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

 

Budget Policy Statement: Spending Wins Over Tax Cuts; Big Ticket Items Get Boost

Income tax cuts are on hold as the government says “responding to the earthquakes and reducing debt are currently of higher priority”, although election year tax sweeteners remain possible. More>>

ALSO:

Fishy: Is Whitebaiting Sustainable?

The whitebait fry - considered a delicacy by many - are the juveniles of five species of galaxiid, four of which are considered threatened or declining. The SMC asked freshwater experts for their views on the sustainability of the whitebait fishery and whether we're doing enough to monitor the five species of galaxiid that make up whitebait. More>>

ALSO:

Crown Accounts: Smaller-Than-Expected Four-Month Deficit

The New Zealand government's accounts recorded a smaller-than-forecast deficit in the first four months of the fiscal year on a higher-than-expected inflow of corporate and goods and services tax. More>>

ALSO:

On For Christmas: KiwiRail Ferries Back In Full Operation After Quake

KiwiRail’s Interislander ferries are back in full operation for the first time since the Kaikoura earthquake, with the railspan that allows rail wagons to be loaded on the Aratere now restored. More>>

ALSO:

Comerce Commission Investigation: Prosecutions Over Steel Mesh Labelling

Steel & Tube Holdings, along with two other companies, will be prosecuted by the Commerce Commission following the regulator's investigation into seismic steel mesh, while Fletcher Building's steel division has been given a warning. More>>

ALSO:

Wine: 20% Of Marlborough Storage Tanks Damaged By Quake

An estimated 20 percent of wine storage tanks in the Marlborough region, the country’s largest wine producing area, have been damaged by the impact of the recent Kaikoura earthquake. More>>

ALSO:

ACC: Levy Recommendations For 2017 – 2019 Period

• For car owners, a 13% reduction in the average Motor Vehicle levy • For businesses, a 10% reduction in the average Work levy, and changes to workplace safety incentive products • For employees, due to an increase in claims volumes and costs, a 3% increase in the Earners’ levy. More>>

Get More From Scoop

 
 
 
 
 
 
 
 
Sci-Tech
Search Scoop  
 
 
Powered by Vodafone
NZ independent news