The bioeconomy is starting to act on soil health, the industry’s greatest – and most neglected – asset
The dirt on soil
Without soil, there is no feedstock. Without feedstock, no renewable materials. Yet despite its importance in the bioeconomy, soil health has historically been neglected by the industry and its consumers, particularly when compared to the issue of carbon emissions.
Perhaps soil is under-valued because it appears cheap and ever-abundant. However, like other seemingly infinite natural resources, human activity has been degrading it for decades.
In 2017, the UN announced that we are losing 24 billion tonnes of fertile soil per year globally. A 2022 FAO announcement held even more foreboding implications for the long-term prospects of humanity: 90 % of the earth’s topsoil, it said, is likely to be at risk by 2050.
The disappearance of topsoil – that thin layer around the earth which supports our entire food system – stems from the way we farm.
Modern intensive agriculture attains ever-higher yields through practices like repeated tilling and over-applying highly concentrated synthetic fertilizers. These techniques are environmentally damaging on multiple fronts: first, agricultural chemicals are extremely fossil-fuel intensive to produce. Apart from this, farmers are encouraged to over-use synthetic fertilisers, meaning excess chemicals leach into the environment and destroy habitats.
Soil also take a hit from intensive farming: overworked, overdosed, and exhausted by supporting vast monocultures year upon year, it loses natural properties that could support crop growth without the need for increasing toxic inputs.
Crop scientists and international bodies now agree that we must implement new forms of agriculture – sustainable alternatives that use organic materials and natural ecological processes to restore and preserve soil quality.
One start-up integrating these ideas into its operations is Spiber, a Japanese bio-textile company that produces a vegan, petrochemical-free dupe for natural spider silk.
Spiber offers a model for soil initiatives
Spiber is now a major name in the bio-manufacturing sector after having bagged $565 million in 2021 to scale production.
Spiber’s spider silk textiles are made using precision fermentation, a low-carbon bio-manufacturing method useful for creating both food and non-food chemicals by exploiting the metabolism of microbes.
Spiber’s flagship product is Brewed Protein. While the name might conjure up images of artisanal beer, this is a bio-based polymer designed to replace petroleum-based materials in clothing and upholstery.
The molecular makeup of Brewed Protein is indistinguishable from natural spider silk, which is one of the world’s strongest organic substances.
Spiber has been lauded by commentators and particularly by segments of the fashion industry that want to move away from petrochemical staples like polyester. However, Spiber is moving beyond greenhouse gas reductions to include soil health within its sustainability remit.
Farmed crops lie at the heart of Spiber’s bio-manufacturing process. Spiber makes its Brewed Protein by using custom-reared microbes to convert corn dextrose into polymers. Just like any industrial process, bio-manufacturing needs high volumes of feedstock – in this case, the humble corn.
In September 2022, Spiber announced a partnership with ADM, an agricultural supply chain services company, to implement regenerative agriculture on the Iowa farms that supply the crop for its fermentation process.
One part of this scheme involves the two partners working with the National Fish and Wildlife Foundation and the US Department of Agriculture to help farmers plant cover crops across 500, 000 acres of land. Cover crops are plants planted to cover the soil to prevent erosion, retain moisture, and enrich the soil when they decompose.
Regenerative agriculture is an umbrella term for diverse farming practices, like cover-cropping, that make conservation an integral part of crop production.
One example is agroforestry, which sees farmers planting trees and crops together. In arid regions, this helps retain moisture without the need for irrigation. Permaculture is another, which focuses on growing crops within managed but diverse ecosystems.
Spiber is not the only bio-based company reaching for soil-supporting cultivation methods. The company that grows corn feedstock for CovationBio – formerly owned by DuPont before its sale to China’s Huafon Group – signed up to a programme in regenerative agriculture in September 2022.
What soil gives us
Sunshine, soil, and water are the three non-negotiable elements of plant photosynthesis. This means that soil is not just the basis of a robust bio-based supply chain but the keystone of all life on earth.
All planetary food chains can be traced back to plants: the only life-form capable of transforming sunlight into glucose. In this form, energy originally from sunlight can be consumed and used by other living organisms.
Thanks to the sunlight-to-energy conversion process conducted by plants, 95% of our food is directly or indirectly produced from the soil. It is what provides plants with essential mineral nutrients that power the photosynthetic process.
The plant-ready nutrients in soil derive from centuries, sometimes millennia’s-worth, of decomposed living matter and broken-down rock. Without the nitrogen, phosphorus, potassium, and other elements that accumulate in this way, plants simply would not be able to grow.
