What is Regenerative Farming, from a Scientific Standpoint, and Why Should We Care?
How do we keep the word “regenerative” from being watered down by the agribusiness industry?
This article describes a groundbreaking study related to regenerative agriculture.
Regenerative agriculture might be defined as that which regenerates the soil and the surrounding ecosystems, as opposed to conventional agriculture, which typically degrades the soil and surrounding ecosystems, including insects, birds and waterways.
Can we define regenerative agriculture in terms of a scoring system that gives higher scores to farms with a greater number of regenerative practices?
How do we distinguish between conventional and regenerative agriculture? We need a definition that allows for shades of gray. That way we can determine whether regenerative practices actually lead to positive outcomes ecologically.
That’s what this study has done. It has devised a scoring system. The scoring system assigns a higher score to regenerative farms, based on the number of regenerative practices. If regenerative farming actually serves to regenerate soil and ecosystems, then farms with a greater number of regenerative practices will exhibit more positive outcomes.
The study is titled: Defining and validating regenerative farm systems... | F1000Research
The authors are:
Tommy L.D. Fenster
Claire E. LaCanne
Jacob R. Pecenka
Ryan B. Schmid
Michael M. Bredeson
Katya M. Busenitz
Alex M. Michels
Kelton D. Welch
Jonathan G. Lundgren
Lundgren and colleagues want a way of defining regenerative agriculture, because without a definition, it becomes just a word and anyone can claim to be regenerative.
Which farming systems did they study?
They chose to study three systems, one involving annual crops, one involving trees and one involving livestock.
Study systems included:
cornfields of the Upper Midwest,
almond orchards of California, and
rangeland systems of the Northern Plains.
What questions did they ask?
They examined the following questions:
How does the land respond?
How does the soil respond?
How does the water respond?
How much water soaks into the ground?
How does the nutritional content of the soil change?
How do pest populations respond?
Do yields go up?
What happens to farm profits?
What are the outcomes that they measured?
The outcomes they are measuring include:
soil carbon and organic matter,
soil micronutrients,
water infiltration rates,
soil microbial communities,
plant community structure,
invertebrate community structure,
pest populations,
yields, and
profit
This means that if regenerative agriculture actually serves to regenerate the soil and the ecosystems, then farms that have higher scores (defined below) will exhibit these nine items in greater measure.
Hereafter, I will set forth quotes, with each quote followed by an explanation.
Did regenerative outcomes correlate to farm scores?
“Regenerative outcomes were strongly correlated with our approach to farm scoring.”
We will describe farm scoring below, but for now …
The following responded positively to regenerative practices:
Soil organic matter
total soil carbon
total soil nitrogen
Phosphorus
calcium
sulfur
All of the above are important components of healthy soil.
Note that carbon, nitrogen and phosphorus are nutrients for which farmers pay dearly. These nutrients eat into farm profits. So if they can occur naturally in the soil, this can save farmers a lot of money and increase farm profits.
Do regenerative practices help the soil soak up more water?
“Water infiltration rates were significantly faster in more regenerative almond orchards.”
Water infiltration rates tend to strongly indicate high soil quality.
The more regenerative almond orchards are the ones that have planted crops in between the trees, the ones that do not use pesticides, etc., thus resulting in higher soil quality.
Do regenerative practices result in greater quantities of soil microbes?
“Soil bacterial biomass and Haney soil health test scores were higher as cropland incorporated more regenerative practices.”
Biological diversity starts in the soil. The Haney soil test measures biological activity in the soil.
The Haney soil test is the industry standard soil test for regenerative agriculture.
Do regenerative practices correlate to greater plant diversity and biomass?
“Plant species diversity and biomass increased significantly with the number of regenerative practices employed on almonds and rangelands.”
Plants are largely the basis of life on land. At least they make up most of the biomass on land, about 80% of it. If you have increases in plant diversity and increases in plant biomass, then that means you will have more biological diversity overall, and more total biomass.
Do regenerative practices result in greater diversity of insects, spiders, worms, etc.?
“Invertebrate species diversity and richness were positively associated with regenerative practices in corn, almonds, and rangelands, whereas pest populations and almond yields were unaffected by the number of regenerative practices.”
