Look Underground for Evidence of GM's Dangers

Among the myriad reasons for rejecting genetically modified crops is one that often slips beneath the radar because it is, literally, underground, writes John Newton.

The more we learn about our planet and what grows on it, the more we learn about fungi.

Not so much the above-ground fruit - mushrooms of all delicious and dangerous kinds - but the mycorrhizal (myco = mushroom, rhiza = root) kind that grow beneath the soil and form relationships with the roots of trees and plants.

This symbiotic relationship was first noticed in the mid eighteenth century, and is complicated beyond the scope of this short piece to explain.But in short,tiny hairs (mycelia) attach themselves to the root cells of plants and swap nutrients for sugar.

The importance of these microscopic fungi to ecosystems was demonstrated in the Amazon basin.

Early settlers, seeing the lushness of the growth of the jungle and the obvious fertility of the soil, cut down the trees and cleared the land.The crops they planted were poor in comparison with the growth they had destroyed. They'd disturbed the dense mat of fungus mycelia that had supported the tropical growth.

The massive surface area of these fungi (a single fungus may cover half a hectare of soil) means that plants are able to access previously unavailable nutrients: particularly important in Australia's ancient,low-nutrient soils.

Their size gives a clue to the impact of systemic herbicide application in conventional agriculture.

Spraying even a small area of a farm will cause wide-spread destruction of the soil fungi,resulting in the loss of one of the most important nutritional aids to farming.How important,we are only beginning to understand.

And what do genetically modified canola seeds allow the farmer to do? Spray as much of the herbicide Roundup, Monsanto's brand name for glyphosate, on his crops as he wants, because the plant is immune to it.

And boy,are they pouring the stuff on in the US. A 2008 report from the Northwest Science and Environmental Policy Centre, Idaho, concludes that the 550 million acres of GMcorn, soybeans and cotton planted in the US since 1996 has increased pesticide use (herbicides and insecticides) by about 50 million pounds. Yet Canadian studies have shown that as little as one part per million of Roundup can reduce the growth or colonisation of mycorrhizal fungi.

And that's not the only problem.The massive use of Roundup means that weeds are becoming tolerant to it and weed communities are shifting towardsspecies tolerant to glyphosate.

If someone,somewhere,could give me one good reason for adopting genetically modified crops, it would be the first time in the 20 years I've been looking at this problem.

The most recent glowing report on the benefits of GMcrops for the environment and the economy was announced last month, in a research report from PGEconomics. And what is PG Economics?  It's linked financially to all the biotech companies - particularly Monsanto - and one of its founders worked for many years in the biotech industry.

As a United States Department of Agriculture report concluded in 2002:"...the 'success' of the introduction of GMcrops in the US owes more to marketing hyperbole than it does to objective science and agronomic delivery."

John Newton is the author of Roots of Civilisation:Plants that changed the world.