What is Regenerative Agriculture?
Last edited - 02 Feb 19
Regenerative Agriculture describes a variety of agricultural practices that focus on soil health and biodiversity. In focussing on soil health, regenerative agriculture aims to produce higher quality and more nutrient dense foods.
The traditional European agricultural model, which dominates around the world, came out of the 'Agricultural Revolution' of the 18th and early 19th centuries. A number of changes in British agricultural technology and practices resulted in greater production efficiency, reduced labour costs and a change to larger scale farms. While this freed up talent and labour for the growing industrial revolution, it left us with a legacy of degrading soils, degrading ecosystems, reducing nutrient density and degrading human health. Not since the dawn of the Neolithic or farming era, had such a large step change in food production, quality and human health occurred.
Modern industrialised monoculture agriculture is highly dependent on pesticides, herbicides, synthetic fertilizers, diesel and iron. Much of the focus of industrialised ag is on 'yield'. You'll often hear the claim that these yields must increase further if we are to feed the earth's growing human population.
Unfortunately, all this 'yield' comes at a cost. Industrialised monoculture agriculture is the single most destructive human activity with regard to natural ecosystems and wildlife habitat loss. Rice and cotton are the most destructive crops, closely followed by soybeans and a multitude of other grains and pulses (beans, peas and lentils) and oilseed crops. A cotton coat results in over 10 times as many animal deaths as a fur coat due to habitat loss.
In addition, while produced in large volumes, these modern agricultural products tend to be high in carbohydrates, low in usable proteins and low in essential micronutrients. In addition, pesticide and herbicide residues are being found in increasing quantities in these products.
In addition, the soils we depend on are degrading at a terrible rate. Each human requires about 1/2 ton of food per year to live a healthy life. To produce that 1/2 ton of food, we currently lose about 10 tons of topsoil per year through erosion and degradation of mineral and biological resources. Soil organic carbon, the cornerstone of healthy soils, has been falling steadily for nearly a century across North America, a pattern that matches much of the world. Clearly, this is not a sustainable situation.
A few key points are worth noting:
1. Removing the grain from a crop removes about 1/3 of the carbon stored by a crop during a year's growing season.
2. Removing the straw removes another 1/3 of the annual carbon storage.
3. Tilling the soil once releases about 1/3 the annual carbon storage back into the atmosphere. Assuming the straw was removed, tilling twice puts the field into a 1/3 deficit.
4. Synthetic fertilizer application causes localised 'burning' of soil biology with a resultant additional release of soil carbon. In addition, this burn kills the biology, slowly sterilising the soil over time.
5. A monoculture crop will support, in general, less than 10 insect species and even fewer birds/rodents etc.
6. A monoculture crop reduces the nutrient quality and diversity needed for pollinator (bees etc) health and survival.
7. I could go on, but that's a fair flavour to be starting with.
All this has been accompanied by an epidemic of autoimmune disease, obesity and a plethora of other diet related human health problems. Logically, it can be inferred that, as the old saying goes, 'all is not well in the State of Denmark'.
Unfortunately, both the public and government policy makers have settled on 'sustainable agriculture' as their goal. This is unfortunate because sustaining a degraded soil resource, habitat loss and poor nutrient density in foods is not a positive move. Sustainable agriculture does nothing to reverse the long term degradation of the soil or trap atmospheric carbon back in the soil where it's a net positive for the ecosystem. We need to rebuild soil health, improve and expand wildlife habitat and raise nutrient density in our foods. To do this we need a revolution.
A wise man once said:
'If you want to make small changes, change the way you do things. If you want to make big changes, change the way you see things.'
This is where regenerative agriculture comes into play. By concentrating on soil health, regenerative agriculture aims to build topsoil by encouraging the return of essential soil biology, minimising disturbance and using diverse polycultures to return atmospheric carbon back into the ecological 'carbon cycle' where it belongs. In a properly functioning ecosystem, the slow loss of soil carbon and soil nutrients can be reversed.
Carbon storage in agricultural soils can vary between 1 and 5 tons per acre per annum, depending on available precipitation, type/diversity of vegetation and length of growing season. In Alberta alone, the potential carbon storage capacity of agricultural lands approaches a billion tons of CO2 per year!
In essence, to reverse the degradation of our ecosystems, we need to learn how those ecosystems function, learn to mimic them in our agricultural practices. This all starts and ends with soil health.
