UCS Blog - The Equation (text only)

7 Fun Facts for National Farmers Market Week

Customers shop at the Crossroads Farmers Market in Takoma Park, Maryland, July 2014. Photo by Union of Concerned Scientists

And now, something we can feel good about. This Sunday marks the start of National Farmers Market Week, an annual celebration of local food systems. To get us in the mood, here are six facts that illustrate the benefits of farmers markets and local food systems.

FACT #1: There are 8,690 farmers markets nationwide. This may actually be a low-ball count, but it’s the number of markets currently listed in the US Department of Agriculture’s (USDA’s) National Farmers Market Directory. Washington, DC, where I live, is particularly fertile ground for farmers markets—the interactive database lists more than 60 markets within five miles of my home (try it for your state or ZIP code). But farmers markets have become commonplace across most of the country, as illustrated by this rather crowded national map generated from the USDA’s data:

FACT #2: In 2015, more than 167,000 US farms sold $8.7 billion worth of food directly to consumers, retailers, institutions (such as hospitals and schools), and local distributors. This was the finding of a farmer survey published by the USDA last year. The survey further found that more than one-third of those sales ($3 billion) were made directly to consumers via farmers markets, CSAs, farm stands, and the like.

FACT #3: Participants in the federal Supplemental Nutrition Assistance Program (SNAP) redeemed more than $20 million in benefits buying food from local farmers in FY 2016. That’s up a staggering 638 percent from 2008. The data from the USDA’s Food and Nutrition Service, which tracks purchases made with SNAP benefits (formerly known as food stamps), shows that nearly 7,000 farmers markets and individual farmers across the country are authorized to accept these benefits. And the USDA’s Food Insecurity Nutrition Incentive (FINI) grant program, established by Congress in the 2014 farm bill, is helping to increase purchases of fruits and vegetables among SNAP participants by subsidizing these purchases at farmers markets and other outlets.

FACT #4: Three out of four farmers who sell at farmers markets use practices that meet or exceed organic standards. That was the finding of a 2015 survey by the non-profit Farmers Market Coalition and American Farmland Trust. More details from the survey: Nearly half of farmers used integrated pest management, information on the life cycle of pests, and their interaction with the environment to manage and prevent crop damage. And the overwhelming majority (81 percent) incorporated cover crops, reduced tillage, on-site composting, and other soil health practices into their operations. (Read more about the importance of soil health here.)

FACT #5: Farms selling fruits and vegetables locally employ 13 full-time workers per $1 million in revenue earned, for a total of 61,000 jobs in 2008. A report by the USDA’s Economic Research Service compared these farms with fruit and vegetable growers not engaged in local food sales, and found the latter employed just three full-time workers per $1 million in revenue.

FACT #6: Farmers themselves benefit economically from farmers markets, pocketing upwards of 90 cents for each dollar of sales there. So says the Farmers Market Coalition. And how does that compare to the return for US farmers overall? The National Farmers Union estimates that farmers’ share of every dollar Americans spend on food in 2017 is a paltry 15.6 cents.

FACT #7: Sales increased by more than one-quarter at farmers markets participating in the USDA’s Farmers Market Promotion Program (FMPP) between 2006 and 2011. Established by Congress in the 2002 farm bill, the FMPP is a competitive grant program designed to increase access to locally and regionally produced foods and develop new market opportunities for farmers. To measure this program’s impacts, researchers in 2012 surveyed organizations awarded grants during the previous six years. In addition to a 27 percent sales increase, the survey also showed that customer counts increased by 47 percent at markets that received FMPP grants, and the number of first-time customers increased at nearly all (94 percent) of these markets.

BONUS “FACT”: Everyone loves a farmers market. Everyone. Even this guy (who is normally not a big fan of facts), proving that farmers markets really do bring people together.

But seriously, the benefits of local food systems—for farmers, consumers, and communities—are worth investing in. Secretary of Agriculture Sonny Perdue recognized those benefits with his official proclamation of the week. But now it’s up to all of us to ensure that the secretary and Congress make those investments. That’s why UCS is advocating for USDA programs (including SNAP, FMPP, and FINI, among others) that are helping to ensure that farmers markets and local food systems thrive.

Happy National Farmers Market Week!

On Healing Sick Ecosystems

Part of the Lehigh Gap Nature Center site before remediation, October 2002. Photo credits: lgnc.org/conservation

I am a person who is fascinated by organisms of all kinds. I like the cute fuzzy ones that most people like, but also the scaly, leafy, prickly, stinky, or slimy ones, as well as the ones we can’t see without a microscope but that have outsized effects on the world around them. I am amazed by how many different ways there are to be alive on this planet, and moved by the intricate connections living things have with each other and their environments.

