Tilling is killing the atmosphere and soil life. If soils could talk...
If bare soils continue to lose carbon, we are unlikely to be able to stop climate change, even after we have eliminated the use of fossil fuels. (Allan Savory)
Degradation of soils from intensive tillage and its carbon footprint are absent from the mainstream debate about climate change. At the same time, healthy carbon-rich soil is what humanity’s been destroying more rapidly than any other resource on the planet. Humans obtain more than 99.7% of their food from the soil and less than 0.3% from the oceans and other aquatic ecosystems. 30% of the world’s cropland has been abandoned in the last 40 years due to soil depletion. Global croplands continue to be abandoned at the rate of 10 million hectares (25 million acres) a year. It takes hundreds of years for an inch of topsoil to form and a single turn of a rotavator blade to destroy it.
There are 3 major carbon sinks on the planet: oceans, soil, and green plants. Although oceans store most of the Earth's carbon, soils contain about 75% of the carbon pool on land, which is three times more than the amount stored in vegetation and animals combined. Soil’s ability to sequester immense quantities of carbon dioxide out of the atmosphere could reverse global warming if we transitioned to no-till soil management.
'I'm not dirt'
Soil is a living community with complex architecture and fragile ecosystem that we intoxicate with chemicals, mutilate by tilling and starve by monocropping - all the conventional farming practices.
Soil is as fertile as the amount of carbon it holds and the number of microorganisms it harbors. Tilling/digging releases carbon from soils into the atmosphere and decimates microbial activity, depleting the soils and heating the planet. This is why nature doesn’t dig with spades or tillage machinery. It “digs” with earthworms and builds fertility by sequestering nitrogen and carbon from the atmosphere during photosynthesis.
Just like us — soil needs to eat. And just like us, it needs a diverse organic diet. It is important to understand that the soil microbiome feeds off plant roots, not fertilizers. Plant roots stimulate fungal mycelium to produce soil aggregates that make soil well-drained and moisture retentive. If you grow a single type of plant on a patch of tilled land, you starve your soil. This is why nature tries to maintain biodiversity. Soil ecosystems contain and support the greatest amount of biodiversity on the planet. We must mimic nature, mimic its ecological choreography, rather than cheat it with chemicals or intrusive technologies, dragging us further in the destabilizing hell of the Anthropocene in the constantly heating world.
Healthy soil microbiome is capable of pulling nutrients from the soil to plants, boosting their resistance to pests/fungal diseases/drought/ frost, and other stress factors. Tilled soils - short on carbon and microbial activity - lose this ability. A study found that modern tomatoes are more sensitive to foliar diseases because they have lost their ability to interact with soil microbes. Researchers now hope to identify the wild-type tomato genes responsible for soil microbe interactions and reintroduce them to modern varieties, to cut down on the number of pesticides they require for protection. This is how we become hostages of 1) synthetic fertilizers to make our crops grow, 2) bee-killing pesticides and fungicides to keep our crops alive, 3) and let's not forget about toxic herbicides annually sprayed in preparation for sowing.
Eat That: Soil depletion and Autoimmune Diseases
Traditional cropland management with its monocropping, intensive tillage, petrochemical fertilization, application of pesticides, fungicides, and herbicides - has destroyed conditions for soil biology to thrive. The nutrients from synthetic fertilizers, while boosting higher yields, do not add nutritional value to the grown food. Annually tilled and fertilized soils are not short on nutrients, they are short on biology. And it is the biology that releases nutrients vital for human gut health. Due to the reduced microbial activity in tilled soils, nutrients from such soils cannot be efficiently transferred to plants. As a result, the nutritional value of today’s food is lower than at any point in history and it has been increasingly linked to the numerous autoimmune disorders which can be cured with fecal transplants. It is another factor that indicates the link between soil microbiome depletion and the imbalance in the human gut microbiome. There has been growing consensus in the scientific community linking poor soil health to the dramatically increased incidence of autoimmune disorders in recent years and insisting that genetic susceptibility alone is not sufficient to drive the dramatic rise in autoimmune diseases (see mutiple references below).
