Bailiwick News - July 7, 2020
Pounds and acres: feeding Centre County. Part 2 of series started April 27, 2020. Non-fiction.
Above: 2001 Sheffer data, aggregated and sorted by pounds of food per year.
Once upon a time, until the mid-1800s, rural farms were the backbone of stable regional food economies, and produced food that was sold for local consumption at markets in regional population centers.
Could deliberate revival of that long-lost economic model improve the lives of Centre County's rural families, farmers, food processors, and farm suppliers, and also help our urban and suburban communities better cope with the impacts of supply chain disruptions?
In 2001, Penn State master's student Eric Allen Sheffer assessed the potential for Centre County farmers to feed the 136,000 people who lived here as of the 2000 census. (Sheffer thesis.)
Part 1 of this series, published April 27, listed foods that Sheffer found could be produced in Centre County, including the carbohydrates, proteins, fats, vitamins and minerals needed for a healthy diet.
For this report (Part 2), I compiled a subset of his data about the weight of food that could be produced annually in Centre County, and how many acres of county farmland would need to be used for local food production to supply the local population's nutritional needs.
I converted Sheffer's data from metric units (kilograms of food and hectares of land) to pounds of food at 2.2 pounds per kilogram, and acres of land at 2.47 acres per hectare.
Population demographics and assumptions
Pre-COVID, Centre County population was about 163,000 (U.S. Census estimates circa 2017), of whom about 100,000 lived in the six urban and suburban municipalities of the Centre Region: State College Borough, Ferguson Township, College Township, Harris Township, Patton Township and Halfmoon Township.
Roughly a third of the county's population lives outside the Centre Region, in Bellefonte, Philipsburg and other small towns and rural villages, including Milesburg, Zion, Millheim, Rebersburg, and Spring Mills. See Bailiwick News, Volume 3, Issue 25, for Centre County municipal land area/population density tables.
Of the 100,000 residents of the Centre Region, about half (roughly 47,000) were Penn State undergraduate and graduate students, based on Penn State enrollment data.
Post-COVID population impacts are hard to predict, so for reporting purposes, I used Sheffer's original 136,000 Centre County population, without trying to update it for the 2020 population.
Caloric and nutritional assumptions
Sheffer defined a food system as "the network of food production, processing, transport, storage, consumption and waste associated with food."
For his analysis, Sheffer used the 1996 USDA Food Guide Pyramid and National Research Council Recommended Dietary Allowances (RDA) for calorie and nutrient sub-categories, and a "higher calorie" diet of 2,800 calories per day per person, so as to "estimate liberally."
Under the 1996 guidelines, 2,800 calories per day includes 11 servings of grains, 5 servings of vegetables, 4 servings of fruit, 2-3 servings of dairy, and 7 ounces of meat or 2.8 servings of nuts, beans or eggs.
Sheffer used data about crop yields per hectare for foods that can be produced in the Centre County climate.
"...all of the RDA for foods could be satisfied throughout the year on a diet consisting of dry stored grains, nuts and beans, fresh or refrigerated meats and dairy products, and fresh or root-cellar stored produce," allowing for import of a few "cherished" non-local items like orange juice, sugar, coffee and chocolate.
Chapter 1 - Literature review
The purpose of Sheffer's study was to compare energy-input requirements for four different food supply scenarios.
He began with an overview of the history of American food supply systems and the history of efforts to anticipate and address actual and potential supply chain disruptions.
He reported that "long-distance transport of food became widespread in the US during the period of 1850-1870 with the development of railroads."
Refrigerated train cars came into use in 1889, first shipping fruits from California to New York City, and later shipping dairy products, vegetables and meats.
By 1969, a study by Brown and Pilz found that most US food was shipped an average of 1,367 miles (2,200 kilometers) "from farm to processor to market."
Sheffer emphasized that all transportation modes (truck, rail, barge and air) depend on a fossil fuel "energy subsidy."
He drew a distinction between non-renewable fossil fuels, and renewable energy resources such as light energy and the energy stored within plant biomass, wind, rain and tidal energy, and labor performed by humans and animals, because the renewable energy sources "can be sustained indefinitely."
Sheffer cited Campbell and Laherrere (1998) for the proposition that global oil production declines would begin as soon as 2010.
