Posted: October 19, 2020

Researchers in the college analyze food supply chain disruptions from COVID-19 with a goal of improving their resilience against future disruptions.

Illustration by Peter Hoey.

Illustration by Peter Hoey.

It was Friday, the 13th of March. Carissa Itle Westrick and her family had planned to do their usual end-of-week work, which included mixing up chocolate milk for the 25 local schools they would service on Monday. But they held off.

"We'd heard a rumor that the schools might close for the pandemic," said Westrick, whose family owns Vale Wood Farms, a 200-cow, family-owned dairy farm in Cambria County, Pennsylvania. "Once milk gets turned into chocolate milk and packaged into half pints, it's too late to do anything else with it. Chocolate skim milk is a product we only make for schools, and we didn't have any other customers we could transition that product to. We didn't want to get stuck."

Westrick's concerns were shared by thousands of other dairy farmers in the United States. By mid-April, the Dairy Farmers of America estimated that the loss of school, hotel, and restaurant customers led to farmers having to dump nearly four million gallons of milk each day.

Fortunately, Westrick was able to find an outlet for her white milk.

"We posted an invitation on our Facebook page for customers to come to our dairy store to purchase the cases of half pints that had been destined for the schools; we sold out of them in a day," she said.

In addition to concessions, Vale Wood Farms also saw an increase in home-delivery sales. Westrick credits her farm's ability to remain in the green during the COVID-19 pandemic to the personal relationships that her family has nurtured with customers over generations.

"Supply chains are built on relationships," she said. "Our close relationship with our customers was our saving grace."

Dairy isn't the only agricultural industry that has been affected by the pandemic. Meat-processing facilities have been suffering as their workers have fallen ill with COVID-19, and fruit and vegetable producers have been struggling to find workers as travel from countries like Mexico has been disrupted.

Meanwhile, consumers are paying higher prices for meat and are often unable to secure staples such as toilet paper, pasta, flour, and frozen goods.

"These disruptions have exposed weak links and a lack of resilience in some U.S. food supply chains," said Dave Abler, professor of agricultural economics. "It is apparent that food and agricultural policy initiatives to increase the resilience of the system are needed."

Abler is one of several researchers in the College of Agricultural Sciences who are investigating the impacts of COVID-19 on food systems with a goal, not only of informing decision making now, but also to better prepare for other types of disruptions--such as those related to pest outbreaks, natural disasters, and economic upheaval--in the future.

Modeling Resilience

Despite the importance of resilience in food supply chains, little research has been done on the topic, according to Abler. "Conceptual models exist to investigate different aspects of supply chains, but the complexity of real-life systems has yet to be explored," he said.

For example, he added, existing supply chain models do not consider the spatial relationships among components. "If gasoline prices were to go through the roof, large urban areas that depend on produce being trucked in from distant agricultural areas may see a drop in availability, whereas small towns that are adjacent to agricultural areas may be less affected."

Existing models also tend to focus on single supply chains in isolation. For example, a farmer produces raw milk and sells it to a company that processes and packages the milk. That company then sells the finished products to retail outlets, which in turn sell the products to customers.

"This is too simplistic," said Abler. "Real-world supply chains interact with each other through competition for products and services. A fungal infestation in the feed source for a large dairy operation could cause milk production to decline, and that may lead to milk processors purchasing milk from other farms that are farther away."

Current models also tend to focus on disruptions that occur individually, whereas real-world supply chains may face multiple disruptions simultaneously that interact with and reinforce each other--for example, disease and drought.

With support from a COVID-19 seed grant from the college's Institute for Sustainable Agricultural, Food, and Environmental Science, Abler and his colleagues--James Shortle, Distinguished Professor of Agricultural and Environmental Economics; Alfonso Mejia, associate professor of civil and environmental engineering; and Caitlin Grady, assistant professor of civil and environmental engineering--are developing a more realistic model of food supply chains in the United States. The team has already built a prototype and generated preliminary results, which they used to apply for a grant from the U.S. Department of Agriculture to further refine their model.


The model includes layered geographical and political boundaries to assess how climate, market, and other forces affect food systems. It can estimate the impact of changes in labor availability, multiple simultaneous shocks, changes in inventory, and other conditions on vegetable and dairy production.

"We know that food supply chains have been disrupted by COVID-19, but we need more information about which regions in the United States and which parts of supply chains have been affected, as well as how disruptions in nonfood supply chains have spilled over into supply chain disruptions for food," Abler said. "Our model can help provide that kind of information. It can highlight weak links, tipping points, and bottlenecks in supply chains and reveal how disruptions to one supply chain in one part of the United States can propagate to other supply chains or products in the same or different parts of the country."