Tillage and global warming
Health issues aside, tilling releases gigatons of CO2 and other greenhouse gases from soil annually, accelerating global warming. 'The NASA capture below (Fig. 1) shows the level of carbon dioxide (red and purple) in the northern hemisphere on April 23, 2006. In March and April, when farmers are tilling to prepare to plant their crops, carbon dioxide is at its heaviest'.
Tilled soils get compacted when they sit bare because only plant roots are capable of stimulating fungi to produce soil aggregates that create pore spaces for water and oxygen to infiltrate. The water that sits on bare soil evaporates. Vapor accounts for 95% of the greenhouse effect. At most 3% of the CO2 present in the atmosphere results from the burning of fossil fuels. And CO2 constitutes only 0.04% of the atmosphere, but unlike vapor (which is too volatile) CO2 is a long-lived greenhouse gas this is why the smallest amount of anthropogenic CO2 is enough to contribute to global warming.
According to the Columbia University Earth Institute 'soils remove about 25% of the world's fossil fuel emissions each year. Because almost half the land that can support plant life on Earth has been converted to croplands, pastures, and rangelands, soils have lost 50 to 70 percent of the carbon they once held. This has contributed about a quarter of all the manmade global greenhouse gas emissions that are warming the planet... It is estimated that with better soil management, global croplands have the potential to store additional 1.85 gigatons of carbon each year – as much as the global transportation sector emits annually.'
Every time you see how rapidly soil is trying to heal itself and lock carbon by desperately shooting weeds up onto the surface after it has been dug, know - it's because soil is not meant to be bare.
Monocropping and soil depletion
Most soil scientists agree that it takes hundreds of years for an inch of fertile topsoil to form (topsoil is the upper layer of soil, usually between 2 to 8 inches in depth, that contains most of the ground's nutrients and fertility). This formation occurs only if the soil is in uninterrupted contact with diverse root systems. The lush green strip of grass that you can see in the middle of Fig. 2 below has shown no indication of moisture stress during a major drought in Australia in the strip that has not been tilled for 30 years and is populated with a mix of perennial grasses, not an annual monoculture. The remaining withering part of this field is a monocrop, struggling to grow in the annually tilled and chemically stimulated imitation of fertile soil.
Fig. 2 above demonstrates how vegetal diversity on the soil surface enables the microbiome to maintain well-structured topsoil with high water-holding capacity. Just like us humans, soil life needs a diverse, regular diet. It can’t live off a seasonal monoculture. Soil covered in monoculture is starving and can neither deliver nutrients to crops nor maintain the resistance of plants to drought.
Fertile, humus-rich topsoil is only a product of photosynthesis and microbial resynthesis. Soil life does not need any force-feeding with fertilizers. Not even deceptively harmless nitrogen-rich manure because the atmosphere itself is 78% nitrogen and this is the way plants have obtained their nitrogen for millennia.
In Fig. 3 below you can see the results of a research trial in North Dakota during a very dry growing season of 2006 with only one inch of rainfall from seeding in May to harvest in late July. By end of July, all of their trial mono-crop fields looked like the one on the right. But where they had sown a multi-species mix, their fields resisted drought (left).
Both photos were taken on the same day on 31 of July 2006. This is what happens when soil life has a balanced diet. Healthy soil protects crops from drought, and also boosts nutrient uptake. This trial was not anecdotal. They've got all the data – the dry matter information, protein contents, energy contents, and so on. Their multi-sown crops were nutrient-rich with vitamins and minerals that protect animals and humans from autoimmune diseases. This is how productive farming can be if it is built on a resilient ecosystem. It also shows that the measure of economic output needs to be reconsidered. With an economy that measures everything in quantity, rather than in quality, the growth eventually turns into malignancy.
