Farm Industry News

Timing nitrogen delivery

Source: DuPont Pioneer

Monitoring nitrogen (N) at key points during the growing season is critical for plant growth and grain fill. A wet spring also could contribute to concerns about N being available to the plant due to leaching or denitrification.

Growers should be evaluating how much N remains in the soil and if it will be enough to meet crop needs. A quick response to N-deficiency stress is often required to minimize yield loss.

Soil tests are one way to gauge nitrogen levels. Optical sensors can also be mounted on fertilizer application equipment, enabling on-the-go N sensing, rate calculation and application all at once. Aerial imagery and chlorophyll meters are also good tools to use.

If N is found to be lacking in the plants and soil, growers have several decisions to make, including:

  • the type of N to apply
  • application method
  • timing
  • volume of N needed
  • need for a nitrification inhibitor

Several research studies show that rescue N applications are effective at recovering yield — as late as three weeks after pollination.

Here are a few resources on N management: