AGRI-BRIEFS
  AGRONOMIC NEWS ITEMS
From Agronomists of the
Potash & Phosphate Institute
655 Engineering Drive, Suite 110
Norcross, Georgia 30092-2837
Phone (770) 447-0335

Summer 2003, No. 4

WHAT HAVE YOUR PHOSPHORUS AND POTASSIUM SOIL TEST LEVELS BEEN DOING?

What are current management strategies doing to the phosphorus and potassium levels of your fields? Are your approaches drawing down, building up, or maintaining them? How can you find out?

The only way to assess soil fertility is by sampling and testing soils. So the first step in evaluating your management practices is to adopt a regular soil testing program.

Keeping good records is important for finding trends. Dig out at the very minimum the last three years of soil tests that were taken on a field or field area. Put them in order from earliest to latest. Have soil tests been increasing, decreasing, or staying about the same?

To understand what you see, review records of management and weather. If samples were taken at different times of the year, under very different moisture and/or temperature conditions, or at different depths, results may not make much sense. Changes in tillage practices can also make a difference.

If you discover that there has not been good quality control in sample collection, don’t despair. The time to start assuring better quality is now. Make sure that you not only collect representative samples, but send them to a quality lab.

You may also discover that your management records are too sketchy to be of much help. Again, if this is the case, don’t fret. Now that you know how important these records are, they can receive higher priority this year.


Regular monitoring of soil tests is an essential part of any fertility program. Looking for trends can help you evaluate and modify your current management approaches.

—TSM—

For more information, contact Dr. T. Scott Murrell, Northcentral Director, PPI, 3579 Commonwealth Road, Woodbury, MN 55125. Phone: (651) 264-1936. E-mail: smurrell@ppi-far.org

A-B Summer 03-4.pdf
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