ISSUE #500

500 - Managing Costly Nitrogen to Maximize RSA in 2008


NOW IS THE TIME for you to consider zone fertility management for your 2008 crop. Nitrogen fertilizer prices remain very high and are not likely to decline anytime soon. Plan the idea now as soil sampling begins soon after grain harvest in many areas. As little as 15 lbs of variability between zones justifies variable rate fertilizer application at today’s fertilizer cost. Benefits of zone managed N can vary from $20 per acre up to $100 or more with higher field variability.

Just as you navigate the highways with a road map to arrive at your destination…satellite imagery and zone mapping helps you navigate where to sample your fields for varying nitrogen content and guide you to your destination of realizing reduced crop inputs and maximized RSA.

Factors Influencing N Variability

  • Residual soil test nitrogen
  • Soil type and organic matter
  • Past field history and cultural practices
  • Rainfall amount - causes leaching or denitrification, effects mineralization rates
  • Variety yield and quality characteristics


  • Zone nitrogen management is key to successful nitrogen management
  • Zone nitrogen management increases revenue per acre every year
  • Zone managed acres have increased from 37,000 in 2002 to about 140,000 in 2006.


2007 Satellite Imagery of Sugarbeet Fields Now Available

The latest image from Landsat taken on 7-19-07 is now available for most ACSC fields through the ACSC/ Satshot web site. Growers that are currently signed up in the system will automatically get a report of their fields with a vegetation management zone analysis. Another analysis will be available in late August / September. Growers that are not signed up are encouraged to go to the ACSC agronomy page and sign in their contact information to receive their free satellite maps and latest updates. If there are any questions on how to sign up, contact your local agriculturist or contact Agri ImaGIS Technologies at 701-235-5767 or go to Also look for upcoming training sessions this fall and winter to learn how to analyze your field and build VRA maps yourself.

  • Use satellite imagery from previous beet crops to establish zones for 2008
  • Yield maps or topography maps can also be used to establish zones
  • Help is available:
    • Go to, log into Members Only, choose Satellite Imagery
    • Contact your agriculturist
    • Contact your fertilizer dealer; many can help you through the process
    • Contact your crop consultant, as they have done an excellent job of providing assistance and service