Invertebrates refers to insects, spiders and earthworms, and other animals. Invertebrates provide food for vertebrates, such as birds an mammals. Invertebrates also provide pest control services. For example, spiders control populations of insect pests.
Do regenerative practices increase yields or profits on corn farms and almond orchards?
“Corn yields were negatively associated with more regenerative practices, while almond yields were unaffected by the number of regenerative practices. Profit was significantly higher on more regenerative corn and almond operations.”
Farmers have been trained to focus on yield, which means the total output of the crop. But high yields do not lead to profits if your expenses are high. Regenerative farming can reduce expensive inputs, thus increasing profits, even if yields decline.
How do the authors define regenerative agriculture?
The authors define regenerative agriculture in terms of five practices:
1) reduce or eliminate tillage,
2) never leave bare soil,
3) maximize plant diversity and productivity on a farm,
4) integrate livestock and cropping operations.
5) reduce or eliminate synthetic agrichemicals.
How does the scoring system work?
“Regenerative practices were scored as 1, and conventional practices were scored as 0.”
Farm practices in cropland and orchards:
fertilizer
Herbicide, fungicide, insecticide
tillage
cover crops
field margins/hedgerow
organic amendments
grazers
You can click on this link to Table 1 to see how the scoring system works. For each practice deemed to be regenerative, the farm gets a score of 1, otherwise 0. You add up all the regenerative practices (e.g., refraining from the use of chemical fertilizers, herbicides, etc.), and you get a composite score that ranges from 0 to 8.
What are regenerative practices in croplands?
“In croplands (Table 1), regenerative includes:
the elimination of tillage,
maintaining ground cover through planting cover crops or fostering resident vegetation,
planting hedgerows, and
use of organic amendments (compost, manure, mulch, compost teas), and
grazing,”
What are conventional practices in croplands?
In cropland, conventional practices include:
Tillage,
maintaining bare soil, and
spraying synthetic insecticides, herbicides, fungicides,
use of chemical fertilizers”
What are the conventional practices in rangelands, i.e., livestock grazing?
“In rangelands, management systems were defined by their:
stocking density,
rotation frequency,
the duration that the pasture rested following grazing, and
use of ivermectin products.”
Composite scores ranged from 0 to 8.
Longer rest periods for livestock pasture are considered regenerative
“ ... rest periods on ranches were scored as continuously grazed (no rest; scored as 0), allowed to rest 1 > and < 30 d (1), or >30 d (2) over a growing season.”
“Matrix of farm practices in rangeland include
ivermectin,
stocking density
rotation frequency and
rest.
How did they score the use of ivermectin in livestock?
“Use of ivermectin in the ranches was categorized as
high (multiple applications during a year; scored as 0),
low (single annual use, not applied during grazing period; scored as 1) and
no ivermectin (scored as 2).”
Ivermectin is a dewormer that also acts as an insecticide. If a cow has been dewormed, then the cow patties can kill insects that would otherwise feed on them.
That’s why the scoring system gives you a 0 for multiple applications of ivermectin, a 1 for a single annual use and a 2 for no ivermectin.
High stock density is considered regenerative
“Operations’ stocking densities (animal units [AU] per ha), were categorized as fewer than 5 animal units (AU) per ha (scored as 0), 5–10 AU per ha (scored as 1), and more than 10 AU per ha (scored as 2).”
Regenerative grazing is characterized by more animals per acre, not less. The reason is that this more closely simulates, or mimics, nature.
Higher rotation frequencies (of livestock) are considered regenerative
“Operations were categorized as having a rotation frequency of 30 days or more (scored 0), between 10–30 d (scored as 1), and less than 10 d (scored as 2).”
Regenerative stock grazing is characterized by more frequent rotation of the livestock.
The study found a strong correlation between regenerative practices and desired outcomes
“Our approach to defining farms based on a small suite of carefully chosen practices was strongly associated with several key metrics that define regenerative systems, including soil health, biodiversity promotion and profitability.”
In other words, the more regenerative practices on a farm, the better outcomes you see in terms of soil health, biodiversity and profitability.
