Readers discuss corn debris biofuel, the color of ancient Mars’ oceans and more

Corny fuel

Genetically modified baker’s yeast can turn corn stover — cornstalks, leaves and other harvest debris that farmers often leave to rot in fields — into ethanol, Nikk Ogasa reported in “Yeast turns corn leftovers into fuel” (SN: 7/31/21, p. 12).

Reader Doug Brown wanted to know how removing the corn leftovers would affect soil systems, considering that the materials contribute to soil structure, health and maintenance.