Sulfur fertilization on alfalfa a likely advantage for central Upper Peninsula farmers

Tissue samples from side-by-side alfalfa fields suggest that sulfur addition is paying off.

Tissue samples for sulfur analysis from Michigan’s Upper Peninsula alfalfa fields were included in the 2015 Michigan Alfalfa Tissue Test Survey organized by Michigan State University Extension forage educator Phil Kaatz. A sample from the George Leckson farm in Garden, Michigan, in Delta County was included in the survey. Leckson has been fertilizing some of his alfalfa fields with ammonium sulfate and is seeing positive results compared to fields not receiving ammonium sulfate.

The results from Leckson’s sample indicated 0.26 percent tissue sulfur, which barely makes it into the sufficient category. The adequate sulfur range for alfalfa tissue samples is 0.26-0.50 percent. Additional second cutting tissue samples were collected from adjacent alfalfa fields on the Leckson farm. One of these fields received 100 pounds of 21-0-0 in addition to normal topdress phosphorus (P) and potassium (K) fertilizer and the other did not. The samples were sent for analysis separately from the larger, statewide project with the following results:

Results of alfalfa tissue samples

Amount of sulfur in fields

% sulfur in alfalfa tissue sample

Tissue sulfur status

Field 1 – received 100 pounds 21-0-0 per acre

0.39

Sufficient

Field 2 – no sulfur fertilizer

0.24

Insufficient

Two other samples in Alger and Chippewa counties were included in the statewide survey. Neither of these additional fields had received sulfur fertilizer or manure. The tissue test results for sulfur indicated 0.19 percent and 0.17 percent, respectively.

A Baraga County farmer related how a topdress application of potash topdress, including sulfur, has made a “day and night” difference in alfalfa yield with the additional cost of sulfur fertilizer paying off nicely.

What does all this mean? The samples were not part of a research project and the information cannot be subjected to statistical analysis. Rather, they should be considered as a strong hint that farmers in the Upper Peninsula region growing alfalfa without sulfur fertilizer or manure should be aware of the potential need for additional sulfur on their crop.

If you suspect a sulfur deficiency, a tissue analysis test is a great way to make sure on individual farms. For a full copy of the article highlighting the results and more detail on how to take an alfalfa tissue test, go to “Michigan alfalfa tissue test survey provides fertility snap-shot.”

For more information, contact me at .(JavaScript must be enabled to view this email address) or 906-387-2530.

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