Corn Side-Dress Options (6/16/11)
If the corn is 2-3 leafs at most, urea broadcast can be done. If you can’t count on at least ½ inch of rain coming at one time to soak the urea into the soil, applying the urea with Agrotain should give about 10 days of safety from urea volatilization. If the corn is more advanced than 3 leaf, too much urea will settle into the whorl and injure the corn too much to tolerate. The option from 4 leaf on is to apply the N between the rows. If the soil will seal, anhydrous can be applied. In most of the state, soils with high clay will not seal and many loam textured soils are also saturated and will have trouble sealing. The next most desirable application method is the application of UAN (28%) with a coulter. This will place the UAN below the soil surface, but shallow enough that practical application can be conducted without going very deep 2-3 inches is plenty of depth. If this is not possible, apply the UAN as a surface band using orifice nozzles. If you anticipate wind (it’s hard not to anticipate wind in North Dakota) configuring the outlet with a stiff hose that drags or nearly drags on the ground will eliminate most splashing on the corn leaves that could be harmful.
Things not to consider-
Stream-bar UAN or Nisol-type products, the consequence is too much burn. Low rates of slow-release N products. The consequences are not much burn, but not enough N. The efficiency factor advertised by product marketing has not been evaluated in research trials.
Dave Franzen - NDSU Extension Soil Specialist