Reclaiming Poisoned Soil—With Cow Manure

But now, researchers might have found a way to neu­tral­ize the ground to at least halt the ero­sion by using cow manure compost.

“The com­post reduces the over­all bulk of the toxic mate­r­ial and the heat it gen­er­ates reduces pathogens and con­cen­trates the inor­ganic nutri­ents,” said Paul White, a research soil sci­en­tist at the Department of Agriculture’s Sugarcane Research Unit in Houma, La.

No one will ever grow crops on the affected land again, White said, but it’s pos­si­ble to grow a ground cover that will stop ero­sion and it surely looks better.

The gen­eral area between Tulsa, Wichita, and Springfield, Mo., had been mined since the 1850s and was in full oper­a­tion for 100 years. Besides smelters—which left toxic sites—the mines pro­duced tail­ings called “chat,” which added to the pollution.

The pol­lu­tion is extra­or­di­nary. Bret Koehler, a geol­o­gist at the California Department of Conservation, said one aban­doned zinc mine near Redding in Iron Mountain, Calif., is so bad that the Environmental Protection Agency des­ig­nated it one of about 1,300 cur­rent Superfund sites in need of com­pre­hen­sive clean-up. The soil pro­duced one of the high­est acid­ity mea­sure­ments on Earth, Koehler said.

The aim of the Midwest exper­i­ment, White said, was to increase the car­bon in the soil so that microor­gan­isms that recy­cle nutri­ents could have a chance. The sci­en­tists also wanted to see whether the com­post could reduce the lead and zinc.

They took 3-by-6 foot plots and spread either 20 or 120 tons of beef cat­tle manure com­post to the land on some. White said they also filled in holes but none of them went very deep; the soil was com­pacted with the min­ing detri­tus. Then they spread switch­grass seed on all the plots and took sam­ples over a two-year period.

The results were both vis­i­ble and demon­stra­ble in the lab. The soils in the plots with the high­est amount of com­post had a greatly ele­vated pH, mean­ing they were much less acidic. There was more phos­pho­rus, nitro­gen, car­bon, and avail­able water in the soil, all things plants need to sur­vive and grow.

Read the rest of this arti­cle at ISNS.