Each year we receive this question and the answer is still no. Grain corn does produce high amounts of crop residue with a high C:N ratio, meaning microbes will immobilize or soak some nitrogen out of the soil during decomposition. But if the corn has been adequately fertilized with nitrogen for good yield potential, there should remain sufficient nitrogen for orderly decomposition.
What minimizes decomposition rate is our lack of suitable conditions for microbial activity, specifically heat and, this fall, perhaps moisture.
More details please visit MAFRI’s website at: https://www.gov.mb.ca/agriculture/soilwater/nutrient/pdf/fer01s03.pdf