Researchers Encouraged by Biomass Crop Growth on Abandoned Mine Lands

But Costs Still Remain The Big Issue

Chris Torres
Staff Writer

PINE GROVE, Pa. — Nearly 180,000 acres of Pennsylvania mine land sit abandoned, relics of an old mining industry that used to dominate areas like Schuylkill County and an area of northeastern Pennsylvania referred to by many as “the coal regions.”

With much of the area’s land depleted of the necessary nutrients to support plant life, it has little use other than possibly putting buildings on it.

Now a group of researchers is hoping to prove that with some work, this land can be a possible source for growing the next generation of biofuels crops.

Representatives from Penn State, the Pennsylvania Environmental Council, and Red Barn Trading and Consulting hosted a field day Tuesday, which brought about 50 people to an abandoned piece of mine land in Schuylkill County.

The crowd included some local landowners, farmers, and representatives from state agencies, including the Pennsylvania Department of Environmental Protection.

Rick Stehouwer, Penn State professor of environmental soil science and Marvin Hall, professor of forage management, have been working on a small, privately owned plot a few miles off Interstate 81 just north of Pine Grove, Pa., for about four years.

The goals are to evaluate the effectiveness of soil amendments on abandoned mine lands, see whether or not the land can support growing biomass crops and determine if the crops are cost effective.

The idea for the experiment came after Stehouwer was approached by a representative of the Pennsylvania Environmental Council asking whether or not manure, of which 1.5 million tons is taken out of the Chesapeake Bay Watershed each year, can be used to help rehabilitate abandoned mine lands.

There are many challenges to growing plants on this land, according to Stehouwer. Topsoil in most places is all but gone, organic matter is virtually non-existent and the terrain, with its many rocks and steep slopes, is hard to get equipment on.

“These are just some of the limitations you struggle with all the time on mine reclamation,” Stehouwer said.

In an attempt to mitigate these issues, the researchers tried two separate soil amendments before seeding the plots: compost and a mixture of manure and paper mill sludge.

They compared the effectiveness of these two mixtures to a “traditional” soil amendment of lime and fertilizer.

Along with this, trenches were dug 12 inches into the ground so they could measure the amount of nutrient leaching from these amendments.

Researchers planted switchgrass seeds three years ago.

Judging by what the plots looked like on Tuesday, results are encouraging. Each plot had some healthy growth on it, particularly the ones with the two soil amendments. Results from the research showed the amount of carbon and nitrogen in the soil in all the plots was increased significantly as a result of the soil amendments.

Leaching of nutrients, according to Stehouwer, has slowed since the soil amendments were applied.

“It looks like the biggest chance for leaching loss happens in the first couple of years,” he said.

But getting these results has not been cheap. Nor will it be an easy endeavor in the future.

Cost is the big question, along with finding a market for switchgrass.

Scott Van de Mark, director of special projects with the Pennsylvania Environmental Council, has evaluated the costs of doing this on reclaimed mine plots in Clearfield County.

Those plots are part of a larger experiment encompassing 30 acres of land that is currently being reclaimed from an operating mine.

Using conventional methods of fertilization, it cost roughly $400 per acre to get the switchgrass growing.

The more advanced soil amendments cost much more. The manure and sludge combination cost roughly $1,000-per-acre, factoring in the costs of storing and transporting the material. Also, to use paper mill sludge requires permitting. Van de Mark noted the mine operator had to get a modified permit and cover the costs to get it done.

“If we want to make this work, we have to drive these costs down,” Van de Mark said.

There is also the question of finding a market for the switchgrass, which Hall said is currently limited. Even though it is thought that switchgrass will be a big source of ethanol in the future, it is still only in the research phase.

It can be used for burning in co-fire plants and also pelletizing. But that market, again, is very limited.

On a fully established plot of switchgrass, Hall said you can expect it to produce between 3 and 5 tons of biomass per acre.

The key is getting it established.

“If you can get it established in the first year, then you should be good to go,” he said.

Harvesting it is similar to a stand of forage. It is usually harvested into round bales. Unlike other forages though, it can only be cut once.

Even with these challenges, researchers are hopeful the market for biomass will become competitive enough for this to be done on a larger scale.

“If the price of oil and the price of natural gas really increase in the next few years, than alternative fuels like biomass could be viable,” Van de Mark said. “It comes back to economics.”