According to an article by Chris Rhodes in Chemistry World (2014) citing several other studies, global oil production of light, sweet crude through conventional means peaked in 2005; that assessment excludes low-EROEI [Energy Return on Energy Invested or net energy] bottom-of-the-barrel, debt-financed extraction methods such as hydraulic fracturing and tar sands, and excludes low-quality oil products from total oil production statistics, which have caused a short-lived, unsustainable production spike in recent years.
Sheffer observed that his review of food system studies showed "a clear link between the timing of studies of food supply and when threats to transportation viability have occurred."
For example, he reported, a moderate recession in 1921 prompted US railroad companies to propose cutting wages to lower their expenses. The plan led to train-service employees threatening to strike, prompting major cities to begin planning for alternative, local sources of food and food transportation.
The strike and related food shortages did not occur, but the possibility motivated public officials in several regions to begin studying the issue of transport-dependent food systems.
After the 1920s, the issue receded again, until the 1960s, when the US Office of Civil Defense looked at the potential effects of a nuclear war disrupting food supplies.
A slew of studies and research projects came out in the 1970s and 1980s, following the Arab-Israeli War in 1973, the OPEC oil embargo, and the Iranian revolution in 1978, mostly focused on New England, Mid-Atlantic and Midwest regions. For example, Vermont created the Center for Studies in Food Self-Sufficiency, and Rodale Press started The Cornucopia Project.
Chapter 2 - Energy consumption as a function of food processing, packaging and transportation
Chapter 2 of Sheffer's study focused on quantitative analysis of the relationship between food processing and packaging methods, food transportation network scale, and fossil fuel energy use.
For his study, Sheffer set the typical American diet of highly-processed, intensively-packaged food, shipped across the country mostly by truck and rail, as 100% dependent on fossil fuels and complex supply chains. He included processing both for palatability (such as hulling, butchering, milling and baking) and for storage (such as canning and freezing).
Then he looked at three hypothetical alternatives.
Maintain the highly-processed, intensively-packaged foods, but reduce the transportation scale to local supply and processing chains. This created a system 64% as dependent on fossil fuels, compared to the 100% dependent, highly-processed, long-distance food system.
Shift to a low-processed, minimally packaged food supply, but use the existing long-distance transportation system. This created a system 43% as dependent on fossil fuels, compared to the 100% dependent, highly-processed, long-distance system.
Change both parameters, to a low-processed, minimally-packaged food supply, transported locally an average of 126 kilometers (78 miles). This created a system 21% as dependent on fossil fuels as the 100% dependent, highly-processed, long-distance system.
Sheffer looked at fruits, vegetables, grains, nuts and beans that can be grown in Centre County's climate and soils, and then dry-stored or stored in root cellars, or consumed fresh, without requiring refrigeration.
Dairy, meats and eggs were considered to be consumed fresh or stored in refrigerators.
For the purpose of assessment, "minimally processed" foods included flour, cookable cereal grain, bread, pasta, raw vegetables, raw fruits, milk, cheese, yogurt, raw meats, eggs, nuts and beans.
Foods such as added sugars, vegetable and fruit juices, ready-to-eat cereals and canned foods were not included as minimally-processed, because they require more energy-intensive processing. Rice was not included because it doesn't grow in Centre County.
Sheffer also didn't look at production of added fats and oils, because crop yield data was unavailable to him at the time.
Sheffer set the local transport distance at 78 miles (126 kilometers) by measuring the distance from three Centre County population centers to the most distant agricultural area in the county, averaged and then doubled to account for transportation of raw foods from farm to processors, and market-ready foods from processors to markets.
Sheffer concluded that the only food supply system (of the four considered) with an Energy Return on Energy Invested (EROEI) greater than one - meaning more calories produced to provide human nutrition and energy, than consumed by the system from processing, packaging and transportation - was a low-processed, minimally packaged, locally-produced and locally-consumed diet.
He found that the current highly-processed diet at long distance transportation scale takes three times as much energy to produce and distribute as the calories in the food itself.
Sheffer found that hypothetical high-processed diets at local transportation scale and low-processed diets at long distance transportation scale would both take about twice as much energy to process and move the food as the calories in the food itself.
Chapter 3 - Carrying capacity of Centre County land
In his third chapter, Sheffer looked at the carrying capacity or "land adequacy" of Centre County, in terms of the list of foods published in the first installment of this series on April 27, 2020.
Above: 2001 Sheffer data, aggregated and sorted by acres per year.
After another literature review, he noted that his study examined two parts of the question: land analysis and seasonal diet analysis, the two aspects of "the potential for a region to produce a nutritionally adequate diet, based on minimally processed foods, in enough quantity to feed its population."