But there is much more to soil health than nutrient levels. The science of soil health is complex: one reason that the bio-based community and the public at large is only just beginning to realise its importance as a sustainability metric.
The complexity of soil health
Soil might be everywhere but not all types can support healthy crop yields. Its fertility also depends on microscopic chemical and biological variables that are invisible to the naked eye and interact in complex ways.
In fact, one of the main problems with the paradigm of intensive agriculture is that it only assesses soil health in terms one metric: mineral nutrient levels. This partly explains why its default method for increasing and maintaining yield is to keep pumping poor soils with chemical fertilisers.
While crop-ready soils must contain a rich mix of mineral nutrients, measuring the amount of minerals is not enough to assess its quality. Over the last 40 years, soil science has uncovered the massive agricultural and biodiversity benefits of soil microorganisms. Bacterial and fungal communities interact with roots, making them healthier and more efficient at taking up minerals. Adding chemical inputs and planting monocultures tends to disrupt these communities.
By comparison, the problem of greenhouse gases and reducing emissions is relatively simple to grasp and communicate. We know, for example, that atmospheric carbon is now at 421 parts per million. This means that for any million gas molecules in the atmosphere, 421 of them would be carbon while the remaining portion would be other gases.
The problem of carbon lends itself to simple quantification, making formulating solutions (if not implementing them) quite straightforward: switching to low-carbon energy and lower consumption are the main ways we can stabilise the climate.
There is no similarly clear pathway for agriculture. There is no single optimum form of soil-supporting agriculture – the most suitable set of sustainable farming techniques will be diverse as the varied regional climates, terrains, geophysical features, economies, and cultures that cover the globe.
The bioeconomy faces a reckoning
The scientific and NGO consensus, nonetheless, is that agricultural transitions must accompany decarbonisation.
Intensive agriculture emerged only in the last eighty years but now dominates global production in crops – whether destined to become food, feed, or industrial materials like biofuels and biomaterials.
Like the food system, the bioeconomy is reliant on intensive agriculture. As it stands, therefore, it is contributing to an ecological crisis undermining the very foundations of its own value chain.
Spiber’s new focus on soil health is a response to projections that the bioeconomy will soon become environmentally unsustainable along current growth projections.
Although making goods from biological sources tend to require far fewer carbon emissions relative to making them from petrochemicals, the sheer amount of plant material needed to scale hemp bio-replacements for plastic or first-generation biofuels still places massive strains on the environment.
Bioeconomy growth will depend on obtaining higher and higher volumes of organic feedstock. With this comes the concern that more land will become subject to the chemical pressures of intensive agriculture, undermining the bioeconomy’s claims to underpin a sustainable economic pathway.
Already, the non-food biobased economy is taking up significant land in Europe. A 2019 study in the journal Environmental Research Letters found the amount of EU land used to grow non-food bio-resources such as make biofuel, polymer, and detergent increased from 10.4 to 14.6 Mha between 1995 and 2010. Oil crops made up 43% of this.
Figures on the EU bioeconomy’s true land footprint was higher. When the study looked at the total feedstock that fed the European bio-processing sector in 2010, it found that it used 19.8 Mha of cropland. A quarter of this land was located in Asia.
On top of this, the EU also imports ready-processed bio-products for sale to consumers. In 2010, this alone demanded 4.4. MHa of cropland in China, 3 Mha from the rest of the Asia pacific, and the USA at 1.6 Mha.
Another study published in the Journal of Risk and Financial Management last year warned that projected bioeconomy growth would soon exceed the sustainable available land capacity. It emphasised that the sector must urgently integrate with the organic chemicals industry to replace the synthetic inputs it currently relies on for its feedstock.
Can the bioeconomy preserve its greatest asset ?
If the biomaterials industry wants to live up to its sustainability promise, it must look at how it can return to the soil as much as it extracts from it.
Many companies involved in the bio-based value chain now accept that the ground beneath our feet serves powerful functions: as a carbon sink that can help prevent emissions leakage into the atmosphere, as the source of all crop production, and as a key element in a secure and sustainable bio-based feedstock supply chain. Spiber could not, for example, operate without its workaday crop feedstock of corn.
While carbon reduction has so far been its main target, soil health is slowly becoming a key target for the bio-based industry. If names like Spiber lead, others will likely follow.
Yet, as we have seen with the murky world of carbon reporting and offsetting, only transparency and regulation will ensure corporate initiatives in sustainable agriculture live up to their vaunted ecological claims.
Reporting procedures for regenerative farming schemes are currently even less developed than for carbon emissions and offsetting – something that might come back to bite companies more keen to market their green credentials than to building genuinely lasting and sustainable feedstock chains.