Nitrogen accumluation by corn
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
Knowing the nitrogen accumulation pattern of corn can be helpful in managing N inputs. Nitrogen accumulation closely parallels biomass accumulation. Only about 5 percent of the total N requirement of corn is accumulated by the V6 stage. From the V8 to R1 stage, N accumulation increases rapidly. (See Table 1).
Table 1. Nitrogen uptake by corn
|Growth Stage||Approximate Percent of Total N Accumulated|
Adapted from “How a Corn Plant Develops” Special Report 48, Iowa State University.
For those looking to micro-manage N inputs by multiple applications, remember the nitrogen needs to be in the root zone for the crop utilize it. This requires the N be placed into the soil or be moved into the soil by a good rain or irrigation. Surface applied N will not be readily available to the growing roots until a good rain occurs to move the N down into the root zone. An extended dry spell after surface N application will result in the N not being utilized and some volatile loss of N from surface applied UAN (28 percent N) or urea may occur.
When considering foliar N application, be aware that during the rapid development period from about V10 until V18 a corn crop will be accumulating from 3 to 5 lbs N per acre per day. And, during the grain fill period, N accumulation continues at 1 to 2 lbs per acre per day depending on the yield being produced.