Should You Apply Pre-Tassel Nitrogen in Corn?
By Rasel Parvej, Dan Fromme, Josh Copes, and Syam Dodla
LSU AgCenter
Nitrogen is the most yield liming nutrient for corn production. Corn requires nitrogen for amino acids, protein, and chlorophyll production. Chlorophyll is the key component for photosynthesis. Chlorophyll deficiency results in reduced yield potential. A 200-bushel corn requires about 200 to 240 lb nitrogen per acre i.e. roughly 1 to 1.2 lb nitrogen per bushel corn harvested. Applying all the nitrogen at or before planting may subject to loss to the environment through volatilization (if nor incorporated, mainly for urea), denitrification (due to water-logged anaerobic conditions), and leaching (due to excessive rainfall for coarse-textured low cation exchange capacity soils). Therefore, nitrogen management in corn is one of the biggest concerns each producer has every year. It is recommended to apply nitrogen in at least 2 splits during the growing season with 1/3 at planting and 2/3 around V5-V6 stage (5-6 leaves with visible collars and plant is about 12-inch tall). Providing adequate nitrogen plus other deficient nutrients (mainly phosphorus and potassium based on soil-test level) around V5-V6 stage is very important because corn initiates ear shoots and tassel and sets yield components at or little after V6 stage.