OP Rana

Soil needs its friend the worm

By OP Rana (China Daily)
Updated: 2011-01-15 07:45

Even a worm will turn. In fact, it had been turning for millions of years before the Bard of Avon recognized it. But the master par excellence thought the worm (earthworm here) would strike only if pushed to the extreme. Perhaps he was right - as time was to tell four centuries later.

The Bard wrote that line and moved on to other immortal ones but the earthworm never stopped turning (or crawling). It took another almost 250 years before it began turning in the world of science, though. And it took the genius of Charles Darwin to recognize it. In a paper prepared a year after his return from the Beagle voyage (1938), the father of evolution reflected on the importance of the tiny invertebrate to soil, plants and humans.

Yet more "important" work prevented him from revisiting the earthworm for four decades. Darwin completed The Formation of Vegetable Mould Through the Action of Worms, with Observations on Their Habits (or Worms, in short) only in 1881, another seminal work.

In the subsequent decades, science advanced at an unprecedented pace. Much of the early half of the 1900s was focused on the atom or the research on how to break it. The final years of the study on the atom coincided with World War II. The years following WWII saw further advances in science and, as demand for food grew worldwide, the processing and use of synthetic fertilizers and pesticides improved.

By that time, the poor little invertebrate was struggling for survival. Humans had found synthetic fertilizers to replace it and pesticides to exterminate it. The earthworm started vanishing from farms and gardens. Birds started losing their prey. Children (or even adults) no longer needed them as baits in their fishing angles. The worm slowly became alien to farms, gardens, to birds and large insects and to the human mind.

And then like some unforgotten data stored in a computer which pops up on screen when we accidentally press a wrong key, the earthworm flashed on the mind screen of someone, somewhere toward the end of the last century. The "little creep" was important after all! Thence started fresh research on the "slimy little creature". But even today research works are few and far between. Some experts still scorn at their "lesser brethren" working on the "insignificant" worm.

But exactly 130 years after Darwin published his Worms, scientists say the common earthworm could also become a useful tool in the processing and safe management of hazardous solid and liquid wastes with high metal content. So is the earthworm more than a friend of the gardener and farmer? Perhaps!

Chemist Lu Mer Marc Parra of the Universidad Centro Occidental Lisandro Alvarado in Cabudare, Venezuela, says his colleagues in Venezuela and Argentina conducted two feasibility studies on the use of earthworms in treating waste. The scientists used compost produced by worms as an adsorbent substrate for remediation of wastewater contaminated with metals such as nickel, chromium, vanadium and lead. Also, they used worms directly for remediation of arsenic and mercury found in landfill soils and showed an efficiency of 42 to 72 percent in about two weeks for arsenic removal and 7.5 to 30.2 percent for mercury removal.

Since the accumulation of solid wastes in landfills creates high risk for soil, and underground and surface water contamination, earthworms can be an effective remediation agent. Effective and non-toxic remediation is becoming increasingly important as toxic metals in a wide range of waste products from obsolete computers to portable electronic devices are disposed of in landfills.

In 1881 Darwin wrote: "It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures."

Maybe their true importance will be recognized now, and they will be saved for posterity to not only fertilize soil, but also cleansing industrial waste. Swiss nature protection organization Pro Natura may have laid the first stone on that path by declaring 2011 as the Year of the Earthworm.

The author is senior editor with China Daily. He can be reached at [email protected]

(China Daily 01/15/2011 page5)