soil health

Migratory bison in Yellowstone

September 30, 2025 By EarthWise Leave a Comment

Tens of millions of bison once migrated across the United States in enormous herds; tribal oral histories speak of it taking days for an entire herd to pass by. These herds shaped the landscape and performed many ecosystem functions. By the 1890s, the bison population had plummeted to fewer than 1,000 individuals. Since then, dedicated conservation efforts – establishing protected areas and breeding programs – have led to the recovery of the species. There are now about 400,000 bison, mostly existing in small, privately owned herds.

Yellowstone National Park is home to the last significant migratory bison herd. Yellowstone was established as a national park in 1872 providing scientists with a unique opportunity to study how large grazing herbivores affect the landscape. More than 5,000 bison live in the 3,500 square miles of the park.

A 7-year study by researchers examined how bison change the soil and vegetation along their migratory route. What looked like overgrazing turns out to allow plants to keep growing. The bison graze and move on, increasing the density of microbes and nitrogen in the soil and significantly improving the nutrition for other herbivores.

The research validated what Indigenous peoples have known for many generations: that bison helped shape this continent and having large numbers of them improve ecosystems for other animals as well. Native American tribes would like to restore bison to their lands. Whether some of the park fences might be removed to permit migration beyond official borders is under consideration.

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In Yellowstone, Migratory Bison Reawaken a Landscape

Photo, posted August 17, 2017, courtesy of Jacob W. Frank / NPS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Feeding the future

June 9, 2025 By EarthWise Leave a Comment

Climate change is already affecting the yields of major staple crops around the world, and researchers warn that the impacts will become more severe over time. Rising temperatures, shifting rainfall patterns, and more frequent extreme weather events are disrupting growing seasons and reducing agricultural productivity.

Addressing these growing threats requires rethinking how we grow, distribute, and consume food. To kick off Climate Solutions Week, we wanted to examine some solutions that could make food systems more resilient, sustainable, and adaptable to our rapidly changing environment.

One solution is Climate-Smart Agriculture, which blends traditional practices with modern techniques to boost productivity while reducing greenhouse gas emissions. Methods like zero tillage, intercropping, and crop diversification could improve soil health, conserve water, and help farms withstand climate extremes.

Expanding the production of highly nutritious and climate resilient food crops – like millet, sorghum, teff, quinoa, chickpeas, and tepary beans – will also have an important role to play. At the same time, reducing food waste through better storage, labeling, and surplus food re-use could help meet demand without increasing production pressure.

Agriculture is the largest user of freshwater globally, and climate change is intensifying water shortages. Farmers will need to transition to water-efficient farming practices, including drip irrigation, rainwater harvesting, and the reuse of treated wastewater.

Together, these solutions could help revolutionize the global food system to both feed a growing population and help protect the planet.

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Climate-smart agriculture

Water for Prosperity and Peace

A Food For The Future

Photo, posted October 16, 2011, courtesy of Alliance of Bioversity International and CIAT via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Restoring Biocrusts | Earth Wise

June 8, 2023 By EarthWise Leave a Comment

Biocrusts are complex ecosystems that form a thin layer on the surface of soils in arid and semiarid environments. They are composed of variety of microbes including cyanobacteria, green algae, fungi, lichens, and mosses. Biocrusts play a crucial role in maintaining soil health and ecosystem sustainability.

Biocrusts are under assault from human activities including agriculture, urbanization, and off-road vehicle use. Climate change is also placing stress on biocrusts, which are struggling to adapt to increasing temperatures.

Researchers at Arizona State University have proposed a novel approach to restoring healthy biocrusts. Their idea is to make use of solar energy farms as nurseries for generating fresh biocrust. The arrays of solar panels serve as shields from excessive heat and allow biocrusts to flourish and develop. The newly generated biocrusts can then be used to replenish arid lands where the existing biocrusts have been damaged or destroyed.

When such biocrusts are harvested, the natural recovery process is rather slow, taking around six or eight years to fully recuperate. But the researchers found that when harvested areas are reinoculated with the microbes, the biocrust cover can reach near-original levels within a year.

The ASU researchers demonstrated the viability of the approach in a three-year study at a solar farm in Arizona’s lower Sonoran Desert. Based on their results, they conclude that the use of large solar farms for this purpose could provide a low-cost, low-impact, and high-capacity method to regenerate biocrusts and enable soil restoration on a regional scale. They have dubbed their new approach as “crustivoltaics.”

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Using solar farms to generate fresh desert soil crust

Photo, posted March 12, 2023, courtesy of Eric Peterson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Agrivoltaics | Earth Wise

November 15, 2022 By EarthWise Leave a Comment

According to a study last year at Oregon State University, co-developing land for both solar photovoltaic power and agriculture could provide 20% of total electricity generation in the United States with an investment of less than 1% of the annual U.S. budget. Widespread installation of agrivoltaic systems could reduce carbon emissions by 330,000 tons annually and create more than 100,000 jobs in rural communities.

Agrivoltaics could provide the synergistic combination of more food, more energy, lower water demand, lower carbon emissions, and improved local prosperity. The problem with agrivoltaics to date is that the existing implementations have used solar arrays designed strictly for electricity generation rather than to be used in combination with agriculture. They are not that well suited to co-exist with growing crops or grazing animals.

A new project is underway at Oregon State that will help researchers to optimize agrivoltaic systems. The five-acre Solar Harvest Project is being built at the university’s North Willamette Research and Extension Center in Aurora, Oregon in partnership with the Oregon Clean Power Cooperative.

The solar array for the project is designed specifically for agrivoltaics research and uses panels that are more spread out and able to rotate to a near vertical position to allow farm equipment to pass through. The project will allow researchers to study the impact of solar panels on soil health, water use, and plant physiology and yields.

Electricity generated from the 326-kW solar system will be available for purchase by Oregon State and community members.

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Construction starts on Oregon State agrivoltaics farm that will merge agriculture and solar energy

Photo, posted April 5, 2020, courtesy of Sean Nealon / Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

What Is Healthy Soil? | Earth Wise

August 30, 2022 By EarthWise Leave a Comment

Soil supports life by providing many critical ecosystem services. For example, soil acts as a water filter, a growing medium, and provides habitat for billions of organisms. Soil is also the foundation of our cities and towns, and the basis of global agroecosystems, which provide humans with feed, fiber, food, and fuel.

For all of these reasons and many more, having healthy soil is vital. But what does soil health mean? And how should it be measured?

According to new analysis by researchers from Cranfield University and Nottingham University in the U.K., how we think about, measure, and study soil must change in order to better understand how to manage this resource effectively.

While the term ‘soil health’ is widely used, it means different things to different people. There is no single agreed upon way to gauge the overall health of soil.

Current approaches to assess soil health measure individual soil properties and use findings to assign a single number giving an overall score. But according to the research team, this does not reflect the wider system perspective that’s needed to fully evaluate the health of soil over time.

Instead, the researchers propose a new system to assess soil health based on a hierarchical framework that takes in several measures, including signs of life, signs of function, signs of complexity, and signs of emergence, which is the extent to which soils recover from multiple stressors.

This new approach, which can be applied to all soils, moves us closer to an interdisciplinary understanding of the whole picture of soil health. After all, healthy soil is fundamental to our survival.

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We need to change how we think about soil

Photo, posted April 8, 2008, courtesy of Brian Boucheron via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.