In Washington, D.C., researchers with the BioEnergy Science Center (BESC) genetically modified switchgrass to produce less lignin to improve ethanol conversion and found that the long-term effects of the modified lignin had no negative impacts on the soil. The study looked at the impact on soil over two to five years and concluded that there was no negative effect from the modified switchgrass in terms of physical, chemical, and biological parameters of soil health.
Researchers found no significant differences between transgenic and control plants in terms of soil pH or the total concentrations of 19 elements. An analysis of soil bacterial communities via high-throughput 16S rRNA gene amplicon sequencing revealed no effects of transgenic plants on bacterial diversity, richness, or community composition. They also did not observe a change in the capacity for soil carbon storage, with no significant effect on soil respiration or soil organic matter.