A new paper in the American Chemical Society’s Journal – Environmental Science and Technology indicates that over fertilizing corn would affect the cellulosic ethanol production. The team lead by postdoctoral researcher Morgan Gallagher discovered that corn grain and corn’s stalks and leaves respond differently when treated with nitrogen fertilizers. Though the presence of excess nitrogen increases the yield of corn grains, it results in twice the amount of lignin, as nitrogen plays a vital role in the biochemical pathway that produces lignin. And since, the lignin is doubled, the whole process of extracting ethanol from corn stovers becomes complex.
Lignin slowly breaks down with the help of bacteria and hence the process becomes more expensive to remove it by mechanical or chemical processes.
The study, conducted at and in collaboration with the National Science Foundation’s W.K. Kellogg Biological Station at Michigan State University (MSU), showed that although feeding the plant more fertilizer increases the grain’s cellulose content, grain yield quickly hits a plateau. At the same time, the researchers found only a modest increase in plant and stem cellulose.
“Morgan E. Gallagher, William C. Hockaday, Caroline A. Masiello, Sieglinde Snapp, Claire P. McSwiney, Jeffrey A. Baldock (2011) Biochemical Suitability of Crop Residues for Cellulosic Ethanol: Disincentives to Nitrogen Fertilization in Corn Agriculture. Environmental Science & Technology 45 (5), 2013-2020 doi: /10.1021/es103252″