By Stephen Sexton, Director of Technical Sales (@AgricenLifer), Agricen
Yellow seedlings are a familiar sight for many corn growers. On continuous corn acres, the carbon-to-nitrogen ratio can be more than double the optimal ratio* for crop residue decomposition due to the buildup of organic matter from multiple years of corn-on-corn rotations. Even if a grower has applied nitrogen during the previous fall or around spring planting, soil microbes can out-compete seedling corn plants for nitrogen when excess carbon is present. The microbes use the nitrogen as a food source, immobilizing it as they work to degrade crop residues; the seedling corn plants, meanwhile, turn yellow due to a lack of available nitrogen.