Any thriving natural or agricultural ecosystem begins with soil. And how we choose to manage soil impacts not just the amount and quality of food we produce, but whether we exacerbate or mitigate climate change, and the health of the terrestrial and aquatic ecosystems on which life depends.
How Soil Matters
Food: Fertile soil is essential for productive agriculture.The right mix of soil biodiversity also helps avoid damage from pests and pathogens, and new science is revealing that how we manage our soil can impact the nutritional content and even the flavor of food. Our capacity to feed the 10 billion people we’ll likely see by 2050 depends on maintaining and restoring soil heath.
Climate: Soil is the largest terrestrial stock of carbon, containing twice as much as the atmosphere. It is also an important source of the potent non-CO2 greenhouse gases methane and nitrous oxide. Retaining and building soil carbon, and reducing emissions of these other gases, is crucial to mitigating climate change. Sequestering more carbon in the soils of crop and grazing lands, preserving it in peatlands and grasslands, and building soil carbon stocks through reforestation are all important pathways for climate action.
Biodiversity: Soil regulates water cycles and controls nutrients that pass through it to water systems. Many of the practices that protect biodiversity and habitats—such as changing vegetation communities and fire regimes—also improve soil properties. Healthy soil more efficiently stores and recycles carbon, water and nutrients, the very foundations of life on our planet.
The last few years have seen a growing recognition of the importance of soil—from movements to expand small-scale farming, to global efforts to improve soil in industrial agriculture, to strategies to boost the role of soil in mitigating climate change. At the global level, UN Sustainable Development Goal 15 pledges to restore degraded land and soil by 2030; the 4 per 1000 Initiative aims to enhance soil quality and carbon sequestration through improved agricultural practices; and the UNCCD Global Land Outlook presents a transformative vision for land management policy, planning and practice.
These are welcome signs that more key stakeholders realize that a tool for addressing many of our most pressing environmental challenges and development priorities is right under our feet.
At a more local level, farmers and other land users are realizing that many of the soil management practices they are already using to avoid erosion or increase productivity in fact fall into a ‘happy coincidence’ category, as they generate multiple positive outcomes. As shown in the table below, most common soil management practices contribute to at least two of three important goals: food, climate and ecosystem health.
Types of Conservation Practices That Could Impact Soil
How Can Science Advance Soil Solutions?
Soil science can be a driving force for achieving sustainable development when it responds directly to the needs of practitioners and decision-makers from local to national and global scales—there is still room for new evidence to generate and guide real-world solutions that boost food production, fight climate change and protect nature.
At The Nature Conservancy, we prioritize three types of applied soil science:
Translational research that converts scientific knowledge into practical, actionable information. This includes systematic analysis of the effectiveness of different land management practices for building soil organic carbon and identifying market-based mechanisms to incentivize soil carbon sequestration. These analyses can help provide a more compelling value proposition for farmers and land managers and a stronger business case for public and private investors, both of which are vital for generating the level of finance needed to scale up improved soil management globally. Priorities include building knowledge on soil organic carbon among potential investors and further research into financial mechanisms that can dismantle barriers to soil carbon projects. By providing clear evidence of both advantages and uncertainties, this kind of research enables informed decision-making, attracts investment and enhances results.
Empirical and modelling studies that expand our knowledge of how to conserve and restore soil more effectively. These include experiments to generate new data on relationships between land management practices and their impacts on food production, water retention and carbon storage. Modelling is often used when we want to simplify a complex system to better understand, define, quantify or simulate a specific aspect of it. These studies can answer fundamental questions related to key conservation, climate and agricultural challenges and produce transformational information. By helping farmers and other land managers to visualize the outcomes of different practices—including to their bottom line—empirical and modelling studies have the power to kick-start action.
Developing tools for measuring and monitoring the impact of different soil management practices. There is growth in this area, including in the fields of remote sensing, spatial science, digital mapping, and rapid and low-cost tools for measuring soil properties. Further developments of these methods could rapidly bring down the costs of monitoring soil organic carbon and soil health. Future goals should include devising a technical method for valuing the multiple benefits of soil organic carbon in watersheds and landscapes. Standardized tools and metrics can be powerful accelerators of progress both in science and on the ground; they are also crucial to monitoring higher-level goals, like the UN Sustainable Development Goals (SDGs). Better monitoring can drive more effective policy, and ongoing innovations in this area of soil science offer huge untapped promise.
