Home / Articles / Pak Agri Outlook / CAN PLANTS BE USED TO CLEAR TOXINS FROM SOIL?

CAN PLANTS BE USED TO CLEAR TOXINS FROM SOIL?




  • The Chinese brake fern or ladder brake fern (Pteris vittata) growing on a brick wall in Chatswood, Australia. Photo by Peter Woodward via Wikipedia
    The Chinese brake fern or ladder brake fern (Pteris vittata) growing on a brick wall in Chatswood, Australia. Photo by Peter Woodward via Wikipedia

    There are highly specialized and exceedingly rare plants that are able to grow on metal-contaminated sites by taking the contaminants up into plant tissues. They are referred to as hyperaccumulator plants.

    One hyperaccumulating tree species, identified in the South Pacific, takes up so much nickel that the sap runs blue. Other hyperaccumulator plants have been identified that take up zinc, copper and nickel. No hyperaccumulators have been found that can take up lead. A fern that takes up arsenic, the brake fern, has also been identified.

    The thought was that these plants could be grown on metal-contaminated sites as a way to clean up the sites over time. There was also a potential to grow crops on these sites as a new form of mining–a green ‘ore’. But the challenges to making this idea a practical reality have been significant.

    For example, if a soil contains 30 parts per million arsenic and the top 15 cm of soil weighs 2000 tons, that means that the arsenic in that soil weighs 60 kgs. If a hyperaccumulating plant contained 1000 parts per million arsenic, that means that every kg of dry plant tissue would have 1 g of arsenic.

    So in order to get those 60 kgs of arsenic out of the soil, you would need to grow 60 dry tons of plant matter. Yields of ferns are low, so you are talking about growing annual crops of ferns for well over 20 years to clean the soil. And that’s assuming the plants can continue to take up arsenic at really high rates even as the soil arsenic goes down. Also, unlike crops like corn and wheat, these are wild species. So it isn’t clear if it would even be possible to grow them like a conventional crop.

    In other words, hyperaccumulators are amazing plants. Can we use them now to clean our soils? No.

    Source

    About Staff

    This post is published by AgriHunt staff member. If you believe it should have your name please contact md@agrihunt.com

    Check Also

    smog lahore

    دھوئیں میں لپٹا ہوا لاہور اور سرسبز شہر کا خواب

    Report Issue: * Suggest Edit Copyright Infringment Claim Article Invalid Contents Broken Links Your Name: …

    Leave a Reply

    Be the First to Comment!

    Notify of
    avatar

    wpDiscuz