The innate connection between humankind and soil is one of the most enduring relationships on Earth. Even the origins of the word ‘Earth’ make reference to the ground and land; an explicit and unsurprising testament to the fact that we are a land-dwelling species, with an inexorable dependence on soils.

Perhaps one of the ultimate demonstrations of our deep-rooted connection with soil came when Neil Armstrong stepped down on the Moon. What eerie vistas, what celestial sensations, what overwhelming emotions he must have experienced during that landmark moment, and yet his first words narrated a much more ‘earthy’ story: “…the surface appears to be very, very fine grained, as you get close to it. It’s almost like a powder. […] Yes, the surface is fine and powdery. I can kick it loosely with my toe. It does adhere in fine layers, like powdered charcoal, to the sole and sides of my boots.” Indeed, his first – the first – direct observations of the lunar surface focused on the fine layered, powdery, charcoal-like ‘lunar soil’.

Should we be surprised? The deep-rooted connection between humankind and its soils is borne out in history, and not only in agriculture. Soils have been central to many ways of life since civilisation began. For example, damp clay-based tablets were once used as a surface for what we now believe represents the earliest recorded example of writing (~3,000 BC). Today, we no longer rely on clay tablets, but our relations with soil are nevertheless maintained (albeit once removed) through our need to grow trees, vegetables, and grasses for the cellulose fibres that are used to make paper. Of course, our time-honoured relationship with clay is still observed in many forms of pottery. Holding a cup of tea aloft is a toast not only to a soil’s ability to grow tea plants, but its capacity to be reconfigured into porcelain.

Today – amidst a digital revolution and even a global pandemic – the services provided to us by soils represent one of the most universal and consistent threads sewn in the tapestry of daily life. From the food we eat, to the water we drink, from the clothes we wear, to the gardens we tender, from the energy we consume, to the foundations of our built environment; our soil resources are indispensable, and they are used across both public and private spaces. At grander scales, soils support a diverse array of habitats and ecosystems, they sequester carbon to help abate climate change, and they support the cycling of vital nutrients required by both flora and fauna. Grounding land management policies with principles that safeguard soils is essential if we are to make effective progress towards realising the United Nations’ Sustainable Development Goals by 2030.

Grounded

On World Soil Day last year – the 5th December 2020 – a large and diverse community of researchers, industries, stakeholders, and decision-makers reaffirmed the importance of soil. The official theme this time around was ‘Keep soil alive, protect soil biodiversity’. Unlike many of our natural resources, soil is alive and home to more than a quarter of the planet’s biodiversity. In fact, it is often said that there are more organisms on a teaspoon of soil than there are humans on the planet! Yet only 1% of soil microorganism species are currently known. This World Soil Day aimed to raise awareness about the significance of maintaining healthy ecosystems and human well-being. Through local, national and global symposia, collaborative workshops and multisectorial meetings, the day sought to address the growing challenges in soil management, such as fighting soil biodiversity loss while increasing soil awareness, and encouraging governments, organisations, communities and individuals around the world to commit to proactively improving soil health.

In the UK, the British Society of Soil Science launched a public engagement campaign on World Soil Day to remain ‘Grounded’1. This recognised the need for effective and, in some cases urgent, action to protect and restore soils. Research led by a team based at Lancaster University has recently highlighted that erosion poses a global threat to a soil’s sustainability. Compiling a large database of soil erosion rates from over 255 locations around the world, the team found that 16% of the soils studied would lose their topsoils within the next century if current rates of erosion are not quelled. Meanwhile, urbanisation continues to encroach upon fertile land, leaving soils fragmented, contaminated, and sealed. The British Society of Soil Science suggested three simple actions to support healthy soils, including removing patio slabs and paving to help soils absorb water in heavy rainfall, planting cover crops instead of leaving soils bare, and refraining from using peat-based compost as the intensive mining of peat bogs can damage ecosystems and have larger-scale impacts on climate.