He collected data about how much farmland exists in Centre County and was zoned for agriculture as of 2000; its varying quality for food production in terms of crop yields and management intensity; and which plants and animals typically eaten by humans can thrive in those soils and our regional climate (temperature and rainfall patterns).
He also accounted for the weight difference between the "raw weight" of the food, and the "consumption weight" after minimal processing. For example, he converted between the raw weight of milk required to produce the consumption weight of cheese, and multiplied daily raw weights by 365 to obtain annual production weight targets for each food.
Most importantly, he looked at how the amount of existing farmland, of the proper quality for each food type, aligned with the land needed to feed the population.
He wrote, of the various food groups and crop types:
"The grains group would require production of small grains and row crops; the vegetable group would require production of row crops; the fruit group would require production of orchard crops and row crops; the dairy group would require row crops and grasses; and the meat/protein group would require row crops, pasture, and legumes," each requiring specific agriculture land classes, managed under specific conditions, to prevent soil erosion.
He described eight "Land Capability Classes" based on "land slope, surface stoniness, surface texture, subsurface texture, depth to bedrock and drainage," citing J. Myers et al, 1990.
Class I lands, the highest quality, "have little to no slope, are deep and well drained, and have little surface stoniness and smooth soil."
Because of their high quality, Class I acreage can be in continuous row crop production with basic soil management.
In contrast, Class IV land - one of the least productive types still appropriate for food production - could include "sloping contours, severe surface stoniness, extremely light, heavy and/or shallow soils, and would not be well-drained." Class IV land requires intensive management, such as rotating row crops with grasses or legumes, contour farming, and conservation tillage.
Sheffer concluded that adequately feeding 136,000 people from Centre County farms growing minimally-processed, locally-transported foods to meet the recommendations from the 1996 USDA Food Guide Pyramid, would require about 49,000 acres for meats and protein beans, 34,500 acres for grains, 9,400 acres for dairy products, 5,800 acres for fruits, and 2,000 acres for leafy and non-leafy vegetables, for a total of just under 101,000 acres. (Sheffer's results in hectares were converted to acres at 2.47 acres per hectare for this report)
In his report, Sheffer further described the classes of land needed for each type of food production under various levels of management intensity, and compared target acreage in each type of production to current (as of 2000) farmland classes and uses.
Sheffer looked at a study by Crew (2001), which reported that Centre County had about 116,000 total acres of agricultural land, including Class I, Class II, Class III, Class IV and Class VI land.
And he looked at National Agricultural Statistics Service data, which reported about 101,000 acres - or 87% of the total agricultural acres - were in production to grow row crops, small grains, orchard crops, legumes, grasses and pasture during the 1997 growing season.
Sheffer concluded that - with some changes in land use and crop production (for example, decreasing grass production and increasing small grain and orchard production) - Centre County farmland could support the county population of 136,000 (as of 2000 census), at a carrying capacity of roughly one person per 0.74 acres of farmland.
He extrapolated that if Centre County’s 116,000 total acres of farmland (as of 2001), were fully planted in the types and quantities of crops suggested by his analysis, local farming in Centre County could support a maximum county population of about 157,000.
The peak of fruit variety would be each July, with about 12 different fresh fruits. Vegetable variety would peak each September, with about 60 types of fresh vegetables available from outdoor production.
The winter diet - using stored vegetables in root cellars and fresh vegetable grown in cold frames - would include about 26 types of vegetables, and winter-stored apples and pears, along with home-canned or frozen summer fruits.
Sheffer summed up the key factors influencing potential adoption of localized food systems:
"...The feasibility of moving toward localized food supplies to conserve fossil fuels hinges on several assumptions: first, that most regions in the US have adequate farm land and a suitable climate to grow enough of the right foods; second, that processing and packaging plants for making some foods palatable (such as grain milling) and to make others storable (such as canning vegetables in the Current Diet/Local Scale treatment) are available locally; third, that local transportation networks are adequate for food distribution; and finally, that if Americans shifted to consuming more minimally processed foods that they would be willing to prepare those foods and sustain a healthy diet."
The third and final installment in this series will look at the current amount of agricultural land in Centre County, and what's being produced on it currently, some data collected by Gene Bazan of Neo-Terra Experts on the potential for backyard food production — including calorie-dense, winter-storage foods such as sweet potatoes — along with some critical analysis.