One tonne of burnt stubble causes 20 kg soil nitrogen loss, say scientists

According to ICAR scientists, stubble burning leads to the complete loss of nitrogen, while phosphorus is only slightly recoverable

As Delhi and its adjoining areas reel from a thick blanket of bad air, senior scientists belonging to the Indian Council of Agricultural Research (ICAR) have said each tonne of stubble burnt leads to a loss of no less than 12-13 kg of phosphorus, 35 kg of potassium, and 20 kg of nitrogen in the soil.

 

They have cautioned against continuing the practice of paddy-stubble burning, saying that it not only pollutes the air but also causes an irreparable loss to the soil.

 

According to them, of the soil nutrient that is lost due to stubble burning nitrogen is completely lost while phosphorus is recoverable to some extent.

 

“We recommend that in any form stubble should not be burnt as it harms everyone,” ICAR Director General Himanshu Pathak said on Tuesday.

 

He was talking to media persons on the sidelines of the three-day Global Soils Conference 2024.

 

Pathak said the problem could be solved through a multi-disciplinary approach and not just relying on a single solution such as bio-decomposers or conversion into pellets.

 

Though significantly lower than what it was last year, the share of stubble burning in Delhi’s air quality index (AQI) is rising since early November.

 

Of late, stubble burning is estimated to account for up to 40 per cent of Delhi’s pollution, according to the System of Air Quality and Weather Forecasting and Research.

 

Punjab and Haryana have been usually blamed for stubble burning, but recent data shows farm fire incidents in Rajasthan and Delhi have reached their highest levels since 2020, with Rajasthan reporting 2,060 cases and Delhi 12.

 

This is according to the data from the Indian Agricultural Research Institute (IARI).

 

This contrasts sharply with Punjab and Haryana, where stubble burning has dropped to a five-year low.

 

Between September 15 and November 17, the IARI detected 25,108 farm fire events, across six states.

 

Punjab reported 8,404 incidents, Haryana 1,082, Uttar Pradesh 2,807, and Madhya Pradesh 10,743. Notably, Uttar Pradesh and Madhya Pradesh recorded their second-highest number of farm fires during this period.

 

On Monday, Delhi recorded its second-worst air quality in six years with the AQI touching 494.