There have been many moments in history when society has been compelled to become more grounded. During World War 2, for example, when cuts to both labour and transportation threatened the stability of conventional food supplies, the public were encouraged to produce their own fruit and vegetables. Nearly three years into the war, most households in the UK were managing their own garden plots, with many public parks also being used for food growing. Similar movements were observed elsewhere. For instance, 20 million citizens in the USA took to the spade, planting ‘Victory Gardens’ in backyards, empty lots, and city rooftops, and producing enough food to equal the total production of commercial operations. Although this level of engagement was not sustained to any great degree after the war, there have been moments of crisis since that have inspired a similar retreat to ‘subsistence’ means.

Eight decades later, and another global conflict ensues – this time with a microscopic enemy that has invaded the lungs of millions. As the COVID-19 pandemic continues to constrain the mobility of goods and people, the need to become grounded has surfaced once more. But what does being grounded look like in 2021? What new and innovative ways of engaging with soils exist that were not possible before now?

Local soils on our doorstep

Constrained to one’s local area, many of us have rediscovered the virtues of our ‘local’ environments; those which, for many of us over the years, may have been neglected in favour of more exotic locations and more thrilling itineraries. Restrictions to travel have permitted us more time to reacquaint ourselves with the parks, gardens, footpaths, and bridleways around our local villages, towns, and cities. For many, national lockdowns have afforded society the time and space to look down. In 2020, public interest in growing fruit and vegetables at home soared in the UK, and allotment waiting lists swelled, with one council receiving a 300% increase in applications. Since more than half of the global population now live in urban areas, weaving food growing into the fabric of urban life could help communities boost the resilience of their fresh fruit and vegetable supplies, improve the health of residents, and help them lead more sustainable lifestyles2. For those with no access to a garden – about one in eight UK households – urban agriculture has recently expanded to other urban spaces, such as rooftops and walls. Not only does this expand food production, but it allows soils to become more of a prominent feature of the urban surface, and our urban lives.

Engaging with one’s local soils does not always require growing plants. Over the last decade or two, soil scientists have worked with communities to develop a number of easy-to-understand and easy-to-deploy citizen science experiments, where non-scientists take an active part in scientific research, be it through making and recording observations (e.g., the Big Butterfly Count) or setting up and/or conducting a basic experiment (e.g., the recent Lockdown Lettuce Beds project)3. In soil science, the use of a citizen science approach can have multiple benefits: it can motivate and educate the public about soils, their functions, diversity, and importance, and can also enhance scientific research, potentially allowing researchers to widen the spatial coverage of their data collection campaign.

One example of a highly successful and globally established citizen science experiment is the Teabag index experiment, developed by a team of researchers at the University of Utrecht, Umeå University, The Netherlands Institute of Ecology, and the Austrian Agency for Health and Food Safety Ltd4. Teabags have been used as a proxy to measure the decay rate of plant material and can provide important insights on the global carbon cycle.

When plant material decomposes, organisms in the soil ‘consume’ the organic matter and convert this to nutrients and soil material. In this process, carbon dioxide is released into the atmosphere, but this is taken up again by the growth of new plants. The rate of decomposition is affected by many different factors, including the humidity, acidity, and temperature of the soil and local environment, the properties of the plant material being decomposed, and the types of organisms present in the soil. Previous research that has sought to understand the effect of these factors on decomposition have used ‘litter bags’ which consist of dead plant material (litter) being added to a small mesh bag. The mesh provides soil organisms the necessary access to the litter, without it becoming lost. The litter bags are installed at a known depth in the soil, left for three months, and then collected. The mass lost between installation and collection is a way of estimating the loss of plant material to decomposition.

In 2010, the ‘litter bag’ experiment was trialled with teabags. In a similar method, tea bags (particularly green tea and Rooibos) are buried in the soil, left for three months, and then retrieved and weighed. Over the three months that the tea bags are in the ground, the tea will decay akin to the decomposition of normal plant material. Since 2010, the method has been developed and published, and a website has been established for the public to take part and submit data to the experiment 4. More than 450 experiments have taken place across the world to date.

