There has been a lot of publicity recently in the media about â€œRegenerative Agricultureâ€ and how this is the way that we all need to be farming.
There are many definitions available to us outlining what Regenerative Agriculture is, but generally the aim is to progressively improve whole agroecosystems (soil, water and biodiversity).Â Mention is often made specifically of improving the solar, water and mineral cycles. Among the claims made by proponents, the following stands out for discussion: â€œArtificial and synthetic fertilizers have created imbalances in the structure and function of microbial communities in soils, bypassing the natural biological acquisition of nutrients for the plants, creating a dependent agroecosystem and weaker, less resilient plants.â€ (https://regenerationinternational.org/2017/02/24/what-is-regenerative-agriculture/)
This would seem to be an evidence-free statement.Â I am not sure what â€œnatural biological acquisition of nutrientsâ€ is â€“ seems like the magic pudding.Â Remember, there is no free lunch in biology.Â All agricultural systems are exploitive and unless nutrients are replaced the system will eventually run down.
Much of the objection to current farming practices lies with the demonisation of artificial fertilizers.
There is ample evidence that the addition or required nutrients (whether they come from a bag or some organic source) improves the mineral, solar and water cycle and creates increased biological activity.Â The plant does not care about the source of the nutrient â€“ all it sees is the nutrient form it can utilise.
Letâ€™s look at a number of examples.
It can be argued that improving water and solar cycles results in increased productivity for the same inputs of water and sun.Â Clearly, it has been demonstrated time and time again that pasture productivity can be increased with the same amount of sun and water by removing nutrient deficiencies.Â Again it doesnâ€™t matter where the nutrients come from.
Improved Soil Biology
Soil biology is incredibly complex and our understanding of soil biology (particularly the micro-organisms present and their interactions) is very rudimentary. It is estimated that one gram of soil contains 10,000 – 50,000 species of microbes and those species fluctuate depending on climate, moisture, nutrient inputs, etc.Â Anybody that claims that they understand how soil biology reacts to stimuli is not basing that on any scientific evidence.
There is a claim by Regenerative Agriculture practitioners and others that the addition of artificial fertilizers has a detrimental effect on soil biology.
Earthworms are a key indicator of soil health and are at the top of the soil biology food chain.Â If artificial fertilizers were detrimental to soil biology then you would expect to see lower earthworm numbers in fertilized soils. The opposite is true.
The graph below shows the impact of adequate nutrition (through artificial fertilizers) on earthworm numbers per square metre, at two sites in North East Victoria.Â Not only were there more earthworms on the high fertility paddocks but those earthworms were fatter.Â Earthworms need to eat as well.
Improved Nutrient cycling
Meridian Agâ€™s Andrew Speirs looked at the feeding habits of dung beetles on the Long Term Phosphorus Experiment at Hamilton PVI.Â He found that dung beetles actively sought out the dung from sheep grazing the high fertility treatments in preference to the dung from poor quality pastures.Â As a result mineral cycling was four times greater on the high fertility treatments.Â This is evidence of improved nutrient cycling in adequately fertilized pastures
Show us the Evidence
The evidence is clear that conventional pasture systems when properly managed can enhance water, solar, biological and mineral cycles.Â This is not to say that there cannot be improvements still.Â An open mind is needed on Regenerative Agriculture and if it can clearly demonstrate benefits in environmental, animal welfare and financial factors over and above what conventional agriculture is achieving, it should be taken seriously.
Article by Jim Shovelton