Tuesday, November 8, 2005

Do We Really Have More Acreage in Lawns Than in Corn?

A researcher with NASA has published a study that suggests that we now have more land area in the United States invested in growing grass than in growing food for humans to eat.

As part of her PhD work, Christina Milesi went looking for a national estimate of land area dedicated to lawns, but found that no data were available. She then got herself grant to study the problem and came up with a methodology, using a variety of satellite imagery and aerial photography data sources, to create "a national estimate of lawn area and the impact of those lawns on ecological factors like the carbon and water cycles."
"Even conservatively,"” Milesi says, "“I estimate there are three times more acres of lawns in the U.S. than irrigated corn."” This means lawns -- —including residential and commercial lawns, golf courses, etc -- could be considered the single largest irrigated crop in America in terms of surface area, covering about 128,000 square kilometers in all.
I find myself floored by that notion.

The entire article is fascinating on several levels.

First, it speaks to that tendency we have to carry with us as we migrate around the country an idealized notion of what our yards should look like, leading to the proliferation of created, non-native lawns in areas that are not meant to have open grasslands. Witness the irrigated oddities of lawns in subdivisions carved into the western deserts, or the patches of lovingly, painstakingly and horribly expensively maintained green alongside the sand dunes and salt marshes of the Atlantic coastline here in Delaware.

Second, the work Ms. Milesi and her team put in to find ways to deduce the amount of lawns around the nation from data sets that don't directly show lawns was instructive. I work in the world of spatial data and often am asked questions for which aerial photos, satellite imagery and GPS -- all now so popularly featured on TV and via Google -- don't provide ready answers. This story reminds us that sometimes we have to be creative; to mix different data sources and rely on intuition to find ways to calculate things that are not easy to measure.

On the issue of lawns, however, I'm proud to say that my otherwise abysmal record on lawn care means that I am, at least by default, maintaining a somewhat native habitat in my yard.

1 comment:

Anonymous said...

Humans eat more than just corn, so your statement "we now have more land area in the United States invested in growing grass than in growing food for humans to eat" is misleading. We grow a heck of a lot of corn up here in Quebec, but those lawns total up. I believe her research.

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