Understanding Soil Health for Human Health

Over the last 50 years, advances in agricultural technology have bolstered food security for the growing global population (FAO, 2015). However, under certain conditions some of these farming practices which include tillage, chemical fertilizers, absence of crop rotation and separation of livestock from crop systems, have degraded our soils and the ecosystems that depend on them. This physical, chemical, and biological reduction in soil quality creates impacts including:

• Environmental: Degraded soils are less resilient and function at a reduced capacity, negatively impacting many critical “ecosystem services” that sustain our planet, such as climate regulation, biodiversity, local water and nutrient cycles, flood regulation, and more ( 2015).
• Economic: Over 1.3 billion people who depend on agriculture are farming degraded soil (UN, 2018). The resulting reduction of crop yields and arable land causes loss of livelihoods, and aggravates food insecurity and malnutrition land (Food Sec., 2009).
• Health: Poor soil can have other negative effects on human health (Air soil water res., 2020). We are just starting to understand the complex interactions that link soil to a range of health factors, such as the quality of our food and the influence on our microbiome’s role in our immune function and absorption of nutrients (EMBO Report, 2020).

Safeguarding Earth for future generations requires a systemic shift towards science and economies that acknowledge the critical role of soil. Robust data at the interface of soils, agriculture, and human nutrition – a central goal of the Periodic Table of Food Initiative – will connect these factors and encourage farming that not only prevents soil degradation but also promotes planetary and human health. Such farming methods include large-scale agroforestry, embracing diversity and local nutrient recycling from diverse sources. While not yet fully understood, these practices can increase productivity and efficiency, yield better nutritional quality, and restore natural ecology.

“Unsustainable agricultural practices lead to a loss of components of soil, such as the organic matter, micronutrients and the soil microbiome, which are all crucial for mediating the transfer of molecules between the soil and plant in ways that don’t degrade the underlying ecological systems,” says David Strelneck, founder of Nourish^n, an international collaborative of entrepreneurs who are developing and spreading economic practices that steward nutrient cycles. “An improved appreciation of the characteristics of soil that impact the quality of food and in turn, our health, will bring significant change in economics and social equity, as well as benefits to the environment.”

The positive environmental value of healthy soils is well documented. The physical and biological structure of soil, as well as water and nutrient cycling, are all optimized when soils are managed sustainably. Soils are the biggest terrestrial carbon sink and when land is degraded soils contribute to, rather than mitigate, climate change (IUCN. 2015). In addition to these environmental benefits, evidence is emerging that healthy soils, managed through sustainable agriculture, can also produce nutritionally superior foods for human health (Front. Nutr., 2019).

“Regenerative farming practices can have a positive effect on soil by increasing the availability of macro and micro nutrients, as well as the amount and diversity of the microbes in the soil,” says David LeZaks, PhD, a Senior Fellow at the Croatan Institute, whose work promotes transitions to agroecological farming and food systems. “Foods produced by these methods often show nutritional superiority and can contain beneficial microbes and their metabolites. For example, reduced-tillage increases nutrient concentrations in stored winter squash and organically-grown oats are more nutrient dense. Studies also show that the biochemical richness of meat and dairy is improved when herbivores feed on a wide-range of plants via managed grazing, a form of regenerative agriculture.”

“A 21st century understanding of the biochemical composition of food, including any contributing factors from soil, will align science and economics to provide investors and decision-makers with confidence to support initiatives that dually improve soil and human health,” adds Strelneck. “It will also ensure that in optimizing for certain aspects of food, we do not break other life-enabling systems on Earth.”

Proposed Solution: A Periodic Table of Food 

Healthy soils are crucial but elucidating their direct links to human and planetary health requires robust, reliable data on food and how it is produced. Currently our knowledge of the biochemical composition of foods is limited to just a fraction of the total component parts, partly because the methods currently used to measure these components vary, reducing the reliability and comparability of data.

The Periodic Table of Food Initiative is a global effort to greatly expand our understanding of the biochemical composition of food. At its core, the initiative will create standardized kits and methods to allow researchers to categorize the tens of thousands of compounds found in foods, culminating in a public database. This database will include multiple forms of metadata about these foods, such as the health of the soil (e.g. nutrient levels, composition, microbes), as well as the food’s quality in terms of nutrients that can be readily absorbed and utilized. This information will be key to establishing how regenerative agricultural practices that benefit soil health can also benefit human health, thereby driving consumer demand for a circular nourishment economy.

Health and Nutrition:

• Increasing food and nutritional security: As evidence around soil health is robustly connected with human health, we will better understand the benefit of fostering sustainable farming landscapes to increase food quality – not just bulk yield or calories. This is particularly important in regions that suffer from malnutrition while farming marginal lands or relying only on staple crops produced by extractive farming methods (FAO, 2015). 
• Improving nutritional quality: Current evidence suggests improved soil health bolsters the nutritional quality of food, in terms of the amount and type of nutrients, as well as how readily they are absorbed and utilized by the body. The Periodic Table of Food Initiative will connect these factors directly, incentivizing improved soils for a better-quality food product.  

Sustainability: 

• Promoting resilient food systems: Healthy soils maintain a diverse array of bacteria, fungi, and other micro and macro biota that form symbiotic associations with plant roots, improve soil structure, help to control plant diseases and pests, recycle nutrients and help to increase water and nutrient holding capacity. All these factors are essential for improving crop production, maintaining productivity, and enabling flexibility during natural or economic disruptions (such as Covid-19) (FAO, 2015). Based on long cultural traditions around the world, more benefits of healthy soils are likely to be uncovered as our understanding grows. 
• Fostering vibrant ecosystem services: Metrics around soil health that are based on an improved understanding of connections to human health will provide large–scale incentives to augment farming landscapes to sustain healthy ecosystems. 

Economic Opportunities:  

• Stimulating economic equity and opportunity: Creating value in soil-food-health relationships via the connections revealed by the Periodic Table of Food Initiative will favor those who know how to manage soil health, including essential farm workers who are often marginalized in today’s economies. Regions once thought of as disadvantaged can leverage local knowledge and experience to drive forward sustainable methods of managing soil health for wider social and economic benefit (Energ. Ecol. Environ., 2017).  
• Encouraging commerce based on food quality: Entrepreneurs ranging from large commodity traders to small organic farmers are working on systems for transacting in new ways, ranging from apps to new product labels. These ventures can be further supported by data provided by the Periodic Table of Food Initiative. 
• Catalyzing innovation: Data and metrics that cut through multiple economic sectors, such as health and food systems are known to stimulate innovation not just of discrete products, but of entire new systems of supply and demand that realize new value chains and efficiencies.  
• Increasing soil wealth for society: Implementing climate-friendly agricultural practices in the U.S. not only strengthens ecosystem and food system resilience, but could also mitigate nearly 170 GtCO2e and generate a nearly $10 trillion net financial return by 2050 (Soil Wealth, 2019). 

LeZaks argues that we need to move from a quantity–based food system that focuses on maximizing calories and yield to one that values the quality of its output. “Taking this approach will mean that measures of food quality are informed by the quality of the input (soil) and outputs (human health). We have the opportunity to completely flip our food system upside down for good reasons, by changing the metrics by which we measure success – quality not quantity. The Periodic Table of Food Initiative can help lay the groundwork needed for that shift.”