.
  • The most efficient technology to counter crop burning at the moment, seems to be the Turbo Happy Seeder (THS). The THS is basically a machine mounted on a tractor that not only cuts and uproots the stubble but can also drill wheat seeds on the soil that has just been cleared up.
  • The straw is simultaneously thrown over the sown seeds to form a mulch cover.

Can We Find Other Use for the Stubble?

  • Traditionally, crop residue had a lot of benefits like thatching, or making beds for livestock and cattle. However, such uses have reduced with modern housing and diary farming.
  • One option is to produce biomass with the residue to generate power.
  •  The straw can similarly be used to make pellets that serve as the sub-strata for mushroom cultivation, but the problem is not in finding alternatives to paddy straw, as there are many.

But Why Is This Only a Problem in the Northern States?

  • India relies on its northern states of Punjab, Haryana, western Uttar Pradesh and Uttarakhand for wheat.
  • Now, states in the south use combine harvesting too.  But the clinching difference is that they don’t have the urgency to remove the stubble to make it ready for the next crop.
  • To sow wheat right after paddy, the field has to be harvested and readied for the next crop.
  • In Punjab-Haryana region farmers normally get only a period of 20 days to sow wheat after harvesting rice to ensure wheat harvest in April, the ideal time.
  • Thus, one major solution to the problem is incentivizing farmers in the north to come out of rice cultivation.


Consider the following statements regarding “Stubble burning”
1.Stubble, in this context, is mainly the residue left in the field after the cultivation of wheat in the rabi season.
2.Use of combine harvesters can reduce the problem of stubbles.
Which of the statements given above is/are correct?
(a)1 only
(b)2 only
(c)Both 1 and 2 
(d)Neither 1 nor 2

Answer to prelims question