Proponents of genetically modified (GM) crops say they could help raise incomes and living standards for millions of poor farmers in developing countries.
But in this article in Seedling, two professors of agricultural ecology say that GM soybeans — the world's most widely planted GM crop — have had the opposite effect in parts of Latin America.
GM soybeans need more fertiliser because glyphosate — the herbicide the beans have been modified to resist — kills not only weeds but also the bacteria the beans use to get extra nitrogen, say Miguel Altieri and Walter Pengue.
They add that glyphosate use has also risen since GM soybeans were introduced, and eight weed species in Argentina are now showing resistance to the herbicide.
Altieri of the University of California in Berkeley, United States, and Pengue of the University of Buenos Aires, Argentina, also say that the introduction of GM soybeans has increased the concentration of land and wealth into the hands of a minority.
Since GM soybeans were introduced, more land has been allocated to growing them. Because the crop is mostly grown for export, not local consumption, it has reduced food security for the region's poor and displaced other forms of farming, they say.