Soils are a component of the ecosystem services that support air quality. They underpin the green space interventions that improve air quality. Supporting healthy soils is a building block in both rural and urban communities in creating healthy air systems. While soils are not a major sink for air pollution, maintaining healthy soils is still a mandatory structural factor in establishing clean air policies.
Disturbed soils increase air pollution
Disturbed rural soils are a contributor to dust emissions. Land use practices that manage the erosion of topsoil also improve general air quality by reducing the blown particulates in dust storms.
As described in a 2021 scientific journal on The role of soils in the regulation of air quality, “Soil dust emissions, from largely natural sources, are estimated to be the largest source of tropospheric aerosols, giving rise to multiple impacts such as influencing the global radiative balance and cloud formation. However, human intervention to mitigate these emissions is challenging, given the vast areas from which the bulk of these emissions arise.”
While agricultural soils are a source of food and income for people, they need to be carefully managed to avoid harmful emissions of dust, NH3, and greenhouse gases to the atmosphere, given these can lead to problems with human and animal health, and environmental degradation.
Healthy soils improve air quality
Soils (and the microbes and plants they support) can, however, be used to improve air quality at a local scale. Examples of this include the use of urban trees to reduce air pollution in cities and soil-based biofilters that can remove contaminants from pollution sources.” From a policy perspective generally, the aim is to cover the soil by using native plants that mirror local ecologies.
For agriculture specifically, regenerative agriculture practices are advantageous in improving soil health. Practices common for regenerative agriculture, such as either plow-less or using no-till agriculture where possible improve soil biodiversity and improve water retention. Soils store water, so every time you plow you not only disrupt soil ecologies, you also lose one inch of water. Exposed soils, particularly vulnerable soils contribute to air pollution as blowing dust.
To reduce dust episodes that contribute to inhaled particulates, regional governments can create policies to prevent the exploitation of vulnerable soils. General policy recommendations that protect soil systems incorporate land use practices that build vegetative cover and plow as little as possible improve, grazing livestock on prairie lands instead of growing grass or grain and then harvesting it to feed livestock, and employing crop rotation instead of monocultures.
The more crop biodiversity the better. Current market dynamics are driving monocultures. Providing farmers incentives for supporting more crop diversity with metrics that are easy to measure would improve their ability to adopt regenerative agriculture practices.
Healthy soils support air quailty
In urban environments, healthy soils are the underpinning of greenspace interventions that act as filters for reducing air pollutants. Many urban settings have degraded soils or impermeable surfaces that make greenspace interventions difficult. Improving surface permeability and soil health are the groundwork for green space improvements. Organic waste management can be used in the bioremediation of degraded urban soils.
Measuring soil carbon and water are insufficient measures of healthy soils. Soil health is broad and includes soil biodiversity. Eugene Kelly, a Professor of Pedology at Colorado State University says that soil health policies should reflect soil biodiversity as well as soil carbon measures. Because marginally productive lands are very vulnerable policy planning should aim to “Keep the ground covered and then build a more biodiverse system once you’ve got it covered.”
Soil Microbiomes are important ecosystem services
Soil microbiomes are ecosystem services that are a component underpinning human health. A One Health approach to soil management and research contributes to the understanding that human health is not isolated but connected to the health of animals, plants, and environments. The Food and Agriculture Organization of the United Nations (FAO), the World Organisation for Animal Health (OIE), the United Nations Environment Programme (UNEP), and the World Health Organization (WHO) agree that a One Health perspective on ecosystem services prevent, predict, detect, and respond to global health threats and promote sustainable development.
A recent joint statement supports these developments with ongoing work to operationalize these goals. A Nature review concludes that “we demonstrate that soils are a cornerstone of one health and serve as a source and reservoir of pathogens, beneficial microorganisms and the overall microbial diversity in a wide range of organisms and ecosystems.”
“Many scholars do not appreciate that soils are a vital part of earth’s ecosystem, contributing organic and inorganic components to air, water, plant and animal life. Similarly, practitioners of “One Health” (ie those studying interconnections between the health of animals, humans, and the environment) do not always appreciate that soils represent a foundational aspect of health for all systems.
Recent publications have asserted the critical role of soils in many processes, and emphasize that consideration of ‘soil health’ is essential to systems-level analyses.” – Sue VandeWoude a Professor at the College of Veterinary Medicine and Biomedical Sciences at Colorado State University. While more work needs to be done transitioning the scientific consensus into practice, many stakeholder groups are leading the way to integrate soil health into public health planning such as the Forum for Agricultural Research in Africa and the European Commission.
Existing programs support soil biodiversity
Planting rows of trees acts as wind barriers to improve soil retention.
Examples of programs supporting healthy soils include the Global Soil Biodiversity Initiative and the Regional OneHealth Aerobiome Discovery Network. The Global Soil Biodiversity Initiative is an available resource for providing guidance on soil biodiversity in environmental policy and sustainable land management to protect and enhance ecosystem services. Policy reports on the site are available for people working in governance including summaries such as the 2020 UN-FAO Report on Global Soil Biodiversity.
The depth of knowledge and camaraderie in the network goes deeper than the available policy reports. If you have soil health-related policy questions, reach out to researchers directly to see if subject experts can assist you with your specific regional policy need. The Biology Integration Institute: Regional OneHealth Aerobiome Discovery Network (BROADN) is doing aerobiome research to investigate how the microbiome of the air is altered by environmental stresses, and how it impacts human, animal, and environmental health. Soil health and regenerative land management practices are tools in our toolbox for integrated clean air practices.