Life Sciences in the 21st Century:
Agriculture Case Study: Dr. Lee Daniels

 
Lee Daniels
CSES
Reclamation of Surface-Mined Lands via Waste Management Techniques
Initiation Date: 1979
New federal law required mining companies to restore specific vegetation to their mine sites within 5 years AFTER finishing the surface mining.
About $1 million to date has been spent on the research aimed at revegetation techniques.
History:

Sludge being applied as an ammendment to surface-mined soils.

The law required each company to post a bond of $10,000/acre PRIOR to mining to insure that there would be monies available to have the land restored following mining. If the companies successfully complete restoration, the money is returned to them. But mine sites provide big challenges to plants and there were few known methods to achieve successful restoration.

Of the many people who became involved in the project, Dr. Lee Daniels' role was to investigate ways to restore pasture land and forests from a soils perspective, working along with Jim Burger of Forestry. To start out, it is important to understand the nature of soils exposed by surface or strip mining: these soils are subsoil in nature with no topsoil left. They are often very acidic and possess large quantities of elements which can be toxic to plants at such high levels. Daniels wanted to restore diverse plant life to the sites by first amending/improving these inhibitory soils so they could once again support plant life, preferably using materials recycled from other processes. So in the early '80s, he started to examine the effects of adding several by-products to existing mine soils: topsoil, sawdust (organic waste from lumbering), sewage sludge (a human waste product high in Nitrogen, Phosphorus, and some metals), or coal flyash (a powdery residue remaining after coal combustion) to the exposed soils.

Contemporary Impact of the Work:
A previously surface-mined area restored with sludge and successfully revegetated.
Sewage Sludge
His initial observations indicated that the natural succession of primarily wild herbaceous plants was encouraged when sewage sludge was added. Compared to untreated mined areas where only 4-5 plant species would grow naturally, sludge-ammended soils supported dozens (= increased botanical diversity). These positive results were initially met with great excitement. Afer all, here was a material that was truly a waste product which ordinarily went into landfills or had to be incinerated. Furthermore, sludge was free and wouldnÕt cost the mine owner anything to use on the exposed soils during closure; in fact, cities often pay someone to remove it!

Although about 20,000 acres of Virginia farmland have had sludge applied, this feasible solution for land reclamation has never fully materialized; primarily because no one anticipated the subsequent negative public reaction to sludge applications. Residents of rural mining regions looked at this as simply a way for the urban areas to ÒdumpÓ their wastes on them. They also rejected any idea of the safety of sludge as an amendment because it is "sludge" (therefore it must be toxic!) in their "backyard!" In fact, the ensuing public outcry when large scale sludge use was being investigated virtually killed the idea for further use in Virginia. You see, the law made no restrictions on the use of the same land after the 5 year period of reclamation; it could be left alone, farmed (exept for root crops), developed, and even strip or deep mined again. There may even be a bill introduced into the Virginia General Assembly to formally outlaw the use of sludge to reclaim surface mined soils.

Coal Flyash
This material is basically the particulate waste left in smokestack filters following coal burning. Of primary importance to plants, flyash contains calcium, magnesium, and traces of several metals; and tests proved it to be just as effective as sludge as a mine soil amendment...but its use is still controversial.

In both instances, there is an inextricable link connecting Science, Politics, and Sociology. Experience has also shown that for waste management to be effective in solving other problems, all three factors must be considered.


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