Video | Business Headlines | Internet | Science | Scientific Ethics | Technology | Search

 


Stubble Burning In Canterbury Damages The Soil

Stubble Burning In Canterbury Damages The Soil

March 11, 2014

An international soil scientist is critical of the practice of burning residue which often occurs on farms after harvest.

Dr John Baker visited Mid Canterbury recently and witnessed a large scale burn off near Chertsey polluting the atmosphere. While it may not have harmed the soil at the time, it certainly will destroy much of the opportunity to improve the soil health in the future he says.

He says burning residues simply removes most of the carbon present in the residues of the previous crop by converting it to CO2 by combustion.

“The main way to maximise arable soil quality and health is to increase its carbon content, not burn it off. Increasing carbon and soil microbial activity in turn builds soil structure and is one of the strongest indicators of soil health or quality,” Dr Baker says.

Dr Baker, who has a MAgrSc in soil science and Ph.D in agricultural engineering from Massey University, has reacted with caution to a recent Foundation for Arable Research (FAR) report that “stubble burning is valued by some farmers as a rapid, economic and relatively benign way of dealing with crop residue.”

“Burning is bad for the soil as it destroys all the available new organic matter which is used to build humus. Residue feeds worms and builds soil organic matter,” he comments.

Dr Baker concedes that occasional burning can help with weed and pest control but is critical that FAR sees burning as creating a basis for a more productive and profitable farming system. Most of the evidence is to the contrary he points out.

“Retaining residue and seeding through it with low-disturbance no-tillage is a far superior method than intensive tillage (ploughing) with or without burning. Any form of tillage is also detrimental to soil quality,” he says.

Dr Baker, who was a finalist for the World Food Prize in 2013, cannot over-emphasise the importance of good quality soil. He says the single greatest challenge facing the world today is feeding the extra 50 percent population by the year 2050.

“Only four percent of the world’s surface has arable soil and that’s not likely to increase so we have to farm it more sustainably which we simply haven’t been doing,” he says.

“To farm it sustainably and increase crop yields requires preserving and maintaining soil quality and organic matter. I don’t see that happening on properties where stubble burning is a regular occurrence.”

Dr Baker has been researching no-tillage for 40 years and invented and manufactured a low-disturbance no-tillage drill that penetrates through crop residue on top of the ground and sows seeds and fertiliser directly into unploughed ground.

“No-tillage is the equivalent of keyhole surgery as opposed to ploughing which is invasive surgery,” he says.

“Good no-tillage causes minimal disturbance to the soil, traps the humidity, preserves micro-organisms and soil life, largely prevents carbon from escaping into the atmosphere and significantly improves crop yields. One kilogram of humus in the soil holds as much water as nine kilograms of clay. So it’s a no-brainer really.”

“It will simply become the key to feeding our world in the years to come.”

Ends

© Scoop Media

 
 
 
 
 
Business Headlines | Sci-Tech Headlines

 

Fossils: Ancient Penguins Lived Alongside Dinosaurs?

Penguins are much older than previously thought and their evolution probably dates back to the days of the dinosaurs, according to research on the fossilised leg bone and toes of a giant ancient penguin found in rocks near Waipara, North Canterbury. More>>

No Voda/Sky: Commission Declines Clearance For Merger

The Commerce Commission has declined to grant clearance for the proposed merger of Sky Network Television and Vodafone New Zealand. More>>

ALSO:

EARLIER:

Power: IEA Report On New Zealand's Energy System

Outside of its largely low-carbon power sector, managing the economy’s energy intensity and greenhouse gas emissions while still remaining competitive and growing remains a challenge. More>>

ALSO:

NASA: Seven Earth-Size Planets Around A Single Star

NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water. More>>

ALSO:

Auckland Transport Case: Men Guilty Of Corruption And Bribery Will Spend Time In Jail

Two men who were found guilty of corruption and bribery in a Serious Fraud Office (SFO) trial have been sentenced in the Auckland High Court today... The pair are guilty of corruption and bribery offences relating to more than $1 million of bribes which took place between 2005 and 2013 at Rodney District Council and Auckland Transport. More>>

ALSO:

Hager Raid: Westpac Wrong To Release Bank Records To Police

The Privacy Commissioner has censured Westpac Banking Corp for releasing without a court order more than 10 months of bank records belonging to the political activist and journalist Nicky Hager during a police investigation into leaked information published in Hager's 2014 pre-election book, 'Dirty Politics'. More>>

ALSO:

EARLIER:

Get More From Scoop

 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news