Contrary to what you might have heard, the most commonly grown crop in the United States is not genetically modified or meant for any industrial or nutritional uses. The most commonly grown crop in the U.S. is grass, not the smokeable kind, and it is sucking up water and land resources for no practical reason.

A recent study looked at the growth of lawns nationwide and then at the ecological impacts, it contrasted the positive effects of carbon sequestration and local heat-reduction with the negative strain on water and fertilizer runoff.

Turf grass takes up an area of approximately 164,000 square kilometers (or 1.9% of total U.S. continental area), and even when we take rainfall into effect it would take about 900 liters per person per day to keep all those grasses green. And unlike with nitrogen fixing cover like clover, turf grass needs fertilizer to grow well on even relatively nitrogen rich soil and can lead to runoff during abundant rainfall.

lawndistribution

Figure 1 from Milesi’s study showing the fraction of turf grass, with 0 representing 0% and 1 representing 100%.

Existing forms of lawn management are, according to the calculations in Milesi’s study, not even necessarily carbon neutral. Since grass clippings are regularly transported away from the soil, we are regularly removing nutrients and reducing the carbon sequestration potential of the soil by 60%. Take all this together and we begin to see that lawn reform needs to come hand-in-hand with other agricultural land reforms.

Lawns are one of the most useless monocultures that is ubiquitously grown in the United States and Europe. Natural grasslands exist, but they aren’t subjected to herbicides, biomass removal, fertilizer runoff, or complete monoculture conditions. When thinking about how to manage your yard and what you want to grow, make sure to think about these often-misconstrewed environmental truths.