Less herbicide use leads to greater plant diversity
“All of the regenerative orchards stopped the use of synthetic herbicides, and this likely contributed to greater plant diversity.”
Naturally, when you reduce herbicide use, you are killing fewer plants, and this is going to lead to greater plant diversity.
The effects of short-term, intense grazing
“In rangelands, short-term, intense grazing stimulates plant communities to diversify and grow if the plant community is allowed to rest following a grazing event.”
In nature, grazers tend to travel in compacted herds, resulting in intense grazing for a short duration. Regenerative grazing mimics this natural pattern.
Soil health
The paper discusses some of the ways in which regenerative practices lead to positive outcomes, in terms of soil health
Plant roots, sugars and microbes
“Plant roots provide the needed polysaccharides [complex carbohydrates] for microbial communities to grow and perform key nutrient cycling services (Philippot et al., 2013).”
Thus, when you have a greater diversity and biomass of plants, they improve the soil, making nutrients more readily available to plants and grazing animals.
Physical soil structure
“Physical properties of soils are also influenced by plants, including water infiltration rates, soil aggregate structure, bulk density, etc. (Gulick et al., 1994; Liu et al., 2005).”
When you have more plants, you have better soil that is better able to absorb water.
Plant diversity and biomass
“Plant diversity and biomass scales positively with the diversity of nearly every other group of organisms (Bianchi et al., 2006; Saunders et al., 2013; Zak et al., 2003), and thus plant communities are a driver of biodiversity within agricultural habitats.”
When you have a greater diversity and biomass in plants, this is good for every other group of organisms, including insects and soil microorganisms.
Phosphorous
“Phosphorous, a mined agricultural nutrient, is becoming increasingly rare and is available at significant economic and environmental costs (Alewell et al., 2020), so enhancing the plant-available forms of phosphorous that are present in the soils is an important outcome of regenerative agriculture.”
Regenerative practices increase the mass and diversity of plant communities and improve the quality of the soil. Thus, nutrients such as phosphorus occur naturally in the soil, reducing or eliminating the need to purchase fertilizers.
Calcium and sulfur
“Micronutrients calcium and sulfur were also enhanced by increasing the number of regenerative practices in almonds.”
In regenerative systems, calcium and sulfur become more prevalent.
Water infiltration rates in almond orchards
“In almonds, water infiltration rates were significantly improved by regenerative production practices.”
Regenerative practices improve the rate at which water soaks into the ground, also known as infiltration rates.
Regenerative practices include refraining from herbicides, insecticides, fungicides and fertilizers. This naturally leads to greater plant diversity and improved soil biology and soil organic matter, making the soil absorb water much more quickly.
Water scarcity
“Water is becoming more scarce (Burri et al., 2019), especially in California (Mall & Herman, 2019), as climates continue to change and ground and surface waters are exhausted from conventional agricultural practices.”
When rainwater readily soaks into the ground, this means more water becomes available for crops, wells, streams, plants and soil.
To till or not to till
“This data supports the argument that no-till practices are an indispensable core component of regenerative agriculture, and argues in favor of mandating that regenerative operations be no-till.”
Tillage disturbs the soil, unlike anything that occurs in nature. Tillage destroys the soil structure and thus the soil’s capacity to absorb water.
Biodiversity among “all organismal groups”
“All organismal groups measured were enhanced as farms became more regenerative.”
This is another way of saying that regenerative practices increase biological diversity, which is the measure of ecological health.
Invertebrates
“Invertebrate biomass, diversity, and abundance in the soil, on the soil surface, and in the vegetation were positively affected by regenerative practices in all three study systems.”
With greater invertebrate biomass, diversity and abundance, you have more food for vertebrates, such as birds and mammals, and also you have natural pest control, because diversity means insect predators are abundant.
Conclusion
Corn cropping systems, almond orchards and grazing systems all positively affected biodiversity, soil health, water infiltration rates, farm profits, etc.
This study creates a situation where scientists and farmers can work together to determine which practices are truly regenerative. It is a powerful tool for farmers, scientists and policymakers.