Collaborative, targeted, applied soil science in these areas will help local land managers to make decisions that can both increase the productivity of their soil and improve water quality and biodiversity, encourage investors and policy-makers to prioritize soil management, and contribute to the global imperative of feeding a growing population while mitigating climate change.
Soil Science Priorities
We have identified ten global soil-related objectives, including four emerging areas that require more applied soil science and are presented in the below table. A large number of them focus on soil organic carbon, because it is a useful proxy for soil health and the common denominator for achieving the multiple benefits we hope for.
The pressing need to meet these objectives creates a compelling case for soil scientists, soil practitioners, non-profit organizations, investors, communities and governments to step up a notch and collaborate to develop and deliver soil solutions for our food, climate and environment. That is the soil science imperative we face.
Overall Priority Areas for Soil Science
Emerging Soil Science Priorities
Ground Level: TNC Soil Projects
Water Funds: Healthy Soil for Healthy Water
The Conservancy is involved in dozens of Water Fund projects—from China to Kenya to Minnesota. Healthy source watersheds are vital for nearly all cities around the world. They collect, store and filter water. Yet, around 40 percent of source watershed areas show high to moderate levels of degradation. The impacts of these changes on water security can be severe; nutrients and sediment from agricultural and other sources raise the cost of water treatment for municipal and industrial users.
Water funds are a proven, successful mechanism for downstream water users to fund upstream land conservation, restoration and improved land management practice in agriculture; in return, they help to secure improved water quality, and in some cases increased supplies.
reThink Soil Roadmap: Expanding Good Soil Management
In 2016, TNC launched a roadmap outlining 10 necessary actions to achieve widespread soil health across United States. croplands. The roadmap spans science, business and policy sectors to ultimately ensure the adoption of soil health and nutrient management practices that improve agricultural and conservation outcomes. The goal is for at least 50 percent of corn, soy and wheat cropland in the US to be managed for soil health by 2025. Working with the Soil Health Institute and the Soil Health Partnership, this project blends data collection from 135 demo sites, the development of new assessment and indicator protocols, communications and outreach, and strategic engagement with key members of the supply chain. The reThink Soil Roadmap is already TNC’s largest soil project and is beginning to expand to other regions.
Colorado Collaboration: Fighting Fire with Fire
Widespread, severe wildfires cause long-term damage to vegetation, biodiversity and soil, release huge amounts of carbon, and are a threat to human lives and property. The Nature Conservancy has long recognized the important role that prescribed fire plays in reducing wildfire risks and restoring forest resilience. Colorado’s Fire Learning Initiative was established in 2015 with the goal of preparing priority landscapes and people to safely and effectively use prescribed fire and to positively influence the culture of fire in Colorado. Further scientific research is needed to better understand links between fire management and soil management, and how prescribed fire can be used to protect against massive soil loss often triggered by wildfires.
Northern Rangelands Trust Partnership: Digging into Soil Carbon Markets
The Northern Rangelands Trust (NRT) is a community-led nonprofit organization in northern Kenya with a mission to develop resilient community conservancies that can transform lives, secure peace and conserve natural resources. NRT has so far created 14 conservancies that work across 2.2 million hectares. One aspect of NRT’s conservation program is to economically incentivize sustainable rangeland practices by tapping into soil carbon market funding and provide conservancies with revenue based on the carbon sequestered. This innovative partnership is putting in place long-term mechanisms to manage ecosystems for soil outcomes as part of an integrated, stakeholder driven approach to rangeland health.
Mangrove Soil Carbon in Mexico
A study by TNC recently showed that Marismas Nacionales in Mexico could be a very successful and large blue carbon project. TNC is using standardized methodologies to first measure blue carbon stored in mangroves, and most importantly their carbon-rich soils, to determine cost-efficient coastal wetland restoration options.
In addition to this pilot project, the team is actively working to continue building ‘blue carbon momentum’ nationally by sharing the state of the art science on methods of measurement of blue carbon storage. The TNC-Mexico Coastal Wetlands team is working on incorporating the mangrove soil carbon data and using it for local projects as well as national policy, such as including it in Mexico’s commitment to the Paris Climate Agreement, which recognizes coastal wetlands as key elements for climate change adaptation.