Turfgrass Is Not the Biggest Crop

Dear Editor: I very much enjoyed and appreciated reading the article by Kristen Coyne, “Maintaining Turf in a Changing Climate” (September 2023, p. 4–11; https://doi.org/10.1002/csan.21113), but did note one issue: The very first line of the article reads “Turfgrass, the biggest crop in the United States, is also among the most hotly debated.” This sentiment was again repeated in the figure on p. 10. These statements unfortunately seem to perpetuate a misconception that has been common in media since Milesi et al.’s landmark 2005 study estimating turf area in the U.S. was published (https://doi.org/10.1007/s00267‐004‐0316‐2).

The article by Milesi et al. seems to make an incorrect assumption that all turf in the U.S. is irrigated… this is captured by the following quote from the abstract “… it was calculated that potentially 163,800 km² (+/–35,850 km²) of land are cultivated with turf grasses in the continental United States, an area three times larger than that of any irrigated crop.”

Milesi et al. estimated total turf area at approximately 40 million acres.

The irrigated corn acreage in the U.S. is actually about 12 million acres (https://bit.ly/irrigation‐water‐use), which indeed is much smaller than the 40 million acres for turf found in the study. But most corn is not irrigated, and the total acreage in corn in the U.S. approaches 100 million acres (https://bit.ly/3Lzk5e0). The assumption in the study that all 40 million acres of turf is irrigated is also a significant over‐simplification because a substantial percentage of turf, like corn, does not receive supplemental irrigation.

I’m not aware of any currently available research‐based estimates on irrigated turf area in the U.S., but we can attempt to back into it in some creative ways: 

• Total irrigated cropland in the U.S. is estimated at 58 million acres (https://bit.ly/irrigation‐water‐use).
• Total water used daily in the U.S. is estimated at 322 billion gallons. Of this, 118 billion gallons per day is estimated to be used for irrigation (https://on.doi.gov/3Puu2ut)
• Water used for outdoor “landscape irrigation” is estimated at 9 billion gallons per day (https://bit.ly/48vTybm)

This means that landscape irrigation accounts for less than 8% of total daily irrigation water use in the U.S., which solidifies the assumption that far less than that 40 million acres of turf are irrigated and verifies that turf is far from the largest irrigated “crop” in the U.S.

Thanks for your consideration, and thanks again for what was an otherwise excellent and well‐thought‐out piece.

Best regards,

—Jason D. Lanier, Extension Specialist, Umass Amherst