In-field rates of decomposition and microbial communities colonizing residues vary by depth of residue placement and plant part, but not by crop genotype for residues from two Cry1Ab Bt corn hybrids and their non-transgenic isolines

► Decomposition rate of Bt corn residues does not differ from that of its non-Bt isoline. ► Decomposition rate and decomposer communities vary significantly by plant part and soil placement, but not by genotype. ► Cry1Ab Bt corn does not appear to pose a significant threat to the ecology of litter decomposer communities in soil.