A Company's Most Valuable Resource

One weak link that has been revealed by the coronavirus pandemic is the availability of workers. By early June, more than 20,000 infections across 216 facilities located in 33 states were reported among employees of meat packing plants. Dozens of plants closed temporarily. Meanwhile, consumer demand for meat had increased as a result of people cooking more often at home. The result was a jump in meat prices. In April, uncooked ground beef rose in price by nearly 5 percent. Pork chops rose 7.4 percent.

Kevin Peter, dairy manager of Wawa, Inc., a chain of convenience store gas stations, had a few employees test positive for COVID-19, which meant that all the associates with whom they'd been in contact needed to quarantine for 14 days, until they showed no symptoms and tested negative.

"Luckily it wasn't bad enough to cause any shutdowns or production interruptions, although one of our customers had to shut down because the virus reduced production volume for a couple of weeks," said Peter. And its school milk sales dropped by 30 to 40 percent. On the other hand, sales of its proprietary half-gallon and gallon milk jugs saw a 25 percent bump in March and are still running about 15 percent above average.

Overall, the company is processing at a lower volume than in the prior year. Because of the lower volume, Peter put two open positions in the plant on hold until things turned around. "It was important to us that we keep all our employees intact," he said.

Fruit and vegetable packing plants have suffered similarly, as routine immigrant visa processing services prevented field workers from entering the country. Such temporary foreign visa workers, especially those from Mexico, account for 20 percent of the country's farm workers, according to the American Farm Bureau Federation.

"Certainly those farmers that are dependent on migrant labor, like the fruit and vegetable industry, are really concerned about the borders being shut down and how we're going to obtain a legal workforce to help harvest these crops on the farm," Joel Rotz, a spokesperson for the Pennsylvania Farm Bureau, told the Philadelphia Inquirer in April.

Yet, according to Armen Kemanian, associate professor of production systems and modeling in the Department of Plant Science, Pennsylvania has a strong family farm community, and therefore some sectors are less reliant on hired labor than other states.

PA Strong

Kemanian and his colleagues have been closely following the ways in which COVID-19 is impacting agriculture in Pennsylvania. The team has observed that despite taking a hit during the early part of the pandemic when restaurants and schools closed, some parts of the sector, like the dairy industry, have managed to stay afloat, in part due to the relatively high proportion of family farms, but also by quickly adapting to the new circumstances and making good use of federal aid. The Commonwealth's farmers have also benefited from being located near highly populated areas and markets.

"Many of Pennsylvania's small dairy farms are members of cooperatives, meaning that milk is pooled and brought to a central location for pasteurization or for processing into other dairy items," he said. "This gave them an advantage when the school and restaurant customers disappeared, as the losses from dumped milk were spread among members of the co-ops. But no industry will remain intact with such a sustained reduction in demand; many producers are now extremely vulnerable."

With a potential surge in COVID-19 cases this fall as schools start back up and employees return to their offices, farms and processing plants could suffer another setback.


"The prospects of dairy farmers are highly dependent on whether the United States experiences a second wave of infection, and of what magnitude," said Kemanian. "It is likely that many farmers will not be able to survive sustained low prices. There will be no packed school cafeterias. The lower demand for milk products may remain well into next spring. And while some small farms may capture a share of the growing demand for locally produced foods at a premium price, the majority of the small- or medium-sized farms will have a hard time. Given that dairy farmers were already suffering from declining milk prices, COVID-19 may just exacerbate the problem, giving farmers less time to seek out alternatives."

A spike in disease cases in the fall could also have environmental consequences. "Pennsylvania is a pioneer in cover cropping, and fall is when cover crops are planted," said Kemanian. "A sudden contraction in cover cropping area because of a decline in the availability of farm workers or simply the need to minimize costs can have immediate effects on our water quality. And green payments to incentivize environmentally friendly practices can be harder to come by when states are facing billions of dollars in budget shortages. Everything is connected. As a result, COVID-19 has the potential to reshape landscapes."

With seed grants from the college's Institute for Sustainable Agricultural, Food, and Environmental Science and the Penn State Huck Institutes of the Life Sciences, Kemanian and his colleagues are building a set of diagnostic tools for assessing risks in the food system, not only from COVID-19, but from other potential disruptions as well. The tools will provide quantitative assessments of emerging risks and plausible interventions.

