DECOMPOSITION OF BT COTTON AND NON BT COTTON RESIDUES UNDER VARIED SOIL TYPES

Abstract

Use of the insecticidal cry proteins from the bacterium, Bacillus thuringiensis (Bt) in cotton has raised a number of concerns, including the ecological impact on soil ecosystems.Greenhouse study was conducted during the 2011 wet season (March to August) at the Institute of Agricultural Sciences of Banaras Hindu University. It was carried out on three different soil orders that includedentisol, inceptisol and alfisol. Bt cotton (var.NCS-138) and its non-transgenic isoline (var.NCS-138) were grown until maturity. A no crop pot was maintained for all the three soil orders. The highest rate of decomposition was found in alluvial soil compared to black and red soils in 50 days after incorporation (DAI). Thereafter the rate of decomposition was slowed downby100 DAI and the constant rate of decomposition was found in 150 DAI. The rate of decomposition was higher in non Bt than Bt crop residues.