From Dr Brian John:
Subject: Toxic effects of Bt crops on soil microbiology
This is very interesting, as it backs up the work done in Hungary by Prof Bela Darvas and colleagues. They too were looking at the effects of Bt corn on soil microbiology etc. As a result of that work, the Hungarian Government placed a ban on MON810 -- and Monsanto refused to allow their corn to be used for a continuation of the research. We have assembled some of the key information from Hungary and elsewhere here:
NOTE: The new research referred to here is not yet published. For some of the many problems with Bt cotton already showing up in published research, including the paper by researchers at Cornell referred to here, see: http://www.gmwatch.org/p1temp.asp?pid=86&page=1
This is from Dr. G. V. Ramanjaneyulu, Executive Director, Centre for Sustainable Agriculture, www.csa-india.org
Studies by Acharya NG Ranga Agriculture University, Andhra Pradesh (AP) and University of Agriculture Sciences, Karnataka show that Bt cotton has far reaching implications. The studies confirm that the Bt cotton is an exhaustive crop and mines more nutrients than its counterpart non-Bt hybrid. This was mainly attributed to the quick growth more bolls and leaves in Bt cotton hybrids during the early stages (<90 days).
Now the studies (unpublished) show that Bt cotton also has serious effect on the soil micro fauna in the root zone of the crop. This is one of the major reasons why the soils are becoming less productive effecting the crop yields (not only Bt cotton but the next crop like wheat in Punjab and chillies in AP). The studies were part of a network project coordinated by CICR. In fact last year there several complaints from the farmers on the reduction of yields in the crop next to bt cotton from AP and Punjab but like every other problem it was ignored. One may note that agriculture department, university and companies are recommending more fertilisers to the Bt cotton crop as it is exhaustive.
These findings raise several important questions like, if the genetic engineering is only about insertion of one gene why is there a change in the physiology of the crop and why is the rhizosphere effected?
This year the scientists also confirmed the incidence of 'Mirid bug' in Tamil Nadu and parts of AP which was never a problem in cotton. You recall that the study by cornell university 'Tarnishing Silver Bullets' also reported the growing Mirid bug problem in china after the introduction of Bt cotton.
Earlier studies by Akola university (reported in planning commissions report on vidharba crisis) and Karnataka state govt confirmed that Bt cotton is highly susceptible to drought conditions and other stress conditions.
University scientists when contacted say they still need to study [further] before publishing their results. In the meantime companies make their business exploiting the farmers.