The researchers are using Sugar Valley, an 18-mile-long valley located in Clinton County, Pennsylvania, as an initial case study. "We chose Sugar Valley because it is enclosed by mountains and has just one waterway outlet, which makes it relatively easy to use as a study unit," said Kemanian.

The team is building a virtual model of the watershed using the agroecosystems model "Cycles" and baseline data on soils, water balance, crop production, livestock numbers, weather, and more.

"We can set up a reference scenario for how agriculture in Sugar Valley operates to ask questions about how changes to one part of the system might affect other parts," said Kemanian. "For example, if COVID-19 makes its way into the valley, we would be able learn what might happen if time-sensitive operations, like planting, are delayed because laborers are out sick or due to other restrictions. That would mean lower production and income in the months ahead during the harvest time. A delay in planting is a delay in harvesting, too. That puts pressure on the following crop or cover crop, and so on. Equipment repairs can get delayed. And what about the need to dump milk? We could predict the signature of these disruptions in production and potential pollution in the water. That is our goal."

According to Heather Karsten, associate professor of crop production and ecology and a collaborator with Kemanian, Sugar Valley is home to several conservation-minded farmers who use no-till practices and cover crops to protect soil from being lost.

"If farmers continue to lose income from restaurants and schools, they could reach a point where they have to shut down," she said. "What if they are replaced with larger dairy operations or vegetable farms? Annual vegetable production is more intensive than dairy farming, requiring more tillage and fewer perennial crops. What might happen to the water quality as a result? The model will give us answers to those sorts of questions."

Kemanian explained that the Sugar Valley case study will provide a realistic assessment of what it will take to scale the model up to a county, state, or even national level. "We have a lot of digital tools and computer resources, like these comprehensive agroecosystem models and databases, available to us. We want to see if we can make use of them to address questions in this and other crises."

Meanwhile, Abler's team is gathering data from news reports and other online sources to develop several real-world case studies to further test and validate their supply chain network model.

"COVID-19 has dramatically altered food supply chains in the United States, with disruptions to food production, processing, transport, and retail," said Abler. "This global health crisis enables us to gather data in near real time and use it to inform our model and generate results that are highly policy relevant."

By Sara LaJeunesse
Illustrations by Peter Hoey

New Institute Fosters Study of COVID-19 and Beyond

The seed for Penn State's Institute for Sustainable Agricultural, Food, and Environmental Science (SAFES) was planted well before the COVID-19 outbreak. The concept had been growing in the College of Agricultural Sciences for about two years when the pandemic emerged.

The aim of the institute is to convene expertise at Penn State to address complex, interconnected food-energy-water-land challenges, such as food security, supply chain disruptions, bioenergy production, biodiversity, changing land uses, environmental degradation, and climate volatility. With the havoc wrought by the pandemic, these issues have emerged as urgently critical.

"We have conducted research on food and agricultural systems, water quantity and quality, environmental systems, and nutrient management in the college for years, and the institute will unify and coordinate these efforts, while increasing collaboration among our researchers," said Gary Thompson, former associate dean for research and graduate education.

But the establishment of this institute and its vision could not have come at a more appropriate and necessary time, Thompson added.

"Now that COVID-19 has revealed serious weaknesses in our agricultural systems--such as supply chain disruptions, processing facility closures, interrupted production practices, and threats to food security in vulnerable communities--the institute will be critical in our efforts to ramp up the effectiveness of our science to deal with these unexpected and unprecedented challenges."

The interdisciplinary institute will integrate research, education, and outreach to address complex, landscape-level challenges by channeling scientific research into solution-oriented policy, business, and practical innovations, Thompson explained. It will provide a synthesizing science-to-practice platform for a collaborative community of researchers, students, and stakeholders in discovering responsible and sustainable policy options, business management solutions, and best practices.

And while SAFES was not originally envisioned as an organization dedicated to responding to problems caused by a pandemic, that will be job one for a while, Thompson noted. The organization has awarded 10 seed grants to researchers to address the impacts of COVID-19 on agricultural, food, and environmental systems.

"The institute has assumed the mantle as an organizing force to facilitate the rapid deployment of the College of Agricultural Sciences' expertise to deal with the current crisis," Thompson said. "Initially, at least, we will focus on the research that needs to be done to address the complicated, landscape-level, interconnected challenges presented by the pandemic."

The director of the institute is Karen Fisher-Vanden, professor of environmental and resource economics. Associate directors are Christina Grozinger, Distinguished Professor of Entomology; Rob Shannon, associate professor of agricultural and biological engineering; and Matt Royer, associate research professor and director of the college's Agriculture and Environment Center.

--Jeff Mulhollem