Landowners aren't getting rich, but they are getting a little something for storing carbon in the ground.

Through a North Dakota Farmers Union program, landowners are getting paid per acre to no-till their crop land, keep it set aside in the Conservation Reserve Program, or maintain grass in rangeland.

The idea is to store the carbon from decaying plant matter in the ground, rather than releasing it to the atmosphere, where it bonds with oxygen to form carbon dioxide.

The carbon dioxide gas is among several greenhouse gases blamed for warming Earth's atmosphere.

The money comes from national and international companies that want to offset their own carbon production, or who want a "green" presence in their company profile.

The carbon credits are traded through the Chicago Climate Exchange. Right now, the exchange is trading at $2.15 a ton, hopefully rebounding to at least the $3.70 per ton that Farmers Union traded out at last year.

North Dakota landowners were paid an average of $3,500 for participating in the program.

They must be willing to sign six-year contracts to be eligible and their payments are based on the kind and number of acres they enroll. It's assumed for payment that no-till practices store .4 tons of carbon an acre and CRP stores 1 ton per acre.

Liz Mathern, who helps manage the carbon credit program for Farmers Union, said the number of North Dakota landowners nearly doubled this year, plus landowners from 25 other states joined for a total of 2,400 signups.

Farmers Union will be marketing those carbon credit signups starting this month.

In the meantime, the program remains open to new signups. Depending on the number of new signups, Mathern said the additional carbon credits may be sold this year, or added to those marketed in 2009.

Landowners interested in the carbon credit program can call 800-366-8331, or visit the Farmers Union Web site at http://www.ndfu.org.