As I began to study the diversity of life, I noticed a pattern: many creatures are in danger because we humans are unintentionally destroying their homes. Whether by pollution, climate change, or clearing habitats to build things of our own, we have made much of the world less habitable for the living things with which we share it. We have already driven some species extinct, and many others are perilously close.

I believe there is a compelling moral case for preserving healthy, diverse ecosystems. There is also a strong practical case: we depend on intact ecosystems for services like clean water, fresh air, and pollinators that help our crop plants reproduce. Living near green spaces also improves our health and society as a whole. Thus, I chose a career studying how to help ecosystems best recover from our more destructive impacts. In my PhD research in Prof. Brenda Casper’s lab at the University of Pennsylvania, I studied how interactions between plants, soil-dwelling microbes, and heavy metals can affect the long-term development of ecosystems on metal contaminated soils.

One of the two zinc smelters responsible for heavy metal pollution in the Palmerton Zinc Superfund Site. Photo credit: Lee Dietterich

Pollution and remediation: one site’s story

I conducted my studies in the portion of the Palmerton Zinc Superfund Site owned and managed by the Lehigh Gap Nature Center. The site consists of over 2000 acres on the side of a mountain in upstate Pennsylvania that was devastated by heavy metal pollution from two zinc smelters operating for much of the 20th century. When the site was at its worst, local residents and passersby on the Appalachian Trail, which traverses the site, frequently compared it to the surface of the moon, or the aftermath of a bomb explosion.

The site badly needed some kind of remediation to remove or contain the pollutants and mitigate their threat to human and environmental health. It was (and still is) crucial that remediation be guided by our best scientific understanding of site histories and the effects of heavy metals on humans and the environment. Interference in the form of censoring data about such sites, or letting corporate or political priorities dominate discussions about environmental stewardship, can only make remediation longer and more difficult.

Part of the Lehigh Gap Nature Center site before and after initial remediation (left, October 2002; right, August 2006). Photos: lgnc.org/conservation

Today, after over a decade of intensive remediation work involving scientists, community members, and numerous federal, state, and private organizations, the mountainside would be unrecognizable from the moonscape described above. Grass species with low metal uptake were planted to build healthy soil while keeping the metals sequestered underground. These grasses, now taller than most people, tower and sway in the breeze. In many places shrubs and small trees are coming in, and in the patches of forest that survived the pollution, dense canopies create cool shade over lush carpets of ferns. Birds, grasshoppers, and butterflies are diverse and abundant, and it is not uncommon to encounter deer at dawn or dusk. Hundreds of hikers and thousands of schoolchildren visit the area each year, largely thanks to land management and educational offerings by the Lehigh Gap Nature Center, which now owns about a third of the site.

Sustained collaboration between scientists, land managers, and community members has been essential to this remediation effort. Early in the process, researchers made valuable contributions by documenting effects of the polluted soils on the site’s plants, animals, and microbes and by testing numerous revegetation strategies. Remediation of a polluted site had not been attempted on such a large scale before, and this early testing was key to the successful establishment of large-scale plantings.

Wildlife returning to the Lehigh Gap Nature Center site. Photo credit: Lee Dietterich

Continuing challenges

Remediation of disturbed landscapes is an ongoing task, and both basic and applied scientific research are crucial to understanding how to do this task well.  Many fundamental questions remained when I began working in the site. For instance, we knew that a group of soil dwelling fungi called arbuscular mycorrhizal fungi (AMF; soil dwelling fungi that trade plants nutrients for sugars) were important for the growth of many plants there, but we had little idea how AMF might affect plant metal uptake or metal tolerance under field conditions. After a couple years of work at the site, in the lab, and on the computer, I found that mycorrhizal fungi have little effect plant metal uptake, but that there is a remarkably close relationship between a plant’s species identity and the chemistry of the soil underneath it. This suggests that once plants are growing in an area, adding AMF will have little effect on their metal uptake. However, knowing what plants are growing in a certain patch of soil can tell us a lot about that soil’s chemistry.

The researchers and managers of the Palmerton site also feared that an uninvited tree species, gray birch, accumulated such high leaf metal concentrations that its leaf litter would elevate metals at the soil surface and poison neighboring plants, including the grasses they had worked so hard to establish. This pollution of soil via leaf litter has been hypothesized to occur but it has not yet been thoroughly tested, and the Palmerton site seemed like an ideal setting for such a test. Again, I investigated, and after a couple years of study, including planting, monitoring, harvesting, and analyzing nearly 500 oak and maple seedlings in the site, my colleagues and I found that metal-contaminated birch leaf litter does not increase surface soil contamination or poison other plants, but that soils under the birches and grasses differ in their concentrations of metals and organic matter in ways that could shape the continued trajectory of plant community development in the site.

