Dakota Salts LLC has been prospecting in North Dakota exploring for potential potash mining opportunities, but has not found promising enough results and will refocus its efforts on a project in England.

A test well was drilled in late 2010 east of Lignite, N.D., after the state issued its first drilling permit in 34 years, according to the North Dakota Geological Survey.

News of the test well and Dakota Salts' leasing of more than 16,000 acres for possible mining spurred the North Dakota Legislature to approve a new 2 percent tax on potash production last year, the Associated Press reports.

But Don Dickie, a senior geologist for Dakota Salts' parent company, Sirius Minerals PLC of London, said the North Dakota potash deposits are "not on the front burner" of the company's plans.

"We had expectations that we would be able to (find) a thick, high-grade potash deposit similar to what you would see in Saskatchewan," Dickie told The Associated Press. "Our results were not up to that level."

Read more here.