Take This With a Grain of Salt

Salt patches on a farm in Somerset County, MD, are visible

 as bare white streaks along the edges of cropland.

Bay Journal, Salt patches, a product of rising seas, are spreading rapidly on the Chesapeake’s Eastern Shore

Climate change is claiming farmland at “an alarmingly high rate” in one of the Mid-Atlantic’s most productive agricultural regions, inflicting tens of millions of dollars in economic damage, a team of scientists says in a new study.

Their research spotlights a pernicious side effect of sea level rise: the salt left behind from water washed onto land after storms or unusually high tides. The resulting “salt patches,” supercharged by evaporation, can poison large swaths of cropland, reducing yields and farm profits.

From 2011 to 2017, the amount of Delmarva Peninsula farmland that converted into salt patches nearly doubled to more than 2,200 acres, the study estimates. That translates into as much as $107 million in annual crop losses in the region, the researchers say.

“Saltwater intrusion is far more extensive than I think we originally anticipated,” said Kate Tully, an agroecologist at the University of Maryland and one of the study’s authors. “There is an important need for us to come up with a suite of solutions for farmers and landowners on the Eastern Shore.”

The study, published by the journal Nature Sustainability in July, shows that farms located in low-lying areas along tidal bays and creeks are most at risk. Rather than overtaking entire fields, the salt appears to be slowly eating away at the edges, another team member said.

“It’s not like you lost half a field,” said Jarrod Miller, a soil expert at the University of Delaware. “It could have been just a foot along the edge of these fields. But when you add it up, it’s a lot of acreage across the region.”

In affected areas, the patches show up as swaths of bare white sand and salt. In cases where salt has just begun to invade, there still may be intermittent sprigs of vegetation.

A memo must have gone out because we have a second article on "salt patches": UMES researchers look at ways to protect coastal areas of the Chesapeake Bay from saltwater intrusion

I don't want to minimize it too much, but given that the Delmarva Peninsula is approximately 5,000 sq miles, 2000 acres (less than 1 sq mile) doesn't mean the end of agriculture as we know it.

There's no doubt that rising sea level, and sinking land is certainly a factor. Even 3 mm/year (roughly the aggregate rise in sea level measured by tide gauges in the area), adds up over years. At this point "climate change" in the version of CO2 driven increase of sea level due to melting ice is not a factor, the current rate of sea level rise in Maryland was established before most of the CO2 was added to the atmosphere:

I do wonder if agricultural practices in the Delmarva could be contributing to the problem. Certainly, in California's Central Valley, wide spread irrigation has led to salinization of land (and the cure, drains has led to other problems.