The Geography of My Meal: Tracing Watermelon and Sweet Potato

Introduction

This week, I am diving into the geography and environmental impacts of two key ingredients from a recent meal I enjoyed at a Milwaukee pop-up event. The meal included a stuffed sweet potato packed with veggies and a fresh-pressed juice featuring watermelon. Even though it felt like a healthy and local meal, these ingredients have complex global journeys and environmental footprints.

Geographic origins of key ingredients
Sweet potato:
Most sweet potatoes in the U.S. come from North Carolina, which produces around 60% of the national supply according to the NCAGR. Other top producers include California and Mississippi, but North Carolina dominates both in acreage and output.

Watermelon:
The U.S. is one of the top global producers of watermelon, and Florida, Texas, Georgia, and California are the leading states for commercial watermelon farming. Watermelon consumed in Wisconsin during the summer likely comes from one of these states, particularly Florida or Georgia during early summer and Texas later in the season.

Environmental impacts of production
Sweet potato impacts:
Sweet potato farming can have environmental effects like soil depletion when rotation is not practiced and erosion from tillage. Fertilizer and pesticide runoff may affect local waterways, harming aquatic life. Fossil fuels are used for machinery, irrigation, and transporting the harvest.

Watermelon impacts:
Watermelon production requires significant irrigation, especially in dry regions like California and Texas, contributing to groundwater depletion. Like other crops, pesticides and fertilizers are used, potentially causing soil degradation and water pollution. The production also contributes to carbon emissions through farm machinery and irrigation systems powered by fossil fuels.

Environmental impacts of transportation, distribution, and consumption
Sweet potatoes probably arrived in Milwaukee by truck from North Carolina or another southern state, while watermelons may have been shipped from Florida or Texas depending on seasonality and availability. Neither of these ingredients would be considered truly “local” to Milwaukee, but both are domestic.

Waste impacts:
The meal created some packaging waste including the plastic cups and lids used for juice, aluminum foil around the sweet potato, and a disposable paper plate. If not properly recycled or composted, these materials contribute to landfill waste and can affect local and global ecosystems through pollution.

Geographic scale and place-specificity of impacts
In North Carolina and southern states where watermelon is grown, farming practices impact local soil, water, and ecosystems directly. These “local” environmental costs are often far removed from consumers here in Wisconsin.

At a global scale, both crops contribute to greenhouse gas emissions due to fossil fuel use during farming and transport. Even a fresh, healthy meal in Milwaukee links us to agricultural regions across the U.S. and environmental impacts we often do not see.

References:
https://ers.usda.gov/data-products/charts-of-note/chart-detail?chartId=104374&utm_

https://www.ncagr.gov/markets/commodit/horticul/sweetpot/