A recent study was conducted in Vidharbha, India to determine the effect of Bt (Bacillius thuringiensis) cotton on the microbial population of various soil micro-organisms. The results indicated a significant decline in total microbial biomass in the Bt soil. If current trends continue, the researcher estimated that 6.7 million hectares of planted Bt transgenic crops in India were in danger of becoming sterile and unable to grown anything within the next 10 years.