Science-based decision making helps us reclaim and remediate ecosystems. Photo credit: Lee Dietterich

How lessons learned from remediation help us rebuild ecosystems better

These findings are already shaping the course of continued remediation and broadening our more general understanding of how metal polluted ecosystems work. We now know that efforts to control plant metal uptake may be better served by altering soils or plant communities directly than by manipulating AMF. We also know that gray birch does not threaten remediation as was feared, though concerns remain that it may shade out the desired grasses or introduce metals into the food chain via its leaves. Furthermore, thanks to the work of dozens of other scientists in this and other contaminated sites, we are learning important information about the continued legacies of pollution, such as how metals do and do not move in groundwater, and the effects of contaminated sites on migrating birds that rest and feed there.

It is clear that conserving healthy, intact ecosystems remains preferable to disturbing them and then trying to rebuild them. As with most diseases, prevention remains far easier and cheaper than cure. However, for those landscapes we have already damaged, science is providing local residents and land managers with tools to improve their lives – and those of their invaluable fuzzy, leafy, or slimy neighbors—by reclaiming and restoring healthy ecosystems.


Lee Dietterich is an ecologist studying how interactions between plants and soils affect the movement of elements such as carbon, nutrients, and heavy metals in and through ecosystems.  He is currently a postdoctoral scholar in Prof. Daniela Cusack’s lab at UCLA.  When not doing science or exploring nature, he likes to play the piano and clarinet. 

Science Network Voices gives Equation readers access to the depth of expertise and broad perspective on current issues that our Science Network members bring to UCS. The views expressed in Science Network posts are those of the author alone.

Dead Zone 2017: Even Worse than Predicted (and That’s an Understatement)

This map of dissolved oxygen levels in the Gulf of Mexico shows the extent of the dead zone in July 2017. Courtesy of Louisiana Universities Marine Consortium. https://gulfhypoxia.net/research/shelfwide-cruise/?y=2017&p=oxy_maps

There’s more bad news for the Gulf of Mexico. A team led by researchers at Louisiana State University this week confirmed the largest Gulf dead zone since standardized measurement began in 1985. The lifeless area of low oxygen in the Gulf is now at least the size of New Jersey, the researchers say, noting in a press release that because they couldn’t map the entire affected area, their measurement is an understatement of the problem this year.

As I wrote when it was predicted in June, the dead zone arises each year due to a phenomenon called hypoxia—a state of low dissolved oxygen that occurs when excess pollutants, such as nitrogen and phosphorus, accumulate in bodies of water. These nutrients enter the Gulf largely as runoff from Midwestern farm fields carried by the Mississippi River and its tributaries. They feed blooms of algae that die and decompose, and the process depletes the oxygen in the surrounding water. Fish and other creatures must either flee or suffocate.

We need to reduce farm runoff…a LOT

This year’s dead zone confirmation comes on the heels of a new study last week by scientists at the University of Michigan and Louisiana State University, who looked at what would be needed to decrease the size of the annual Gulf dead zone. Note these researchers aren’t talking about eliminating the dead zone, just shrinking it down…to the size of Delaware. (Delaware! Still an entire state, and not even the smallest one.)

Accomplishing just that, they estimated, would require bold action—a 59-percent reduction in the amount of nitrogen runoff coming from farmland in the Midwestern Corn Belt. That’s a very large reduction, one that farmers almost certainly can’t achieve just through more careful applications of fertilizer. The study’s lead author, University of Michigan aquatic ecologist Don Scavia, was pretty clear about that:

“The bottom line is that we will never reach the Action Plan’s goal of 1,950 square miles until more serious actions are taken to reduce the loss of Midwest fertilizers into the Mississippi River system,” Scavia said.

Instead, the Midwest farming system—which today leaves soil bare and vulnerable to runoff for months out of every year—will need to change.

And speaking of change, our changing climate poses a further challenge to tackling dead zones and related water quality problems in the Gulf and elsewhere. Yet another new study published in Science last week linked toxic algae blooms—a problem also caused by excess nutrient runoff, in which algae by-products can make water unsafe to drink or swim in—to climate change. The authors warned that increased rainfall in future years may wash even more fertilizer into rivers and lakes (e.g., Lake Erie), worsening the problem.

Soil is the solution!

Okay, so we need dramatic reductions in current rates of fertilizer runoff in the Midwest. In recent months, UCS has documented innovative farming practices such as extended crop rotations and perennial prairie plantings that can substantially reduce fertilizer use and runoff. We’ve also shown that such practices and systems are also good for farmers’ bottom lines.

And the evidence that farming practices that keep soil covered year-round can solve multiple problems by reducing rainfall runoff keeps coming. Next week, we’ll release an exciting new report that shows how farmers can create healthier, “spongier” soils, and how Congress and the USDA can help. Stay tuned!