“teabags have been used as a proxy to measure the decay rate of plant material and can provide important insights on the global carbon cycle”

Another means by which local communities have engaged with soils and contributed to science is through the mySOIL app5. Launched in 2012, and hosted by the British Geological Survey and Centre for Ecology and Hydrology, this free-to-download mobile application on Apple and Android platforms allows one to anonymously submit basic soils data from any location within Europe, which are then added to a crowd-sourced database and uploaded to a map. Sharing information about soil in one’s local area can include writing a short description, capturing photographs, and/or submitting measurements. Easy-tocomprehend instructions are provided to users who wish to undertake a basic soil pH or soil texture test. To date, the platform has 50,000 registered users, with more than 4,000 data records that are freely available. Recently, the project integrated the mySOIL app into the UK Soil Observatory map viewer, which allows anyone with web-browser access to participate in the project.

Global soils from our doorstep

Re-engaging with local soils represents a step along a path to becoming more grounded. There is a basic, almost primordial, quality about it; the knowledge that, in the moment of placing soil in the cup of one’s hand, and kneading out its essential qualities, one is reconnecting with one’s ancestors. Few activities have such an extensive and rich legacy as the one-on-one interaction with soil. Today, such an interaction is essential for reawakening the public to the importance of safeguarding soils, and their delivery of ecosystem services for future generations.

“re-engaging with local soils represents a step along a path to becoming more grounded”

It has often been commented that the establishment of digital technology, particularly the accelerated uptake of ‘virtual’ living over the past few decades, has discouraged citizens from directly engaging with their local soils. That the functionality and accessibility of digital technology has disincentivised us from maintaining active and tangible contact with soils is a charge often purported. However, there is another possibility: that online platforms facilitate a unique opportunity for the public to engage with soils from around the globe, and while there is arguably no substitute for face-to-face (or face-to-soil) interaction, it raises awareness about the sheer diversity of soils as well as their significance at grander, global scales.

There are a number of free, publically-accessible, online resources that showcase the grand variety of soils at national and global scales, and encourage a wider understanding of how soils interact with the wider landscape. One popularly used example is the ‘Soilscapes Viewer’6, which is a soil reporting tool that produces a summary of basic soils data for a specific location across England and Wales, communicates the variations which occur between different soil types, and demonstrates the relationships between these soil types and the local environment. The tool is based on the LandIS ‘Soilscapes’ dataset that was produced from the National Soil Map held by Cranfield University, Bedfordshire, UK. Users can select a location across England and Wales, and instantaneously access soil characteristics such as soil texture, drainage status, soil fertility, habitat, and landcover. Soilscapes also quantifies each soil type as a proportion of the national stock of soils across England and Wales so that one can determine how common these are. Similar platforms have been developed to catalogue and visualise data for Scotland, such as the National Soil Map of Scotland created by the Macaulay Institute (or The James Hutton Institute, as it is now called) and based on data collected from field surveys7. Likewise, the Agri-Food and Biosciences Institute’s Soil Survey project marks the only systematic study of the soils of Northern Ireland, from which many published maps have been produced.

Platforms exporting world soil information are also available. The International Soil Reference and Information Centre (ISRIC), the only World Data Centre for Soils within the World Data System of the International Council of Science (ISCSU), has worked for over half a century on compiling and harmonizing data on soils and their properties from around the globe. Mediated through the SoilGrids digital soil mapping interface, users can explore physical data (bulk density, clay content, and texture), and chemical data (cation exchange capacity, nitrogen, soil organic carbon, and pH) for a global compilation of soil profiles9. In addition, SoilGrids has also developed a data-driven, globally consistent system that can predict soil properties using models. Not only does this help scientists to virtually inspect a field site and construct hypotheses prior to a site visit, it also facilitates members from industry, such as those working in agriculture, engineering, and construction, to determine certain soil properties prior to undertaking groundwork.

