Where are you and these other commenters getting this falsehood that a significant portion of alfalfa is exported? Is it one of those articles about that Saudi owned land exporting their alfalfa?
> Based on USDA data for 2021, only 3.9% of all U.S. hay produced and 6.4% of all alfalfa hay entered the export market. [1]
In case that's unclear, 96.1% of hay and 93.6% of alfalfa is consumed domestically.
Probably they are considering the data for California (relevant to this discussion) rather than the US as a whole. Although the link you posted doesn't break out the percentage for California, it does say that 20% of western state alfalfa is exported.
However, the percentage is less important than the overall amount.
"If California only produced enough almonds for the United States, than it would have about 8 percent more available water. If California only produced enough alfalfa for the U.S., it would have at least 3 percent more available water."
> Based on USDA data for 2021, only 3.9% of all U.S. hay produced and 6.4% of all alfalfa hay entered the export market. [1]
In case that's unclear, 96.1% of hay and 93.6% of alfalfa is consumed domestically.
[0]: https://hayandforage.com/article-3825-year-end-hay-exports-s...