Regenerative agriculture practitioners speak very well, use the words and jargon of science, but are factually incorrect, Lincoln University professor Leo Condron says.
He was commenting on Landcare’s white paper on regenerative agriculture (RA) in New Zealand.
It reported anecdotal evidence for the benefits of RA is growing and farmers are recording their observations and sharing them via social media.
NZIAHS president Jon Hickford said with regeneration there was the suggestion of degeneration and that NZ was bad, but there was not a lot of evidence to support this,
The white paper identified 17 priority research topics to be looked into.
Hickford’s colleague adjunct professor Jacqueline Rowarth was now going through the 17 “priority research topics,” identified in the white paper putting references against them to show that the research has been done.
Agricultural scientist Dr Ants Roberts said research in soil biology was still in its very early stages. This meant some of the claims made by RA could not be verified, as the science was yet to be developed, or it would cost hundreds of millions of dollars to do the research.
“...it [science] was like building a house block by block, each scientist works on their block, understanding it, learning how it works, and then the scientists work together to build the house.”
Roberts said what was known was soil biology cannot create mineral nutrients, but it could change the form of the nutrients, which affected plant availability. It was clear, no matter how numerous, active and diverse the soil biology was, nor how many diverse species of plants are growing in harmony with root systems exuding all manner of elicitors and bioactive substances at different depths in the soil profile, this would not create new minerals.
The fact was, if plants are harvested by machine or animal and removed, eventually soil nutrients will be depleted. Then at some point externally sourced nutrients would need to be applied to sustain the soil’s life supporting capacity.
Condron said science conducted small steps. Scientists need to be a specialist in their field, which takes a lot of training, and each scientist researches an intricate area. He said it was like building a house block by block, each scientist works on their block, understanding it, learning how it works, and then the scientists work together to build the house.
According to Condron, nothing of what the RA proponents said is new. For example, 25 years ago a market gardener who was concerned about his soil asked Condron, in his capacity as an agronomist, for advice. He suggested resting the land to give it time to recover, and planting a green manure. The farmer who needed to get two to three crops a year from the land, to keep up with demand and meet costs, did not think it would be possible. However, he followed the advice of adding a green manure into the rotation, and was very proud to show Condron the results of his advice.
Solving one problem can create another, solving one problem can also accidentally solve another, he said. Decades ago Canterbury Plains, with its light soils and low rainfall was used a lot for growing grains, but with high winds soil was blown away, to mitigate this pasture was introduced to the system and crop farms changed to half cropping and half sheep, with the grass stabilising the soil. This mostly solved the problem and diversified farmer’s income, he said. Now that much of the Canterbury Plains was used for dairying, with the pasture required for cows, there was no wind erosion and a permanent increase in the soil’s organic matter.
The use of anecdotes to create an emotional response, to support a persuasive argument that the writer is putting forward was a concern for Massey University associate professor Kerry Harrigan. He said if the white paper authors were hoping that the meagre research dollars available for agricultural research in NZ might get sucked into this type of study, it would leave no money for more constructive research into improving the sustainable farming systems already operating.