Studies confirm that regenerative agriculture increases farmland’s profitability by reducing input costs and labor, even with an initial diminished yield. A study by Ecdysis Foundation found that regenerative practices are 78% more profitable than conventional farms. Regenerative farmers are able to benefit from a higher-value product, even if they aren’t able to produce the same high yields in terms of bushels per acre. It suggests that soil organic matter is a more important driver of approximate farm profitability than yield. Stronger crops cost less to produce.
There is not a day goes by that we are not learning more as to how soil functions. Even though it may take industrial crop producers a few decades to accept the urgency of transitioning to regenerative soil management, home gardeners can do it without unnecessary delay. I did. Just make sure you don’t use commercially extracted peat or peat-based compost in your garden. I explain why in my next post.
Vi Brazh for PARKLIFE Collab (SOIL) - interdisciplinary project of the LSAD Fine Art students, in collaboration with the 39th EVA International Biennial of Contemporary Art and Limerick City Gallery of Art. All information in this blog is based on my research as part of Year 4 course in Fine Art- Painting, LSAD-TUS.
Blum, W.E.H., Zechmeister-Boltenstern, S. and Keiblinger, K.M. (2019). Does Soil Contribute to the Human Gut Microbiome? Microorganisms, [online] 7(9), p.287. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6780873/ [Accessed 8 Apr. 2020].
Can Soil Help Combat Climate Change? State of the Planet, ( February 21, 2018).
Danzer, C., Mattner, J. Impact of Microbes on Autoimmune Diseases. Arch. Immunol. Ther. Exp. 61, 175–186 (2013). https://doi.org/10.1007/s00005-013-0216-3
Global Sequestration Potential of Increased Organic Carbon in Cropland Soils. Scientific Reports, 7(1).Zomer, R.J., Bossio, D.A., Sommer, R. and Verchot, L.V. (November 14, 2017).
How Tilling Is Killing The Atmosphere: A Year Of Carbon Dioxide Accumulation. Joyce Farms,(July 20, 2018)
How to fight desertification and reverse climate change. Allan Savory, (February 2013)
Laura E.G., Marie J.E., Susan C.A., Ran B., Gideon B., Jenny T., Elizabeth A.A. Genes, geology and germs: Gut microbiota across a primate hybrid zone are explained by site soil properties, not host species. Proc. R. Soc. B: Biol. Sci. 2019;286
Mycorrhizal Fungi (mycorrhiza) Myth. Garden Myths. (2017).
Mycorrhizal Fungi, The Proof is in the Roots! Green Bean Connection, (2013).
No-till on the Plains 2019 Christine Jones Community Tipping Points (Youtube), (February 13, 2019)
Pickles, B.J., Truong, C., Watts‐Williams, S.J. and Bueno, C.G. (2020). Mycorrhizas for a sustainable world. New Phytologist, 225(3), pp.1065–1069.
Rothschild D., Weissbrod O., Barkan E., Kurilshikov A., Korem T., Zeevi D., Costea P.I., Godneva A., Kalka I.N., Bar N., et al. Environment dominates over host genetics in shaping human gut microbiota. Nature. 2018;555:210–215. doi: 10.1038/nature25973.
Stone M. Root and gut microbiomes are strikingly similar. Microbe. 2016;11:107–110 doi:10.1128/microbe.11.107.1.
Stop abusing land, scientists warn. BBC News, (August 4, 2019).
Understanding Soil Microbes and Nutrient Recycling. Osu.edu., (September 7, 2010).
Von Hertzen L., Hanski I., Haahtela T. Natural immunity. EMBO Rep. 2011;12:1089–1093. doi: 10.1038/embor.2011.195.
Wall D.H., Nielsen U.N., Six J. Soil biodiversity and human health. Nature. 2015;528:69–76. doi:10.1038/nature15744.
Why 500 million bees have died in Brazil. BBC News, (August 20, 2019)
Zhou, D.R., Bai, Z.M., Zhang, H.L., Li, N., Cheng, F.D., Jiang, H.T., Mao, C.B., Sun, X. and Lu, Z.H. (2018). Soil is a key factor influencing gut microbiota and its effect is comparable to that exerted by diet for mice. F1000Research, 1588(7).