Isaac Larsen Serves as Lead Author on UN Soil Resources Report
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Isaac Larsen, an associate professor in the College of Natural Sciences’ Department of Earth, Geographic, and Climate Sciences, is a lead author of a new report from the Food and Agriculture Organization of the United Nations (FAO) entitled Status of the World's Soil Resources 2026. The report draws on recent scientific literature and contributions from hundreds of experts around the world. Its findings identify erosion as one of the most serious threats facing soils globally.
Isaac Larsen's research contributes to the report's discussion of agricultural soil erosion and the gap between human-caused erosion and natural rates of soil formation.
“The report was a big undertaking,” explained Larsen. “Our charge was to synthesize a decade’s worth of research on the current condition and threats to soils, and to do so in a way that makes that information accessible to policy makers. When I arrived at UMass, my goal was to use new methods that had emerged in other fields to study soil erosion in the United States. The report draws on recent work done by UMass graduate students and postdocs, some who were contributing authors in the report. We are continuing our work on soil erosion through ongoing projects supported by the UMass Center for Agriculture, Food, and the Environment.”
In Chapter 3, “Threats to soil functions,” the report draws on Thaler, Larsen, and Yu (2021), which used satellite imagery and field data to estimate that about "35 percent of the cultivated area in the study region [the Corn Belt of the United States] had lost A-horizon soil, decreasing crop yields in the corn belt by 6 percent...and leading to annual losses of USD 2.8 billion.”
Chapter 12, “Regional assessment for North America region,” for which Larsen served as a lead author, provides a detailed assessment of soil erosion in North America. The chapter examines the condition, drivers, and consequences of soil degradation across the continent, emphasizing agricultural and post-fire erosion, regional differences, and the need for improved soil-management practices and assessment methods.
“Current policies and practices tend to focus on short-term economic gains at the expense of soil health—that model just isn’t going to serve our nation in the long run,” argued Larsen. “Soil in the United States erodes faster that it forms, which causes both loss of agricultural productivity and reduction in the ecosystem services soils provide to humanity. Although the overall picture is not rosy, there are some bright spots. No-till farming reduces soil erosion rates to levels comparable to rates of soil formation, but there are many parts of the nation, including Massachusetts, where the adoption of no-till farming needs to increase. There is also growing recognition that soils can respond positively to changes in farming that aim to improve soil function, but the concept of soil regenerative agriculture is still new and needs stronger support from our traditional agricultural institutions.”
Chapter 12 also cites work by Larsen’s former postdoc Jeffrey Kwang arguing that failing to account for tillage erosion causes national erosion models to underestimate the magnitude of soil loss. In addition, the chapter references Larsen's 2009 research on post-fire runoff and erosion when discussing erosion associated with wildfires in North America.
Larsen's research illustrates a central concern of the FAO assessment: soil can be lost far faster than it can naturally regenerate. His studies have used high-precision surveying, satellite imagery, and geochemical techniques to measure erosion and reconstruct historical soil loss.
The FAO report points to practices such as reduced tillage, cover crops, crop diversification, and agroforestry as ways to reduce erosion, and emphasizes the need to translate scientific knowledge into broader changes in land management.
“Soils are fundamental to the wellbeing of humanity,” says Larsen. “The way we treat soils impacts our health, water, climate, jobs, and our ability to feed ourselves—the future of food depends on the future of soil. The report demonstrates that there has been substantial growth in the science underpinning sustainable soil management practices, but at the same time, it concludes that most of the world’s soils are being managed in ways that are unsustainable. I hope the report draws attention to the disparity between what we know and what we do, and enables policy makers to better incentivize farming practices that conserve and regenerate soil.”
Click here to read the report.