The five tenants of soil health are:
1. Minimise soil disturbance; no-till if possible. Key soil organisms like arbuscular mycorrhizal fungi (AMF) are damaged or destroyed by tillage.
2. No bare soil. Plant litter on the surface, the 'detritusphere' in technical terms, or 'armour' as most practitioners call it, protects soil from extremes in temperature and weather. It stimulates soil fungi to stabilise the surface, prevents the erosion of sediment and provides a living space for other soil organisms.
3. Diversity. Nature is abhorrent of monocultures. Prairie grasslands ecosystems can support over 140 species of plant. In monoculture agriculture, multi-species mixes of 8+ species are common, and some are using up to 25 species mixes. In it's simplest form, a polyculture crop containing a mix of warm and cool season grasses and warm and cool season broadleaves seems to produce the greatest improvement.
4. Keep a living root in the soil for as long as possible. Soil health means soil that is ALIVE. Plants excrete soil exudates to feed the biology in the soil, which return the favour and provide nutrients to the plants. The longer this can be sustained in each growing season, the greater the soil health. Polyculture cropping systems have proven they can extend the growing season by at least two weeks at either end of the season, sometimes longer. Biology heats up the soil and stimulates growth in the spring and sustains it in the autumn.
5. Integration of grazing herbivores. 40+% of the world's land surface was once covered by a grasslands ecosystem and these ecosystems are highly dependent on the influence of mob grazing herbivores, particularly ruminants acting and moving under predator pressure. Studies over the last 60 years have demonstrated that these herbivores are 'keystone' species, meaning that the ecosystem cannot survive without them. In agriculture, domestic livestock can be used to simulate the effects of these wild herds. In 'conservation agriculture', we take the additional step of returning to wild species.
It is interesting to note that a significant percentage of plant species in native grassland ecosystems rely on animal hooves to re-seed the plant. The plants and animals are co-dependent with the plants feeding the animals and the animals re-seeding the plants. This brings us to two more points:
1. Removing grazing herbivores from the ecosystem results in a loss of biodiversity and a loss in carbon sequestration in top soil. The 'science' that labels grazing animals as bad for the environment is not just poor science, but it's totally wrong. Our grassland ecosystems depend on grazing herbivores for full system function and health.
2. In brittle and semi-brittle environments (most grasslands), dead plant matter will simply oxidize if not mechanically trampled into the surface. Hoof action is required to continually regenerate the detritusphere and keep 'armour' on the soil surface.
3. Removing predator pressure allows grazing herbivores to develop 'lazy' herding habits. Wild bison grazed and moved in a density that varied between 25 and 60 animals per acre (75 to 150 animals per hectare). When multiplied over thousands and hundreds of thousands of animals, the animal hoof action replanted many species and trampled most of the plant matter into the surface of the soil where it could break down biologically. This 'mob' herding instinct was a defensive mechanism in response to predators.
4. Where predators are no longer present, modern regenerative farmers and holistic rangeland managers use fencing to force animals to 'mob' up and act in a more wild fashion. Herds are kept bunched up and moved from one paddock to another fairly rapidly, preventing overgrazing and mimicking the effects of nomadic wild herds. Electric fence is particularly effective in this effort as it 'bites'. Animals instinctively treat an electric fence as a predator and they don't 'pressure' the fence the way they'll pressure a barbed-wire or plank fence. This instinct helps the farmer or rancher to simulate wild herd interactions with the soil ecosystem.
Here are a few 'Take-Away' points to note:
1. A 1000lb bison cow, despite emitting 60kg of methane per year, the equivalent of 1610kg of CO2, help store enough plant biomass in a well managed grassland ecosystem to store the equivalent of 29+ tonnes of CO2 in soil carbon. The 32 tonnes of carbon storage per year dwarfs the 1.61 tonnes of emissions.
2. A 1200lb beef cow consumes slightly more dry matter biomass per day, resulting in a carbon sequestration capacity of 33+ tonnes per year. Despite the beef cow emitting 100kg of methane per year (2300kg of CO2 equivalent), her carbon storage contribution of over 35 tonnes more than makes up for her emissions.
The same principle is true for most mob grazing ungulates, particularly ruminants.
In addition, without these animals being used to regenerate grasslands ecosystems, the soil carbon currently retained in topsoil is slowly released into the atmosphere through direct emission and topsoil loss. The result is desertification and long term loss of carbon cycling within the ecosystem. When photosynthetic activity fails, the whole ecosystem fails.
To understand these processes, the following videos provide some guidance: