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 2001, No. 5

CHECK FIELDS FOR DEFICIENCY SYMPTOMS

Farmers and their advisers should walk through each field regularly to check for nutrient deficiencies, along with other problems. It is easy to get busy with other tasks and forget to check the condition of the crop. Some deficiencies are very obvious, even in a “windshield survey”, but others are more subtle and easily overlooked. Some may occur early in the season and then disappear, so that unless identified early, they can affect the crop and yet go undetected. Others show up later in the season and may be missed because scouting is difficult in fully-grown crops.

Setting a few minutes aside each day to walk fields and observe changes in the crop is a good management practice. It is no less important than checking grain prices or weather forecasts and should demand at least equal time. Walking a random pattern across the whole field, with notebook and camera in hand, is a good approach.

Photos provide important documentation and identification of problems and for long-term records. Using a digital camera makes it is easier to add the photos to field records and to pass copies on to others who might have an interest or might assist in diagnosis. Photos of healthy plants should be included for comparison. A yardstick or other standard of reference helps in documenting plant height differences. Notes on date and exact location of each photo are also critical. A backpack or handheld GPS unit can help document location if available.

In-field tissue tests can help identify deficiencies. Electronic tools are available as well as traditional test kits. Where significant areas of the field are affected, collecting samples for laboratory analysis is advised. Analytical laboratories can provide information on how to collect and ship the samples. University and commercial diagnostic laboratories can help identify problems from plant samples or from photos submitted electronically. Fertilizer dealers and county Extension offices have information on where to send such samples or photos and what other information is needed to aid in the diagnosis.

Records of deficiencies noted should be kept from year to year, with location coordinates noted as accurately as possible. Areas of the field that have recurring problems, or problems that appear to be spreading from one year to the next, should be more carefully sampled for both plant and soil analysis and evaluated for special management needs.

Thinking about growing crops as “investment accounts” may help farmers understand the importance of regular field visits. The investment is no less worth watching than the grain market or the stock market. Some problems can be corrected in-season; others are more long-term in correction. The important point is that they cannot be corrected at all until they are detected and identified. Pictures of deficiency symptoms of common crops are available on the PPI website (http://www.ppi-far.org) and from most fertilizer dealers and Extension offices. Learning to recognize deficiency symptoms and understanding the conditions that are most often associated with them is time well-spent. Remember, there is no better fertilizer than a farmer’s footsteps.


— HFR —

For more information, contact Dr. Harold F. Reetz, Jr., Midwest Director, PPI, 111 E. Washington Street, Monticello, IL 61856-1640. Phone: (217) 762-2074. E-mail: hreetz@ppi-far.org
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