ISRIC also hosts the World Soil Museum10. Based in the Netherlands, the museum is home to over 1,000 soil monoliths, each of which showcases the composition, layering, colour, and structure of soil down vertical sections of a soil profile. They are, as the museum describes, “very close as to how the soil may be viewed in the soil pit in the field”. Each soil in the collection has been sampled and analysed, affording visitors the opportunity to understand these soils in more detail. Not only is the museum visitable, albeit currently restricted due to COVID-19, one can also access the collection online. By navigating through this virtual museum, the public can see photographs of profiles captured from around the world, as well as their accompanying datasets. There are also learning resources available that discuss soils in the context of some key themes such as food security, biodiversity, landscape, land degradation, climate, and water.
A day before World Soil Day in 2020, an ambitious new initiative called ‘uksoils’ was launched11. Coordinated by a growing group of scientific, campaigning, and awareness-raising organisations, this initiative aims to ‘kickstart a nationwide appreciation and understanding of the economic, societal and ecological importance of soil health to support action and research’. The uksoils is an online community hub that helps share information, generate new knowledge, and support the formation of new proactive communities, to increase awareness and action to improve soil health in farmland, woodland, conservation areas, towns and cities. The materials shared on the ‘uksoils’ platform have been neatly categorised. The ‘Inspire’ page showcases new creative tools that exhibit soils in fresh, fun, and imaginative ways, such as the ‘Our Living Soil’ Art/ Science programme, which is a two-year initiative that aims to showcase soils-focused exhibitions, residencies, film screenings, and performances, among other outputs. Links to poems, visual art, photographs, relevant books, and museums also appear, helping to dispel misconceptions about the resources under our feet. The ‘Learn’ page similarly provides an array of digital, on-line learning technologies (e.g., lessons, training courses, degrees, activities, maps, and data) suitable for different audiences including primary school students, PhD researchers, and farmers. Finally, ‘uksoils’ has a ‘Connect’ page that signposts relevant events, forums, organisations and groups, and also the Living Labs and Lighthouses. Living laboratories are locations where new and innovative techniques are being developed for soil health, while lighthouses are locations or activities where best soil-health practices are currently being showcased.

“free online resources showcase the grand variety of soils at national and global scales, and encourage a wider understanding of how soils interact with the wider landscape”

Remaining grounded

COVID-19 has compelled many households to become reacquainted with their local spaces, environments, and communities. A re-energized enthusiasm for home-growing, the fear of local food shortages, or the yearning for a healthy hobby have presented households with opportunities to cultivate new relationships with their neighbouring soils. Sustaining this momentum after the ebb of COVID-19 is essential. Whilst a vaccine may prove effective against a deadly virus, we are still left confronting other – and similarly severe – global challenges. Soil degradation continues to threaten the health, longevity, and productivity of society. Combatting against this will require a wholeheartedly collective response, not simply from policy-makers, land-managers, and decisionmakers, but from local citizens around the world; a community spirit akin to that which has been evidenced so vividly in the recent response to the pandemic. Even when travel restrictions are lifted, and we begin to move again, we should also remain grounded to a common principle: that of safeguarding our soils for future generations.

As this article has demonstrated, there is a suite of activities that can help communities remain engaged with their local soils. Planting seeds, raising plants, and tending to the earth on your doorstep is an excellent way to interact with your local soils, and the ecosystems that they support. Participating in citizen science experiments are fantastic initiatives that can stimulate citizens to have these meaningful encounters, not to mention the benefits in facilitating research. In addition to these are a raft of web-based opportunities to engage with soils on a global scale. Publicly available databases and maps, virtual museums, and portals now allow individuals to place their local soils within a global context and understand some of the reasons why some soils look, feel, and smell the way they do. These may seem like relatively small steps, but if we take them together, as a globally united and grounded community, a giant leap will have been made – a giant leap towards a planet with safeguarded soils, a planet we are proud to call Earth.