Source: Stock & Land

Aug. 10, 2012 — The grains sector needs to lose its attachment to tillage if it wants to continue to feed the world according to the founder of a leading Argentinian no-till farming organization.

Roberto Peiretti, who spoke at the recent Victorian No-Till Farming Association (VNTFA) conference in Australia, said it went against agriculture’s long history to do away with tillage, but it was clear it was what needs to happen.

“We have been tilling for 10,000 years, we’ve only begun to understand the principles of no-till in the past 30 years.”

However, he said the advances made at home in Argentina as a result of embracing zero-till principles had convinced him no-till would be a crucial component of producing enough food to feed the world.

“There’s going to be 10 billion people on earth by 2050, so the pressure is on farmers to provide extra food.”

Peiretti, who farms in Cordoba Province in central Argentina, said changing diets, in particular in Asia, where people are moving from rice-based diets to more wheat products and more protein, also increased demand for milling wheat and feed grain, an increase which could not be met simply by increasing cropping acreages.

“In the past we have worked on both increasing productivity and increasing acreage," he says. "At some stage, we’ll run out of new arable land, so the increases will have to come from producing more grain off the same amount of land.

“I am convinced we need to change to continue to feed the world. Tillage is still very strong in many areas, but it is bad for the environment, if the conditions are bad you can lose between 10-50 tons of topsoil for every ton of grain produced.

“We need to abandon the concept of tillage.”

A combination of increased yields from using no-till, along with better varieties developed using biotechnology would stop the pressure of expanding farmlands in to forests.

“If we are getting better yields we will be in better shape to not be pushing to remove forests to produce more grain," he says.

Peiretti said no-till had markedly boosted water use efficiency in his crops, which in turn had added environmental benefits by not having nutrient running off into waterways.

He said the fundamental tenet he followed on his own property was ensuring the soil was as well fed as the crop.

This involves leaving stubble standing, as a ‘food’ source for micro-organisms in the soil.

“The grain is for us, the stubble is for the soil," he says, adding that crop residues broke down and provided carbon into the soil.

“Crop residue is the key into improving soil carbon – you can almost see with the naked eye the improved carbon levels in soils in Argentina that have been no-tilled for a number of years. Crop residues are the food for the soil.”

He said the technology was out there to allow no-till to work successfully.

“You don’t need to cut and chop and burn, we can go in and plant in clay soils and well balanced soils, and in sandy soils and can go across crop residue without clogging, hair pinning or smearing.”

Mr Peiretti uses a double-disc system with a coulter in front and says he manages to get through all conditions with it. He adds that crop rotation also helped improve the soil.

“When you get in with deep rooted crops they can push down and open the soil up," he says. “We say we are getting enough biological tillage through our pivot rooted crops to not need conventional tillage.”

Peiretti says decaying roots left stable soil pores which allowed moisture infiltration and root penetration in future crops. The biopores are very stable and tillage would destroy that, he says.

He says this improved ability to store moisture had allowed him to grow 4.5t/ha of wheat on just 30mm of growing season rainfall.